If you’re concerned that sometimes you follow your morning cup of coffee with a second cup or third cup, a new study may make you feel better about that habit. Participants who drank coffee, tea, or a combination of the two had a lower risk of stroke and dementia, and the risk was reduced the most for those who drank two to three cups of coffee or three to five cups of tea.
Although this study didn’t prove that coffee or tea was the reason cases of stroke and dementia were lower in this population, the association is believable. Several studies have found an association between caffeine consumption and decreased risk of stroke, dementia, Alzheimer’s disease, and Parkinson’s disease.
That’s good news to many of us, given that overall tea and coffee consumption shows an incline with the average person downing just over three cups a day.
Today we have increased incidence of strokes and dementia reported in the country. Approximately seven out of eight strokes are ischemic strokes which occur when something blocks blood supply to part of the brain, whereas a hemorrhagic stroke is when a blood vessel in the brain ruptures. Dementia is a general term for an impaired ability to remember, think, or make decisions that interferes with daily life and activities, with Alzheimer’s disease being the most common type.
To examine how coffee or tea may impact the risk of stroke and dementia, international investigators studied over three lakh participants between ages 50 and 74 between 2006 and 2010 and followed until 2020. During the study period, 5,079 people developed dementia and 10,053 experienced at least one stroke.
A small study published in 2016 found that over-the-counter anti-wrinkle creams containing hyaluronic acid decreased the depth of wrinkles around the lips and eyes by 10% to 20% over a three-month period. Skin tightness also improved by 13% to 30%.
Coffee and tea intake were reported by the participants at the start of the trial. After adjusting for many factors that could influence stroke or dementia risk, including sex, age, ethnicity, body mass index, physical activity, smoking status, and previously existing health conditions, investigators found the following:
People who drank two to three cups of coffee, or three to five cups of tea per day, or a combination of four to six cups of coffee and tea had the lowest incidence of stroke or dementia.
Two to three cups of coffee with two to three cups of tea daily was associated with a 32% lower risk of stroke and a 28% lower risk of dementia compared with people who drank neither coffee nor tea.
Coffee alone or in combination with tea was associated with lower risk of post-stroke dementia. Post-stroke dementia is a condition where symptoms of dementia occur after a stroke.
Researchers acknowledged limitations in the research. Relatively few people developed dementia or stroke during the study period, which can make it difficult to extrapolate rates accurately to larger populations. In addition, the trial was observational, and although coffee and tea consumption were associated with a lower incidence of dementia, stroke, and post-stroke dementia, the study wasn’t set up to prove causality.
Although cause and effect hasn’t been established, one possible explanation could be related to caffeine’s stimulating effect on the brain, which in turn impacts our mood and makes us more alert. Stroke and dementia are both brain disorders; increased brain excitability may impact brain reserve and delay dementia, experts suggest.
Previous studies have shown that coffee was associated with a decreased risk of heart failure. There is evidence that heart failure is associated with an increased short-term and long-term risk of stroke.
Drinking up to 400 milligrams of caffeine a day isn’t associated with negative or dangerous health effects. The average cup of green or black tea has 30 to 50 mg of caffeine, and a regular cup of coffee has about 80 to 100 mg.
But you can have too much of a good thing — too many cups of coffee or tea can cause insomnia, jitters, anxiousness, and an upset stomach. And keep in mind that the recommendations for coffee are for black coffee, experts warn that many coffee-based drinks have a lot of added fats and sugar and are high in calories.