UNIVERSITY OF CALIFORNIA
COOPERATIVE EXTENSION
NUTRITION PERSPECTIVES
Volume 28, No. 2
March/April 2003
TABLE OF CONTENTS PAGE
Advances in Food Safety, Coming to California
The Centers for Disease Control Handouts Address Care of Kids’
Teeth
While Organic Products Are No More Nutritious Than Other Foods
Some Prefer Them Because They Are Environmentally Friendly
Organic Labeling Requirements
Soft Drink Sales Benefit Schools, Not Kids’ Health
Low-Birth Weight Equals Higher Health Risks
Supplement Use Among Cancer Survivors
Healthy Living In Retirement
Wholesome Whole Grains
Obesity and Breastfeeding
Fat and Fiction
HHS Issues National Plan to Reduce Impact of Diabetes On Women
The National Heart, Lung, and Blood Institute Study Finds All-in-One
Approach to Lifestyle Changes Effectively Lowers Blood Pressure
Herbs for Minor Depression?
The CLA Paradox
Subscription for NUTRITION PERSPECTIVES
Sheri Zidenberg-Cherr, PhD, Editor
Department of Nutrition
University of California
Davis, CA 95616
NUTRITION PERSPECTIVES is prepared by Sheri Zidenberg-Cherr, PhD, Nutrition
Specialist, Cristy Hathaway, and staff. It is designed to provide research-based
information on ongoing nutrition and food-related programs. It is published
bimonthly (six times annually) as a service of the University of California
Cooperative Extension and the United States Department of Agriculture. Subscription
to NUTRITION PERSPECTIVES is available from UC Cooperative Extension, Department
of Nutrition, University of California, Davis, California. Cost is ten dollars
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on articles may be addressed to: NUTRITION PERSPECTIVES, Department of Nutrition,
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752-8905.
ADVANCES IN FOOD SAFETY, COMING TO CALIFORNIA
Great strides are being made in food safety. Through use of Hazard Analysis
Critical Control Point (HACCP) and multiple interventions, the contamination
rate for meat and poultry has decreased. Some pathogens remain, however despite
extensive industry efforts. Irradiation of ground beef and poultry can further
enhance food safety for the home and in food service.
The meat and poultry industry practices of visual observation, steam vacuum
and pasteurization, hot water and organic acid rinses, have reduced pathogens.
The US Department of Agriculture’s (USDA) data shows an improvement in
1998-2001 testing over baseline studies. Test results from 1998-2001 showed
an average of 10.7 percent of broilers tested positive for Salmonella, compared
to 20.0 percent prior to HACCP; steers and heifers averaged 0.4 percent positive
compared to 1.0 percent; ground beef averaged 3.4 percent compared to 7.5 percent;
ground chicken averaged 15.7 percent compared to 44.6 percent; and ground turkey
averaged 29.2 percent compared to 49.9 percent. Samples that tested positive
for generic Escherichia coli (not a pathogen, but an indicator of sanitation)
in ground beef, decreased from 7.5 percent to 2.8 percent. E. coli O157:H7 is
estimated to be in less than four tenths of one percent of ground beef (1).
Although these figures are encouraging, they are not adequate to provide the public with the protection from foodborne illness they expect. Irradiation uses electrical energy to destroy foodborne pathogens. The treatment used provides a 5 log reduction of E. coli O157:H7. (At 1.25kGy, 99.999 percent of the bacterium is destroyed).
As part of a pilot project, three school districts in Minnesota are taking part in a food irradiation education program. At the conclusion of the program, school districts will indicate if they wish to purchase irradiated ground beef. Cases of foodborne illness have been traced to school lunches in California, with over 500 cases in 1996 and over 50 cases in both 2001 and 2002 (2). In the future, school districts in California may have the option to reduce this number through purchasing safety-enhanced irradiated ground beef.
A supermarket in Minnesota offered irradiated ground beef in May 2000. This offering was well received, and today six to seven thousand supermarkets in about 40 states offer fresh or frozen irradiated ground beef. In California, consumers can purchase frozen irradiated ground beef through Schwans home delivery and Omaha steaks. California may have fresh or frozen irradiated ground beef in the supermarket sometime this year.
The Centers for Disease Control has estimated that if half of the ground beef, poultry, and processed (luncheon) meats were irradiated; over 350 lives would be saved each year. Furthermore, over 6,000 catastrophic illnesses and over 8,000 hospitalizations would be prevented (3).
Unfortunately, the special interest group, Public Citizen (PC), does not want people to have this choice, either in the market place or in the school. Through half-truths and irrelevant comparisons, they attack scientific and health groups, such as the World Health Organization (WHO) and raise questions about the safety of irradiated foods.
The following seven points are taken from recent PC releases.
1. Public Citizen states, “Irradiation exposes food to a dose of ionizing
radiation that is equivalent to millions of chest X-rays.”
· This comparison is irrelevant. Food is routinely exposed to treatments
that would be unsafe for the human body. For example, bread is baked in a hot
oven and pasta is dropped in boiling water. People would not go into a 350 degree
room, nor would people enter a hot tub set at 212 degrees. The irradiation treatment
is at the energy level needed to destroy pathogens, not X-ray bones.
2. “Irradiation disrupts the chemical composition of everything in its
path not just harmful bacteria.”
· While the irradiation destroys harmful bacteria, the food itself exhibits
so little change that it is virtually indistinguishable from fresh.
3. “Irradiation creates chemicals called ‘radiolytic products’
that do not occur naturally in food and that the Food and Drug Administration
(FDA) has never studied for safety.”
· There are some chemicals formed when food is irradiated just as there
are chemicals formed when food is cooked. Scientists have long debated whether
these chemicals are unique. Chemicals originally believed to be unique, upon
further examination, were found to occur in cooked food. Recently compounds
called cyclobutanones were identified in irradiated food. They have not been
found elsewhere, yet.
· While these chemicals have not been extensively studied in isolation,
the FDA has reviewed a large number of studies where a variety of laboratory
animal (rats, mice, dogs, monkeys, etc.) have been fed a diet of 30 percent
to 100 percent irradiated food. These studies include short term and multiple
generation analysis. The studies reveal no ill effect from consuming irradiated
food. It is not the presence of a compound that indicates risk, but the level
of that compound. These animal studies indicate no increased risk from consuming
irradiated food.
4. “In legalizing food irradiation, the FDA did not determine a level
of radiation to which food can be exposed and still be safe for human consumption,
which federal law requires.”
· The FDA is mandated to respond to petitions to use irradiation. These
specify the level of treatment to be used to achieve a given effect, such as
increase microbiological safety. The FDA evaluates the studies relative to this
application and approves a given level of treatment if the data support safety.
