Could Too Much Coffee Lead to Alzheimer’s? New Study Finds Link

It's no secret that Americans have a love affair with coffee. Almost six in 10 of us drink coffee every day and choose it over any other beverage. We now sip two cups per day, on average, according to the National Coffee Drinking Trends report. Up until now, it's believed to be the best way to get antioxidants, help us focus, and even boost brain health.

Yet now a new study adds a caveat to all this good news about America's favorite beverage: If you overdo the cups of joe, all that coffee could actually cause harm to your brain, increasing your risk of dementia. The new study finds that too much of a good thing is not better. Here’s what you need to know to sip safely.

If coffee is a staple in your morning routine, you already know that it comes with the short-term benefits of increasing your focus, alertness, and mood. It also contains a host of nutrients and healthful antioxidants that appear to benefit the brain, says Kitty Pham, Ph.D. candidate at the University of South Australia in Adelaide. That may explain why it’s on the list of the top 20 foods that nourish your brain, according to the work of Drs. Dean and Ayesha Sherzai, authors of The 30-Day Alzheimer’s Solution.

The caffeine in coffee "stimulates the production of neuroprotective agents in the brain and coffee contains potent antioxidants,” they explain in a piece for The Daily Mail. In their book, however, they note that this is true only if you don’t have heart disease and/or psychological issues (like anxiety or sleep disorders) and only if you’re drinking filtered coffee as opposed to unfiltered espresso or brewed coffee. The filters remove a compound called cafestol, which actually increases blood lipid levels.

In terms of staving off dementia or Alzheimer’s, which is the most common form of dementia, the evidence on coffee is mixed. “Some observational studies report that drinking coffee is associated with long-term benefits to brain health, while others have shown that there are no such associations,” says Yuko Hara, Ph.D., director of Aging & Alzheimer’s Prevention at the Alzheimer’s Drug Discovery Foundation in New York City.

What is dementia? Dementia is a general term for the loss of memory, diminished ability to conjure the right language or a loss of problem-solving skills and other functional thinking abilities. Dementia is more than the normal aging process of being forgetful or having a word escape you – but is diagnosed when these symptoms are severe enough to interfere with an individual's ability to function in daily life. Alzheimer's is the most common type of dementia.

One of the newest studies has even found deleterious effects from coffee. In this study from the journal Nutritional Neuroscience, among individuals aged 37 to 73, those who drank more than six cups of coffee a day had a 53 percent higher risk of dementia versus those who sipped just one to two cups of coffee a day. This didn’t surprise Pham, one of the study investigators.

“An earlier genetic study looking at lifestyle factors and Alzheimer’s disease reported an association between higher coffee consumption and higher odds of Alzheimer’s,” she says. “Evidence from a recent randomized control trial also reported an association between higher caffeine and smaller grey matter volumes.”

Researchers haven’t yet determined why coffee might increase the risk of dementia or whether the increase is driven by the coffee itself or the caffeine in the coffee. What they do know, though, is that high amounts of coffee aren’t good for the brain, especially because that much coffee, especially if it’s caffeinated, can cause anxiety, palpitations, or interfere with quality sleep at night. “Getting quality sleep is an important lifestyle factor for brain health and Alzheimer’s prevention,” Hara says.

Numerous factors increase your risk of dementia, a general term that refers to loss of memory, problem-solving, and other cognitive abilities that hamper daily life. Alzheimer’s is the most common one, as it accounts for 60 to 80 percent of dementia, according to the Alzheimer’s Association. Even more alarming? Every 65 seconds, another individual in this country develops Alzheimer’s, and rates are on the rise.

Typically, though, experts focus on the 12 risk factors reported by the Lancet Commission on Dementia Prevention, Intervention, and Care. Things that you can control include not getting enough exercise, smoking cigarettes, having (and not treating) type 2 diabetes, having (and not treating) high blood pressure, being obese, and being socially isolated, Hara says.

While sipping coffee isn’t officially on the list of 12risk factors for dementia right now, there is one beverage-related risk factor that did get added in 2020: Excessive alcohol intake. “Heavy drinking is associated with cognitive impairment and dementia, and alcohol use disorders have been associated with a greater than a three-fold increased risk of dementia,” Hara says, adding that low-to-moderate alcohol intake has been associated with beneficial effects for the brain. Yet just as with coffee, the evidence on alcohol’s brain benefits is inconsistent.

Other drinks that contain caffeine are cola, green tea, and Yerba mate, along with cocoa drinks and energy drinks.  While these were not in the study, adding more caffeine on top of your copious coffee habit could theoretically result in inadvertently overdosing on caffeine.

Fortunately, there are steps you can take to improve brain health, even help ward off dementia and Alzheimer’s. Hara points to seven: Eat healthy (the plant-strong Mediterranean diet is one of the most studied in terms of having a healthy brain), get enough sleep (seven to eight hours), especially after the age of 50, and log daily exercise. Try to alleviate chronic stress, stay socially engaged, and keep learning. Manage chronic illnesses like diabetes and hypertension.

A mostly plant-based diet has also been shown to help stave off or protect against early onset of dementia, in review studies on population data and diet. Whether you choose a "greener Mediterranean diet" or a fully plant-based approach, research supports eating more plant-based and avoiding meat and dairy to support memory and overall brain health.

So what should coffee-loving fans do if they’re focused on brain health? Practice moderation. “Low to moderate coffee/caffeine intake, about one to three cups a day is generally considered safe and is likely better for brain health than excessive coffee drinking (six-plus cups a day),” Hara says. And don’t forget to sip a cup of water with your coffee to stay hydrated, Pham says.

If, though, you want to play it safe, cut back to one or two cups of coffee a day, or try a coffee detox cleanse altogether. When you've had your allotment, stick with water or decaffeinated green tea, which has been shown to improve memory and attention in people with mild cognitive impairment, considered a precursor for Alzheimer’s.

In one observational study, greater green tea intake was associated with a 27 percent lower risk of dementia in people who drank at least five cups a day, Hara says. Or cut caffeine completely by following these tips from the Cleveland Clinic.

There are known health benefits of coffee, but a new study tells us that drinking more tthan six cups of coffee a day has been linked to a higher risk of dementia. Here’s what to know about the risks of coffee