Go ahead, get that refill.
Starting your day – or your afternoon – with coffee or tea may be giving you additional benefits beyond just a little more energy or focus. In a peer-reviewed study published in PLOS Medicine, more than 365,000 study participants age 50 to 75 (who self-reported how much they drank) were followed for more than a decade, and the results are in: Those who consumed coffee or tea each day had the lowest risk of stroke or dementia.
“Compared with those who did not drink tea and coffee,” the study reports, “drinking two to three cups of coffee and two to three cups of tea per day was associated with a 32% lower risk of stroke and a 28% lower risk of dementia.”
The study also sought to evaluate any differences in coffee alone or in combination with tea consumption each day.
“We found that drinking coffee and tea separately or in combination were associated with lower risk of stroke and dementia,” the team wrote. “Intake of coffee alone or in combination with tea was associated with lower risk of poststroke dementia.”
As two of the most popular beverages across the world, researchers at UK Biobank – a large biomedical database and research hub with access to health statistics of half a million U.K. participants – have been evaluating the health effects of caffeine, antioxidants, flavonoids and other bioactive compounds found in both coffee and tea. The two beverages have already been found to reduce mortality rates in patients with type 2 diabetes in an earlier study from Japan, and this new large-scale study appears to reinforce the power of coffee and tea, especially as people age.
“Preventing the risk of stroke and dementia is particularly important,” the study authors wrote. “Despite advances in understanding the pathophysiology of stroke and dementia, clinical treatment of stroke and dementia continues to be suboptimal. Therefore, identifying the preventable risk factors for stroke and dementia is of high priority. Our findings raise the possibility of a potentially beneficial association between moderate coffee and tea consumption and risk of stroke and dementia, although this study cannot establish a causal relationship.”
The potential decreased risk of poststroke dementia from drinking coffee (or in combination with tea) was especially critical because it’s believed a stroke doubles a person’s risk of dementia. Poststroke dementia has been shown to develop in 30% of stroke survivors, and the risk of new onset dementia increases dramatically over time for stroke victims—from 7% after the first year to 48% after 25 years.
Researchers believe the brain benefits are a result of the increased production of granulocyte-colony stimulating factor (G-CSF), which is believed to help the growth of neurons and neural stem cells. Unfortunately, for the decaf drinkers out there, the benefit only extends to caffeinated coffee, writes the UK Alzheimer’s Society:
“Intriguingly, this effect is not seen with caffeine alone or decaffeinated coffee, suggesting that there could be a combination effect between caffeine and an unknown compound in coffee.” So, while researchers are hesitant to say the popular hot beverages will, in fact, prevent a stroke or dementia later in life, this promising study may help you enjoy your next cup a little more.