Why soy serious?
Sue Bull, a 58-year-old breast cancer survivor, used to hate almond milk. She thought it tasted like water. Because of a dairy sensitivity and a penchant for the taste of soy milk, Bull had always been a regular consumer of soy products.
But after Bull was diagnosed with estrogen-positive ductal carcinoma in situ in 2008, she was told by two different doctors to stay away from soy.
Doing everything she could to stay healthy, Bull began limiting her soy intake to an occasional indulgence.
She has now grown fond of certain richer-tasting, vanilla-flavored almond milk varieties.
Soy has been widely acclaimed as a nutritional superfood, but recent health concerns have tarnished its healthful reputation.
“The thinking is that it’s dangerous to increase the amount of estrogen in your body once you’ve had an estrogen-positive cancer,” said Bull.
According to Understanding Nutrition, a nutrition textbook used at Santa Monica College, soybeans are rich in isoflavones, a type of phytochemical—more specifically, phytoestrogen—structurally similar to the hormone estrogen.
They can “weakly mimic or modulate the effects of estrogen in the body,” which has raised some potential concerns, most notably for estrogen-positive breast cancer survivors.
“Currently, it is typically recommended that women with a history of breast cancer avoid soy, and consult with their physician about whether soy is contraindicated,” said Deborah Novak, an SMC nutrition professor and a registered dietitian.
However, results from a 2009 study from the Journal of the American Medical Association—performed on 5,042 breast cancer survivors to assess the possible link between soy consumption and breast cancer recurrence—suggest that “moderate soy food intake is safe, and potentially beneficial, for women with breast cancer.”
“I have talked with another doctor recently who thinks it’s okay to have soy occasionally,” said Bull. “I think one has to do whatever it takes to help you sleep at night and not worry. I still do worry about it coming back, but I know I did the best I could to improve my situation.”
According to the Harvard Health Letter, isoflavones in soy are not only “estrogen impersonators” but also estrogen “opponents.” As such, when moderately consumed throughout life, soy may actually generate protective effects against cancers.
“Some research shows that [the isoflavones in soy] may actually be beneficial, in that they bond onto the receptors for estrogen,” said Novak. “That then reduces the impact on the body’s endogenous estrogen, and this actually may reduce the risk of breast cancer.”
For men, consuming products that may yield estrogen-like effects seems counterintuitive, and there has been increasing apprehension about the effects of soy intake on males.
“Isoflavones do not exert feminizing effects on men at intake levels equal to, and even considerably higher than are typical for Asian males,” according to a study from the Department of Nutrition at the Loma Linda University School of Public Health.
“There is no evidence that soy affects men’s health or fertility,” said Novak. “Men who are obese actually have a high level of endogenous estrogen that is produced by adipose cells, so there are other factors that have a much bigger impact on men regarding estrogen than their soy intake.”
According to the U.S. Department of Agriculture, 94 percent of all soybean crops in the U.S. in 2011 were genetically engineered with herbicide-repellent or insect-resistant traits.
The World Health Organization defines genetically modified organisms as “organisms in which the genetic material (DNA) has been altered in a way that does not occur naturally.”
The Food and Drug Administration maintains that genetically modified foods do not have significant differences, nor do they present greater safety risks than their traditional counterparts.
However, the genetic engineering of crops remains a controversial issue, as its many adversaries worry about the repercussions of biotechnology.
These concerns include environmental and human health issues such as potential allergic reactions, the transferring of genetically modified genes into humans through consumption of GMOs, and the unintentional outcrossing of modified genes into conventional plants, according to the WHO.
“By definition, organic soy cannot be genetically modified.” said Novak. “So organic soy does not include any GMO-soy, and if it does not say ‘organic,’ it can definitely be GMO. Probably in many cases, [it] is.”
Despite the hearsay surrounding soy, the evidence of its health benefits remains strong.
“Soy is fairly well-supported for reducing the risk of heart disease,” according to Novak, due to the possibility of its ability to lower levels of triglycerides and cholesterol.
“The health benefits, especially the role the phytochemicals play in potentially reducing the risk for cancer, come from whole soy products like tofu and edamame,” Novak said.
The phytochemicals in soybeans act like antioxidants, possibly lessening the probability of cancer initiation and development.
“Soy milk is a great alternative to cow’s milk; it has almost the same amount of protein, and is fortified to provide the same micronutrients,” Novak said. “The benefits of making a moderate intake of soy a regular part of one’s diet outweigh any potential risks.”