Vitamin E and carotenoids
One factor that may contribute to cognitive decline with age is oxidative stress—when levels of pro-oxidants exceed levels of antioxidants in the body. Doctors believe brain matter, which is rich in fatty acids, is particularly vulnerable to this antioxidant/oxidant imbalance. Earlier studies suggest that diets rich in antioxidants, and taking antioxidant supplements, can protect brain function with age.
In this study, doctors measured dietary and circulating levels of antioxidants in 3,270 adults, aged 30 to 65. Participants took cognitive tests over the course of six years, periodically reporting their diets, and giving blood samples.
Overall, those with higher dietary and circulating levels of carotenoids, especially lycopene and vitamin E, had better verbal memory, verbal fluency, attention, and reasoning and decision-making performance, compared to those with lower levels of these antioxidants and carotenoids.
Matcha green tea for women
This is the first study to evaluate daily matcha green tea and cognition in older adults. In this trial, 39 women and 15 men, average age 74, took a placebo drink, or 1.5 grams of decaffeinated matcha green tea extract, twice per day.
After 12 weeks, while there was no effect in men, women taking matcha saw a 1.95 increase in cognitive test scores compared to 0.15 for placebo. Working memory—the ability to reason and make decisions—was the most improved cognitive area. Doctors said vitamin K in matcha may be the bioactive compound responsible for the cognitive benefit in healthy, older women.