Coffee May Reduce Risk of Dementia
Are you a coffee drinker? Tea? If so, you may be improving your odds of enjoying optimum brain function during your later years.
In a study recently published in the Journal of the American Medical Association (JAMA), results show that people that regularly drink coffee or tea have an 18% lower risk of developing dementia.
This is no small, insignificant study. It was conducted by researchers from Mass General Brigham, Harvard T.H. Chan School of Public Health, and the Broad Institute of MIT and Harvard. Researchers examined data from 131,821 participants in the Nurses' Health Study (NHS) and Health Professionals Follow-Up Study (HPFS).
Results indicate a positive relationship between regular consumption of coffee or tea and healthy long-term brain function.
I’ll cut to the chase and reveal the significant findings before diving into the details. The strongest benefit was associated with people who drank 2-3 cups of coffee or 1-2 cups of tea daily.
"When searching for possible dementia prevention tools, we thought something as prevalent as coffee may be a promising dietary intervention -- and our unique access to high quality data through studies that has been going on for more than 40 years allowed us to follow through on that idea," said senior author Daniel Wang, MD, ScD, associate scientist with the Channing Division of Network Medicine in the Mass General Brigham Department of Medicine and assistant professor at Harvard Medical School. – Science Daily
The study is remarkable in the number of participants as well as the length of the study, following the participants for up to 43 years.
Coffee and its effect on protection from dementia and cognitive problems related to aging have been studied by many other researchers. In a study published in 2025, researcher Joseph Pergolizzi Jr. stated: “The caffeine in coffee can inhibit adenosine, but this mechanism is not well understood. Whether or not coffee has protective effects against neurodegenerative conditions is being actively studied. Coffee may confer significant neuroprotective, anti-inflammatory, and cognitive benefits, which are of particular interest in aging populations and warrant greater study.”
Of course, there are problems in trying to interpret the studies and determine a practical recommendation for readers and patients. In the large study mentioned first in this article, the authors summarized that 2-3 cups of coffee or 1-2 cups of tea were associated with the optimum cognitive benefit. They stated in the journal article that this applied to caffeinated coffee – not decaffeinated.
But there are many different types of coffee, and ways to prepare it. Does a cup equal a measuring cup of 8 ounces? With varying sizes of coffee drinks casually consumed by people in today’s environment, a “cup” could range from 4 to 20 ounces. How strong the coffee is made could make a difference as well.
The primary author of the study, Zhang, is quoted in one article as saying that the study does not mean that people should start drinking coffee to hope to obtain the result of protecting their brain function. He says it is merely an observational study that presents the data that they found.
In preparing for these columns, I always try to perform meaningful research to obtain factual data. If possible, I then summarize what I find to provide helpful suggestions for readers wherever possible.
My research into the benefits of coffee have revealed a sizable list of potential health advantages for people that regularly drink coffee.
For example, the following benefits have been attributed to drinking coffee regularly:
· Protect brain and enhanced cognitive function. May help protect from Alzheimer’s and Parkinson’s disease and other forms of dementia.
· Diabetes protection. Lowers risk of developing Type 2 diabetes.
· Colon cancer protection. Less risk of colon cancer.
· Protects your liver. Decreased risk of cirrhosis, fatty liver disease, and liver cancer.
· Less risk of heart and vascular disease, including stroke.
· Improves mood. Lower risk of depression.
· Increased mental alertness. This leads to better productivity, fewer accidents, and other benefits.
· Better weight management. Coffee may help manage body fat. It has been shown to enhance gut health and may be involved in fat storage.
Can too much coffee be a bad thing? Of course. While the nutritional experts suggest that your intake of caffeine should be less than 400 milligrams per day, some individuals may be more sensitive to caffeine and may not tolerate that amount.
Today’s “energy drinks” are often packed with excessive amounts of caffeine. It is not unusual to find the label report up to 200 mg of caffeine, which is 2-3X the amount of caffeine found in a normal cup of coffee.
Caffeine is a stimulant that results in heightened alertness, attention, and enhanced brain function. It effectively blocks a brain chemical adenosine, which can cause drowsiness. Caffeine can boost chemicals dopamine and adrenaline, increasing mood, heart rate, and cognitive function.
Too much caffeine can cause jitters, anxiety, insomnia, and rapid or irregular heart rate.
In my recent work with patients with essential tremor, I caution against too much caffeine which can exaggerate movement disorders.
There are many more chemicals in coffee than caffeine. There are over 1000 different known chemicals in coffee. The number and variety of chemicals vary from cup to cup, depending on many factors. Roasting coffee, for example, creates hundreds of new chemicals not present in unroasted coffee.
I think I will go brew another cup.
Dr. Mark Kestner
