Get Off the Blood Sugar Roller Coaster

One of the most crucial factors in maximizing mental processing is keeping blood sugar on an even keel. “If you’re not well-nourished, your brain is going to work a lot harder to focus,” said Federica Amati, who holds a Ph.D. in clinical medicine research from Imperial College London and works as the head of nutritional science for WellFounded Health, a performance-medicine clinic in the U.K. (Fun fact: Our brains consume a full 20% of the body’s total energy). Amati tells clients to stick with “glucose-steady” meals of protein, complex carbohydrates, fiber, and fat, which keep glucose steady while also providing a variety of brain-boosting nutrients. 

Breakfast might be full-fat yogurt with berries and seeds, or eggs with spinach and feta; for lunch, a large salad that includes whole grains and lean protein. Skip refined carbohydrates from foods like pastries, pasta, and white rice, which send blood sugar spiking and crashing. 

SMART MOVE A desk snack of berries and nuts can provide a sustained energy boost rather than a sharp spike and crash.

Caffeinate Confidently

Max Lugavere, a science journalist and the author of the bestselling 2018 book “Genius Foods,” said that in addition to coffee’s immediate impact on focus, a growing body of evidence shows that coffee drinkers tend to be healthier overall than non-coffee drinkers. Observational research even indicates that the drink protects against dementia. “Coffee supports mental and physical performance, in addition to being full of brain-boosting plant polyphenols,” Lugavere said. He did advise to limit caffeinated coffee to pre-2 p.m. so it doesn’t impact your night’s sleep. And if you know it makes you jittery or anxious, cut down on it or skip it. 

Join Club Med

Puja Agarwal, a Ph.D. nutritional epidemiologist at Rush University Medical Center in Chicago who focuses on nutrition and cognitive health, said no single nutrient is key to focus. But researchers do have an increasingly clear picture of the mix of foods that keeps our brains operating at peak performance long-term. “Over the years, nutrition research has shifted from nutrient-based research to food-based and dietary pattern-based research,” Agarwal explained.

She added that there is strong scientific support for the brain-boosting power of the Mediterranean diet, rich in whole grains, fruits, vegetables, nuts, seeds and fish. Among the chemicals believed to play the biggest role in brain health are pigments called carotenoids, found in bright-colored fruits and vegetables; Omega-3 fatty acids from fatty fish and chia seeds; and creatine and choline from animal products. 

Honorable Mentions

All the experts stressed that an eating pattern that prioritizes whole, unprocessed foods is more important for peak cognition than seeking out any one nutrient. But two foods came up again and again as standouts. 

Berries are loaded with a class of chemicals called anthocyanins that appear to have major cognitive benefits. Studies show a relationship between blueberries in particular and improved memory and brain function in the short term and protection against dementia long term. 

Leafy greens are a top source of nitrates—shown to increase blood flow to the brain, improving cognitive performance—as well as carotenoids, folate and vitamin C, all considered crucial for a healthy brain. A 2017 study showed that people who ate dark leafy greens every day had brains that performed up to 11 years younger than those who did not. 

Research on the “gut-brain axis”—the biochemical signaling between the brain and trillions of microbes residing in the digestive tract—further supports the importance of maxing out your lettuce and kale. “Leafy greens bring fiber, and we’re understanding that it’s really a critical nutrient for the gut microbiome,” said Dr. Uma Naidoo, M.D., director of nutritional and metabolic psychiatry at Massachusetts General Hospital and the author of “This Is Your Brain on Food.” 

If all this seems a long way from your current workday diet, don’t scramble to change everything at once. When Dr. Naidoo started her clinic, she would give patients a long list of dietary changes to make—before realizing they were becoming overwhelmed and giving up. Now she focuses on one shift at a time: “As much as it’s informed by the research, you have to interact with the human and know what’s possible.”

5 SNACKS TO POWER YOU THROUGH THE AFTERNOON LULL

1. Hard-Boiled Egg, Clementine, and Green Tea

Eggs are a good source of lutein and zeaxanthin—shown in studies to improve visual-spatial processing and neural efficiency—plus choline, which the body uses to make the neurotransmitter acetylcholine. They’re also a convenient protein go-to. Add a clementine for a hit of sugar and vitamin C and green tea, with brain-boosting EGCG and caffeine. 

2. Blueberries and Cheese

The evidence is good that over time, the anthocyanins in blueberries improve brain function. Pair with a few cubes of cheese for enough protein and fat to stave off hunger until dinner. 

3. Nuts and Dried Fruit

Combining protein- and fiber-rich nuts (raw, if possible) with a bit of sugar from dried fruit will perk you up fast, and then keep you full. 

4. Hummus With Celery and Red Peppers

Any fresh vegetable will offer antioxidants and fiber, but celery is particularly rich in lutein and folate, and red peppers are a top source of vitamin C. Hummus brings filling protein to the mix.

5. Dark Chocolate With Nuts

Cocoa delivers flavonoids, which may increase blood flow to the brain, and magnesium, required to produce ATP, the main energy source for cells. Nuts such as almonds or hazelnuts blunt a blood-sugar spike.