Soy Improves Sleep

Soy isoflavones have many well-known benefits, from cancer and menopause to cholesterol and bones. But here’s a new one: new research shows that soy isoflavones may be able to improve your sleep. . . .

This study assessed isoflavone intake by measuring the amount of soy eaten by 1,076 Japanese people between the ages of twenty and seventy-eight. It turns out that the people who got the most isoflavones also got the most sleep. They were 84% more likely to get the optimal seven to eight hours sleep a night, and they were more likely to enjoy adequate sleep quality than people who ate the fewest isoflavones.

Though this study doesn’t offer conclusive proof that it was the isoflavones alone that improved sleep, there is other suggestive evidence. An earlier study found that isoflavones significantly improve sleep efficiency and decrease the frequency of insomnia in postmenopausal women (Menopause 2011;18:178-84). Again, this evidence is not conclusive, because the improved sleep could be because of improved menopausal symptoms like hot flashes, which soy isoflavones do so well.

However, the two studies taken together offer suggestive evidence that soy isoflavones may be a novel approach to improving your sleep.

Nutrition Journal 2015;14:127