Fermented soy products, such as miso and natto, are becoming more popular in Western cultures in recent years. Now, Japanese researchers have concluded that fermented soy products might reduce mortality risk.
A study on fermented soy products
The researchers looked at data from nearly 93,000 men and women between the ages of 45 and 74. All of the men and women had filled out questionnaires about their diet, health and lifestyle and the scientists followed the group for almost 15 years. They found that:
- The more miso and natto the person consumed (i.e., fermented soy), the lower the mortality risk.
- People who consumed the most fermented soy had a 10% lower risk compared to those with the lowest intake of fermented soy.
- In particular, there was a significant reduction in cardiovascular mortality risk for the people who consumed the most fermented soy.
- The consumption of soy products in general (i.e., fermented or unfermented) didn’t influence the risk of cancer-related mortality.
“In this large, prospective study conducted in Japan, with a high rate of soy consumption, no significant association was found between intake of total soy products [fermented and unfermented]and all-cause mortality. In contrast, a higher intake of fermented soy products was associated with a lower risk of mortality.”
Even though people who ate more natto also ate more vegetables, which might affect the lower mortality risk, the same was true even after the researchers adjusted for vegetable intake.
Caveats of the study
It’s important to note that this was an observational study, so the research team can’t rule out that the result was due to other factors.
In addition, the study relied on self-reported food consumption, which could be inaccurate
The dietary information that the participants provided was from a slice of their life and dietary habits can change drastically over time.
