Older people who regularly drink coffee are at lower risk of developing dementia, a new study suggests. But there’s a flip side to the story: The association only applies to unsweetened, caffeinated coffee.
The link was discovered from a study of the medical records of 204,847 people in the United Kingdom, aged 40 to 69 at the start of the study period, by researchers from institutions across China. The records included both coffee drinking habits and diagnosis of dementia cases, over an average of nine years.
“Higher consumption of caffeinated coffee, particularly unsweetened coffee, was associated with reduced risks of Alzheimer’s disease and related dementias, as well as Parkinson’s disease,” the researchers write in their paper. published. “No such association was observed for sweetened or artificially sweetened coffee.”
To help do the math, the researchers used participants’ reports of their coffee consumption to divide them into five groups: non-coffee consumers, 0 to 1 cup per day, 1 to 2 cups per day, 2 to 3 cups per day, and more than 3 cups per day.
It is this latter group that presents the greatest statistical significance. But overall, compared to non-coffee drinkers, coffee drinkers, regardless of quantity, were at least 34% less likely to develop Alzheimer’s disease and related diseases, 37% less likely to develop Parkinson’s disease and 47% less likely to die from a neurodegenerative disease. during the study.
However, the coffee had to be unsweetened and caffeinated for these associations to hold. Researchers believe that certain properties of caffeine may protect the brain against dementia – and perhaps sugar and artificial sweeteners interfere with caffeine’s benefits – but more studies will be needed to know for sure.
“Multiple mechanisms suggest a potential link between unsweetened and caffeinated coffee consumption and neurodegenerative diseases,” the researchers write.
The data presented here are not comprehensive enough to show a direct causal relationship. It is not clear whether coffee consumption prevents dementia, whether early stages of dementia alter coffee consumption, or whether there is a third, unknown factor affecting both coffee consumption and dementia risk.
It is likely that many different factors are at play, given the complexity of the brain and neurodegenerative diseases.
But these findings about the health benefits of coffee didn’t come out of nowhere: Previous studies have shown that coffee could prevent dementia from getting worse and possibly extend our lives by additional years. However, the association seems to depend on how much we have available and when we tend to drink it.
For example, data suggests that there is some sort of relationship between coffee ingredients and cognitive decline, particularly caffeine.
“Adding sugar or artificial sweeteners to coffee may have harmful effects and should be approached with caution,” the researchers write. “Instead, the recommendation leans toward drinking unsweetened, caffeinated coffee.”
The research was published in the American Journal of Clinical Nutrition.
