Isn’t it nice when a study comes along that supports a common daily habit that was long regarded as an unhealthy vice?

Such is the case with a study published recently on the brain health benefits of coffee drinking.1 While we all know that a cup of coffee—or maybe two—can kick-start our focus and memory in the morning, for many years coffee has been viewed as a health hazard.

In fact, as recently as 1991, the World Health Organization listed coffee as a possible carcinogen! However, by 2016, the organization had reversed its stance.2 More on this in a minute…

So, grab a cup of coffee and let’s dig into the new research.

This most recent study published in the journal PLOS Medicine adds to a growing body of evidence showing that a few cups of Joe may reduce the risk of many ailments including memory loss, diabetes,3 cancer and even early death.4

For this study, researchers at Tianjin Medical University in China studied the coffee-drinking habits and health of 365,682 men and women between the years 2006 and 2020. They evaluated these study participants using data stored at the UK Biobank. Over the study period, 5,079 of these folks developed dementia and 10,053 experienced at least one stroke.5

Coffee drinkers, however, had the lowest incidence of these health problems.

Coffee Drinking Linked to a Healthier Heart and Brain 

The Chinese research team found that among individuals aged 50 to 75, those who drank two to three cups of coffee per day had the lowest incidence of stroke and dementia.

Indeed, those who drank more coffee had a 32 percent lower risk of stroke and a 28 percent lower risk of dementia, compared with those who did not drink coffee at all.

But what about tea drinkers? Good news there, as well…

The researchers found that drinking three to five cups of tea per day also dramatically lowered the risk of stroke and dementia at the same rates of 32 percent and 28 percent respectively. The same held true for those who enjoyed both beverages—drinking a combined four to six cups of coffee and tea per day. Additionally, the study found that combined coffee and tea consumption lowered the risk of post-stroke dementia.

Understanding Coffee and Tea’s Brain Health Benefits 

At first blush, one would point to the caffeine component as the active ingredient providing these heart and brain health benefits. While this is partially true, experts say caffeine certainly doesn’t account for all of the health benefits of these beverages.

For one thing, both coffee and tea are derived from plants with plenty of beneficial compounds and antioxidants outside of caffeine.

One such compound is flavonoids– a category of antioxidant associated with a reduced risk of Alzheimer’s disease. Foods rich in flavonoids include apples, pears, spinach, and you guessed it… coffee and tea.

“These phytonutrients — chemicals that plants produce to keep themselves healthy — can actually reduce inflammation in our brains, protect brain cells from injury, support learning and memory, and deliver other obvious benefits for brain health,” said Dr. Scott Kaiser, the director of Geriatric Cognitive Health at Providence Saint John’s Health Center in Santa Monica, California.6

While there are limitations to this self-reported study, the authors wrote that “our findings suggested that moderate consumption of coffee and tea, separately or in combination, were associated with lower risk of stroke and dementia.”

But why then was coffee ever considered dangerous to your health?

Coffee, Toxins and Cancer 

For years the WHO and other health experts warned that coffee can cause cancer. That’s because acrylamide, a chemical compound produced naturally in the roasting of coffee beans, is a toxin. Acrylamide is also produced when foods are fried or cooked at very high temperatures.

However, the WHO changed its mind in 2016 after its International Agency for Research on Cancer (IARC) reviewed more than 1,000 human and animal studies and concluded that coffee is not causing cancer.7

Dr. Dana Loomis, the IARC official who was responsible for the evaluation, says that the body of scientific evidence on coffee had become much stronger since 1991, when the IARC first classified coffee as a possible carcinogen. Dr. Loomis and his team say they “found no conclusive evidence for a carcinogenic effect of drinking coffee.”

Since then, numerous studies have suggested that coffee actually decreases cancer risks. For instance:

  • One 2017 review discovered that a daily cup of coffee is associated with a reduced risk of liver cancer and endometrial cancer.
  • A study from the Dana-Farber Cancer Institute found that regular consumption of caffeinated coffee may help prevent the return of colon cancer after treatment and improve the chances of a cure.8 Additional research found that coffee was associated with lower risk of death after being diagnosed with colorectal cancer.
  • And a 2018 review found that drinking four cups of coffee per day was associated with a lower risk of postmenopausal breast cancer.

Of course, that doesn’t mean that you should sit around drinking coffee all day long.

The Downsides of Caffeine 

You don’t have to be a scientist to know there are downsides to drinking large amounts of coffee—that’s the caffeine. The number one health drawback of caffeine is how it affects sleep, of course. Some of us are more sensitive to the effects of caffeine than others, and these sensitivities may increase with age.

In his book, Caffeine, writer Michael Pollan calls caffeine “the enemy of good sleep” because studies show that it interferes with deep sleep.

If you count yourself a caffeine-sensitive person, then lay off the coffee and stick to teas that have little to no caffeine. Another option is to relegate your caffeine consumption to the early morning hours, when it’s less likely to disturb sleep.

You can also choose decaf coffee—which is not without its health benefits. As with caffeinated beverages, the flavonoids can help fight inflammation in the body and the brain.

Whatever and whenever you decide to drink– coffee or tea– just make sure you stay away from those sugar laden specialty drinks that can negate all of the beverage’s positive benefits.


  1. https://www.sciencedaily.com/releases/2021/11/211116144813.htm 
  2. https://www.iarc.who.int/wp-content/uploads/2018/07/pr244_E.pdf 
  3. https://pubmed.ncbi.nlm.nih.gov/24150256/ 
  4. https://www.ahajournals.org/doi/pdf/10.1161/CIRCULATIONAHA.115.017341?sid=5c4b9ef3-96dd-
    44b8-8188-0a3ca2ec8c9d 
  5. https://www.ukbiobank.ac.uk 
  6. https://www.pacificneuroscienceinstitute.org/people/scott-kaiser/ 
  7. https://www.npr.org/sections/thetwo-way/2018/03/30/598348764/fact-check-calif-judge-rules-
    coffee-must-come-with-a-cancer-warning-but-should-i 
  8. https://www.wsj.com/articles/world-health-organization-to-drop-coffees-status-as-possible-
    carcinogen-1465946753