Gastro doc swears by these 3 superfoods for boosting brain power

By MDLinx staff

Published April 2, 2025

Key Takeaways

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“Black coffee has been shown to help with cognitive health, cardiovascular health, liver health—especially in fatty liver disease—and decreases your risk of liver cancer.” — Joseph Salhab, MD, a gastroenterologist

More and more research is proving that the connection between the gut and the brain is real, and it has big implications for cognitive health. Gastroenterologist Joseph Salhab, MD, recently shared his top-three foods for cognitive function on Instagram, and they’re all backed by solid science.

These aren’t just trendy recommendations—they’re evidence-based choices that can have a real impact on brain and gut health. Dr. Salhab says he incorporates these foods into his daily morning routine, which gets him ready for a productive, positive day. Let’s dive into why these foods are key players in maintaining cognitive function and overall health.

Blueberries: The tiny powerhouses

Blueberries are a staple in Dr. Salhab’s morning routine. They're packed with flavonoids—antioxidants that help protect the brain from oxidative stress, a major contributor to cognitive decline. Research from the Journal of Agricultural and Food Chemistry has shown that regular consumption of blueberries can improve memory and even delay cognitive aging. ^[]

Dr. Salhab enjoys the cognitive benefits of blueberries, but there’s another perk: they also support a healthy gut microbiome. The polyphenols in blueberries help nurture the growth of beneficial gut bacteria, which is essential for maintaining the gut-brain axis. ^[]

Cashews, walnuts, and more

Nuts are another crucial part of Dr. Salhab’s morning routine. He often pairs blueberries with a mix of walnuts, cashews, and pistachios. “People who eat more nuts tend to have a lower risk of dementia and colon cancer,” Dr. Salhab said. This isn’t just personal preference—nuts are rich in omega-3 fatty acids, which are vital for brain health. ^[] Walnuts, in particular, are packed with nutrients that help maintain cognitive function and protect against age-related decline, as evidenced by research in Frontiers in Aging Neuroscience.^[]

But nuts don’t just support brain health—they’re also fantastic for the gut. Full of healthy fats and fiber, nuts act as prebiotics, feeding beneficial bacteria in the gut and supporting a balanced microbiome. A healthy gut means better digestion, improved nutrient absorption, and enhanced brain function.

Related: The best nuts for heart health

Caffeine is more than a morning boost

Dr. Salhab also incorporates coffee into his morning routine. “I try to drink black coffee every morning,” he says. "I use monk fruit sweetener instead of sugar. I try to use a light roast because a light roast keeps the nutrients intact better than a dark roast.”

"Black coffee has been shown to help with cognitive health, cardiovascular health, liver health—especially in fatty liver disease—and decreases your risk of liver cancer."

— Joseph Salhab, MD

Caffeine isn’t just about staying awake—it’s a powerful cognitive booster. Studies in The Journal of Nutrition show that moderate caffeine intake improves memory, alertness, and overall cognitive function.^[] But coffee doesn’t stop there.

Dr. Salhab’s choice of black coffee, particularly light roast, is a great way to maximize nutrient retention and support his overall health. The antioxidants in coffee contribute to cognitive health, and research also shows that coffee can benefit cardiovascular and liver health.

Caffeine also supports a healthy gut. Research suggests that caffeine can promote the growth of beneficial gut bacteria, helping to maintain a balanced microbiome.^[] For Dr. Salhab, a cup of coffee isn’t just a morning ritual—it’s an important part of his gut and brain health routine.

Why this matters

The connection between the gut and the brain is no longer just a theory—it’s a proven phenomenon (aka the gut-brain axis). Research continues to uncover how a balanced gut microbiome can influence brain function, mood, and even cognitive performance. By incorporating foods like blueberries, nuts, and caffeine into his daily routine, Dr. Salhab is offering himself—and by extension, his patients—a holistic approach to brain and gut health.