Archives for September 2012
Nearly 300 million people worldwide have asthma, a chronic inflammatory lung disease that causes wheezing, coughing, chest tightness, and shortness of breath. Asthma is caused by a combination of genetic and environmental factors. Although symptoms can be prevented by avoiding triggers such as allergens and irritants, the prevalence of asthma has increased significantly since the 1970s.
Diet is increasingly recognized as an important risk factor for asthma. Foods that are rich in antioxidants, such as fruits and vegetables might be protective against this disease since decreased consumption of these foods is associated with an increased prevalence of asthma. There is also growing interest in the effects of soyfoods. Their isoflavone content may make them a protective food as well, which could be part of the explanation for the lower rates of asthma in Japan.
Researchers from the Johns Hopkins University School of Medicine compared the isoflavone intake of 300 patients with poorly controlled asthma. They measured isoflavone intake with a questionnaire that assessed intake of soyfoods, which are the only foods that provide relevant amounts of isoflavones. Patients with the lowest isoflavone consumption had worse asthma symptoms. For example, on a test that measured the amount of air that patients could expel from their lungs, those with the lowest isoflavone intake had a reduced capacity that was equivalent to 6 to 7 years of age-related lung function decline. Also, a higher proportion of patients in the low isoflavone group reported an episode of poor asthma control. While more research is needed to confirm the relationship, it’s possible that including soyfoods in your diet could aid in asthma control.
Bime C, Wei CY, Holbrook J, Smith LJ, Wise RA. Association of dietary soy genistein intake with lung function and asthma control: a post-hoc analysis of patients enrolled in a prospective multicentre clinical trial. Primary care respiratory journal : journal of the General Practice Airways Group 2012.
- 2 cups salted soynuts (plain or a sweeter flavor variety)
- 1/3 cup unsweetened cocoa powder
- ¾ cup powdered sugar
- 2-4 Tablespoons soybean oil
- In a food processor with metal blade, add soy. Sprinkle cocoa powder and powdered sugar.
- Process 1-2 minutes to combine.
- Drizzle in oil 1 Tablespoon oil at a time while processing.
- Process until mixture becomes smooth approximately 3-5 min, adding oil until the desired consistency is achieved.
- Jim and Jan’s notes
- We used Butter Toffee soy nuts from Super Soynuts (soynuts.com). Depending on the sweetness that is desired, would not use as much or any powdered sugar as it was sweet enough. If add, I would decrease the amount of powdered sugar. It would cut down on calories big time! We serve with Zucchini bread made with tofu. YUM!!
While they are relatively new to western menus, tofu and the fermented soybean paste miso have been on the menu throughout Asia for centuries. Today, soyfoods are finding their way onto more American tables than ever. Packed with high quality protein, these foods also provide healthy fats and beneficial phytochemicals like isoflavones. Research suggests that isoflavones lower risk for heart disease and certain cancers.
Recently, their relationship to thyroid function has become an active area of research. The thyroid gland, found at the front of your neck, regulates metabolism and energy use through production of two thyroid hormones, T3 and T4. Synthesis of these hormones requires the mineral iodine, which attaches to tyrosine, an amino acid.
In animal studies, iodine can also attach to the soy isoflavone genistein, which has a similar chemical structure to tyrosine. That’s raised concerns that eating too much soy could lead to a reduction in active thyroid hormone. But until now, it wasn’t known whether this happens in humans. However, a new study from the Czeck Republic has allayed concerns about the effects of genistein on thyroid hormone production.
The researchers provided subjects with about 80 milligrams of isoflavones—the amount in about three servings of soyfoods—to men and women for 3 months. All of the subjects were consuming adequate amounts of iodine. At the end of the trial, thyroid hormone levels were essentially unchanged. The research did find that some iodine attached to genistein, but the amount was insignificant, representing less than 1% of the total iodine consumed. Based on these findings, the authors concluded that soyfoods have no impact on thyroid function as long as iodine intake is adequate.
Sosvorova L, Miksatkova P, Bicikova M, Kanova N, Lapcik O. The presence of monoiodinated derivates of daidzein and genistein in human urine and its effect on thyroid gland function. Food Chem Toxicol 2012.
The amount of research conducted throughout the world on diet and health produces new findings daily, many of which make their way into print and online media. However, not all research results are equal, and the strength of claims made about different studies is based on many factors. Study design, when the research was done, and how the findings fit into the overall research picture on a particular topic, all affect the strength of the evidence.
Red Flag: Definitive statements that are based on anything other than the results of large clinical studies often suggest bias on the part of the study authors. This is especially true when definitive claims are made on the basis of animal research. …