The FDA is not charged with making a statement about maximum treatment. The
WHO has determined that irradiation should be considered comparable to heat
treatments. The WHO indicates no need to set an upper limit for safety.
5. “Irradiation destroys vitamins, essential fatty acids and other nutrients
in food. Each process a food undergoes depletes nutrients. Irradiation is an
additional step, so once the food is cooked, it is less nutritious than food
that has not been irradiated.”
· The FDA is mandated to consider the effect of irradiation on nutritional
value. While thiamin is lost when pork is irradiated, if all the pork were irradiated
at the maximum level permitted, the American diet would not become deficient
in this nutrient, as pork is a minor source of thiamine. There is a slight loss
of vitamin A when eggs are irradiated, but eggs are a minor source of vitamin
A. (Eggs may be irradiated to destroy Salmonella.)
· PC may quote papers that show large losses, but these are old studies
that do not use modern nutrient analysis methods or the irradiation treatment
used is in an order of magnitude higher than approved by the FDA.
6. “Irradiation and pasteurization are completely different processes!
Pasteurization merely heats the food/drink to kill bacteria.”
· Pasteurization uses thermal energy to destroy bacteria. Irradiation
uses electromagnetic energy. Heat causes as many or more changes in food, including
loss of some nutrients. These losses are minor, however, and pasteurization
is considered a “life saving” technology. Irradiation offers the
same benefit. Irradiation can destroy E. coli O157:H7, Salmonella, Campylobacteria,
Listeria and other pathogens that account for illness and death in the US.
7. “Irradiation masks and encourages filthy conditions in slaughterhouses
and food processing plants” and “Irradiation can kill most bacteria
in food, but does not remove the other filth that carries this bacteria.”
· Irradiation takes place after the product is packaged and ready for
sale. Products must meet all handling requirements and food safety standards.
Irradiation is an “add on” process, to further increase the safety
of products already destined for the supermarket or restaurant.
· Similar accusations can be made for pasteurization, as the effect of
enhancing food safety is the same. The record indicates that the safety of raw
products increased after pasteurization laws were implemented. We have more
than two years of data for plants offering irradiated ground beef. I am aware
of no study that indicates those selling irradiated meat operate at a lower
level of safety. I expect the opposite. Why use a costly process on a lower
quality product. In fact the record shows that the microbiological safety of
raw poultry is increasing. These statements are another ploy by PC that is not
supported by data.
· The Health community endorses the safety of irradiated food. The American
Medical Association, American Dietitian Association, Centers for Disease Control
and Prevention and others endorse the safety of this technology. I am aware
of no health or professional society that agrees with the claims of PC.
Health professionals have the opportunity to clarify these issues for the public so they are not mislead by special interest groups. Following is a list of peer-reviewed, scientifically sound information on the safety of irradiated foods and the potential impact of using irradiation to reduce foodborne illness.
For a free publication for the lay audience, go to http://anrcatalog.ucdavis.edu Click on Home and Garden. In the search box type “Irradiation”. This publication has been peer reviewed by the University of California. The International Food Information Council has a clear and accurate lay publication on this topic. Go to www.ific.org , then click on food safety or food processing. The American Dietetic Position Paper on irradiation can be downloaded at http://www.eatright.org/adap0200.html.
References:
1. USDA Ground Beef Sampling Program; 2002 USDA data show a reduction of Salmonella
in raw meat and poultry. USDA Press Release 054.02.
2. [Online source]: Review the Centers for Disease Control site on irradiation.
Go to www.cdc.gov , type “irradiation” in the search box.
3. Tauxe, R. (2001). Food Safety and Irradiation: Protecting the Public from
Foodborne Infection. Emerging Infectious Diseases; Supplement, 7(3):516-521.
(This is also available on the web at cdc.gov)
Source: Dr. Christine M. Bruhn, Director, Center for Consumer Research, Department
of Food Science and Technology, University of California, Davis.
THE CENTERS FOR DISEASE CONTROL HANDOUTS ADDRESS CARE OF KIDS’ TEETH
The US Centers for Disease Control and Prevention (CDC) has developed two handouts for parents regarding early care for their children’s teeth, Brush Up on Healthy Teeth, and Pediatric Oral Health Tips.
These fliers were derived from the report, Recommendations for Using Fluoride to Prevent and Control Dental Caries in the United States, published in Aug. 17, 2001, Morbidity and Mortality Weekly Report. The intent of these handouts is to educate parents regarding the importance of cleaning baby teeth as soon as they erupt and to supervise tooth brushing until the child can master the skill independently, which typically is not until school age.
Parents should be familiar with all the resources of fluoride in the child’s diet, (i.e. city water vs. well water), the CDC advised. Parents should also make sure the child is receiving an appropriate amount of fluoride to prevent dental caries and at the same time avoiding fluorosis (white spots of the teeth). The critical period to avoid too much fluoride exposure is while the crowns of the permanent teeth are forming (from birth through age 6). Parents need to ensure that the child is not swallowing fluoridated toothpaste or any fluoride mouth rinse during this critical tooth development. Several infant/toddler fluoride-free toothpastes have been developed recently to prevent swallowing too much fluoride during the early years of tooth brushing.
Most children who have mastered spitting out their toothpaste receive an adequate amount of fluoride to help prevent dental caries if they drink fluoridated water and brush their teeth with a pea-sized amount of fluoridated toothpaste twice a day. Parents should consult their pediatrician or dentist regarding their child’s individual risk for dental cavities and specific fluoride needs. In children with a high risk for dental caries and exposure to only water without fluoride, additional fluoride supplements may be indicated.
Print copies of the CDC report can be ordered by contacting the Superintendent
of Documents, US Government Printing Office, Washington, D.C., 20402, or by
calling (202) 512-1800. To read the report online, visit www.cdc.gov/mmwr/preview/mmwrhtml/rr5014al.htm.
Source: Martha Ann Keels, DDS, PhD; AAP NEWS; 22(2); February 2003; p. 52.
WHILE ORGANIC PRODUCTS ARE NO MORE NUTRITIOUS THAN OTHER FOODS SOME PREFER THEM BECAUSE THEY ARE ENVIRONMENTALLY FRIENDLY
If parents ask whether they should feed their children organic foods, the short answer is that it doesn’t make much difference in terms of safety or nutrition.
There may be other benefits, however, and experts say the question also can pave the way for discussions on topics such as food safety and healthy diets.
The US Department of Agriculture (USDA) recently set national standards for food labeled as “organic.” The new rules, which took effect Oct 21, 2002, require that organic meat, poultry, eggs, and dairy products come from animals that are given no antibiotics or growth hormones. In addition, organic food must be produced without the use of most conventional pesticides; petroleum-based fertilizers or sewage sludge-based fertilizers; bioengineering; or ionizing radiation.
