Ankeny, IA February 8, 2019—Since ancient times, women across nations and cultures have looked for botanical skin care treatments to reduce the effects of aging. According to traditional Chinese folklore, women working in the tofu industry had the most beautiful skin. Today, many women—and men—desire youthful-looking skin and are looking for ways, including diet, to lessen the visible effects of aging.
Worldwide sales in the cosmetics industry are estimated to be over $500 billion annually (USD), with skin care products accounting for the largest segment of sales. Now it appears that the benefits of soy go beyond the well-recognized moisturizing and topical applications. Although more research is needed, the existing evidence strongly suggests that the isoflavones in soy may be an important ingredient for combating the effects of skin aging, including alleviating wrinkles.
The notion that eating soyfoods can improve skin health aligns with the increasing attention being paid to how the food we eat affects our skin—it is the beauty within concept. That diet affects skin health isn’t surprising given the impact diet has on overall health.
Clinical evidence increasingly supports the notion that isoflavones favorably impact skin. Soyfoods are uniquely-rich sources of these naturally occurring compounds. One study supporting the benefits of isoflavones, which was published in the International Journal of Cosmetic Science, found a statistically significant reduction in wrinkles in postmenopausal women in response to an active treatment that included just 25 mg of isoflavones—an amount provided by approximately one serving of traditional soyfoods. This amount is well within the range consumed by older people in Japan—and is an amount that can easily be incorporated into the diet.
It has been observed that wrinkling in Asians is not noticeable until age 50, and that even then its degree is not as marked as in the Caucasian population. Now those observations are bolstered by science. The aforementioned randomized double-blind study showed that isoflavones, when part of a beverage of bioactive ingredients, lead to a reduction in wrinkles in postmenopausal women.
In this 14-week study, women were assigned to one of three groups—a control group, or one of two groups receiving a beverage containing a mixture of bioactive compounds including isoflavones. Results show that the two test groups experienced a reduction in the severity of skin roughness compared with the placebo group. Especially noteworthy is that there was a change in the parameter considered the primary indicator of wrinkle depth. The average wrinkle reduction was 10 percent, and there was a positive correlation between baseline wrinkles and the response to the active beverage. That is, the greater the wrinkle depth at baseline, the greater the improvement.
More recently, Japanese researchers enrolled postmenopausal women into an 8-week study to determine whether fermented soymilk or regular soymilk improved skin health. This is notable because it assessed both subject and objective skin changes. The women filled out facial skin questionnaires three times—at the beginning of the study, eight weeks after consuming the soymilk, and four weeks after they were no longer consuming soy—answering questions about the condition of their facial skin. Questions covered dryness, elasticity, moisture, coarseness, pigmentation, and overall satisfaction. Also, at the beginning and end of the study, samples were also taken of skin underneath the forearm from each study participant.
After eight weeks of drinking either type of soymilk, the results showed that for all six questions, the condition of the skin significantly improved. Furthermore, the skin samples taken from underneath the forearm also were consistent with the improvements reported by the women themselves. After four weeks of abstaining from soymilk, questionnaires indicated that most of the benefits were lost. That is, the condition of the skin approached the condition at the beginning of the study.
The Soyfoods Council publicizes soy-related research and highlights the work of experts conducting studies on the health effects of eating soyfoods. Interest in the effects of isoflavones on overall skin health is not surprising, given that isoflavones bind to estrogen receptors, which are present in the skin. Estrogen therapy is thought to improve skin elasticity, water-holding capacity, pigmentation and vascularity. Estrogens also influence hair follicles.
Mark Messina, PhD, MS, Executive Director of the Soy Nutrition Institute points out that several questions regarding isoflavones and skin health still need to be addressed. “At what point does the reduction in wrinkles in response to isoflavones plateau? And, will long-term use permanently slow the development of wrinkles that normally accompanies aging? The answers to these questions will help solidify the precise role of isoflavones and soyfoods on aging skin.” Meanwhile, when considering the totality of the clinical evidence, a strong case can be made that isoflavones are important contributors to skin health.
About The Soyfoods Council: The Soyfoods Council is a non-profit organization, created and funded by Iowa soybean farmers, providing a complete resource to increase awareness of soyfoods, educate and inform media, healthcare professionals, consumers and the retail and foodservice market about the many benefits of soyfoods. Iowa is the country’s number one grower of soybeans.
About the Role of Soyfoods in a Healthful Diet: Soyfoods have played an important role in Asian cuisines for centuries. In recent years they have become popular in Western countries because of their nutrition and health properties. Soyfoods are excellent sources of high-quality protein and provide a healthy mix of polyunsaturated fat. In addition, independent of their nutrient content, there is very intriguing evidence indicating soyfoods reduce risk of several chronic diseases including coronary heart disease, osteoporosis and certain forms of cancer. All individuals are well advised to eat a couple of servings of soyfoods every day.