March 2007

Diet and Weight Loss Study
Unhealthy Girl Scout Cookies
Vitamin D and Colon Cancer
Maintaining Muscle with Aging
Selenium and Cognitive Function
Chronic Lead Exposure and Cognition

Diet and Weight Loss Study

A new research report in the Journal of the American Medical Association 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 were 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 LA 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). 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.
For ideas on how to include healthier complex carbohydrates and whole, natural foods in the diet, check out prior newsletters and the recipes that you will find in them. At least avoid being misled by fad diets that focus only on weight loss rather than overall long-term health.

Unhealthy Girl Scout Cookies

A recent news report noted that Girl Scout’s Cookies are now being produced with “little to no” trans fats, the byproduct hydrogenation, found in partially hydrogenated vegetable oils, that increase the risks for heart disease and probably cancer, and immune disorders. (Girl Scouts cut trans fats from cookies. Associated Press, February 23, 2007.) Trans fats occur naturally in only minuscule amounts in some foods (such as meat and dairy products), and they raise LDL cholesterol while lowering levels of the good HDL cholesterol.

However, although the Girl Scout cookies may be labeled as containing no trans fats, regulations still allow them to contain some trans fats! A small serving (most people probably eat more than one serving at a time) may contain half a gram of trans fats, so someone might accumulate a significant trans fat intake over a day.

In any case, while Girl Scouts use the cookies as a significant money maker, they are not in any way healthy. Aside from any residual hydrogenated oils, they also contain primarily saturated fat, white flour, and plenty of refined sugar, as well as artificial flavors, colors, and preservatives. In fact, one flavor contains over two teaspoons of sugar per serving. In others, sugar is the first ingredient.

Considering the massive and growing problem with obesity among children, including girls of Girl Scout age, perhaps the Girl Scouts could send a healthier message. Their spokesperson says they “know they are not selling broccoli” and that their cookies are not meant to be a major part of the diet. This does not diminish the negative effects of these harmful snacks. Maybe they should be promoting broccoli (and other vegetables and fruits) and find other ways to fund activities.

Vitamin D and Colon Cancer

A new study shows that higher intakes of vitamin D can prevent colorectal cancer (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 IU per day. This is higher than most people get from the sun and food sources, 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.)

While some sun exposure, but not excessive amounts, is a good idea, it is safer and as effective to take supplements of natural vitamin D. Natural vitamin D is listed as D3 (or cholecalciferol) on labels, as opposed to the synthetic D2 (ergocalciferol) that is often added to foods or commercial dietary supplements. I have noticed that some soy milk has recently been produced with natural vitamin D, rather than the synthetic form that I used to see on the labels.

Maintaining Muscle with Aging

Elderly people tend to lose muscle strength and muscle mass, but it is possible for the elderly to build muscle with exercise. A study of 20 women and 4 men showed that a training program of resistance exercise for 12 weeks led to a gain of 6.4 pounds of new muscle and a loss of 8.8 pounds of fat (Wieser M, Haber P, The effects of systematic resistance training in the elderly. Int J Sports Med. 2007 Jan;28(1):59-65). The exercises were as effective whether they were done twice or three times a week, as long as the total number of repetitions was the same. Average muscle strength increased 15 percent, while maximum strength went up between 26 and 38 percent, depending on the muscle group tested. Muscle oxygen use went up 12 percent by the end of the study. This once again shows that it is never too late to start a health program. Of course, the earlier you start a health program the more likely you are to achieve the long-term benefits, rather than getting weak and ill and having to play catch-up.

Selenium and Cognitive Function

Selenium is an important trace mineral nutrient. With age, plasma selenium levels frequently decline, and at the same time aging is associated with worsening brain function. A large study in France shows that loss of cognitive function is worse in those people in whom selenium levels decline the most. Researchers followed 1389 subjects for 9 years plus follow-up evaluations (Akbaraly NT, et al., Plasma selenium over time and cognitive decline in the elderly. Epidemiology. 2007 Jan;18(1):52-8). Those whose selenium level in the plasma declined the most had the worst cognitive decline, after accounting for other risk factors. As selenium is an anti-oxidant cofactor (essential for the activity of the antioxidant enzyme glutathione peroxidase), this is one further piece of evidence that oxidative damage is one contributor to loss of brain function. Selenium is a safe supplement, and is often low in the diet.

An earlier report by this same research group on the same subjects showed that overall mortality rates were higher in subjects with low selenium levels compared to those with higher serum selenium. (Akbaraly NT, et al., Selenium and mortality in the elderly: results from the EVA study. Clin Chem. 2005 Nov;51(11):2117-23.) Selenium is frequently in multi-vitamin/mineral formulas, but it is important to make sure to get adequate amounts. Many areas of the country have low soil selenium, leading to low dietary intake, in spite of the fact that many of our foods come from a variety of geographic sources.

Chronic Lead Exposure and Cognition

Total lifetime lead exposure is related to cognitive function in the elderly. A study of blood and bone lead levels showed that as lead concentration in bone went up, cognitive function declined, as measured by vocabulary studies, reaction times, and pattern comparison tests. The relationship did not hold for blood lead alone, indicating that it is lifetime exposure to lead that leads to the problem. (Weisskopf MG, et al., Cumulative lead exposure and cognitive performance among elderly men. Epidemiology. 2007 Jan;18(1):59-66.) Long-term exposure results in lead accumulation in the bones (as well as liver and neurological tissues) and, as are other heavy metals, is associated with acute and chronic health problems, including heart disease and cancer. Treatment with chelation therapy, such as intravenous treatment with EDTA for vascular disease or oral treatment with DMSA for toxic metal excess, is safe and effective.