A new research report in the Journal of the American Medical Association purportedly suggests that the high-protein, high-fat Atkins-type diet does better for weight loss over 12 months than the three other diets studied: the Zone, Ornish, and LEARN (U.S. Guidelines) diets. (Gardner CD, et al., “Comparison of the Atkins, Zone, Ornish, and LEARN Diets for Change in Weight and Related Risk Factors Among Overweight Premenopausal Women. The A TO Z Weight Loss Study: A Randomized Trial,” JAMA. 2007 March 7;297(9):969-977.)

The 311 non-diabetic, pre-menopausal female subjects were all overweight or obese (body mass index, or BMI, of 27-40) at both the start and the end of the study. However, the differences in weight loss between the Atkins diet and the Ornish or LEARN diets were not statistically significant, and by the end of the study virtually none of the subjects was following any of the diets closely, making it hard to draw any firm conclusions about the value of the diets for weight loss.

This did not, however, stop the press from drawing such conclusions, at least in their headlines. “Atkins beats other diet plans…” said the AP; “Diet study tips scale in favor of Atkins” said Reuters (and went on to say that the Atkins subjects lost twice as much weight as the others, even though the difference was not statistically significant!); “Atkins diet wins for losing” said the Los Angeles Times. What is lost in all the hype is the real information that people need. All of the subjects were very overweight or obese. When the study started, their average weight was 190 pounds, so a weight loss of 10 pounds is barely meaningful (unless it is a harbinger of continued weight loss, which it apparently was not, as they had already fallen off the diets and started to gain their weight back by the end of the study). Between 6 months (the peak weight loss in the Atkins group) and the end of the study at 12 months, the subjects had already gained back 20 percent of their weight.

The real guidance that people need is what dietary practices will make them healthy in the long term, not simply help them with weight reduction for a few months, and for this the data is fairly clear. It is also common sense and not likely to generate headlines. Reducing refined carbohydrates (particularly sugar, corn syrup, and white flour) is important in any diet; but fresh, whole foods that contain complex carbohydrates (from whole grains, vegetables, beans, and fruits) are important sources of nutrients, phytochemicals, and fiber.

These foods are associated with a reduction of the risk of heart disease, cancer, hypertension, strokes, and diabetes, the most significant causes of premature death. Diets that emphasize fats and animal proteins at the expense of healthier whole, natural, plant-based foods preclude adequate intake of these protective nutrients.

Higher intakes of Vitamin D can prevent colorectal cancer according to a new study (Gorham ED, et al., “Optimal vitamin D status for colorectal cancer prevention a quantitative meta-analysis,” Am J Prev Med. 2007 Mar;32(3):210-6.) This study was a meta-analysis (study of studies), pooling data from five different published reports. Researchers found that among all the subjects, the highest serum levels of Vitamin D were associated with a 50-percent reduction in the risk of colorectal cancer. They estimated that the highest serum levels were correlated with a Vitamin D intake of 1000 to 2000 IUs per day. This is higher than most people get from the Sun and food sources combined, especially in elderly people (who do not manufacture Vitamin D efficiently), people in northern latitudes who have less sun exposure, or those who carefully avoid all sun exposure. (Of course, excessive sun exposure is still associated with an increased risk of skin cancer.) Some products fortified with Vitamin D do use natural Vitamin D3, the preferred form, including some soy-milk brands.

Lignans are estrogen-like compounds found in plant foods such as seeds, nuts, fruits, vegetables, whole grains, and beans. Lignans from non-soy sources are far more common in the Western diet than those from soy foods. Flax and sesame seeds contain far more lignans than most other good sources. Flax seeds contain 85 mg per ounce, and sesame seeds contain 11 mg per ounce, while other food sources contain less than 1 mg per serving.

A study from France, published in the Journal of the National Cancer Institute, shows that post-menopausal women who consume large amounts of lignans have a lower risk of breast cancer. Risk reduction was 17 percent for women with the highest lignan intake (greater than 1.4 mg per day) compared to those with the lowest intake. (Touillaud MS, et al., “Dietary lignan intake and postmenopausal breast cancer risk by estrogen and progesterone receptor status,” J Natl Cancer Inst. 2007 Mar 21;99(6):475-86.) This study involved 58,049 post-menopausal women followed for an average of 7.7 years. Over that time there were a total of 1469 cases of diagnosed breast cancer. Earlier studies were unclear on the relationship of lignans to breast cancer; but in this study, they were clearly helpful in this age group.

After flax and sesame seeds, the best sources of lignans are brassica-family foods (kale, broccoli, and cabbage), apricots, strawberries, and whole grains. These lignan-rich foods are also high in fiber, vitamins, minerals, antioxidants, and other phytochemicals that protect against heart disease and other cancers.

Flavonoids are plant pigments that have antioxidant activity and other healthful properties, including reducing both LDL cholesterol levels and inflammation. A wide variety of these phytochemicals (also called bioflavonoids) is found in many plant foods. The Iowa Women’s Health Study reports that women who had the highest intake of flavonoids had a lower risk of death from heart disease and a lower incidence of heart and blood-vessel diseases.

The study evaluated 34,489 women over 16 years and specifically looked at intake of three kinds of flavonoids – anthocyanins, flavones, and flavanones. Specific foods that were helpful included bran from whole grains, apples, red wine, pears, strawberries, and grapefruit. (Mink PJ, et al., “Flavonoid intake and cardiovascular disease mortality: a prospective study in postmenopausal women,” Am J Clin Nutr. 2007 Mar;85(3):895-909.) Risk reduction ranged from 10 to 22 percent. Although this may seem small, reducing heart deaths by this amount could prevent 50 to 100,000 deaths per year in the United States.

 

Michael Janson, M.D., is Past President of the American College for Advancement in Medicine and the author of four books, including Dr. Janson's New Vitamin Revolution and the User's Guide to Heart Healthy Supplements.  He writes and publishes a free monthly newsletter, Dr. Janson's Healthy Living, available at his website, www.drjanson.com. Dr. Janson does phone and email consults on nutrition, lifestyle, and dietary supplements. He is also a consultant for companies in natural health care. He can be reached at drjanson@drjanson.com.