Does Coffee Cause Alzheimer’s Disease?

We Americans love our coffee. It’s the most popular hot beverage in the U.S. with double the number of drinkers compared with tea.

It’s not surprising, really.

Coffee not only picks you up at the start of the day and provides a much-needed lift after a mid-afternoon slump, it also has a plethora of health benefits for both the body and the brain.

But can you have too much of a good thing? The latest research suggests the answer is “yes.” Researchers say there is a tipping point when it comes to drinking coffee and it can result in memory loss and in some cases, Alzheimer’s disease.

Before we get to the bad news, let’s start with some of the brain health benefits of coffee—and there are many…

A large number of studies demonstrate that coffee consistently improves the health of the brain. The studies show coffee promotes mental focus, clarity and sharpens memory. What’s more, coffee can even help reduce your risk of Alzheimer’s disease!

Coffee Protects Against Dementia and Alzheimer’s Disease

Dr. Chuanhai Cao, a neuroscientist at the University of South Florida, led one study on coffee’s effects on memory. Dr. Cao explained his findings, saying, “We firmly believe moderate coffee consumption can appreciably reduce your risk of Alzheimer’s or delay its onset.”

Dr. Arfan Ikram, assistant professor of neuroepidemiology at the Erasmus Medical Center in Rotterdam, said most studies suggest “regular coffee consumption over a lifetime is associated with a reduced risk of developing Alzheimer’s Disease, with an optimum protective effect occurring with three to five cups of coffee per day.”

A review of 201 studies published in the British Medical Journal in 2017 found moderate coffee drinking was associated with a lower risk of dementia. Regarding brain health in particular the review team wrote that coffee was “consistently associated with a lower risk of Parkinson’s disease…depression and cognitive disorders, especially for Alzheimer’s disease…”

The benefits didn’t stop there. The researchers went on to say that moderate coffee drinking also lowered the risk of some cancers, diabetes and liver disease. The key word from their findings?

Moderate coffee drinking.

When Coffee Increases Dementia Risk

Some studies on coffee show a U shaped relationship to human health. This means that a few cups of coffee are beneficial to our brains and bodies, but then diminishing returns set in, with increasing amounts causing harm.

In fact, the latest study published in the journal Nutritional Neuroscience last July revealed that high consumption of coffee actually increases dementia risk.

In the largest study of its kind, researchers led by the University of South Australia used the UK Biobank, a biomedical database, to analyze habitual coffee consumption data on 398,646 adults between the ages of 37 and 73.

The research team looked at the number of people who went on to develop dementia and stroke, and also analyzed brain volumes among 17,702 members of the group using MRI scans that were performed four to six years following enrollment in the database.

After taking into account a wide range of factors that could influence the findings such as socioeconomic status, health conditions, physical activity, stressful life events, and body mass index, smoking, alcohol and tea consumption—an important factor for the British undoubtedly—they came to an interesting conclusion.

More Than Six Cups is Dangerous to Your Memory

Non-coffee drinkers, or those who prefer decaffeinated coffee, had a slightly higher risk of developing dementia than moderate coffee drinkers. But the interesting findings were for those who drank more than six cups of coffee a day.

First of all, researchers found these folks had smaller brain volumes. Remember, the brain shrinks with age and that loss in volume has been linked to memory loss. The team theorized this additional brain volume loss could be caused by the dehydrating effects of coffee.

Second, those that drank more than six cups of coffee a day had a 53 percent increased risk of dementia compared to those who drank one or two cups a day. The bright side? They didn’t have any significant increased risk of stroke.

Senior investigator professor Elina Hyppönen explained the findings, saying, “Together with other genetic evidence and a randomized controlled trial, these data strongly suggest that high coffee consumption can adversely affect brain health.

“While the exact mechanisms are not known, one simple thing we can do is to keep hydrated and remember to drink a bit of water alongside that cup of coffee.”

She added that a few cups a day is generally fine but “if you’re finding that your coffee consumption is heading up toward more than six cups a day, it’s about time you rethink your next drink.”

Walter Willett, professor of epidemiology and nutrition at Harvard T. H. Chan School of Public Health, was asked for his opinion on the study. Prof. Willett said “…it provides reassurance about lack of adverse effects of coffee for those consuming three or four cups per day, and little increase in risk, if any, with five cups per day.

“But six or more cups per day is a lot, and those who drink that much might consider cutting back a bit while research continues.”