Postmenopausal women who consumed soy protein saw a decrease in skin wrinkling severity and pigment intensity and an increase in hydration—all beneficial effects.
ST. LOUIS (October 26, 2023) — Results of a new clinical trial involving postmenopausal women show that consuming soy protein containing isoflavones benefits skin health, building on a body of existing literature. Women who consumed 30 grams of soy protein daily for six months experienced a decrease in wrinkle depth and pigmentation and an increase in skin hydration. This peer-reviewed research was conducted by scientists from Integrative Skin Science and Research in Sacramento, California, commissioned by Soy Nutrition Institute (SNI) Global, and funded by the United Soybean Board.
“We are encouraged by these results, which show that soy protein-based supplementation can benefit skin health. Postmenopausal women are especially susceptible to facial aging and these results show that soy isoflavone supplementation may improve skin health,” said Dr. Raja K. Sivamani, board-certified dermatologist and bioengineer, and the lead researcher.
Although there may be multiple components of soybeans that promote skin health, most evidence points to isoflavones being the reason for the observed beneficial effects. Soybeans are a uniquely rich source of these naturally occurring plant compounds. The amount of isoflavones women consumed for this study is found in just two servings of soy foods, such as two cups of soymilk or one cup of tofu. The improvements observed in wrinkle reduction, pigment intensity, and skin hydration underscore the significance of making soy foods part of diets aimed at promoting skin health.
For this trial, women were randomized into two groups: one consumed soy protein daily and the other an equivalent amount of casein, which is the predominant protein in cow’s milk. Neither the study participants nor the researchers were aware of which group consumed which protein until the results were analyzed.
Summary of key findings:
- Wrinkle Reduction: Women in the soy group experienced a significant reduction in wrinkle severity. By weeks 16 and 24, wrinkle severity decreased by -4.8% and -6.5%, respectively, compared to casein group.
- Pigmentation Improvement: Pigment intensity was significantly reduced in the soy group compared to the casein group, with a 2.5% reduction observed at week 24.
- Hydration Enhancement: Among women in the soy group, skin hydration increased by 39% in the left cheek and 68% in the right cheek, compared to measurements at the beginning the trial. No improvements were noted in the casein group.
In addition to observed changes in the skin, soy consumption may exert other health benefits in postmenopausal women.
For example, evidence suggests that soy isoflavones can alleviate menopausal hot flashes and may improve memory in older women. In addition, the amount of soy protein provided in this study has been extensively tested and (consistently) demonstrated to support heart health by lowering blood cholesterol levels.
“When considering the nutrition that soy foods provide and the many possible health benefits, it certainly makes sense to add these foods to the diet. The wide range of soy foods available makes doing soy quite easy,” said Mark Messina, Ph.D., Director of Nutrition Science and Research, Soy Nutrition Institute Global.
Soy foods can be included in the diet in many ways and provide a variety of vitamins and minerals that can be part of a healthy diet. Soy can provide high-quality protein to a variety of foods found in most grocery stores, from beverages and soymilk to bars, snacks, and meal items, such as plant-based burgers. Soy foods, like tofu, edamame, tempeh, and soymilk are also versatile, nutritious options. Soy protein is a high-quality protein, providing all nine essential amino acids in amounts needed by the body. For recipe ideas, visit soyconnection.com/recipes.
About Soy Nutrition Institute Global
Soy Nutrition Institute (SNI) Global is a 501(c)(6) non-profit corporation that funds research and shares evidence-based information on the impact of soybeans and soy ingredients for human health and nutrition. For more information about the SNI Global, visit www.SNIGlobal.org.
About United Soybean Board
United Soybean Board’s 77 volunteer farmer-leaders work on behalf of all U.S. soybean farmers to achieve maximum value for their soy checkoff investments. These volunteers create value by investing in research, education and promotion with the vision to deliver sustainable soy solutions to every life, every day across the three priority areas of Infrastructure & Connectivity, Health & Nutrition, and Innovation & Technology. As stipulated in the federal Soybean Promotion, Research and Consumer Information Act, the USDA Agricultural Marketing Service has oversight responsibilities for USB and the soy checkoff. For more information on the United Soybean Board, visit unitedsoybean.org.
