Drinking 4 to 6 cups of coffee and tea a day may reduce risk of stroke and dementia, study says

• Coffee and tea have both been found to have several protective effects on health.
• A massive study showed drinking either brew can be tied to a brain health benefit.

Coffee and tea drinkers can unite over a recent study that showed both drinks may benefit long-term brain health.

The study, a peer-reviewed paper published in PLOS Medicine, found that older adults who had two or three cups of coffee or tea a day — or a combination of both for four to six cups a day — had a lower risk of dementia or stroke compared to those who did not imbibe.

Researchers followed up with more than 360,000 participants in the UK Biobank, a population health database, over 10 to 14 years. They focused on adults aged 50 to 74 and ruled out anyone who had a stroke or dementia prior to the study.

Those who drank two to three cups of coffee, three to five cups of tea, or a combination of both had the lowest risk of dementia or stroke out of all levels of consumption. Compared to those who didn't drink coffee or tea at all, those in the two to three cup range had a 32% lower risk of stroke and a 28% lower risk of dementia.

Coffee drinkers also had a lower risk of developing dementia after a stroke, but those who only drank tea did not see the same effect.

Both coffee and tea usually contain some amount of caffeine. Past studies have shown the stimulant may have a protective effect on the brain; however, the coffee drinkers group in the Biobank study included those who preferred decaf.

Coffee and tea also share similar polyphenols, a family of micronutrients naturally found in plants. It's possible that this polyphenol profile, or the common antioxidants between the two beverages, could be protective against brain degeneration and other health problems.

The study authors cautioned that the relationship between coffee, tea, and brain health is not causal. In other words, drinking copious amounts of coffee and tea won't prevent you from having a stroke or developing dementia.