In recent years, coffee has undergone an image makeover. While in the past it was accused of increasing blood pressure, causing sleep disorders, and damaging the heart, today more and more studies are accumulating that point precisely to the potential benefits of drinking coffee in moderate amounts.
Various studies have linked coffee to a reduced risk of type 2 diabetes, improved liver function, a reduction in the risk of heart disease, and now, also to a certain level of protection for the brain.
And today, I want to elaborate on a very encouraging new study, published in the prestigious medical journal JAMA, which adds a particularly intriguing figure: Drinking 2 to 3 cups of caffeinated coffee a day was found to be associated with a significant decrease in the risk of developing dementia.
Decades of monitoring
The study was conducted by researchers from Harvard University and other medical centers in the United States, and is considered one of the largest and longest studies ever conducted in the field of nutrition and the brain.
The researchers followed more than 130 thousand women and men for up to 43 years: A definitively extraordinary figure among scientific studies. During this period, over 11 thousand cases of dementia were documented.
The participants filled out detailed dietary questionnaires over the years, including information about the amount of coffee they drank, types of beverages, diet, smoking, physical activity, health status, and other lifestyle habits. The great advantage of the study is that it is not a one–time measurement of drinking habits, but rather a very long follow–up that was repeated over and over throughout life.
According to the results of the study, people who drank 2 to 3 cups of caffeinated coffee a day had an approximately 18 percent lower risk of developing dementia compared to people who drank almost no coffee.
In the population under the age of 75, the effect was even stronger, with up to a 35 percent reduction in risk.
Additionally, the researchers found fewer complaints of memory decline and less cognitive deterioration among regular coffee drinkers.
The effect of caffeine on brain cells
One of the interesting points in the study was that the effect was found in caffeinated coffee only. In decaffeinated coffee, no similar link was found.
The researchers explain that caffeine acts as a blocker for receptors of a substance called adenosine in the brain. Adenosine is linked, among other things, to the feeling of fatigue, but also to inflammatory processes in the nervous system. When caffeine blocks adenosine activity, there may be a certain decrease in inflammatory processes in brain cells.
Additionally, studies indicate that caffeine may reduce oxidative damage and improve cerebral blood flow. Some researchers believe that these effects could help in the direction of slowing down processes that cause Alzheimer's disease and other types of dementia. It is interesting to note that the protective effect was also found in people with a higher genetic predisposition to Alzheimer's.
Coffee is not a medication
Despite the impressive results, it is important to remember that this is an observational study. This means that the study found a link between coffee drinking and a reduction in the risk of dementia, but did not prove that coffee itself prevents the disease.
It is possible that people who drink coffee regularly also have other lifestyle habits that affect brain health, such as physical activity, a better diet, or a different social and economic status.
And yet, when such a large study finds consistent results over decades, it is difficult to ignore the connection that was found.
According to most studies in the field, moderate consumption of coffee is considered safe for most healthy people. Usually, this refers to 2 to 4 cups a day, depending on the size of the cup, the type of coffee, and personal sensitivity to caffeine, and there have been studies that pointed to a health benefit even at a higher number (even 6–8 cups).
Pregnant women, people who suffer from heart arrhythmia, significant anxiety, or sleep disorders should, of course, limit the amount of caffeine.
In conclusion, the new study does not prove that coffee prevents Alzheimer's, but it certainly joins a long line of studies indicating that coffee, especially with caffeine, can have a positive effect on brain health. For those who, like me, already enjoy a few cups of coffee a day, this is probably particularly good news.