Miso & Other Fermented Soy Linked With Longevity In New Research

Soy? Longevity? That headline may be surprising if you're privy to all the conflicting information about soy that's out there.

But we're talking fermented soy products, which seem to offer more benefit than their non-fermented counterparts. Fermented soy products like tempeh, for example, may be easier to digest with their gut-healing and nutrient absorbing abilities, and according to new research, they may be linked with a lower risk of death, too.

A team of Japanese researchers studied over 90,000 men and women between the ages of 45 and 74, who were participating in an existing Japanese health study. They were looking for connections between different types of soy products and death by any cause.

The participants answered questions about their diets and lifestyles, as well as their overall health, and after 15 years, the researchers used death certificates and residential registries to find out who had died since the original research 15 years prior.

Researchers note that as an observational study, causation between eating fermented foods and longevity cannot be guaranteed. But we do know fermented soy products are loaded with protein, fiber, and good bacteria (more so than regular soy products).

"In this large prospective study conducted in Japan with a high rate of soy consumption," the authors note, "no significant association was found between intake of total soy products and all cause mortality. In contrast, a higher intake of fermented soy products was associated with a lower risk of mortality."

The authors say more research is necessary to figure out if soy, particularly fermented soy, has specific health effects. But for now, there's definitely enough research to support the power of fermentation in your diet.

Future studies will be conducted, according to the research team, "to refine our understanding of the health effects of fermented soy," which they hope will "inform the development of healthier and more palatable products" and "be collaborative, including not only researchers but also policymakers and the food industry."