Like favorite foods from the state fair or family reunion picnics, soyfoods have all the makings of traditional summertime favorites. For some of us, it’s the idea of grab-and-go foods, skewered and grilled or frozen and served on a stick, that remind us of summer and its outdoor events. Other people think of food eaten around a campfire or along a hiking trail, and still others fondly recall summer picnics with the grill going and fruit pies or homemade cookies for dessert. Soyfoods are a natural for creating new warm-weather traditions of your own. Ingredients such as tofu, edamame, soymilk and soy yogurt offer cool and convenient protein that fits in with active summer lifestyles….
Archives for July 2011
It’s been 12 years since the US Food and Drug Administration approved a health claim for soyfoods and coronary heart disease based on the cholesterol-lowering effects of soy protein. The research that first brought these benefits of soy protein to the attention of the medical and scientific communities was conducted by James Anderson, MD, from the University of Kentucky.
In 1995, Dr. Anderson and his colleagues published a meta- analysis of 34 different clinical trials which showed that soy protein lowered LDL-cholesterol by nearly 13 percent. This effect was greater than what has been shown for any other single food, and was comparable to the results achieved from the available cholesterol-lowering drugs. Despite these impressive results, findings from individual studies have been inconsistent, raising questions about the true magnitude of the cholesterol-lowering effects of soyfoods. Now, 16 years later, those questions have been answered.
Dr. Anderson has confirmed his initial findings about the effects of soy protein in a new analysis of the literature, which included 20 studies published after his 1995 analysis. He and colleague Heather Bush, PhD found that, among subjects consuming soy protein, LDL-cholesterol was lowered by 5.5 percent compared to those subjects who consumed a non-soy control protein (usually casein from milk). The effect was much greater in subjects who had elevated cholesterol to begin with. In addition, soy protein raised good HDL-cholesterol by about 3 percent and lowered triglycerides by approximately 11 percent. Although the cholesterol-lowering effects of soy protein were found to be less robust than initially reported, Drs. Anderson and Bush estimated that the collective effects of soy protein on LDL-cholesterol, HDL-cholesterol, and triglycerides would lower heart disease risk by 12 to 20 percent. Soyfoods are likely to have a further positive impact on heart disease risk since they are also low in saturated fat and high in healthy unsaturated fats. Soyfoods like tofu, tempeh, soymilk and veggie meats can play an important role in heart healthy diets.
Anderson JW, Bush HM. Soy Protein Effects on Serum Lipoproteins: A Quality Assessment and Meta-Analysis of Randomized, Controlled Studies. J. Am. Coll. Nutr. 2011; 30: 79-91.
Researchers in India recently examined the effects of soybean isoflavones on a variety of health outcomes in women who have had their ovaries removed. Soybeans and soyfoods are essentially the only foods to contain nutritionally relevant amounts of isoflavones. An abundance of research involving postmenopausal women has been published, but relatively few of the findings have involved women who have entered menopause because of surgical removal of their ovaries.
In this study, one group of women consumed 75 mg of isoflavones—the equivalent of about three servings of soyfoods—as a daily pill. Women in the control group consumed a placebo. The study was double blinded which means that neither the researchers nor the women knew which group they were in. Thyroid hormone function and menopausal symptoms were assessed at the beginning of the study and then after 6 and 12 weeks. Menopausal symptoms included depression, anxiety, fatigue, hot flashes, cardiac complaints, sleeping disorders, joint and muscle pain, vaginal dryness, sexual problems, and urinary complaints.
At the end of the 12 weeks, there were no differences in thyroid hormone function between the two groups. However, among the women who consumed the isoflavone pill, there were improvements in overall menopausal symptoms. Most notable in this regard was the improvement of urogenital symptoms (sexual problems, urinary complaints, and vaginal dryness) in the isoflavone group and the worsening of these symptoms in the placebo group. This study adds to the existing evidence that postmenopausal women can benefit from consuming soyfoods.
Mittal N, Hota D, Dutta P, Bhansali A, Suri V, Aggarwal N, Marwah RK, Chakrabarti A. Evaluation of effect of isoflavone on thyroid economy & autoimmunity in oophorectomised women: A randomised, double-blind, placebo-controlled trial. Indian J. Med. Res. 2011; 133: 633-40.