Soy foods may explain why Japanese-American women not only have the lowest rates of hot flashes in the United States but also have the lowest rates of vaginal dryness.
Soy Milk for Vaginal Menopause Symptoms
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
Japanese-American women at menopause not only have the lowest rates of hot flashes in the U.S., but they also have the lowest rates of vaginal dryness. Might it be due in part to their greater soy consumption? One consensus panel of experts concluded that soy can be considered a first-line treatment for menopausal hot flash and night sweat symptoms. What about for vaginal dryness?
There have been a few studies on the topical application of soy isoflavone vaginal gels, which in general have shown beneficial effects––for example, showing a significant improvement in dryness and pain-with-intercourse over placebo gels. In fact, they’re roughly on par with estrogen cream in a head-to-head test. But what about just eating soy? Soy isoflavones improve female sexual dysfunction of mice, significantly increasing vaginal blood flow, but what about in people?
The data using isolated soy supplements is mixed. Some studies totally flopped, showing no benefit over placebo, all the way up to studies showing comparable efficacy when pitted head-to-head against hormone therapy for both hot flashes and muscle pain––as well as vaginal dryness, with no significant differences between the two. And of course, soy has the benefit of “no increased risk of breast and uterine cancer or cardiovascular disease,” unlike systemic hormonal menopause therapy.
What about soy foods, though, rather than soy supplements? Well, there was a muffin study. Women randomized to daily muffins containing soy flour or ground flaxseeds saw no difference in menopausal sexual symptoms compared to wheat flour placebo muffins. Similarly, women randomized to 12 weeks of a daily scoop of soy protein powder experienced a significant improvement in sexual quality of life symptoms, but not compared to the milk protein control group.
What about soy milk? There have been three studies. Compared to women randomized to drink about two cups of dairy milk a day for eight months, those randomized to soy milk ended up with significantly fewer menopausal sexual symptoms, though this appeared to be more due to symptoms getting worse on the dairy than getting better on the soy. That reminds me of a study in Thailand where women randomized to a soy-free diet experienced a worsening in vaginal dryness and overactive bladder-type symptoms, but adding extra soy didn’t seem to make them better.
The second soy milk study found about two cups a day over two months appeared to drop vaginal and sexual symptoms by a whopping 60 to 70 percent, compared to the do-nothing control group. But since the control group didn’t drink anything special, it’s impossible to rule out placebo effects. The latest study found significant improvements in sexual symptoms after just six weeks of less than a cup of soy milk a day, but again, the control group did nothing. So, does soy milk work? We really don’t know, but it can’t hurt to give it a try—unless you overdo it.
A 44-year-old New Yorker presented to her gynecologist with an “increase in desire that required her to self-stimulate to orgasm approximately 15 times daily.” It turns out a month before, she started eating in excess of four pounds of soy foods a day. Thankfully, within three months of cutting back, her desire cooled to the point that she was able to “engage in satisfying sexual activity only twice daily.”
Please consider volunteering to help out on the site.
- Amsterdam A, Abu-Rustum N, Carter J, Krychman M. Persistent sexual arousal syndrome associated with increased soy intake. J Sex Med. 2005;2(3):338-340.
- Manonai J, Songchitsomboon S, Chanda K, Hong JH, Komindr S. The effect of a soy-rich diet on urogenital atrophy: a randomized, cross-over trial. Maturitas. 2006;54(2):135-140.
- Nikander E, Rutanen EM, Nieminen P, Wahlström T, Ylikorkala O, Tiitinen A. Lack of effect of isoflavonoids on the vagina and endometrium in postmenopausal women. Fertil Steril. 2005;83(1):137-142.
- Zhang J, Zhu Y, Pan L, Xia H, Ma J, Zhang A. Soy isoflavone improved female sexual dysfunction of mice via endothelial nitric oxide synthase pathway. Sex Med. 2019;7(3):345-351.
- Lima SMRR, Bernardo BFA, Yamada SS, Reis BF, da Silva GMD, Galvão MAL. Effects of Glycine max (L.) Merr. soy isoflavone vaginal gel on epithelium morphology and estrogen receptor expression in postmenopausal women: a 12-week, randomized, double-blind, placebo-controlled trial. Maturitas. 2014;78(3):205-211.
- Gold EB, Sternfeld B, Kelsey JL, et al. Relation of demographic and lifestyle factors to symptoms in a multi-racial/ethnic population of women 40-55 years of age. Am J Epidemiol. 2000;152(5):463-473.
- Carmignani LO, Pedro AO, Costa-Paiva LH, Pinto-Neto AM. The effect of dietary soy supplementation compared to estrogen and placebo on menopausal symptoms: a randomized controlled trial. Maturitas. 2010;67(3):262-269.
