Acute inflammation—characterized by redness, heat, swelling, and pain around an injury—is a normal immune response to infection or injury. It’s healthy and temporary. In contrast, low-grade, chronic, and “systemic” inflammation is an abnormal condition that may raise risk for heart disease, diabetes, Alzheimer’s Disease and arthritis, among many other conditions….
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….
It’s been nearly 20 years since the first research suggested a link between early soyfood consumption and a reduced risk for breast cancer. Researchers believe that consuming soy isoflavones during puberty can affect breast cell development in a way that provides protection against cancer. Since then, several studies have confirmed this relationship in Asian women but there have been fewer findings among non-Asians.
New research from Canada suggests that soy may be protective in Caucasian women as well. Women with and without breast cancer filled out a food frequency questionnaire designed to assess isoflavone intake within the past two years and also during puberty and early adolescence. In this study, adult intake of soyfoods wasn’t associated with risk for breast cancer. However, women who consumed the most soy isoflavones during their teenage years were about 20% less like to have cancer later on in life.
Isoflavones were protective primarily against estrogen-sensitive breast cancer, that is, breast cancer whose growth is stimulated by estrogen. More importantly, the women in this study consumed very little soy during adolescence since soyfoods were not commonly consumed at that time. This raises questions about whether such low intakes of soy isoflavones could possibly be protective. But while further research is needed to confirm the findings, they add to the growing body of data suggesting a protective role for soyfoods in the diets of young girls.
Anderson LN, Cotterchio M, Boucher BA, Kreiger N. Phytoestrogen intake from foods, during adolescence and adulthood, and risk of breast cancer by estrogen and progesterone receptor (ERPR) tumour subgroup among Ontario women. Int J Cancer 2012.
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….
The effect of soyfoods on cognition has been a topic of some controversy. Because soybeans contain isoflavones, which are phytoestrogens, some researchers have theorized that they could prevent cognitive decline that occurs with aging as estrogen is believed to do. However, the results from a Hawaiian population study published in the year 2000 linked soy consumption with greater risk of cognitive impairment.
A number of studies since then have challenged the findings from Hawaii. Recently, an expert panel organized by the North American Menopause Society recently concluded that clinical research suggests soy could favorably impact cognition in women younger than 65, with little effect in older women. The panel also emphasized the need for further research, and especially for larger and longer studies.
That call has been answered with a study by investigators from Stanford University and the University of Southern California Keck School of Medicine. In this three-year study, 350 healthy postmenopausal women received either 25 grams of soy protein or 25 grams of milk protein daily. The soy protein provided 91 mg of isoflavones, the amount found in about 3 to 4 servings of traditional soyfoods. At the end of the study, women who had consumed soy protein showed more improvement in tests of visual memory—the ability to recall pictures. Generally, however, there were no differences between the groups in terms of global cognitive function.
The study is important because of its size and duration. These findings refute concerns that soyfoods could be harmful for cognitive function although they don’t support the theory that they are protective. However, the study did show heart health benefits for younger postmenopausal women in that their progression of subclinical atherosclerosis, an indicator of stroke and heart disease risk, was markedly reduced in response to soy intake.
Henderson VW, St John JA, Hodis HN, et al. (2012) Long-term soy isoflavone supplementation and cognition in women: A randomized, controlled trial. Neurology 78:1841-8.
Hodis HN, Mack WJ, Kono N, et al. (2011) Isoflavone soy protein supplementation and atherosclerosis progression in healthy postmenopausal women: a randomized controlled trial. Stroke 42:3168-75.
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.
Interest in the anti-cancer effects of soy spans more than two decades. Most of the attention has focused on potential protective effects of soy against breast cancer, due in part to the low rates of breast cancer in countries like Japan, where soyfoods are a regular part of the menu. More recently, though, research has put the spotlight on a possible role for soyfoods in reducing risk of endometrial cancer.
Cancer of the endometrium—which forms the inner lining of the uterus—is the fourth most common cancer in US women. In 2011, more than 46,000 cases were identified in the United States. Rates vary markedly throughout the world, though, suggesting that lifestyle plays a bigger role than genetics in risk for this cancer. One established risk factor is estrogen exposure. That’s why, unless a woman has had a hysterectomy and isn’t at risk for endometrial cancer, estrogen therapy combines estrogen with progesterone. Progesterone inhibits the harmful effects of estrogen on the uterus.
Since the isoflavones in soyfoods are related to estrogen, questions have been raised about their potential effects on endometrial cancer risk. To investigate those effects, researchers from the University of Hawaii Cancer Center analyzed the diets of 46,027 postmenopausal women living in Hawaii and compared them to the incidence of endometrial cancer. The women were enrolled into the study between 1993 and 1996 and at that time provided detailed information on their diets and other endometrial cancer risk factors. Over 13.6 years 489 women were diagnosed with endometrial cancer.
Women in the group consuming the highest amounts of isoflavones were about one-third less likely to develop endometrial cancer in comparison to women whose diets were low in soyfoods and therefore low in isoflavones. The results showed that the amount of isoflavones associated with protective effects is provided by about one serving of a traditional soyfood—one cup of soymilk, 1/2 cup of tofu or 1/4 cup of soynuts. Based on these findings, even small amounts of soyfoods could reduce risk for developing endometrial cancer.
Ollberding et al., Journal of the National Cancer Institute. 2011.