How many cups of coffee should you drink to prevent dementia?

How many cups of coffee and tea should you drink a day? Apparently there isn’t one set answer to this question. Yet, a new study has found the recommended amount of coffee and tea a day that can prevent dementia and stroke.

As the weather cools down from summer into fall, many people start to drink more hot drinks every day, such as several cups of coffee or tea. 

Now a new study involving hundreds of thousands of participants over 10 years has found that your cup of coffee or tea may be associated with a lower risk of stroke and dementia.

Of the more than 360,000 participants studied over a period of 10 to 14 years, those who drank two to three cups of coffee, three to five cups of tea, or a combination of four to six cups of coffee and/or tea a day, had the lowest risk of stroke and dementia, according to researchers from Tianjin Medical University, China. 

"Our findings suggest that moderate consumption of coffee and tea, alone or in combination, is associated with a lower risk of stroke and dementia," the study authors said.

Drinking coffee or tea alone was also associated with a lower risk of both conditions, but people who drank two to three cups of coffee and two to three cups of tea daily - four to six cups in total - were 28% less likely to develop dementia and 32% less likely to have a stroke compared to those who didn’t drink these beverages.

Participants' information came from UK Biobank, a database of anonymous health information from half a million volunteers in the UK collected between 2006 and 2020, which included participants aged 50 to 74 who self-reported their coffee and tea consumption. 

According to the study, published in PLOS Medicine, during the study period, 5,079 participants developed dementia and 10,053 experienced at least one stroke.

 Everything in caffeine

This of course is not the first study linking drinking tea or coffee to our health. For example, a 2021 study using the British Biobank showed that for people without a diagnosis of heart disease, regular consumption of half to three cups of coffee a day is associated with a reduced risk of death from heart disease, stroke and early death for any reason compared to those who don’t drink coffee. 

Several studies have also shown that three cups of coffee a day can reduce the risk of Alzheimer's disease.

According to the British Alzheimer's Association, coffee containing caffeine can help the brain in several ways by increasing the production of granulocyte colonies (white blood cells) that help protect and repair brain cells connected with the nervous system.

Because this is a study that relies on self-reporting there are limitations to the accuracy of the data. 

Dr. Lee H. Schwamm, chairman of the American Stroke Association Advisory Committee and a neurologist at the Massachusetts General Hospital, told CNN that researchers can’t definitively say that drinking more coffee or tea is good for your brain. Yet, they can say that in this study, people who reported moderate coffee/tea drinking were less likely to have a stroke or dementia during the 10 years of follow-up, Schwam added.

Moderation is the name of the game

The results of the latest study may indicate some benefits of drinking coffee and tea, but that doesn’t necessarily mean that everyone should start drinking more cups of coffee and tea during the day.

"Not all coffee drinks have the same amount of caffeine, and people value a cup of coffee or tea differently. In any case, it's worth remembering that it's best to consume most things in moderation," Schwam said. "If you avoid caffeinated beverages, there may be a good reason for it.” 

He added that there is no evidence showing it’s beneficial to start drinking coffee or tea. Instead, he said, people should enjoy their morning coffee, and drinking a few more cups during the day was fine, too.