The Food Journal and Food, Nutrition & Science

An alliance between The Lempert Report and The Center for Food Integrity

Soy

Soy

Health and Wellness

March 30, 2008

Soy
HEALTH & WELLNESS
A majority of Americans view soy as a healthy ingredient, says a 2007 United Soybean Board survey. The study, which looked at consumer attitudes about nutrition, found that 85% of respondents view soy positively, up from 67% in 1998. Thirty-three percent of consumers say they eat soy foods or drink soy beverages at least once a month. But is all the fuss warranted?
 
Soy is a legume crop originally from East Asia but is now also grown in the United States and South America. Composed of about 40% protein, 20% oil, 35% carbohydrates and 5% trace minerals (like isoflavones), soy can, like the protein found in meat, milk and eggs, be considered a “complete” protein – meaning that all essential amino acids are present in sufficient quantity to support normal growth and development.
 
Research has shown that soy can assist in decreasing LDL oxidation, lowering total and LDL cholesterol levels in the blood. This in turns lowers the risk for coronary heart disease. Other benefits may include decreasing the risk of developing breast cancer in both pre- and postmenopausal women, as well as improving bone mass, slowing bone loss, reducing “hot flashes,” and reducing the risk of prostate cancer.
 
Common soy products include tofu and soy sauce, and “second generation” soy products like soy milk and soy protein are becoming more and more prevalent. According to Nielsen LabelTrends, products with a “soy” claim on the label reached $1.95 billion is sales in 2007. Frozen and refrigerated breakfasts with soy rose more than 7,000 percent to nearly $2 million in sales. Soy breakfast bars soared to $8.5 million – a gain of more than 150%, while oriental noodles rose 79.9% to $1.6 million.
 
Only equivalized unit volume (EUV) was down slightly, by .7% in 2007 and 2.1% in 2006, perhaps because soy-related cancer concerns are on the rise. The issue has become quite controversial, as consumers weigh things like the FDA’s 1999 health claim associating soy protein consumption with reduced risk of coronary heart disease against concerns about the relationship between soy and estrogen-sensitive breast cancers.
 
Most research suggests that soy reduces breast cancer risk, although a few studies performed in cell culture and animal models suggest that they may stimulate tumor growth. Because the evidence is inconclusive, moderation is recommended (until more conclusive research can be conducted) for those with higher breast cancer risks.
 
“We don’t have the definitive answer yet. The vast majority of animal research has shown that soy reduces cancer risk. When soy is consumed during childhood, before puberty, the result appears to be a reduction in later life breast cancer risk. Without a doubt, populations that consume soy have a lower breast cancer risk. Although a few studies suggest that there might be some dangers for women who have breast cancer, these concerns stem from animal studies and cell cultures – and not human studies,” says Dr. Mindy S. Kurzer, Professor in the Department of Food Science and Nutrition at the University of Minnesota.
 
In fact, women in Asia tend to have lower breast cancer rates than those in the United States, and many attribute this difference to a life-long relationship with soy. The average amount of soy consumed in Asia is much higher than the average amount of soy consumed in west, says Kurzer, at one to two servings per day. Down the road, she says, we may even learn that the greatest health benefits come from consuming soy at extremely high levels – higher than those consumed in Asia.
 
In the smaller amounts of consumption currently studied, research suggests that soy can be a beneficial tool for weight management and heart health. As a low-saturated fat protein, soy can be a good option, especially for those looking to limit their saturated fat intake from meat. Consumed as part of a well-rounded, balanced diet, soy can be extremely valuable on many levels, and consumers are most definitely responding to this notion.
 
Manufacturers are jumping on board, too. A Soyatech report pegs international soy protein growth at 7.4% annually over the next three years. Soy is now incorporated into thousands of different foods, from tofu to tempeh, miso to milk. This decade, manufacturers brought more than 2,700 new foods containing soy to market – 161 in 2007 alone.
 
“The popularity of soy has risen dramatically in recent years thanks to improved awareness of soy health benefits,” says Kurzer. “A petition has been filed requesting that the FDA is reconsider their 1999 health claim for soy, and we’ll have to follow that story to see if there’s an impact in the marketplace.”