The “New Menopause,” Hormone Therapy, and the Role of Soy Foods

Menopause is a hot topic, and a “new” approach to it is being driven largely by a generation of mid-life female OB-GYNs and health professionals who are aimed at destigmatizing this natural transition in a woman’s life. This approach to menopause addresses symptoms with lifestyle changes, such as diet, nutrition, and exercise, along with a renewed use of hormone therapy (HT) (estrogen alone or combined with and a progestogen).

As background, the use of HT to ease menopausal symptoms fell dramatically in 2002 when findings from the Women’s Health Initiative study indicated women taking HT had an increased risk of breast cancer, heart disease, stroke, and blood clots.1 However, current thinking is that HT use in certain circumstances is safe and beneficial.2 Women should talk to their healthcare practitioner about the risks and benefits of HT, which is approved for the treatment of hot flashes during the menopause transition and the prevention of postmenopausal osteoporosis.2

Common menopausal symptoms include but are not limited to, hot flashes, weight gain, body composition changes, and skin changes. Symptoms occur as the production of estrogen and progesterone, hormones naturally produced by the ovaries, declines when a woman enters menopause. Additionally, postmenopausal women are at greater risk of chronic conditions including heart disease and osteoporosis.3,4   

With nutrition prioritized in this new approach to menopause, soy foods can play a role. Soybeans are a uniquely rich source of isoflavones. Isoflavones have a similar chemical structure to estrogen, bind to estrogen receptors, and exert estrogen-like effects under certain experimental conditions. For this reason, they are commonly classified as phytoestrogens. Research suggests that isoflavone-rich soy foods such as tofu, tempeh, edamame, roasted soybeans, and soymilk help ease some menopausal symptoms and provide other benefits as well.

Hot Flashes

Women experiencing menopause may benefit from eating more soy foods because soy isoflavones may reduce the frequency and severity of hot flashes. A systematic review and meta-analysis of 36 studies found that menopausal women consuming 30-80mg of soy isoflavones daily had 21% fewer hot flashes that the severity of those hot flashes was decreased by 26%  in comparison to the placebo group.5

Weight Loss and Body Composition Changes

Dietary protein is increasingly recognized as important for weight loss, with evidence suggesting it enhances satiety. The authors of a comprehensive review of the scientific literature concluded that soy protein supports weight loss similarly to other proteins.6 Also, the high-quality protein in soy foods promotes strength and muscle mass gains in those who engage in resistance training offering comparable benefits to animal proteins such as whey.7

Skin Changes

A recent 6-month clinical trial involving 159 postmenopausal, lighter-skinned women found that those who consumed 50 mg of isoflavones daily – an amount provided by just two servings of traditional Asian soy foods – experienced a decrease in wrinkle depth and pigmentation and an increase in skin hydration.8 Previously published research supports these exciting results.9,10

Heart Disease and Osteoporosis

Soy foods have been studied extensively for their role in reducing risk of heart disease and osteoporosis. Soy protein carries a Food and Drug Administration (FDA) authorized health claim related to its ability to lower blood cholesterol levels, which states that 25 grams of soy protein a day, as part of a diet low in saturated fat and cholesterol, may reduce the risk of heart disease. There is also evidence that in postmenopausal women, isoflavones improve endothelial function, the thin layer of cells that line blood vessels.11,12

Finally, intriguing research suggests soy foods, likely because they contain isoflavones, promote bone health. Some observational studies have reported that soy intake is associated with a reduced fracture risk among women, and the results of clinical trials indicate soy decreases bone resorption.13,14 Although it is premature to recommend soy foods for bone health solely due to their isoflavones, the calcium found in fortified soymilk and calcium-set tofu can help maintain bone health.15

For more information about soy, isoflavones and women’s health, download the Soy and Women’s Health Fact Sheet.

References

Crawford SL, Crandall CJ, Derby CA, El Khoudary SR, Waetjen LE, Fischer M, Joffe H. Menopausal hormone therapy trends before versus after 2002: impact of the Women’s Health Initiative Study Results. Menopause. 2018 Dec 21;26(6):588-597.

