Soy Isoflavones May Help People Who Have Trouble Sleeping
Isoflavones resemble human estrogen in chemical structure, and previous studies have shown that estrogen helps modulate sleep duration and quality. A recent study from Japan suggests that increasing daily intake of soy isoflavones may improve sleep duration and quality.
Participants in the study included 1,076 Japanese adults between the ages of 20 and 78. They all completed self-administered diet history and sleep evaluation questionnaires. The food questionnaire asked about the frequency of consumption of three soy foods common in Japan: natto, tofu, and fried tofu. The sleep questionnaire asked questions such as “How many hours do you usually sleep per day?” and “Do you usually feel refreshed after sleep?”
After examining the data, the researchers found that a high daily intake of soy isoflavones was associated with between seven and eight hours of sleep per night, which they considered optimal. They also noted that the chemical structure of isoflavones has the potential to make it a sleep aid.
The association between high soy isoflavone intake and improved sleep remained even after the researchers adjusted for age, sex, BMI, total energy intake, coffee or vitamin consumption, smoking and drinking habits, level of education, depression, and hypnotic drug use.
Researchers from Tohoku University Graduate School of Biomedical Engineering in Japan and Tianjin Medical University in China conducted the study. It was published on December 29, 2015, in Nutrition Journal.
Previous studies have found that consumption of soy isoflavones may result in the widening of blood vessels and improvement in artery function. Additionally, soy isoflavones have been associated with reduced menopause symptoms, reduced bone loss, decreased risk of prostate cancer, and improved bone health.
Soy products can be easily found at many grocery stores in the form of tofu or soy milk. If those products don’t appeal to you, they are also available in supplement form.