Along with the national organic standards, the USDA developed labeling rules to help consumers know the organic content of the food they buy. The USDA Organic seal can be used on products that are at least 95 percent organic.
“Before, we just had to take it as truth that they were being honest,” said Nelda Mercer, RD, MS, a spokesperson for the American Dietetic Association. “Now they actually have a process that functions under the federal government that they have to go out to the farms and certify that [farmers] are following these organic practices.”
As food with the new labels begins hitting supermarket shelves, parents and
patients may begin asking their physicians questions.
“The most important thing for pediatricians to know is that recommending
anything, including foods, needs to be based on scientific studies,” said
Fima Lifshitz, MD, FAAP, member of the AAP Community on Nutrition.
While food bearing the organic label is grown, handled, and processed differently than conventionally produced food, the USDA makes no claim that organic food is safer or more nutritious. So why do some farmers go to the trouble of growing food organically, and why would anyone want to pay a premium for organic products? While there may be no direct benefits to consumers, there could be benefits to the environment, Dr. Lifshitz pointed out. Organic food is produced by farmers who emphasize the use of renewable resources and the conservation of soil and water. In addition, some people like the fact that no pesticides, antibiotics, or growth hormones are used.
If parents are environmentally focused and concerned about protecting the environment for future generations, “you can’t just pooh-pooh it and say all foods are the same,” Mercer noted. “Those are important issues that we as medical people need to respect in our patients.”
Some people also like the taste of organic foods better than the taste of conventional foods. Mercer said she prefers organic dairy and poultry and is willing to pay more for those products. Mercer and others, however, caution that the higher price of organic foods could present problems for low-income families.
Pediatricians should make it clear to families, especially those on fixed incomes, that there are no proven health benefits to buying organic, said Melvin B. Heyman, MD, FAAP member of the AAP Committee on Nutrition.
“When somebody says, ‘Do I need to buy organic?’ I would get into a brief discussion on what organic is and what does it mean and turn it into a discussion of what’s a healthy diet,” Dr. Heyman said. “If you can get into a diet that is promoting a healthy choice of foods so that your child gets adequate nutrition and isn’t becoming overweight, I think you’ve gained a lot more in the long run than you will by buying organic.”
Dr. Lifshitz added that most children do not consume the recommended amount of fruits and vegetables. “It’s hard to get them to eat fruits and vegetables,” he said. “It’s not going to change their mind if it is organic or not organic.”
Mercer said those who work with patients should discuss using safe practices once food is brought home. “In terms of health, food safety is so much more important than do I choose organic or not,” she said. Mercer emphasizes the importance of washing produce, washing your hands every time you switch tasks, disinfecting cutting boards and counters, cooking meats thoroughly, refrigerating leftovers promptly, and making sure your refrigerator is set at the proper temperature.
“The bottom line is that the USDA is making no claims that organically
produced food is safer or more nutritious than conventionally produced food,”
Mercer concluded. “Nutritionally, if you eat a conventionally grown apple,
you’re going to get the same things.”
Source: Carla Kemp; AAP News; 22(2); February 2003; pp. 55-56.
The US Department of Agriculture’s (USDA’s) organic labeling rules
apply to raw fresh products and processed foods that contain organic ingredients.
The requirements are based on the percentage of organic ingredients in a product:
· “100 percent organic”: Contains only organically produced
ingredients; can use the USDA Organic seal.
· “Organic”: consists of at least 95 percent organically
produced ingredients; can use USDA seal.
· “Made with organic ingredients”: Must contain at least
70 percent organic ingredients; cannot use USDA seal but can list up to three
of the organic ingredients or food groups on the front of the package.
· “Some organic ingredients”: Less than 70 percent of the
ingredients are organic; can’t make any organic claims on the front of
the package but may list organically produced ingredients in the information
panel of the package.
Before a product can be labeled organic, a government-approved certifier inspects
the farm where the food is grown to make sure the farmer is following the rules
necessary to meet USDA organic standards. All organic products must include
the phrase, “Certified organic by...” followed by the name of the
certifying agent. Finally, “organic” and “natural” are
not interchangeable.
Source: Carla Kemp; AAP News; 22(2); February 2003; p. 56.
SOFT DRINK SALES BENEFIT SCHOOLS, NOT KIDS’ HEALTH
Despite well-documented and widely reported epidemic levels of childhood obesity, pediatricians face an uphill battle in the war against soft drinks in schools. “The big problem with soda is that it’s calories replacing milk,” said Melvin B. Heyman, MD, FAAP, a member of the American Academy of Pediatrics (AAP) Committee on Nutrition.
According to Dr. Heyman, people drank four times more milk than soft drinks
in 1945. In 2000 they drank twice as much soda as milk. “This illustrates
the problem that soda is replacing healthier beverages, in particular milk,”
Dr. Heyman said.
Increased soda consumption and less milk consumption decreases calcium in bones,
raising the likelihood of osteoporosis when children become older, Dr. Heyman
said. In addition he cited dental caries and obesity as other health problems
correlated with soda consumption.
Seeing dollar signs
“Pediatricians need to advocate for healthier school food choices,” Dr. Heyman said. “The problem is that the soft drink industry supports the schools by giving back some money from soft drink sales.”
More schools are signing exclusive contracts with soft drink manufacturers to earn money for school programs, activities, and equipment. School districts that agree to exclusively sell a manufacturer’s drinks often are paid thousands of dollars a year, including commissions for selling a minimum number of cases.
“We have to recognize the financial needs of schools,” said Robert
P. Schwartz, MD, FAAP, immediate-past chair of the AAP Section on Endocrinology.
“Vending machines are a reality. The problem isn’t the machine;
it’s what’s in the machine.”
Suggested soda substitutes include bottled water and 100 percent fruit juice
drinks that are also made by soft drink manufacturers. In addition, recent studies
indicate that milk sales can be just as lucrative for schools, according to
Robert D. Murray, MD, FAAP, a member of the AAP Committee on School Health (COSH)
(1).
“There’s nothing wrong with soda. It’s drinking one three times a day that’s bad,” said Dr. Schwartz, who added that super-sized food portions, excessive television viewing, and decreased physical activity in schools also contribute to the obesity epidemic.
State’s bills fizzle
A bill proposed in North Carolina that would have put a moratorium on exclusive contracts between schools and soft drink manufacturers was defeated in 2001, Dr. Schwartz said. He hopes to start a pilot project that will compare revenue from milk sales and other healthy beverages to the revenue generated from soda sales to encourage schools to substitute healthier drinks for soft drinks.
