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Research Suggests Limiting Coffee for Brain Health

woman holding a paper coffee mug

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Key Takeaways

  • A new study links excessive coffee consumption to increased risk of dementia.
  • While caffeine can boost focus and energy levels, moderation is key.
  • Cutting down on cups or opting for other natural sources of caffeine like freshly brewed green tea can help limit your intake.

Brewing a pot of coffee or going out to grab a cold brew can feel like an important step in a morning routine that often fuels productivity throughout the rest of the day. And for good reason: Research has shown that caffeine is linked to increased alertness, focus and concentration while also improving energy levels and mood.

But as with anything health-related, moderation is key. A recent study from the University of South Australia found that drinking too much coffee may negatively impact brain health.

The Research

In the largest study of its kind to date, researchers assessed data from 17,702 participants and found that the risk of dementia increased by 53% for those who consumed more than six cups of coffee a day.

To reach this conclusion, researchers compared participants' habitual coffee consumption with total brain volume. The findings, published in Nutritional Neuroscience, show that higher consumption may lead to brain atrophy or reduction in brain size. This could explain the association with dementia risk, says study author Elina Hyppönen, PhD, but exactly why this happens is not well established.

Elina Hyppönen, PhD

Our findings reinforce the message that moderation is important with respect to coffee intakes, as it is with most things in life.

— Elina Hyppönen, PhD

"Caffeine has been used to induce apoptosis, programmed cell death, in cancer studies using brain cells," Hyppönen says. "Also, adenosine receptors which mediate many of the effects of caffeine on the brain have been suggested to influence the release of growth factors, which affect how cells grow and divide in the brain, and may also affect the formation of new blood vessels in the brain."

Another potential explanation could involve the fact that some coffees contain cafestol, a natural compound in coffee beans that's known to increase blood cholesterol and have adverse effects, Hyppönen says.

As coffee is one of the most popular drinks in the world—global consumption now exceeds 10 billion kilograms a year—it's important to understand the potential health risks associated with it.

"Our findings reinforce the message that moderation is important with respect to coffee intakes, as it is with most things in life," Hyppönen says. "It will be important to conduct further work to establish exactly why higher coffee consumption seems to affect brain size or dementia risk, which will also help establish healthy limits and if there are groups of people who are the most likely to be affected."

The Food-Brain Connection

Needless to say, the food we consume affects more than just our weight or physical health. Uma Naidoo, MD, a nutritional psychiatrist, professional chef, nutrition specialist, and author of the bestselling book “This Is Your Brain on Food,” notes that the brain and gut are inextricably linked and communicate through chemical messages as the food we eat gets digested.

"The gut and brain are connected because they arise from the exact same cells in the developing embryo as our bodies are being formed," Naidoo says. "These two organs are anatomically connected throughout our lives by the vagus nerve. Think of [it] like a two-way superhighway connecting the brain and gut, and allowing for two-way communication all the time, day and night."

Uma Naidoo, MD

Eating to help your cognition is key. After all, a healthy body needs a sharp mind to function and vice versa.

— Uma Naidoo, MD

While the study also found that light coffee consumption (1–2 cups per day) is linked to protective effects against dementia when compared to zero coffee consumption, it’s not difficult to overdo it and tip into the more dangerous habits the research warns against. Naidoo urges caffeine drinkers to listen to their bodies in order to form healthier habits.

"Due to the uniqueness of every individual’s microbiome, lifestyle and environment, we all react to foods differently, which can result in differing health outcomes," she says. "In relation to coffee, caffeine specifically, I suggest that people consume mindfully and pay particular attention to how they feel mentally and physically before and after consumption."

If you're cutting out coffee but still want to experience caffeine's benefits, Naidoo recommends other natural sources, rather than sugary sodas or energy drinks that are often loaded with additives that disrupt the microbiome and can negatively impact mental health.

"This means choosing fresh brewed green tea or a caffeine alternative such as mushroom teas," Naidoo says. "These beverages are naturally stimulating and provide an array of anti-inflammatory and antioxidant properties that can further improve brain health and may ward off neurodegenerative diseases."

It's important to stay mindful of the connection between gut health and brain health when it comes to the foods we consume on a daily basis. For a brain boost, experts recommend a diet that contains foods rich in omega-3 fatty acids, like salmon, albacore tuna, and nuts; produce like green leafy vegetables, blueberries, and oranges; as well as turmeric and dark chocolate.

"When we are eating a healthy whole foods diet and paying attention to quality nutrients, both our physical and mental health improve," Naidoo says. "So eating to help your cognition is key. After all, a healthy body needs a sharp mind to function and vice versa."

What This Means For You

Coffee might help you get through the work day, but research shows exceeding six cups can negatively impact brain health. Keep consumption light, or opt for less intense sources of caffeine like green tea.

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