Traditional Korean Soybean Paste Doenjang Shows Promise in Easing Menopause Symptoms

A new study investigated the effectiveness of a Korean soybean paste known as doenjang on alleviating symptoms of menopause. The findings show that traditionally produced doenjang successfully reduces menopausal symptoms. Doenjang paste is one of the oldest fermented foods in Asia, dating back over 2,000 years. It significantly predates miso paste, which first became popular in China before returning to Japan. While miso is made from peeled soybeans that ferment over weeks, doenjang matures from several weeks to two years.  

It consists of fermented, unpeeled soybeans. Its subtly tangy, strong umami flavor has undertones of nuttiness and earthiness. Miso, made from peeled soybeans, is not as thick and is milder and sweeter. 

Like miso, doenjang is typically salty since it is fermented with salt, which can be a cardiometabolic concern. Both miso and doenjang can serve as the basis of broths and flavoring in various dishes. The recent investigation of Doenjang is part of ongoing explorations of the impact of fermented foods on the gut microbiome. One of the study’s goals was to determine if more bacteria content in doenjang produced better results than less. 

In this study, researchers tested three types of doenjang. The first two were traditionally produced, with one containing a low dose of beneficial microbes and one containing a high dose. The effectiveness of these was compared to commercially produced doenjang, which contained more beneficial microbes than either traditional sample. The level of bacteria microbes increased in the two types of doenjang, which had the highest levels of beneficial microbes. While beneficial in the human gut, Bacteriodetes can cause severe infections in other body parts. All three types of doenjang lowered participants’ Kupperman index, but the doenjang with the lowest level of beneficial microbes proved most effective at reducing menopausal symptoms. 

The researchers also measured changes in obesity, inflammation, and levels of LDL, or “bad cholesterol,” that can lead to cardiovascular issues. Lower LDL cholesterol was seen only in participants consuming the traditional doenjang. No effect on obesity or inflammation was observed. 

Researchers also reported that the vegan diet led to a 96% decrease in moderate to severe hot flashes and a reduction in daytime hot flashes by 96% and nighttime hot flashes by 94%. Overall, adequate sources of lean protein, fiber — both soluble and insoluble — omega-3 fatty acids, possibly a reduction in saturated fats, caffeine, alcohol, refined carbohydrates, and added sugars may also be beneficial to preserving bone mass, staving off common symptoms and supporting energy, mood and managing weight fluctuations.