Maryland was also unsuccessful at passing legislation that proposed replacing soft drinks with healthier drinks in vending machines and prohibiting commercialization in schools. Businesses that sell products in schools are interested primarily in establishing early brand loyalty, said Daniel J. Levy, MD, FAAP, AAP Maryland Chapter communications chair.
“We need to work with schools to make them look at the negatives of having vending machines in schools and what that mean on long-term health,” said Steven Tuttle, executive director of the Maryland Chapter, which initiated state legislation on vending machines and commercialization in schools. “Schools need to look at the long-term effects of feeding children an unhealthy diet and what that means next year and the 20 years down the road when these children are adults.”
Tuttle said the legislation will be reintroduced in Maryland “since it’s becoming an easier sell with the epidemic of obesity.” The proposed legislation will also suggest limiting the number of hours the vending machines are available.
In addition to Maryland, Hawaii, Iowa, Kentucky, New Mexico, Oklahoma, Tennessee, and Wisconsin considered vending machine legislation in 2002. Texas, however, was successful in implementing a vending policy, banning soft drink sales in schools cafeterias, hallways, and common areas where federally subsidized schools meals are served or eaten.
Healthy alternatives
California enacted state legislation in 2001 that restricts the sale of junk food and soda on a limited number of school campuses, though time will tell what the effect of this legislation will have on school nutrition policies statewide.
To augment this legislation, the Los Angeles Unified School District recently implemented regulations on soda vending machines. In 2004, soft drink sales will be banned from all schools in the district. Vending machines will be stocked with healthier options such as bottled water, milk, fruit juice, and sports drinks that must meet requirements for glucose content. Some schools in the district already voluntarily have made the switch, and other schools whose contracts expire before 2004 cannot renew their contracts.
According to Francine R. Kaufman, MD, FAAP, a member of the AAP Section on Endocrinology executive committee, sales will be tracked to determine what kind of impact, if any, the switch has on school budgets.
“There is a commitment by the school board that this [selling soft drinks] isn’t what they want to model because it’s not a healthy choice for children,” said Dr. Kaufman, president of the American Diabetes Association. “If there are financial implications, we will work out some way to remedy them.”
Talking it over
The AAP is developing a policy statement to address the problems with soda vending machines in schools and to encourage pediatricians to begin discussions with schools about the issues that surround this problem, said Dr. Murray.
The AAP Ohio Chapter already issued its own statement “as a caution to parents, superintendents, and members of district school boards about the health consequences of exclusive soda contracts in Ohio’s schools.”
In addition to working with their AAP chapters for changes on the state level, pediatricians can work on these issues with local school officials as well.
Howard L. Taras, MD, FAAP, Committee on School Health (COSH) chair, said there were several things pediatricians can do locally to educate school officials about the health hazards of selling soft drinks in schools.
First, he recommends contacting the superintendent’s office or the area school board representative to determine which schools have vending machines, where they are located, when they are accessible, whether schools are making money from contracts, and when contracts were signed and for how long.
Dr. Taras said it’s best to be cooperative rather than confrontational. Instead of insisting that vending machine contracts be canceled, he recommends acknowledging that vending machines provide financial assistance to schools. It is important to educate school leaders about the sacrifice soft drinks make on children’s health and to work with them on other ways to earn revenue, he said.
Dr. Levy recommends speaking to patients, attending PTA meetings, and talking to local media to turn soft drink vending machines in schools into a public issue that will capture the attention of lawmakers.
“One of the biggest issues for pediatricians is that someone has to take the leadership role.” Dr. Levy said. “If pediatricians think globally and act locally, they will reconnect with their original motivation for getting into pediatrics to do something that has significance and (sustenance) in their community.”
Reference:
1. Dairy Counsel Digest. School milk pilot test: dairy as part of the solution
to improving children's nutrition. http://www.nationaldairycouncil.org/lvl04/nutrilib/digest/dairydigest_742c.html.
April 28th, 2003.
Source: Lori O’Keefe; AAP News; 22(2); February 2003; p. 72.
LOW-BIRTH WEIGHT EQUALS HIGHER HEALTH RISKS
In the year 2000, about 58,000 infants were born weighing less than 3.3 pounds
(1500g). Although this figure accounts for just 1.4 percent of all births, very
low-birth-weight infants account for the highest rates of neonatal morbidity
and mortality.
In particular, such infants are at risk for neurological impairments, abnormal
cognitive development, speech and language delay, hearing loss, behavioral disorders,
learning disabilities, visual impairment, pulmonary impairment, and growth impairment,
concludes a new evidence report from the Agency for Healthcare Research and
Quality (AHRQ).
The report (available at http://www.ahr.gov/clinic/epcix.htm), the latest in AHRQ’s evidence-based practice program, screened 16,614 abstracts found in PubMed and other medical databases, reviewing 1,693 of them in-depth. The best studies were then used to compile the report.
Some specific studies include:
· Glucocorticoid therapy for prevention or treatment of neonatal lung
disease increases the long-term risk for neurological disorders.
· Bronchopulmonary dysplasia, a common problem in low-birth-weight infants,
confers a two-fold increase in risk for abnormal cognitive development and mental
retardation.
· Low-birth-rate infants are at increased risk for learning disabilities.
Source: JAMA; April 16, 2003. 289 (15); p. 1915.
SUPPLEMENT USE AMONG CANCER SURVIVORS
Despite rising interest in the possible role of vitamin and mineral supplements
in preventing and treating cancer, national surveys show that cancer survivors
do not differ much from the rest of the population in their use of vitamin and
mineral supplements (1).
The researchers combined data on the use of multivitamins; vitamins A, C, and
E; and calcium from the 1987 and 1992 National Health Interview Survey Cancer
Epidemiology Supplement, conducted by the National Center for Health Statistics
and Centers for Disease Control and Prevention. Data on vitamin and mineral
supplement use were available for 461 cancer survivors and 20,581 people reporting
no history of cancer in 1987 and for 228 and 11,186 in each group, respectively,
in 1992. Survivors were defined as those reporting having had a cancer other
than non-melanoma skin cancer more than five years before the survey.
About three-quarters of both groups used multivitamins, making them the most commonly used supplement, regardless of gender or cancer status. About half of both groups used vitamin C, and about a fifth used vitamin E. Use of calcium supplements was more common among women than among men.
According to researchers, this is the first report of vitamin and mineral use in a nationally representative sample of survivors. They hasten to add, however, that although the information is important to report, the estimates do not address the issue of whether using supplements increases survival rates among cancer patients.
