Fermented Soy May Be the Secret to Sharper Memory After 70

A new study published in *Nutrients* suggests that a humble food—fermented soy—might play a key role in keeping our minds sharp with age. In a 12-week randomized controlled trial, older adults who consumed fermented soy daily showed measurable improvements in memory compared to those given a placebo (1^✔ ✔Trusted Source
Effects of Fermented Soy on Cognition in Older Adults: Outcomes of a Randomized, Controlled Trial

Go to source). The results were particularly striking among postmenopausal women over 70, hinting that a natural, diet-based approach could help maintain cognitive function in later life. Researchers believe the fermentation process enhances soy’s neuroprotective power by making its key compounds—isoflavones and polyphenols—more bioavailable and potent.

Why Brain Health Needs Nutritional Support

With rising life expectancy, the world’s aging population faces a parallel surge in dementia and cognitive decline. Factors such as oxidative stress and neuroinflammation damage brain cells and accelerate memory loss.

Plant-based diets rich in antioxidants and anti-inflammatory compounds are known to offer protective effects. Soy, a staple in many Asian diets, contains isoflavones like genistein and daidzein, which act as both antioxidants and mild estrogen-like agents—potentially explaining their beneficial effects on brain and cardiovascular health.

However, traditional soy products often have low bioavailability. Through fermentation, these isoflavones are converted into more active forms (aglycones), boosting their absorption and brain-protective potential.

Inside the 12-Week Trial: Soy vs. Placebo

Researchers at Loma Linda University, USA, conducted a triple-blind, placebo-controlled trial involving 61 cognitively healthy participants aged 65 and above. They were randomly assigned to receive either Q-Can Plus®—a fermented soy powder—or a whey-based placebo, twice daily for 12 weeks.

Each soy serving delivered 36.3 mg of isoflavones, along with fiber, protein, and antioxidants. Participants maintained their usual diet and physical activities during the study.

After three months, the fermented soy group showed significant memory improvement (p = 0.041), while no major differences were observed in other cognitive domains.

The mean improvement in memory scores was 8.47% in the soy group versus 2.05% in the placebo group. Exploratory data also indicated that women over 70 experienced gains in both memory and global cognition.

What Makes Fermented Soy Special?

Fermentation transforms soy into a more bioactive, gut-friendly superfood. It enhances antioxidant capacity and boosts anti-inflammatory effects, both critical for protecting neurons.

Prior studies on mild cognitive impairment had shown similar benefits, but this is among the first to demonstrate memory improvement in cognitively healthy seniors.

The lead investigators believe fermented soy’s cognitive benefits stem from its effects on brain-derived neurotrophic factor (BDNF)—a molecule that supports neuron growth and connectivity.

Future Directions and Caution

While the findings are encouraging, the authors emphasize that the results are preliminary and hypothesis-generating. The study was limited by its small sample size and short duration. Larger, longer-term studies are needed to confirm whether fermented soy can meaningfully prevent or delay cognitive decline.

Still, the evidence adds to a growing body of research supporting dietary interventions for brain health. Instead of supplements, the answer might lie in everyday foods—especially fermented ones like miso, tempeh, or natto.

As the researchers conclude, “Fermented soy could be a simple, natural way to help preserve cognitive health in aging adults.” don’t use italics

Reference:

1. Effects of Fermented Soy on Cognition in Older Adults: Outcomes of a Randomized, Controlled Trial - (https://www.mdpi.com/2072-6643/17/18/2936)

Source-Medindia