An article in the Aug. 5 issue of New Scientist magazine has struck another note of bad news for the antioxidant business. Titled "The antioxidant myth: a medical fairy tale," the article states: "Evidence gathered over the past few years shows that at best, antioxidant supplements do little or nothing to benefit our health. At worst, they may even have the opposite effect, promoting the very problems they are supposed to stamp out."
The writer, Lisa Melton, cited two New England Journal of Medicine studies supporting the use of antioxidants—namely, vitamin E—but mentions numerous examples of negative results, including a 1992 U.S. National Cancer Institute trial of beta-carotene's cancer-prevention properties that was discontinued because of poor mid-trial results. Similarly poor evidence is cited for vitamin C and polyphenols.
Melton is a science writer in residence at the Novartis Foundation in London, a scientific and educational charity, formed in 1949 by the Swiss company Ciba (now Novartis).
Andrew Shao, Ph.D., vice president of scientific and regulatory affairs for the Council for Responsible Nutrition—who was interviewed for the New Scientist article—said he tried to get across the point that the current manner in which many nutrients are studied uses a drug-based approach.
"Scientifically it's certainly valid, that reductionist approach of 'what single entity is responsible,'" he said. "But it may not be the most appropriate method to study nutrients." Taking nutrients out of their context ignores the holistic nature of these substances, Shao said.
The article recommended a diet rich in fruits and vegetables saying, "The conclusion is becoming clear: Whatever is behind the health benefits" of such a diet, "you cannot reproduce it by taking purified extracts or vitamin supplements."
Melton speculated on various hypotheses as to why a nutrient-enriched diet works while supplementation doesn't. One is a generally healthier lifestyle among healthy eaters; another is that antioxidants in food are "bound into tough, fibrous material" that the body is more able to make use of as it slowly digests.
Finally, Melton said, antioxidant-containing tea and coffee are also "bursting with reactive oxygen," which is exactly what antioxidants should be fighting. "How come tea and coffee might be beneficial? One possibility is that they can help nudge our own internal antioxidant systems into action."
Eating fruits and vegetables has become an oft-repeated public health message, Shao said, "My reaction is that the five-a-day program has never been studied in a randomized, controlled trial, yet it's well-accepted." But he notes that it doesn't mean it's not true or that he doesn't believe it. "The fact that smoking causes lung cancer has never been subjected to a trial either …"
Shao noted that the very nature of the trials was deficient in another important manner—"the idea that in a lot of these trials, they're testing them in diseased populations. … They aren't testing whether they reduce risk of disease in a healthy population."
In related news, a recently published study in the American Journal of Clinical Nutrition tested antioxidant levels in 1,113 foods and beverages. The July study found that spices and herbs, nuts and seeds, berries and fruits and vegetables were the food groups that contained items with "very high" antioxidant content.
"Of the 50 food products highest in antioxidant concentrations, 13 were spices, eight were in the fruit and vegetables category, five were berries, five were chocolate-based, five were breakfast cereals, and four were nuts or seeds," the researchers wrote. Based upon typical serving size, the study found that the top five highest foods were blackberries, walnuts, strawberries, artichoke hearts and cranberries. The top five overall were all spices—cloves, oregano leaf, ginger, cinnamon and turmeric.
Researchers used the FRAP (ferric reducing ability of plasma) assay in studying the products, as opposed to the more recognizable—in the naturals world—ORAC assay, or oxygen radical absorbance capacity.
Shao, of CRN, called the study interesting, noting: "These types of assays are important. They help to identify foods that may have health benefits." But he also said that the assays are not necessarily indicative of the benefits these foods may have in the human body. "My point is that these assays aren't accepted by the scientific community and regulators as being a marker for their in vivo effects."
Other recent science news
Researchers at The Pennsylvania State University have used fatty acids commonly found in dairy products to successfully treat diabetes in mice, according to a news release. Conjugated linoleic acids "have also shown promising results in human trials."
Jack Vanden Heuvel, professor of molecular toxicology and co-director of Penn State's Center for Excellence in Nutrigenomics, and other researchers tested mice prone to type 2 diabetes. Mice treated with CLA had "an improvement in insulin action and a decrease in circulating glucose." Researchers also concluded that CLA works in a way similar to synthetic drugs. "We wondered if CLA was using the same mechanism, in which case it could be used as an anti-diabetes drug," Vanden Heuvel said.
CLA is found in milk, cheese and meat, and is formed "by bacteria in ruminants" that convert fatty acids from plants into CLA.
"And compared to the synthetic drugs used to treat this disease, CLA does not cause weight gain and may in fact decrease overall body fat," Vanden Heuvel said.
Teens found deficient in vitamin D
A new study is suggesting that teenagers may benefit from vitamin D supplementation. Published in the Archives of Disease in Childhood, the study recruited 51 teenage girls of an average age of 15.3 years, and found that 73 percent of them were vitamin D deficient. Nine of the girls had vitamin D levels so low that they were equivalent to what is typically associated with rickets. Nonwhite girls had "significantly" lower levels of the vitamin, but the difference was related to sun exposure and not diet.
"Further studies are required to determine if subclinical vitamin D deficiency … results in reduced bone mass accrual around puberty, and whether vitamin D supplementation can help to prevent this," the researchers wrote.
The study was conducted in the United Kingdom in an inner-city population.
More bad DES and cancer news
The August issue of Cancer Epidemiology, Biomarkers & Prevention published a study by a nationwide team of researchers. It found that women over age 40 born to mothers who used the anti-miscarriage drug diethylstilbestrol had 1.9 times higher risk of developing breast cancer compared with unexposed women.
Also, researchers found that the highest risk of developing the disease was found in women with the highest cumulative exposure to DES.
"This is really unwelcome news because so many women worldwide were prenatally exposed to DES, and these women are just now approaching the age at which breast cancer becomes more common," wrote lead author Julie Palmer, Sc.D., of the Boston University of Public Health, in a release.
Natural Foods Merchandiser volume XXVII/number 9/p. 16