The researchers pointed to an earlier study suggesting that vitamin supplements could reduce the risk of some cancers, They said those results could be skewed, because supplement users are also more likely to adopt recommended preventative behaviors such as regular exercise, low-fat and high-fiber diets, and cancer screenings. Another study found that people with at least one health problem are more likely to take supplements.
Thus, the researchers conclude that future studies will have to control those factors. Additional studies could also look at the role vitamin and mineral supplement use plays in improving quality of life for cancer survivors, including those who suffer a recurrence of their disease.
Supplements and Risk Reduction
Another recent study reports on a nested case-control study that suggests carotenoids may protect against breast cancer (2). The study looked at women in Washington County, Maryland, who had given blood in 1974 or 1989, or in both years, and subsequently were followed up to check on their incidence of breast cancer. Between January 1, 1975, and July 1, 1994, 364 of the women developed breast cancer, including 295 who had donated blood in 1974, 115 who had donated blood in 1989, and 64 who had donated in both years. The study selected 295 of those cases along with 295 matched controls. Micronutrient levels were determined on serum that had been stored since the subjects donated blood in 1974 and 1989.
In general, the controls had slightly higher median concentrations of micronutrients than did those with breast cancer. The control subjects had significantly higher median concentrations of beta-carotene, lycopene, and total carotenoids than did the cases from the 1974 cohort. The risk of developing breast cancer among the control subjects who were in the top 20 percent in terms of serum concentrations of beta carotene, lycopene, and total carotenoids was approximately one half of that of women in the lowest 20 percent based on serum concentrations. In the 1989 cohort, only lutein was marginally higher in the control group.
“The central finding from this study is that total carotenoids were associated with reduced risk of breast cancer, although a significant dose response trend was only achieved for the 1974 cohort. In addition, the individual carotenoids, lycopene and fl-carotene were also significantly associated with reduced risk of breast cancer in the 1974 cohort. In the 1989 cohort, lutein showed a reduced risk of breast cancer for women in the higher four-fifths, but there was no significant trend.” according to the study report. These results are consistent with recommendations to consume diets rich in fruits and vegetables.
References:
1. McDavid K, Breslow RA, and Radimer K. Vitamin/mineral supplementation among
cancer survivors: 1987 and 1992 National Health Interview Surveys. Nutrition
and Cancer; 2001; 41(1–2):29–32.
2. Sato R, Helzlsouer KJ, Alberg AJ, Hoffman SC, Norkus EP, and Comstock GW.
Prospective study of carotenoids, tocopherols, and retinoid concentrations and
the risk of breast cancer. Cancer Epidemiol Biomarkers Prev; 2002; 11: 451-7.
Source: Nutrition & the M.D.; September 2002; 28(9):5-6.
Today, many people over 60 are healthier, more fit, and having more fun than ever before. And scientists now know a lot more about the diet and lifestyle habits that can sustain health and vitality for years to come.
First things first: if you’re a smoker, quit. Smoking is the largest contributor to an early death, but it’s never to late to stop. Some people find it much easier to stop smoking once they are no longer faced with the stresses of working life.
When it comes to eating a healthful diet, it’s important to remember that as people age they need fewer calories, but more nutrients. Choose “nutrient-dense” foods, foods with few calories but a lot of nutrition, like whole grains, fruits, and vegetables. For cancer prevention and weight management, cover at least two-thirds of your plate with plant foods; fish, poultry or meat should take up no more than one-third.
Keeping our brains active is another good way to ensure we live our retirement
years to the fullest. In fact, studies show that if we “exercise”
our minds, for example, by pursuing hobbies and social activities, it is more
likely that we will stay mentally agile as we age. Here are six essentials of
healthy eating for our “golden years.”
1. Aim for at least five daily servings of fruits and vegetables.
· These foods are full of the vitamins, minerals, dietary fiber, and
phytochemicals needed for overall good health and protection against chronic
illnesses like heart disease, type 2 diabetes and many cancers.
2. Boost your nutrition.
· Health experts now recommend people over age 50 take a basic 100 percent
DV vitamin-mineral supplement (known as a “multivitamin”) to help
provide nutrients that may be somewhat lacking in our daily diets. Our need
for vitamin B6, B12, calcium, and vitamin D increases as we age. Individual
nutrient supplements, however, should not be taken unless discussed with your
physician.
3. Choose healthy fats over unhealthy fats.
· Cut down on saturated fats, found in animal foods such as meat, full-fat
dairy products, and tropical oils such as coconut, palm, and palm kernel. Also
limit your intake of trans-fats, found in stick margarine and many bakery goods,
and omega-6 fats, from corn and safflower oils. Instead, opt for omega-3 fatty
acids and monounsaturated fats found in fatty fish, canola and olive oils, nuts,
and avocados.
4. Drink enough fluids.
· Make sure to consciously drink plenty of fluids, because the sense
of thirst can dull as we get older. As a rule, try to drink at least eight glasses
of water or other nonalcoholic beverages a day. Non-caffeinated beverages are
preferable.
5. Exercise regularly.
· Staying physically active is important at any age, but keeping bones
strong becomes crucial as we grow older. Weight-bearing exercise is vital for
slowing bone loss, as well as reducing the risk of heart disease, stroke, osteoporosis,
and colon cancer. Exercise can help maintain a healthy weight, improve flexibility
and balance and improve the way we look and feel. Join a gym, go to a fitness
class, play golf with friends, or take a brisk walk. Swimming may offer a gentler
workout for those with painful joints.
6. Focus on fiber.
· Constipation becomes more common with age, so try to eat more whole
grains. Experiment with whole-wheat pitas, bulgur, spelt pasta, and brown rice,
among other options. Beans, lentils, vegetables, and fruit are also good sources
of fiber. Be sure to increase your dietary fiber intake slowly and to drink
adequate fluids.
Source: AICR; Winter 2003; 78:11.
What’s the scoop on whole grains? They contain dietary fiber, vitamins, and minerals that provide a myriad of health benefits.
Try these tips for a variety of delicious ways to add them to your meals.
Most Americans follow the US Department of Agriculture’s advice to eat between 7 and 11 servings of grains each day. Unfortunately most of those servings are refined grains, white bread, pasta, and rice, which offer less nutrition. Whole grains, on the other hand, retain the nutritious bran and germ and also offer B vitamins, vitamin E, selenium, zinc, copper, and magnesium. The soluble fiber in oats and barley may help lower blood cholesterol, while the insoluble fiber in whole wheat and bran helps keep the digestive track healthy.
Whole grains are also a rich source of phytochemicals, health-protective substances that occur naturally in plant foods. In fact, according to Dr. Winston Craig, an expert on phytochemicals at Andrews University in Berrien Springs, Michigan, “The level of phytochemicals in refined wheat may be less than 5 percent of that found in whole grain wheat.”
