Guest post by Colin McArdle

Whether you take it with two sugars, black, extra cream, or decaf, coffee is an essential part of many people’s morning routines. It’s almost instinctual—brew a pot or visit your favorite café to start the day. In fact, some of you reading this might be sipping a warm mug right now.

We know why coffee is so popular: it helps us feel more awake and alert. But have you ever wondered how it does that—or whether its effects go beyond just boosting energy?

Here’s where it gets really interesting: recent research suggests that caffeine—the key ingredient in coffee—might also play a protective role in long-term brain health. Specifically, scientists are investigating whether coffee could help reduce the risk of Alzheimer’s disease. Let’s explore how that morning cup of joe might do more than just get you through your 9 a.m. meeting.

How Does Caffeine Make Our Brains Feel More “Awake”?

If you search “caffeine” on Google, you’ll quickly learn that it boosts brain activity and helps us feel more energized. But how exactly does it do that? The answer lies in a brain chemical called adenosine. Adenosine builds up in the brain throughout the day, gradually making us feel tired and ready for sleep. It works by binding to specific receptors on neurons, which slows down brain activity and promotes drowsiness. In short, adenosine is your brain’s natural signal that it’s time to rest.

Now, how does caffeine play into this interaction between the brain, sleepiness, and adenosine? Long story short, caffeine can block and prevent the actions of adenosine. How does that work? Caffeine has a very similar chemical structure to adenosine, which allows it to take the spot on receptors that are originally meant for adenosine compounds. Since adenosine now has trouble decreasing brain activity when caffeine is on board, the body feels less tired and fatigued throughout the day (1).

Can Coffee Be the Missing Link for an Alzheimer’s Cure? 

Although there are several medications currently available to treat Alzheimer’s disease, scientists continue to search for more effective—and accessible—ways to alleviate its symptoms. Surprisingly, some of these potential treatments can be found right in your kitchen. Compounds like vitamin C in oranges and capsaicin in chili peppers have shown therapeutic benefits in early studies. But what if one of the most promising tools was already brewing in your morning coffee pot? Emerging research suggests that caffeine itself may help slow the progression of Alzheimer’s symptoms and underlying brain changes.

So how did scientists investigate the idea that coffee might protect against Alzheimer’s? A 2021 study set out to explore whether caffeine consumption was linked to the rate of cognitive decline in older adults. Researchers followed 227 participants, all around the age of 70, and grouped them based on their daily coffee intake: low (0–26 mg/day), moderate (36–250 mg/day), and high (360–750 mg/day). Over a period of 10 years, participants completed a battery of neuropsychological tests every 18 months to track changes in cognitive abilities—including memory, attention, language, processing speed, and executive function. They also completed the AIBL Preclinical Alzheimer Cognitive Composite (AIBL PACC), a sensitive tool used to detect early signs of Alzheimer’s-related cognitive decline.

After the 126-month study period, the researchers concluded that higher levels of coffee consumption were linked to better cognitive performance and a reduced risk of significant cognitive decline. In particular, greater caffeine intake was associated with improvements in executive function and attention. Results from the AIBL PACC further revealed that participants who consumed more coffee were less likely to progress from a cognitively normal state to a cognitively impaired one (2).

These findings naturally led neuroscientists to the next big question: What is caffeine actually doing in the brain to lower the risk of Alzheimer’s disease? One major suspect is a key hallmark of the disease—amyloid beta (Aβ) plaques. These sticky protein clumps build up in the brain, much like grease clogging a drain. Over time, they disrupt communication between brain cells and contribute to memory loss and other cognitive impairments.

To test the relationship between coffee and Aβ plaque buildup, a 2019 study examined 411 participants and measured their brain levels of amyloid beta. The results were striking: individuals who drank more than two cups of coffee per day showed significantly lower levels of Aβ plaques than those who drank less than two cups per day (3).

Over the past several years, scientists have uncovered growing evidence that caffeine may offer more than just a temporary jolt of energy. By blocking adenosine receptors, boosting executive function and attention, and even lowering amyloid beta plaque buildup in the brain, caffeine might support long-term cognitive health and reduce Alzheimer’s risk.

Of course, more research is needed to fully understand the relationship between caffeine and Alzheimer’s disease. But in the meantime, moderate coffee consumption—1 to 2 cups per day—may be a simple and accessible way to support your brain.

So next time you reach for that latte or espresso shot, know that you might just be doing your future self a favor.

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Colin is a neuroscience PhD student at Wake Forest University. His research focuses on the role of inhibitory GABAergic receptors in a preclinical model of Alzheimer’s disease. Outside of the lab, Colin enjoys cooking, crafting, and DIY interior design projects. 

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References:

(1)Reichert CF, Deboer T, Landolt HP. Adenosine, caffeine, and sleep-wake regulation: state of the science and perspectives. J Sleep Res. 2022 Aug;31(4):e13597. doi: 10.1111/jsr.13597. Epub 2022 May 16. PMID: 35575450; PMCID: PMC9541543.

(2) Gardener SL, Rainey-Smith SR, Villemagne VL, Fripp J, Doré V, Bourgeat P, Taddei K, Fowler C, Masters CL, Maruff P, Rowe CC, Ames D, Martins RN and the AIBL Investigators (2021) Higher Coffee Consumption Is Associated With Slower Cognitive Decline and Less Cerebral Aβ-Amyloid Accumulation Over 126 Months: Data From the Australian Imaging, Biomarkers, and Lifestyle Study. Front. Aging Neurosci. 13:744872. doi: 10.3389/fnagi.2021.744872

(3) Kim, J.W., Byun, M.S., Yi, D. et al. Coffee intake and decreased amyloid pathology in human brain. Transl Psychiatry 9, 270 (2019). https://doi.org/10.1038/s41398-019-0604-5