It’s human nature. Since the days of Descartes and the “dualistic” theory of the mind-body distinction, we tend to think of our thoughts — and our brains — as separate from our bodies. We’re accustomed to our geniuses looking like Albert Einstein or Bill Gates, and if someone seems a little thick in the head, we rarely think, He needs a better diet. The mental is mental; the physical is physical.

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Yet current research says otherwise. Dr. Liz Applegate, the director of sports nutrition at UC Davis, is part of a growing wing of scientists who believe in the power of “brain foods” — that as we get older and become more at risk for Alzheimer’s, a certain type of diet can boost our cognitive potency. Decades ago, science proved food can impact our heart health. Why should the brain be different?

“On a cellular level, we have normal wear and tear on our body,” Applegate tells me. “What we eat influences the integrity and lining of our blood vessels.” She explains that we always have some amount of inflammation in our brains — just as we can have inflammation throughout our bodies — and as we age, that inflammation accelerates.  Certain foods contain nutrients, vitamins and compounds that are better able to fight this inflammation. “Inflammation is always going to happen,” she says. “The question is, are you going to let it get out of control?”

Nutritionist Linda Clark, of Sacramento’s Universal Wellness Associates, is another believer. “Brain inflammation causes us to experience brain fog, memory lapses, lack of focus and concentration, and feeling overwhelmed by even small stressors, and eventually leads to cognitive decline,” she says. “The key to boosting brain energy is to provide the nutrients that the brain needs to thrive.”

To illustrate the link between food and our brains, it’s helpful to look at a more extreme example. “When you look at people who have schizophrenia, they have lower instances of psychological breaks when gluten is removed from their diets,” says Amy Eubanks, another Sacramento-based nutritionist. Studies on this have shown mixed results. In 1986, for example, researchers took 24 patients  with psychotic disorders and stopped feeding them bread and gluten. Two of the patients improved — but when they began eating bread again, they relapsed. Not all the patients recovered, but if there’s a link between food and psychology — however tenuous — couldn’t there be a link between food and brain potency?

The science says yes.  We think of our thoughts as abstract, but of course they are in our physical brains, and our brains consume energy. The energy comes from food. Consider this 2012 study published in Annals of Neurology: After tracking the cognitive decline of 16,000 nurses for over a decade, researcher Elizabeth E. Devore found something fascinating: “Greater intakes of blueberries and strawberries were associated with slower rates of cognitive decline,” she writes. Specifically, snacking on berries slowed the rate of decline by approximately two years. “Berries are high in flavonoids, especially anthocyanidins,” explains Devore, and these flavonoids serve as a protector that can tamp down the brain’s inflammation.

Other studies have shown similar results. True, most of these studies look at the long-term impact of reducing cognitive decline. As for getting an immediate boost? “That is less conclusive,” Dr. Applegate concedes. “There are so many claims made, and when you look at the research, it’s questionable.”  

Fair enough. I know this might not meet the standards of a peer-reviewed academic study, but if I load up on “brain foods” and follow the experts’ advice, can I actually see an improvement in my brain?  

Game on.

My Baseline

To kick this off, I needed some kind of baseline for my own brain — what am I working with here? Since much of the studies are about blunting cognitive decline in the elderly, I turned to an institution I knew I could trust for an official brain test. At age 40, I might be the youngest person on the planet to sign up for AARP.

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The test begins. Words flash in front of me such as “cow,” “oil” and “apple.” Seconds later I’m asked to remember the words and pluck them from a list — easy peasy.  More tests: recalling sequences of numbers (so easy!), clicking the cursor every time two letters appear twice in a row (yawn) and sussing out the pattern of a maze (OK, harder). The test takes 15 minutes. I start thinking maybe this is a bad idea. I’m taking a test designed for 80-year-olds, so it’s not exactly the fairest measurement.

Instantly my score is calculated: 4.6 out of 10.

Wait. Wait. What?