In grocery stores, whole grains are sold next to the refined versions, as well as in the ethnic food aisle and the bulk food section. Choose products that list “whole grain” or “whole wheat” as the first item on the ingredient list and that provide 3 grams of dietary fiber per serving.
Go With the Whole Grain
· When making baked goods like muffins, breads, and cookies, replace
one-third to one-half of the all-purpose flour with whole-wheat flower, whole-wheat
pastry flour, cornmeal, millet flour, oat flour, or rice flour. Or you can replace
one-quarter of the flour with oat or rice bran.
· Try purchasing whole grain crackers, pretzels, tortillas, bagels, waffles,
pita bread, and pizza crusts. You and your family may not even notice the difference.
· Experiment with spelt or other whole grain pastas instead of the traditional
semolina.
· Try whole-grain hot cereals made with oatmeal or whole wheat.
· Make great-tasting pancakes using buckwheat flour.
· Crush whole-grain dry cereals and use them to coat fish or poultry
before cooking.
· Snack on a few handfuls of air-popped popcorn.
· Try recipes that highlight unfamiliar grains like barley, roasted buckwheat
(also called kasha) quinoa, millet, and wheatberries.
Source: AICR; Winter 2003; 78:4.
A large study of low-income mothers has confirmed that those who are obese before pregnancy tend to breastfeed less than slimmer mothers (1).
While noting that the average difference in duration of breastfeeding was “not large,” the study’s authors, from the Centers for Disease Control and Prevention (CDC), write that the increasing prevalence of obesity and the known benefits of breastfeeding herald the significance of the findings.
Earlier studies had hinted that obesity, in addition to other sociodemographic factors, hinders breastfeeding. The research tested the idea by mining data from 124,151 mother-infant pairs in the CDC’s Pediatric Nutrition Surveillance System.
The study also found that lack of education, smoking during the third trimester, and young age were associated with less breastfeeding.
Reference:
1. Ruowei Li, Sandra Jewell, and Laurence Grummer-Strawn. Maternal obesity and
breast-feeding practices. Am J Clin Nutr; 2003; 77:931-936.
Source: JAMA; April 16, 2003. 289 (15); p. 1915.
Reduced-fat, low-fat, and fat-free products line the shelves of supermarkets, suggesting that fat is the great taboo to the health-conscious consumer. Yet some dietary fat is essential for proper human development and functioning. There are even good fats that researchers encourage us to eat more of for disease prevention.
In the minds of most people, fat is unequivocally bad. As a consequence, low-fat, fat-free, and fat-substitute products have flooded the grocery stores. Many people believe they can lose weight and stay healthy just by avoiding fat in their diet, even if they eat too many calories and don’t exercise.
In moderate amount, however, fat is necessary for health. In fact a fat-deficient diet can lead to deficiency in essential amino acids. Extremely low fat diets also leave people feeling hungry, so they tend to compensate by overeating and brining on high-fat or high-calorie treats. That’s why, for weight management, it makes more sense to include a moderate amount of fat in your eating plan.
Know Your Fats
All fats are not equal. Fats or fatty acids are divided into three major categories: saturated, monounsaturated, and polyunsaturated. There are also trans fatty acids, which food manufacturers create by saturating vegetable oils in a process called hydrogenation. Trans-fatty acids (also called trans-fats), found in shortening as well as commercially prepared baked goods and deep-fried foods, behave like saturated fat in the body.
Saturated fats come mostly from animal foods: meat, whole milk, cheese, and tropical oils like coconut, palm and palm kernel. For good health, these are the kinds of foods you should limit in your diet. There is evidence that a diet high in saturated fat possibly increases the risk of several cancers, including lung, colon, rectal, breast, endometrial, and prostate. Heart disease risk is also heightened.
The American Institute of Cancer Research (AICR) recommends that less than 30 percent of your calories should come from fat. By shifting to a mostly plant-based diet, you can reduce your fat intake, which will offer protection against diseases related to overweight and obesity such as cancer, high blood pressure, heart disease, stroke, and type 2 diabetes.
Good Fat
In the 1960’s, a fifteen-year study revealed that men from the island of Crete were healthier than men from Greece, Italy, the Netherlands, Finland, Yugoslavia, Japan, and the US. Compared to the Americans, the men from Crete had half the cancer mortality rate and one-twentieth the death rate for heart disease. Yet, about 40 percent of their calories came from fat, mostly monounsaturated, due to their high consumption of olive oil.
That’s why, even as health experts say Americans are eating too much total fat, they advise increasing consumption of certain healthful fats, namely, by substituting monounsaturated and polyunsaturated fats for saturated fat in the diet.
Researchers have since discovered that good nutrition may also depend upon a healthy ratio between two types of polyunsaturated fats known as linoleic acid (an omega-6 fatty acid). In healthy populations that consume traditional diets, the ratio of omega-6 fat to omega-3 fat ranges from 5:1 to 10:1. In the American diet, the ration is currently estimated to be 20:1. This imbalance is now being potentially linked to a long list of serious conditions, including cancer, heart disease, and arthritis. Recent evidence suggests that as little as two to three 3-ounce servings per week of fatty fish (a good source of omega-3 fatty acids) can have significant health benefits.
The bottom line is that the simplistic “fat is bad” mentality is inaccurate. Although saturated and trans-fats have harmful effects, monounsaturated and polyunsaturated (particularly omega-3 fats) play an important role in disease prevention and overall god health. Instead of trying to cut out all fat, it’s more important to consume fat in moderation and to emphasize healthy fats over unhealthy fats.
Improve Your Ratio
Eat fewer
· Omega-6 fatty acids: corn, safflower, sunflower, and cottonseed oils
· Saturated fats: fatty meats, full-fat diary products
· Trans-fats: partially hydrogenated fat, stick margarine, shortening,
pastries, and commercially prepared French fries
Eat more
· Omega-3 fatty acids: fatty fish (salmon, albacore, tuna, herring, and
mackerel) canola oil, flaxseed oil, and walnuts
· Monounsaturated fats: olive oil, avocado, canola oil, nuts, and nut
oils
Source: AICR; Winter 2003; 78:1,3.
HHS ISSUES NATIONAL PLAN TO REDUCE IMPACT OF DIABETES ON WOMEN
Health and Human Services (HHS) Secretary Tommy G. Thompson recently introduced a national plan to address the growing health epidemic of diabetes in women. Diabetes is the sixth leading cause of death in the United States and is a major contributor to heart disease, the number one killer of women.
