As a staple in our daily lives, coffee is most people’s primary source of caffeine. Coffee and caffeine have poured themselves so thoroughly into our routine that it’s easy to forget that it serves as a drug first and foremost. With 90% of Americans consuming some kind of caffeine on a daily basis, it is the world’s most commonly used drug.
Caffeine has long been known to affect our cognition, used by most to jump start their morning and keep yawning at bay. However, caffeine’s benefits might not be limited to just keeping us awake. Recent research suggests that regular caffeine intake can protect memory and reduce the likelihood of developing age-related diseases.
Caffeine and memory
The effect of caffeine on memory has been extensively researched on people of all ages. A particular focus in recent years has been the effect of caffeine on older adults, especially those at risk of MCI (mild cognitive impairment).
With age, many adults experience better memory in the mornings and notice a decline as the day progresses. One study found that participants over the age of 65 who drank caffeinated coffee both in the morning and afternoon had no performance difference between memory tasks taken at both times, whereas those who drank decaffeinated coffee in the morning and again in the afternoon displayed a degraded performance as the day progressed.
Caffeine has also been tied to long-term memory. Those who consumed 200mg of caffeine (the equivalent of two espressos) after studying a set of images were significantly better at remembering them 24 hours later compared to those who had had no caffeine after the task.
Caffeine and cognitive decline
Researchers have found promising evidence that regular caffeine intake may protect against cognitive impairment. The Women’s Health Initiative, a study of more than 6,000 women over 10 years, found that women who consumed an average of 261mg of caffeine per day (the equivalent of two to three cups of coffee) were far less likely to have developed dementia or any other form of cognitive impairment compared to women who drank less than 64mg per day on average (less than one cup of coffee).
Further research has found that those who drank 3-5 cups of coffee per day at midlife decreased their risk of later developing dementia and Alzheimer’s by 65%.
For those who have already developed MCI, no participant who had blood caffeine levels greater than 1200ng/ml (the equivalent of having a few cups of coffee) progressed to dementia over a four year time period. Comparatively, the normal rate of conversion from MCI to dementia is between 5-10% per year. Those with MCI who progressed to dementia by the end of the study had half the blood caffeine levels as those who remained stable.
How caffeine might impact the brain
Given the evidence, researchers have endeavoured to identify what it is about caffeine that could protect against cognitive decline. Chronic inflammation has been identified as a cause for most non-communicable diseases of aging, including Alzheimer’s. Researchers at Stanford University recently identified that caffeine directly blocks the inflammatory mechanism from activating. Specifically, they identified cluster of genes associated with the production of an inflammatory protein called IL-1-beta. Those who drank caffeine had low levels of this gene cluster and they were both significantly more likely to have low blood pressure and to live past 93.
All things in moderation
Caffeine can be found in many forms, from sodas to tea. However, most research on the benefits of caffeine has been done with coffee. If you’re looking to add caffeine to your diet, we discourage turning to sources high in sugars such as colas and energy drinks.
It seems that moderate daily caffeine intake, the equivalent of two to three cups of coffee, can be beneficial to brain health. However, the FDA does not recommend having more than 600mg of caffeine per day, which is about four to seven cups of coffee. Caffeine does act as a diuretic, which means it causes the body to get rid of water, so you should make sure to drink enough water throughout the day to prevent dehydration. Finally, although a number of studies have shown promising results, caffeine is not a silver bullet when it comes to Alzheimer’s prevention. If you want to protect your brain health, you should consider the full range of lifestyle changes scientifically proven to support cognitive function.