- Schmidt M, Arjomand-Wölkart K, Birkhäuser MH, et al. Consensus: soy isoflavones as a first-line approach to the treatment of menopausal vasomotor complaints. Gynecol Endocrinol. 2016;32(6):427-430.
- Crisafulli A, Marini H, Bitto A, et al. Effects of genistein on hot flushes in early postmenopausal women: a randomized, double-blind EPT- and placebo-controlled study. Menopause. 2004;11(4):400-404.
- Basaria S, Wisniewski A, Dupree K, et al. Effect of high-dose isoflavones on cognition, quality of life, androgens, and lipoprotein in post-menopausal women. J Endocrinol Invest. 2009;32(2):150-155.
- Lewis JE, Nickell LA, Thompson LU, Szalai JP, Kiss A, Hilditch JR. A randomized controlled trial of the effect of dietary soy and flaxseed muffins on quality of life and hot flashes during menopause. Menopause. 2006;13(4):631-642.
- Nourozi M, Haghollahi F, Ramezanzadeh F, Hanachi P. Effect of soy milk consumption on quality of life in Iranian postmenopausal women. J Family Reprod Health. 2015;9(2):93-100.
- Ghazanfarpour M, Latifnejad Roudsari R, Treglia G, Sadeghi R. Topical administration of isoflavones for treatment of vaginal symptoms in postmenopausal women: A systematic review of randomised controlled trials. J Obstet Gynaecol. 2015;35(8):783-787.
- Hanachi P, Golkho S. The effect of soymilk on menopausal symptoms and total antioxidant levels in menopausal women. Malaysian J Med Health Sci. 2008;4(1):33-40.
- Lima SMRR, Yamada SS, Reis BF, Postigo S, Galvão da Silva MAL, Aoki T. Effective treatment of vaginal atrophy with isoflavone vaginal gel. Maturitas. 2013;74(3):252-258.
- Padmapriya S, Kumar SS. Quality of life of postmenopausal women receiving plant-based phytoestrogens. Int J Pharm Sci. 2020;11(10):4998-5003.
Motion graphics by Avo Media
Below is an approximation of this video’s audio content. To see any graphs, charts, graphics, images, and quotes to which Dr. Greger may be referring, watch the above video.
Japanese-American women at menopause not only have the lowest rates of hot flashes in the U.S., but they also have the lowest rates of vaginal dryness. Might it be due in part to their greater soy consumption? One consensus panel of experts concluded that soy can be considered a first-line treatment for menopausal hot flash and night sweat symptoms. What about for vaginal dryness?
There have been a few studies on the topical application of soy isoflavone vaginal gels, which in general have shown beneficial effects––for example, showing a significant improvement in dryness and pain-with-intercourse over placebo gels. In fact, they’re roughly on par with estrogen cream in a head-to-head test. But what about just eating soy? Soy isoflavones improve female sexual dysfunction of mice, significantly increasing vaginal blood flow, but what about in people?
The data using isolated soy supplements is mixed. Some studies totally flopped, showing no benefit over placebo, all the way up to studies showing comparable efficacy when pitted head-to-head against hormone therapy for both hot flashes and muscle pain––as well as vaginal dryness, with no significant differences between the two. And of course, soy has the benefit of “no increased risk of breast and uterine cancer or cardiovascular disease,” unlike systemic hormonal menopause therapy.
What about soy foods, though, rather than soy supplements? Well, there was a muffin study. Women randomized to daily muffins containing soy flour or ground flaxseeds saw no difference in menopausal sexual symptoms compared to wheat flour placebo muffins. Similarly, women randomized to 12 weeks of a daily scoop of soy protein powder experienced a significant improvement in sexual quality of life symptoms, but not compared to the milk protein control group.
What about soy milk? There have been three studies. Compared to women randomized to drink about two cups of dairy milk a day for eight months, those randomized to soy milk ended up with significantly fewer menopausal sexual symptoms, though this appeared to be more due to symptoms getting worse on the dairy than getting better on the soy. That reminds me of a study in Thailand where women randomized to a soy-free diet experienced a worsening in vaginal dryness and overactive bladder-type symptoms, but adding extra soy didn’t seem to make them better.
The second soy milk study found about two cups a day over two months appeared to drop vaginal and sexual symptoms by a whopping 60 to 70 percent, compared to the do-nothing control group. But since the control group didn’t drink anything special, it’s impossible to rule out placebo effects. The latest study found significant improvements in sexual symptoms after just six weeks of less than a cup of soy milk a day, but again, the control group did nothing. So, does soy milk work? We really don’t know, but it can’t hurt to give it a try—unless you overdo it.