Faubion, Stephanie S. MD, MBA, FACP, NCMP; Crandall, Carolyn J. MD, MS, MACP, NCMP, FASBMR; Davis, Lori DNP, FNP-C, NCMP; El Khoudary, Samar R. PhD, MPH, FAHA; Hodis, Howard N. MD; Lobo, Roger A. MD; Maki, Pauline M. PhD; Manson, JoAnn E. MD, DrPH, MACP, NCMP; Pinkerton, JoAnn V. MD, FACOG, NCMP; Santoro, Nanette F. MD; Shifren, Jan L. MD, NCMP; Shufelt, Chrisandra L. MD, MS, FACP, NCMP; Thurston, Rebecca C. PhD, FABMR, FAPS; Wolfman, Wendy MD, FRCSC, FACOG. The 2022 hormone therapy position statement of The North American Menopause Society. Menopause 29(7):p 767-794, July 2022.

What is Menopause? (September, 2021) Retrieved from the National Institutes of Health https://www.nia.nih.gov/health/menopause/what-menopause#transition Accessed August 15, 2024.

Lephart ED, Naftolin F. Menopause and the Skin: Old Favorites and New Innovations in Cosmeceuticals for Estrogen-Deficient Skin. Dermatol Ther (Heidelb). 2021 Feb;11(1):53-69. doi: 10.1007/s13555-020-00468-7. Epub 2020 Nov 26. PMID: 33242128; PMCID: PMC7859014.

Taku K, Melby MK, Kronenberg F, Kurzer MS, Messina M. Extracted or synthesized soybean isoflavones reduce menopausal hot flash frequency and severity: systematic review and meta-analysis of randomized controlled trials. Menopause. 2012 Jul;19(7):776-90. doi: 10.1097/gme.0b013e3182410159. PMID: 22433977.

Cope MB, Erdman JW Jr., Allison DB. The potential role of soyfoods in weight and adiposity reduction: an evidence-based review. Obes Rev. (2008) 9:219–35.

Messina M, Lynch H, Dickinson JM, Reed KE. No Difference Between the Effects of Supplementing With Soy Protein Versus Animal Protein on Gains in Muscle Mass and Strength in Response to Resistance Exercise. Int J Sport Nutr Exerc Metab 2018;28(6):674-685.

Rizzo J, Min M, Adnan S, Afzal N, Maloh J, Chambers CJ, Fam V, Sivamani RK. Soy Protein Containing Isoflavones Improves Facial Signs of Photoaging and Skin Hydration in Postmenopausal Women: Results of a Prospective Randomized Double-Blind Controlled Trial. Nutrients. 2023; 15(19):4113. https://doi.org/10.3390/nu15194113

107. Draelos ZD, Blair R, Tabor A. Oral soy supplementation and dermatology. Cosmetic Dermatology. 2007;20202-4.

108. Izumi T, Makoto S, Obata A, et al. Oral intake of soy isoflavone aglycone improves the aged skin of adult women. J Nutr Sci Vitaminol. 2007;53(1):57-62.

Adachi JD, Rizzoli R, Boonen S, et al. Vertebral fracture risk reduction with risedronate in post-menopausal women with osteoporosis: a meta-analysis of individual patient data. Aging clinical and experimental research. 2005;17(2):150-6.

Rand WM, Pellett PL, Young VR. Meta-analysis of nitrogen balance studies for estimating protein requirements in healthy adults. Am J Clin Nutr. 2003;77(1):109-27.

Zhang X, Shu XO, Li H, Yang G, Li Q, Gao YT, et al. Prospective cohort study of soy food consumption and risk of bone fracture among postmenopausal women. Arch Intern Med. (2005) 165:1890–5.

Akhlaghi M, Ghasemi Nasab M, Riasatian M, Sadeghi F. Soy isoflavones prevent bone resorption and loss, a systematic review and meta-analysis of randomized controlled trials. Crit Rev Food Sci Nutr. 2020;60(14):2327-2341.

Messina Mark, Duncan Alison, Messina Virginia, Lynch Heidi, Kiel Jessica, Erdman John W., The health effects of soy: A reference guide for health professionals, Frontiers in Nutrition, 11 August 2022.

This blog is supported by SNI Global and U.S. Soy.