Factors that affect the developing fetus may affect risk of cancer, heart disease and other conditions later in life. More than 30 years ago, it was proposed that the origins of many chronic diseases could be traced to exposures in utero or during early infancy. Following up on this hypothesis, Dutch researchers recently looked at the effects of antioxidants on the offspring of pregnant mice….
While skin aging is inevitable, it’s possible to slow the damage, and—according to new research—perhaps even reverse aging that has already occurred.
A decline in estrogen is part of the explanation for skin changes seen with menopause. Estrogen therapy in older women produces increases in collagen—the protein that gives skin its elasticity and resilience—and also increases skin thickness. It’s possible that plant estrogens, like the isoflavones in soyfoods, can have a similar effect. Soy phytoestrogens are not the same as the hormone estrogen but phytoestrogens and estrogen do share some properties in common….
Researchers Dr. Pamela J. Magee from the University of Ulster and Dr. Ian Rowland from the University of Reading (United Kingdom) extensively reviewed the evidence related to soyfood consumption and breast cancer risk (2). They looked at studies focusing on prevention as well as prognosis in women who have had breast cancer….
Cianci A, Cicero AF, Colacurci N, et al. (2012) Activity of isoflavones and berberine on vasomotor symptoms and lipid profile in menopausal women. Gynecol Endocrinol.
For more than a decade uncertainty has surrounded the issue of whether women with a history of breast cancer can safely consume soyfoods. Concern is based on the estrogen-like effects of soybean isoflavones which are phytoestrogens. While isoflavones stimulate the growth of mammary (breast) tumors in one type of mouse study, the findings from Chinese and U.S. epidemiologic studies convey a different picture. In these studies, the prognosis of thousands of breast cancer patients is tracked for several years and the results analyzed according to the amount of soy consumed by the participants. The findings indicate that post-diagnosis soy consumption actually reduces tumor recurrence and improves survival. This is true for women with tumors that respond to estrogen as well as those that don’t.
The results from the most recent study to examine this issue are a bit mixed. Among Korean HER2- breast cancer patients, with a type of breast cancer referred to as HE2-, higher soy intake was associated with about a 75% reduction in tumor recurrence. These findings support previously published epidemiologic research. However, among HER2+ patients, soy intake was associated with about a fourfold increased risk of recurrence. Approximately three-fourths of all breast cancer patients are HER2-, so the Korean results suggest that soy consumption is beneficial for the vast majority of women with a history of breast cancer. On the other hand, because in general, women with HER2+ breast cancer have a poorer prognosis, it’s especially important to identify factors that affect outcome.
Perhaps even more importantly, the small size of the Korean study raises doubts as to whether the findings in HER2- or HER2+ patients are worthy of consideration. There were only 339 women in this most recent study, whereas there were over 5,000 participants in the largest Chinese study and nearly 3,000 in the largest US study. In fact, in the Korean study, only 25 women reported having a recurrence whereas in the Chinese and US studies, there were approximately 500 recurrences. The total number of women and the number of women with recurrences are just too small for the Korean results to impact current understanding of the relationship between soy intake and breast cancer prognosis. However, they do serve to illustrate the need to understand how soy intake affects different types of breast cancers. More information about soy and HER2+ breast cancer is forthcoming.
Woo HD, Park KS, Ro J, et al. (2012) Differential influence of dietary soy intake on the risk of breast cancer recurrence related to HER2 status. Nutr Cancer.
If you’ve just made a New Year’s resolution to eat more healthfully in 2012, The Soyfoods Council can help. Soyfoods offer protein, and may help protect against heart disease. They’re low in saturated fat, high in polyunsaturated fat and provide essential omega-3 fatty acids. And yes, they have a direct cholesterol-lowering effect and contain isoflavones that may directly improve the health of the arteries as well. But that’s not why you’ll want to include them in your diet this year. Simply put, they fit your active lifestyle. Soyfoods are convenient and versatile ingredients….
Two new studies add to the existing evidence that eating soyfoods can reduce risk for prostate cancer in men at risk for this disease or aid treatment for prostate cancer patients. The possible protective effects of soy against prostate cancer have been rigorously studied for two decades.
Although prostate cancer is the sixth most common cause of male cancer deaths worldwide, it ranks second among cancer deaths in American men. Because risk increases among men who move from low-risk to high-risk countries, it appears that differences in prostate cancer rates are linked to lifestyle rather than genetics. Regular consumption of soyfoods like tofu, soymilk, and miso could be one of the reasons why men in Japan are less likely to get prostate cancer compared to westerners.
Researchers in Japan tested that theory in 158 men, ages 50 to 75, who had elevated PSA levels. PSA, or prostate specific antigen, is linked to prostate cancer risk (1). An increase in the level of this protein can be associated with tumor growth. Half of the men took a supplement containing 60 milligrams of isoflavones, which are compounds found in soybeans. The amount of isoflavones they consumed was the equivalent of about 2 ½ servings of traditional soyfoods, such as a cup of soymilk, 3 ounces of tofu or 1 ounce of soynuts. The other men were given a placebo.
At the end of the 12-month study period, there was no difference in PSA levels between the two groups. However, while 34 percent of the men in the placebo group developed prostate cancer, only 21 percent of those taking isoflavones developed this disease. The difference was much greater among men over the age of 65. In this group, 57 percent of those taking a placebo had prostate cancer compared to 28 percent of men consuming isoflavone supplements. Since isoflavones didn’t affect levels of testosterone, the reason for their protective effect in this study isn’t known.
In another study, this one conducted at Pennsylvania State University, 10 men with prostate cancer who had not responded to conventional treatment were asked to consume three servings of soyfoods per day for two years (2). All of the men had been treated with radiation and surgery, and three of them had also received hormonal treatment to suppress levels of testosterone, since this hormone can stimulate tumor growth. These treatments were known to be ineffective because the subjects’ PSA levels continued to rise. It is not clear how best to further treat patients in this situation.
Nine of the men chose to drink three glasses of soymilk each day, and one used a combination of soy snacks. Among the seven participants who had not received hormonal therapy, soy consumption was associated with beneficial changes in PSA levels (which stayed the same or declined) in four of them. PSA levels were favorably affected in one of the three men who had had hormonal treatment. Overall, half of the men benefited from daily consumption of soyfoods. The researchers concluded that “soy supplementation using commercially available soy products can have durable beneficial effects on PSA levels … in some men with prostate cancer.”
1. Miyanaga N, Akaza H, Hinotsu S, Fujioka T, Naito S, Namiki M, Takahashi S, Hirao Y, Horie S, et al. A prostate cancer chemoprevention study: An investigative randomized control study using purified isoflavones in men with rising PSA. Cancer Sci. 2011.
2. Joshi M, Agostino NM, Gingrich R, Drabick JJ. Effects of commercially available soy products on PSA in androgen-deprivation-naive and castration-resistant prostate cancer. South Med J. 2011; 104: 736-40.