A 44-year-old New Yorker presented to her gynecologist with an “increase in desire that required her to self-stimulate to orgasm approximately 15 times daily.” It turns out a month before, she started eating in excess of four pounds of soy foods a day. Thankfully, within three months of cutting back, her desire cooled to the point that she was able to “engage in satisfying sexual activity only twice daily.”
Please consider volunteering to help out on the site.
- Amsterdam A, Abu-Rustum N, Carter J, Krychman M. Persistent sexual arousal syndrome associated with increased soy intake. J Sex Med. 2005;2(3):338-340.
- Manonai J, Songchitsomboon S, Chanda K, Hong JH, Komindr S. The effect of a soy-rich diet on urogenital atrophy: a randomized, cross-over trial. Maturitas. 2006;54(2):135-140.
- Nikander E, Rutanen EM, Nieminen P, Wahlström T, Ylikorkala O, Tiitinen A. Lack of effect of isoflavonoids on the vagina and endometrium in postmenopausal women. Fertil Steril. 2005;83(1):137-142.
- Zhang J, Zhu Y, Pan L, Xia H, Ma J, Zhang A. Soy isoflavone improved female sexual dysfunction of mice via endothelial nitric oxide synthase pathway. Sex Med. 2019;7(3):345-351.
- Lima SMRR, Bernardo BFA, Yamada SS, Reis BF, da Silva GMD, Galvão MAL. Effects of Glycine max (L.) Merr. soy isoflavone vaginal gel on epithelium morphology and estrogen receptor expression in postmenopausal women: a 12-week, randomized, double-blind, placebo-controlled trial. Maturitas. 2014;78(3):205-211.
- Gold EB, Sternfeld B, Kelsey JL, et al. Relation of demographic and lifestyle factors to symptoms in a multi-racial/ethnic population of women 40-55 years of age. Am J Epidemiol. 2000;152(5):463-473.
- Carmignani LO, Pedro AO, Costa-Paiva LH, Pinto-Neto AM. The effect of dietary soy supplementation compared to estrogen and placebo on menopausal symptoms: a randomized controlled trial. Maturitas. 2010;67(3):262-269.
- Schmidt M, Arjomand-Wölkart K, Birkhäuser MH, et al. Consensus: soy isoflavones as a first-line approach to the treatment of menopausal vasomotor complaints. Gynecol Endocrinol. 2016;32(6):427-430.
- Crisafulli A, Marini H, Bitto A, et al. Effects of genistein on hot flushes in early postmenopausal women: a randomized, double-blind EPT- and placebo-controlled study. Menopause. 2004;11(4):400-404.
- Basaria S, Wisniewski A, Dupree K, et al. Effect of high-dose isoflavones on cognition, quality of life, androgens, and lipoprotein in post-menopausal women. J Endocrinol Invest. 2009;32(2):150-155.
- Lewis JE, Nickell LA, Thompson LU, Szalai JP, Kiss A, Hilditch JR. A randomized controlled trial of the effect of dietary soy and flaxseed muffins on quality of life and hot flashes during menopause. Menopause. 2006;13(4):631-642.
- Nourozi M, Haghollahi F, Ramezanzadeh F, Hanachi P. Effect of soy milk consumption on quality of life in Iranian postmenopausal women. J Family Reprod Health. 2015;9(2):93-100.
- Ghazanfarpour M, Latifnejad Roudsari R, Treglia G, Sadeghi R. Topical administration of isoflavones for treatment of vaginal symptoms in postmenopausal women: A systematic review of randomised controlled trials. J Obstet Gynaecol. 2015;35(8):783-787.
- Hanachi P, Golkho S. The effect of soymilk on menopausal symptoms and total antioxidant levels in menopausal women. Malaysian J Med Health Sci. 2008;4(1):33-40.
- Lima SMRR, Yamada SS, Reis BF, Postigo S, Galvão da Silva MAL, Aoki T. Effective treatment of vaginal atrophy with isoflavone vaginal gel. Maturitas. 2013;74(3):252-258.
- Padmapriya S, Kumar SS. Quality of life of postmenopausal women receiving plant-based phytoestrogens. Int J Pharm Sci. 2020;11(10):4998-5003.
Motion graphics by Avo Media
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Soy Milk for Vaginal Menopause Symptoms
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Content URLDoctor's Note
This is the third and final video in this series on vaginal menopause symptoms. The first two were The Best Moisturizers and Lubricants for Vaginal Menopause Symptoms and Hormone Treatment (Estrogen Pills and Creams) for Vaginal Menopause Symptoms.
What about soy foods for other menopausal symptoms like hot flashes and night sweats? See Soy Foods for Menopause Hot Flash Symptoms.
You may also be interested in How to Delay the Age of Menopause with Diet and Lifestyle Factors.
For more on how to live your longest, healthiest life, preorder my new book How Not to Age. (As always, all proceeds I receive from all of my books are donated to charity.)
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