1. Parsley and Thyme
A recent study from Brazil found that a flavonoid in these spices, called apigenin, strengthened connections between neurons and even coaxed stem cells—our "raw material" cells that can form other specialized ones—into becoming neurons. While these results were produced in a lab setting and not in living, breathing humans, the researchers hypothesize that a diet rich in apigenin might influence brain cell formation and communication, too, which, in theory, could help ward off depression, Alzheimer's, and Parkinson's.
Apigenin's chemical structure is similar to that of estrogen, explains Giana Angelo, PhD, a research associate at the Micronutrient Information Center at Oregon State University's Linus Pauling Institute, who was not involved in the research. Estrogen's long been known to influence neuron development, she says. "In this study, apigenin was able to mimic estrogen and elicit the same types of cellular changes."
Chamomile
A perennial favorite of late-night tea drinkers, chamomile is, at least anecdotal, a tried and true stress destroyer. (Check out these 12 other stress-reducing foods.) Like with apigenin, we've only got lab studies to go on when we think about how chamomile works its herbal magic on the brain, but it contains compounds that might bind to receptors for certain brain chemicals, reducing anxiety in the process, Angelo explains. In one study—in actual humans!—a small group of people with generalized anxiety disorder were randomized to either take a chamomile extract or a placebo. Eight weeks later, the people who had been taking chamomile reported a bigger drop in their anxiety.
Turmeric
Bear with us for some important-to-understand background: We've all got these immune cells called macrophages that destroy foreign particles, Angelo explains, but in some patients with Alzheimer's, macrophages can't do their jobs as well. With subpar macrophage-ing, the buildup of beta amyloid plaques thought to contribute to the disease can't be swept away. Certain compounds found in turmeric (read up all about the super-spice here) have been shown to kick-start those macrophages, she says, potentially helping to clear the plaques from the brains of people with early signs of Alzheimer's. What's still to be determined is how the high dose of these isolated compounds applied in petri dishes translates to how much curry you'd need to eat regularly to really make an impact, she cautions.
Sage
Aptly named for the cause, sage seems to improve memory. In two small studies, capsules of sage extract improved people's performance on memory tests, compared with placebo—for hours after popping the pill. "Other studies in animals indicate that essential oils and extracts of sage block the activity of an enzyme that degrades a neurotransmitter involved in many brain functions," Angelo says, "including learning, memory, and attention." In other words, sage might bolster that all-important enzyme. Be cautious when considering sage supplements, though, she says, as they can be dangerous for some people, including those with high blood pressure, since sage might make BP even higher.
Garlic
It would be truly miraculous if the cure for a deadly brain tumor was simply to eat more garlic, as some headlines seemed to suggest back when 2007 research was making waves. What the study actually showed about garlic was that certain active compounds in the odoriferous bulb can kill cancer cells—grown in a petri dish. "We can't make the leap from this study to what ingestion of garlic will actually do in a real live human brain," Angelo warns, especially because the researchers used much higher amounts of those specific garlic compounds than would be found in an actual clove, but it's certainly a promising start.
