To the Editor:
Freedman et al. (1) provide an excellent review of the effectiveness of popular diets on weight loss and other health outcomes. Although many health benefits of very-low-fat diets high in complex carbohydrates are described, we are concerned about the statement that these diets “are low in vitamin E, vitamin B-12, and zinc” (1). This statement is based on a 1-day sample menu, which may not be representative of the average nutrient intake of a well-planned, low-fat, plant-based diet. For example, in our ongoing Prostate Cancer Lifestyle Trial, where participants adhere to a vegan diet with 10% of calories from fat, analyses of 3-day food diaries reveal adequate micro- and macronutrient intake compared with standard reference values (2). Although low-fat diets may be low in vitamin E, the dose to yield plasma concentrations of vitamin E that raise antioxidant activity cannot be obtained from diet alone (3). For this reason, we and others have recommended that micronutrient supplementation, or the use of fortified foods, should be included in a plant-based diet (4) (5).
Finally, we would like to add that plant-based diets are not only low in disease-promoting substances (e.g., cholesterol, saturated fat, oxidants, trans fatty acids, arachidonic acid, and total fat), but also high in protective dietary factors (e.g., antioxidants, folate, soluble fiber, saponins, flavonoids, carotenoids, isoflavones, soluble fiber, plant sterols, and optimal n-6:n-3 ratio) (6). This type of diet not only contributes to weight loss and the prevention of many chronic diseases, but also results in plasma cholesterol lowering of the same magnitude as achieved by statin drugs, a 40% reduction in low-density lipoprotein cholesterol after 1 year, and the reversal of heart disease (7).