Soy - potential in many areas but more research needed
brain and kidney health but more research is needed in many areas,
heard a large audience attending this year's Soy and Health
conference.
Demand for soy proteins and other products has been growing rapidly, driven largely by the research showing its health benefits. Market analysts The Freedonia Group predict that by 2007 US demand alone for soy products will rise by nearly five per cent each year to €6.7 ($8.23) billion.
Some of the research driving this demand was reviewed by industry experts last week and highlighted many areas with potential for pushing growth further. For example, recent studies suggest that dietary supplementation with soy may favourably alter insulin resistance, glycaemic control and serum lipoproteins in post-menopausal women with type 2 diabetes, a disease that is rising rapidly around the world.
The evidence for a role for soy in weight reduction, however, is less conclusive, noted speakers. A review of the literature could only hint that there may be some advantage in including soy protein in weight reducing diets for the obese and overweight.
Interest in the potential role of soy isoflavones as an alternative to HRT continues to grow but not all research has been convincing. Talking recently to NutraIngredients.com, Tova Arditi, scientific adviser to Solbar, highlighted that isoflavones had not been shown to combat menopausal symptoms in women to the same extent as HRT, despite high expectations from the public.
"Soy isoflavones are believed to reduce frequency of hot flushes but in severe cases, they don't really help," she said. "It is wrong to view these supplements as an alternative to HRT. There have been huge expectations from women who take them but the small effect is evident only after a period of time and many women are looking for a quick remedy."
However soy does seem to have more potential in the prevention of osteoporosis, appearing to slow bone loss in post-menopausal women, although high levels of soy isoflavones (around 80 mg per day) may be required.
Again, the role of soy in the prevention of breast cancer remains controversial as clinical trials provide mixed results. Increasingly, however, the first 20 years of a woman's life are believed to be important with large babies, early pregnancy, and caloric restriction associated with a lower risk of developing breast cancer. Animal studies suggest that prepubertal consumption of soy may protect against breast cancer in later life.
Animal studies have also shown that soy isoflavones inhibit the growth of prostate cancer cells. More human studies are needed but evidence to-date suggests a protective effect with soy acting in the later stages of prostasis possibly as an anti-inflammatory agent.
The conference, held last week in Bruges, Belgium, attracted 350 scientists, health professionals, and food industry representatives.
