We love brain food. We love it. “Eat Smart for a Healthier Brain,” reads a WebMD headline. Boost your brainpower! Improve your cognitive function. The brain-health-conscious and -curious are raised on a strict diet of columns, listicles, newsletters, and infomercials. Academic journals, press releases, workshops, coaching services, recipe books that moonlight as self-help texts. Thinkfood: Recipes for Brain Fitness. The Alzheimer’s Prevention Cookbook:100 Recipes to Boost Brain Health. A distressing tome called Eat Healthy with the Brain Doctor’s Wife Cookbook. Nutritional neuroscience feeds a formidable cottage industry, and with it, our imagination. If we could just find the right sauce, we could upgrade the ol’ noodle.
It doesn’t hurt that the field is ripe for puns: eat smart, food for thought, etc., etc. Even scientific journal articles are in on the game. “Fishy business: effect of omega-3 fatty acids on zinc transporters and free zinc availability in human neuronal cells.” “A berry thought-provoking idea: the potential role of plant polyphenols in the treatment of age-related cognitive disorders.” I’ll eat anything recommended by an article with a title like that. Whether or not I’m actually evidentially justified in doing so is an open question.
Health or hype?
The scientific literature can be treacherous, and a hearty dose of skepticism is crucial for parsing health from hype. When curry made headlines last week, thanks to a flurry of recent scientific articles suggesting its neuroprotective action, I raised an eyebrow and decided to take matters into my own kitchen. The task: Construct the brain recipe with the most robust evidence base.
What kind of brain health are we actually talking about, though? And what are the ingredients that pack the biggest punch? Why is any of this stuff actually good for my brain? As any good neuroscientist would, I turned to PubMed and started reading.
Back in the kitchen, I’m flicking the charred base off the fruits of my research labors. Salmon and blueberries have some hefty science behind them. Curry checks out, too. The key there is turmeric—specifically, an active ingredient in turmeric called curcumin. Curcumin is an antioxidant, which is mostly to say it’s one of those words that we can toss around when we want to sound informed.
Here’s the basic biology. In order to carry out a handful of necessary functions, your body needs to maintain a stock of highly reactive chemicals called free radicals. Pop nutritionists have taught us that Free Radicals Are Bad, but that’s only true when we have too many of them or can’t turn them off. While few high-quality studies of free radicals and their discontents have been conducted in humans, as with most things in life, balance is probably key.
Free radicals are not free
Free radicals often have an appetite for negatively charged particles—electrons—and if left to run amok, they’ll start stealing them from places where you need them most. When a free radical bumps into one of your body’s cells, for example, it might gobble up an electron from a fatty molecule in the cell’s outer layer. This molecule is now a radical in its own right: a lipid peroxyl radical, or LOO•. We’ll call him Radical Lou.
Radical Lou is bad news. He’s the kind of guy that comes to your party uninvited and thinks it’ll be funny to punt an orange through your TV. Hits on your sister; smokes indoors. When he’s around, you’re stressed.
Biologically, this is called oxidative stress—LOO• is systematically ripping apart the walls of your cells. When these cells happen to be neurons, you’ll experience a wealth of neurological defects.
But Radical Lou has a vice: The punk loves curry. He loves it.
Curcumin is a type of antioxidant that nutrition researchers call a radical scavenger. If Radical Lou is a jerk, curcumin is a friendly, slightly rotund fellow with some extra snacks to pass around. Curcumin donates an electron to the LOO• radical, and Radical Lou settles down to plain ol’ vanilla Lou. He’s actually quite pleasant once you get to know him.
Oxidative stress can arise from a whole host of brain maladies, including stroke, traumatic brain injury, and Alzheimer’s disease. This is why antioxidants tend to be heralded as the ultimate brain saver: They balance out the excess free radicals that can accumulate after brain injury, whether the injury was external or internal. Few foodstuffs have been celebrated as much as the mighty indigo orb that is the blueberry. The blueberry is nothing else but a basket of antioxidants.
Does anything work in humans?
Nutrition.gov is a USDA-funded website that provides “easy, online access to government information on food and human nutrition for consumers.” Aside from its content having apparently been written by our robot overlords (and like most government websites, designed using what appears to be Microsoft Paint), nutrition.gov ostensibly offers the definitive guide to currently recommended health foods. But they’ve got nothing to say about the brain.
Of course, there are plenty of promising animal studies of brain food. The problem appears to be the translation of these findings to the human body. My quest for a rigorous neurological recipe dredged up a fantastically healthy dish for rodents. Turmeric, blueberries, salmon (those omega-3’s, you know?), ginger, spinach: There’s no reason not to eat these things. We’re just not sure how much they help.
Part of the problem is that there’s a bit of evidence for everything. Try searching “[your favorite ingredient] and brain” in PubMed. Everything improves your cognitive functioning, just like everything causes cancer.
There’s a yearning buried beneath our glitzy headlines. Alzheimer’s—one of the chief causes of dementia—is stubborn and insidious. A heart attack is tragic, yes, but a heart attack doesn’t kill you slowly over seven years, looting your memory as it bulldozes your cortex. Dementia is posed to strike 65.7 million people worldwide by 2030. It’s a burden we cannot afford to ignore. But as the evidence continues to develop, we’re stuck with the inescapable truth that right now, we simply do not know the best way to improve our brain health. Of course, a couple blueberries won’t hurt.
Photo: Zsolt Fila/flickr