The AARP gives me a description: “Average.” It’s right smack in the middle of the normal curve. (It’s only a minor comfort that the score is, in fact, adjusted for others in my age bracket, but still.) The news is devastating. I’ll confess that I’ve always thought myself a little smarter than the average person — but no. I’m not smarter than the average guy; my brain is average. I’m not special. The detailed breakdown of my score feels like a withering critique of my very existence: Processing Speed: 4.5, average. Sustained Attention: 6.0, average. Working Memory: 5.0, average. Executive Function: 2.5, below average.

My situation is worse than I thought. The test began as something of a lark, or even, to be candid, a cute way into this story. But it’s now bordering on an existential crisis.  

OK nutritionists, help. How can food make me smarter?

Clark sends me a cheat-sheet of suggested meals that she gives to her clients, and it’s remarkably similar to the brain foods suggested by Applegate at UC Davis. These are the heavy-hitters:

Green leafy vegetables: The backbone of a healthy brain diet. They’re packed with antioxidants, folic acid, vitamin C, vitamin E and a gamut of nutritional goodies. One credible study found that people who ate two servings of green leafy vegetables per day had the cognitive abilities of people 11 years younger. Dr. Applegate says to eat them raw or steamed — and the darker and brighter, the better. She specifically recommends bok choy, arugula, spinach, collard greens and, of course, the poster boy of power-produce — kale.    

Berries: “Berries change the way neurons in the brain communicate,” Clark explains. She recommends a full cup a day. Careful, though: this is not carte blanche to load up on other fruits — watermelon, pineapple, bananas and grapes deliver loads of sugar without the antioxidant benefits. And if you can’t find the berries in season? “Frozen is as good as fresh,” reassures Dr. Applegate.

Poultry: At least twice a week, as it’s a potent source of B12.

Beans: “This is the biggie I find that a lot of people are not doing,” Applegate says. She gives a simple tip: Take beans from a can and toss them into a salad. I take note and add red kidney beans to a salad every day.

Nuts and Seeds: “They provide minerals such as zinc, selenium and fatty acids as well as vitamin E, which is needed to prevent cognitive decline and to support healthy circulation, especially to the brain,” Clark says.

Red wine: Applegate recommends a daily, five-ounce glass of red wine. “A five-ounce glass,” she stresses, chuckling. “And you can’t save them all for Friday and have seven. I always have to tell the college students that. It still hasn’t sunk in.”  

Avocados: “Rich in vitamin K, folate, vitamin C and rich in B vitamins, especially vitamin B6, which is needed to boost brain neurochemicals such as serotonin, dopamine and GABA,” Clark says. They are also delicious.

Seafood: Ideally twice a week. “There are reasons this is not a vegan diet,” says Applegate, as seafood is loaded with B12 and essential omega-3 fats. “Wild-caught ocean salmon is one of the best sources of EPA and DHA — two essential fatty acids that support the integrity of all cells and especially the neurons in the brain,” explains Clark. (New plan: When dining out, splurge on the salmon.)

Olives and olive oil: Don’t fear the fat in olive oil. As Clark reminds us, “Since the brain is made mostly of fat, it is mostly dependent upon the essential fatty acids” that are only found in food.

Chocolate: This one’s tricky. Too much chocolate can cause sugar overload and trigger insulin resistance. But in a 2016 study published in Appetite, researchers tracked the cognitive performance of 1,000 adults, and happily conclude that “more frequent chocolate consumption was significantly associated with better performance” in both working memory and abstract reasoning. Well if you insist…

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OK, easy! I’ll just sprinkle these foods to my diet and suddenly get smarter. Yet, Clark quickly punctures my delusion, telling me, “It’s not just about ‘brain food,’ but also, what are you currently eating? You could be eating things that cause systematic brain inflammation.”  

Translation: I need to go on a diet. “Sugar and starches only provide quick bursts of energy and set us up for sugar cravings,” Clark says. Now take another look at that above list of brain foods. Notice any glaring omissions? Wheat. Pasta. Sugars. Even milk, dairy and yogurt — no good. Clark calls these  “brain zappers,” as they all lead to insulin resistance and brain inflammation.  