“We need to change the way we think about diabetes with an eye on preventing the disease in women throughout their lives, and on reducing disease-related complications for the more than 9 million American women who already have the disease,” Secretary Thompson said. “We need to help women understand the disease and what they can do to take care of themselves. This new effort shares a common philosophy with our broader prevention initiative, Steps to a Healthier US, which includes a special focus on reducing diabetes.”
The National Agenda for Public Health Action: The National Public Health Initiative on Diabetes and Women's Health is designed to mobilize the Nation to address diabetes as a growing health concern. It calls for expanding community-based health education programs, promoting risk assessment, supporting quality care and self-management for diabetes and its complications, and encouraging research into the factors that influence diabetes and women's health.
With the increasing lifespan of women, the rapid growth of minority, racial, and ethnic populations in the United States, who are hardest hit by the diabetes burden, and the apparent increase in new cases of diabetes among younger women in their adolescent years, the number of women at high risk for diabetes and its complications continues to increase.
“This plan offers a vision of a nation in which diabetes in women is prevented or at least delayed whenever possible,” said Dr. Julie Gerberding, director of HHS' Centers for Disease Control and Prevention (CDC). “Given the dramatic increases in newly diagnosed diabetes cases and associated health risks such as obesity and heart disease, it is essential that we bring diabetes under control and make this vision a reality.”
Secretary Thompson announced the National Agenda with representatives from other national organizations that are working to implement it, including the American Diabetes Association (ADA), the Association of State and Territorial Health Officials (ASTHO), and the American Public Health Association (APHA). The announcement coincides with American Diabetes Alert Day, an annual ADA-sponsored call-to-action for people to find out if they are at risk for diabetes.
The goal of this national partnership is to address the growing problem of
diabetes in women and create a nation in which:
· diabetes in women is prevented or at least delayed whenever possible;
· women at risk for diabetes receive the family and community support
they need to prevent or delay diabetes and its complications;
· appropriate care and disease management of diabetes is promoted across
their life stages; and
· complications from diabetes are prevented, delayed, or minimized.
“Diabetes touches everyone. Whether diabetes is a personal battle, or affects a family member, neighbor or friend, this disease affects all of us,” said Dr. Francine R. Kaufman, president of the ADA. “It is essential that we, where possible, prevent new diabetes cases and help those who already have the disease to prevent serious complications.”
Implementation of the National Agenda relies on the effective collaboration among many partners. The co-sponsors will be seeking to engage public and private health care organizations, business and industry; education, communication and media, and policy makers at local, state, and federal levels in implementing the key strategies.
Actor Dorian Gregory, who co-hosts the nationally syndicated talk show, “The Other Half,” participated in today's announcement. “As a diabetic with others in my family who have suffered from this disease, I feel passionately about educating the public, especially women, who suffer disproportionately from it. I am grateful to be a part of Secretary Thompson's new initiative.”
According to the CDC, diabetes has increased to epidemic proportions in the
United States. Diagnosed diabetes (including gestational diabetes) among women
has increased almost 50 percent during the past decade. The prevalence of type
2 diabetes is at least two-to-four times higher in Black, Hispanic, American
Indian, Asian, and Pacific Island women than in whites.
The CDC estimates that more than 17 million Americans have diabetes, and about
6 million are undiagnosed. About 1 million new cases of diabetes are diagnosed
each year. The total economic cost of diabetes in the US was estimated to be
$132 billion annually in 2002, according to the ADA. In addition, an estimated
16 million Americans have pre-diabetes and can reduce their risks of developing
the disease by losing a modest amount of weight and increasing their physical
activity levels.
Source: HHS Press Release; March 25, 2003.
THE NATIONAL HEART, LUNG, AND BLOOD INSTITUTE STUDY FINDS ALL-IN-ONE APPROACH TO LIFESTYLE CHANGES EFFECTIVELY LOWERS BLOOD PRESSURE
Lifestyle changes to prevent or control high blood pressure need not be made one at a time. According to a study supported by the National Heart, Lung, and Blood Institute (NHLBI), with special counseling, Americans can make all the needed changes at the same time. The best results were achieved when the lifestyle changes included adoption of the DASH diet, which is rich in fruits, vegetables, and lowfat dairy products (1).
“This is the first time a host of behavioral steps to prevent or control high blood pressure has been put together in one intervention,” said NHLBI Director Dr. Claude Lenfant. “Past studies looked at one or two changes at a time, and it was thought that doing more would prove too hard. But PREMIER shows that an all-in-one approach works and can help Americans reduce their blood pressure, lowering their risk for heart disease and stroke.”
“PREMIER underscores the importance of lifestyle changes as a first-line
weapon in the fight against high blood pressure,” said Dr. Lawrence J.
Appel, Professor of Medicine at The Johns Hopkins Medical Institution in Baltimore,
MD, and a coauthor of the article. “Those in the study who made the greatest
lifestyle changes had the best blood pressure results. Millions of Americans
can benefit by using these lifestyle changes to control high blood pressure,
or prevent it in the first place.”
High blood pressure is a major risk factor for heart disease and the chief risk
factor for stroke. Even blood pressure slightly above normal increases the risk.
About 50 million American adults, one in four, have hypertension and the risk of developing it increases with age.
Recommended lifestyle steps to prevent or control hypertension are to:
· lose weight if overweight,
· follow a heart-healthy eating plan, which includes reducing salt and
other forms of sodium,
· increase physical activity,
· limit consumption of alcoholic beverages, and
· quit smoking.
Additionally, results of earlier studies, published in December 2001 and April 1997, showed that the DASH diet significantly lowers blood pressure, especially when combined with reduced sodium intake (2,3). DASH stands for “Dietary Approaches to Stop Hypertension.”
PREMIER dealt with all of the hypertension prevention and control steps. The study began in 1998 and was conducted at four clinical centers. It included 810 participants with blood pressures of 120-159 mm Hg systolic and 80-95 mm Hg diastolic. (Higher-than-optimal blood pressure is 120- 139/80-89 mm Hg; stage 1 hypertension is 140-159/90-99 mm Hg.) At the start of the trial, 38 percent of participants had hypertension, and most were overweight and sedentary. Sixty-two percent were women and 34 percent were African American.
Participants were randomly assigned to one of three groups: Advice-Only, Established, and Established Plus DASH. All three groups received printed materials about blood pressure and lifestyle. In addition, those in the Advice-Only group received a 30-minute individual session with a nutritionist, which did not include counseling on how to make behavior changes. Those in the Established group had 18 counseling sessions in 6 months, 14 group meetings and 4 individual sessions. They kept track of their diet, including calorie and sodium consumption, and their physical activity. Those in the Established Plus DASH group had the same intervention schedule as those in the Established group, but also were taught to follow the DASH diet and to record their daily servings of fruits, vegetables, dairy products, and fat.
