Caffeine reduces dementia risk according to a huge study published today in JAMA. Investigators at Harvard University analyzed the caffeine intake of 131,821 individuals (86,606 females, and 45,215 males) with a follow-up of up to 43 years. The researchers collected mounds of evidence indicating that consuming higher levels of caffeine (from coffee, tea, and other beverages) reduces the risk of dementia.
Admittedly, the positive effects weren’t humongous, but they were significant. Higher caffeinated coffee intake was associated with a lower dementia risk (141 vs 330 cases per 100 000 person-years when comparing the highest quartile of caffeine consumption with the lowest quartile).
Alzheimer’s disease, the most common cause of dementia, currently affects more than 7 million people in the US (see here), so, if my back-of-the-envelop calculation is correct, more than 13,000 of those patients might have warded off their disease had they consumed more caffeine.
Higher caffeine consumption over those long periods also was associated with modestly better cognitive function. There are a number of reasons why caffeinated beverages may have these modest therapeutic effects. For example, in addition to caffeine, coffee contains other bio-active compounds, such as polyphenols, that along with caffeine may offer neuroprotection by reducing oxidative stress and inflammatory effects on the brain. I’ve written about promising polyphenols such as resveratrol and pterostilbene before (see here, and here).
Other side of the coin
As everyone knows, there also are possible side effects of caffeine. For a discussion of these potential drawbacks, as well as other possible benefits of this ubiquitous chemical, see here. I’ll close by acknowledging that I have consumed considerable caffeine over my life. For years I brewed 7 cups every morning and rarely did a single drop remain in my pot by late afternoon. I modulated my intake about a year ago. Now I brew only 6 cups daily. Whether related to my caffeine consumption, or not, I’ll add that I haven’t been diagnosed with dementia, but I concede that my cognitive function has been sliding downhill for decades.
So many plus/minus coffee studies! Who is paying for these? Is this similar to the back and forth for diet?
https://youtu.be/5Ua-WVg1SsA?si=w2IHAkKImkbQn2yk
You’re right. Research findings are widely scattered regarding the benefits/undesirable side-effects of coffee and caffeine. This is not uncommon in science because results often are determined partly by what researchers are looking for. Looking for heart palpitations or upset stomachs? You may find some. Looking for changes in mood, or states of alertness? You may find some. To top it off, and I say this from my years of laboratory experience, the quality of research varies widely. Often even scientists in the same field cannot determine how carefully an investigation in another laboratory was performed, how solid the published results are. Finally, to answer your question, this coffee study was funded by various grants from the National Institutes of Health, which of course is, in turn, funded by us taxpayers.
At 94 you are still one of the brightest people I know dad, so sliding downhill might be an over estimate. Maybe a slight decline that is 100% normal with aging? 🙂
Cheers (with my coffee mug)!
Thank you, dear daughter, but you don’t have the experiences with my inoperative neurons that I have. Those withered little rascals delay the retrieval, or completely black out, volumes of what once was instantly-available information. And they frequently disconnect names from faces. Nonetheless, I do accept these changes as a normal part of aging. I even feel remarkably lucky to remain alert on this planet, to continue enjoying life, to still derive pleasure from stringing words together into sentences.