Deep breath. OK, so for the next two weeks, I overhaul my entire diet. Breakfast cereal — gone. Sandwiches — see ya. My breakfasts are eggs, beans and spinach, garnished with a side of blueberries. For lunch I have salad (with tons of dark leafy greens) topped with grilled chicken and a scoop of avocado. Dinners are a mash-up of grilled chicken, turkey chili and spinach, spinach and more spinach. Half my day is spent eating spinach, the other half is spent flossing spinach from my teeth.

“It’s not just what you eat, but when you eat … Eating regular meals — and eating to feed the brain — will sustain brain energy throughout the day.” Linda Clark, nutritionist, Universal Wellness Associates

As for my brain? There is one immediate and surprising benefit: Rejiggering your diet compels your brain to actually work harder when preparing your meals and navigating your day. And the mental workout matters. In her lecture, Dr. Applegate reminds the crowd that food is hardly the only variable that influences the brain, as other factors include active stimulation, sleep, stress — and the number of hours spent watching “The Bachelor”.

Confession: I’m not exactly a purist. Real life intervenes. I didn’t totally purge all refined grains from my diet — I had a date night that involved a pizza, a party that had some nachos. Yet the science says maybe even that’s OK.  In one study, people who rigorously stuck to the MIND diet (the one prescribed by Dr. Applegate) reduced their risk of Alzheimer’s by 53 percent, but when the participants just “mildly” followed the plan, they still slashed the risk by 35 percent. I like this factoid. Usually diets are framed as all-or-nothing, but in this case, it could be that some brain food is better than no brain food. Baby steps.

There’s another variable that I hadn’t considered. “It’s not just what you eat, but when you eat,” Clark tells me. “The brain needs a steady state of glucose in order to function. Eating regular meals — and eating to feed the brain — will sustain brain energy throughout the day…Otherwise it’s like trying to fuel your car to get to Los Angeles, but you can only get to Modesto.” I take her advice and snack on almonds, blueberries and protein shakes (not really a recommended brain food, but not expressly forbidden). With more frequent snacks, I feel less foggy in the afternoon, sharper and better-able to concentrate. I do not gain or lose weight. I feel lighter on my feet.

Eubanks, the nutritionist, has a “slap in the face” theory that helps describe this phenomenon. “Let’s pretend that you wake up every day, from the first day you can remember, and someone slaps you in the face,” she says, laughing a bit. “You would think that’s a normal part of life. But if you went 30 days without someone slapping you in the face you would say, ‘Hey, my life’s a little more enjoyable.’”

Was my old, wheat-heavy diet slapping me in the face? It’s difficult, of course, to untangle all the variables. Should we credit the magic of “flavonoids” in the blueberries, the vitamins in the leafy greens, the reduction of wheat, the higher frequency of caloric intake or simply a placebo effect? Such is the conundrum scientists face. It’s tough to isolate any one variable — and never blindly trust a sample size of one.

So now it’s time for me to retake the AARP test. Once again I try to remember “corn” and “cheese” and “box.” Once again I try and recall numeric sequences. I finish, hold my breath, remember what it feels like to dread the SAT and click to see a final score of … 6.8!  A massive improvement from 4.6. This still sounds embarrassingly low, like an F+, but the dot is comfortably on the right of the normal curve, which means “above average.”  Yet there are gobs of caveats.  The experts tell me it should take several weeks or months to see a real difference. It’s possible that I was simply more familiar with the test, and it’s also possible that I was more alert this go-round or that, potentially, I just had an off-day to begin with.  All that said, I’ll take it.

I can’t promise that I will go the next 40 years avoiding pizza and pancakes — I like my carbs. Yet, I’m convinced that brain foods are legit, that the research has clearly established a link between what we eat and how we think, and that if I want to boost my 6.8, I should probably take this stuff seriously. And also, more red wine. Because science.