After 6 months, blood pressure levels had declined in all three groups but the reduction was significantly more in the two intervention groups and most in the Established Plus DASH group. Systolic blood pressure decreased on average by 11.1 mm Hg in the Established Plus DASH group, 10.5 mm Hg in the Established group, and 6.6 in the Advice-Only group; diastolic blood pressure decreased on average by 6.4 mm Hg in the Established Plus DASH group, 5.5 mm Hg in the Established group, and 3.8 in the Advice-Only group.
The percent of those with hypertension dropped after 6 months from 37 to 12 in the Established Plus DASH group, from 37 to 17 in the Established group, and from 38 to 26 in the Advice-Only group.
After 6 months, the percent of those able to control their high blood pressure also was greatest in the Established Plus DASH group. Seventy-seven percent of hypertensives in that group lowered their blood pressure to under 140/90, by comparison, drug treatment typically controls blood pressure in about 50 percent of those with stage 1 hypertension, according to the article. About 66 percent of hypertensives in the Established group and 48 percent of hypertensives in the Advice-Only group brought their hypertension under control.
Other key results include:
· Optimal blood pressure (less than 120 mm Hg systolic and less than
80 mm Hg diastolic) was achieved in 35 percent of the Established Plus DASH
group, 30 percent of the Established group, and 19 percent of the Advice-Only
group.
· Fewer of those in the two intervention groups who started the trial
without high blood pressure went on to develop hypertension, 6 percent in the
Established Plus DASH group, 8 percent in the Established group, and 11 percent
in the Advice-Only group.
· Consumption of fruits, vegetables, and dairy products significantly
increased in the Established Plus DASH group, compared to the other two groups.
A third of those in the Established Plus DASH group consumed nine or more servings
of fruits and vegetables daily, compared with only 6 percent of those in the
other groups. Fifty-nine percent of those in the Established Plus DASH group
consumed two or more dairy servings a day, compared with about 34 percent of
the Advice-Only and about 28 percent of the Established groups.
· Significant weight loss occurred in all groups, the average losses
for those who were overweight at the start of the study were about 13 pounds
in the Established Plus DASH group, about 11 pounds in the Established group,
and about 3 pounds in the Advice-Only group.
“One of the key findings in PREMIER is that people can not only follow the DASH diet on their own but also can lose weight on it, even though it calls for many more servings of fruits and vegetables a day than Americans typically consume,” said Dr. Eva Obarzanek, NHLBI nutritionist and PREMIER Project Officer. “The new findings mean that it's feasible for Americans to use the eating plan, lose weight if they're overweight, and protect themselves against the risks of high blood pressure.”
References:
1. Effects of Comprehensive Lifestyle Modification on Blood Pressure Control:
Main Results of the PREMIER Clinical Trial. JAMA; April 22, 2003; 289: 2083-2093.
2. NIH Press Release; December 17, 2001.
3. NIH Press Release; Apr. 16, 1997.
Source: HHS Press Release; April 22, 2003.
The National Institutes of Health has launched a study of the popular herb St. John’s Wort (Hypericum perforatum) in individuals with minor depression. The three-armed, double-blind study will test the herb against the prescription and antidepressant citalopram (Celexa) and placebo.
Patients who improve after 12 weeks will continue with the same treatment (or placebo); those who do not will be switched to a second arm.
Two recent studies found that St. John’s Wort was not effective in treating minor depression (1).
Reference:
1. JAMA. 2001;285:1978-1986 and 2002;287:1807-1814
Source: Brian Vastag. JAMA; April 16, 2003. 289 (15); p. 1915.
An anti-carcinogenic substance known as conjugated linoleic acid (CLA) is causing scientists to take a new look at fats found in dairy and meat. They are trying to harness the benefits of CLA while avoiding the detrimental health effects of eating large amounts of meat and dairy foods.
A sound body of evidence shows that a high intake of total fat and saturated fat (found in animal foods like meat and diary) is possibly linked to cancers of the lung, colon, breast, and prostate. That’s one of the reasons American Institute of Cancer Research (AICR) recommends filling your plate with two-thirds (or more) vegetables, fruit, whole grains, and beans and one-third (or less) meat and dairy products. Yet scientists have now identified another type of fatty acid, CLA, naturally present in very small amounts in meat and dairy fats, which instead may actually inhibit different types of cancer.
CLA is the collective term for one or more types of conjugated linoleic acid that have small differences in their chemical makeup and are present in meat and dairy foods. Dairy fats contain the highest natural level of CLA dietary sources, although the amount can vary seasonally and regionally, depending on the dietary content of the pasture or grain on which dairy cows graze. Synthetic CLA has been shown to inhibit the growth of a variety of human tumor cells, including cancer cells of the skin, colon, breast, and lung, as well as protecting against the spread of cancer in animal models
Increasing CLA intake without eating more meat and dairy
CLA appears to be effective as a potent inhibitor of breast carcinogenesis at the very low dietary level of 0.005 percent of the total fat in the diet, regardless of the overall fat content. Scientists are trying to determine whether the trace amounts of natural CLA in the Western diet play a role in moderating the effect of high fat consumption on breast cancer risk. If true, however, these results would not lead health experts to eat more meat and dairy products, which could cause serious negative health consequences.
Instead researchers are looking for ways to increase the level of the most active type of CLA in animal and dietary foods. In that way, people might get added cancer protection without consuming large amounts of “bad” fat. They have found that altering the fat composition of the cow’s diet can increase the levels of CLA in milk. Evidence shows that one product, CLA-enriched butter fat, helps inhibit mammary carcinogenesis.
CLA and breast cancer risk
Margot Ip, PhD, from the Roswell park Cancer Institute in Buffalo, New York, has shown that CLA can exert a twofold punch to breast cancer. First, according to in vitro studies (in which cells are studied in an artificial environment, instead of in the body), CLA inhibits the growth of breast cancer cells. Second, it inhibits the growth of new blood vessels (a process called angiogenesis) in the mammary gland, which reduces the rate of mammary tumor growth.
Dr. Ip believes that these results may have major implications for the future
prevention of breast cancer. “If there were an inexpensive way of enriching
food with CLA, it could reduce the need for current anti-angiogenic treatments
that may be expensive or cause side effects,” Dr. Ip says. She and her
colleagues continue to study the various cancer-protective powers of CLA. Someday,
it may be possilbe to obtain CLA-enriched meat and dairy products. Until then,
continue to follow AICR’s guidelines for eating only small portions of
meat and dairy products as part of a mostly plant-based diet. This eating pattern
will provide the health benefits of CLA without the potential risks associated
with consuming too much meant and dairy fat.
Source: AICR Newsletter; Winter 2003, 78; p. 8.
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