Effect of S-equol and Soy Isoflavones on Heart and Brain

Author(s): Akira Sekikawa*, Masafumi Ihara, Oscar Lopez, Chikage Kakuta, Brian Lopresti, Aya Higashiyama, Howard Aizenstein, Yue-Fang Chang, Chester Mathis, Yoshihiro Miyamoto, Lewis Kuller, Chendi Cui.

Journal Name: Current Cardiology Reviews

Volume 15 , Issue 2 , 2019

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Background: Observational studies in Asia show that dietary intake of soy isoflavones had a significant inverse association with coronary heart disease (CHD). A recent randomized controlled trial (RCT) of soy isoflavones on atherosclerosis in the US, however, failed to show their benefit. The discrepancy may be due to the much lower prevalence of S-equol producers in Westerners: Only 20-30% of Westerners produce S-equol in contrast to 50-70% in Asians. S-equol is a metabolite of dietary soy isoflavone daidzein by gut microbiome and possesses the most antiatherogenic properties among all isoflavones. Several short-duration RCTs documented that soy isoflavones improves arterial stiffness. Accumulating evidence shows that both atherosclerosis and arterial stiffness are positively associated with cognitive decline/dementia. Therefore, potentially, soy isoflavones, especially S-equol, are protective against cognitive decline/dementia.

Methods/Results: This narrative review of clinical and epidemiological studies provides an overview of the health benefits of soy isoflavones and introduces S-equol. Second, we review recent evidence on the association of soy isoflavones and S-equol with CHD, atherosclerosis, and arterial stiffness as well as the association of atherosclerosis and arterial stiffness with cognitive decline/ dementia. Third, we highlight recent studies that report the association of soy isoflavones and S-equol with cognitive decline/dementia. Lastly, we discuss the future directions of clinical and epidemiological research on the relationship of S-equol and CHD and dementia.

Conclusions: Evidence from observational studies and short-term RCTs suggests that S-equol is anti-atherogenic and improves arterial stiffness and may prevent CHD and cognitive impairment/ dementia. Well-designed long-term (≥ 2years) RCTs should be pursued.

Keywords: S-equol, soy isoflavones, atherosclerosis, arterial stiffness, coronary heart disease, cognitive decline, cognitive impairment, dementia.

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Article Details

Year: 2019
Page: [114 - 135]
Pages: 22
DOI: 10.2174/1573403X15666181205104717

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