Coffee

• Drinking two to three cups of caffeinated coffee daily was linked to a lower risk of dementia.

• The findings come from a long-term study of more than 130,000 people.

• Decaffeinated coffee did not show the same association with brain health.

If your day doesn’t really start until that first cup of coffee, there may be some encouraging news. 

A large new study suggests that moderate coffee consumption — specifically about two to three cups a day — may be linked to a lower risk of developing dementia later in life. 

The research adds to a growing body of evidence exploring how everyday habits might influence long-term brain health. But before you start refilling your mug, it’s important to note: this study shows a connection, not a cause-and-effect relationship. 

“When searching for possible dementia prevention tools, we thought something as prevalent as coffee may be a promising dietary intervention — and our unique access to high-quality data through studies that have been going on for more than 40 years allowed us to follow through on that idea,” senior author Daniel Wang said in a news release. 

“While our results are encouraging, it’s important to remember that the effect size is small and there are lots of important ways to protect cognitive function as we age. Our study suggests that caffeinated coffee or tea consumption can be one piece of that puzzle.”

The study

To understand the link between caffeine and cognitive health, researchers analyzed data from more than 131,000 participants across two long-running U.S. studies. Participants regularly reported their coffee and tea intake over time, and researchers tracked who developed dementia, along with changes in memory and thinking skills. 

The study followed people for up to 40 years, making it one of the more comprehensive looks at diet and brain health. Over that period, more than 11,000 cases of dementia were documented. 

Researchers also accounted for a range of factors that could influence results, including lifestyle habits, overall diet, and health conditions. By adjusting for these variables, they aimed to isolate the potential role of caffeinated beverages in cognitive outcomes. 

What the results actually showed

The findings point to a clear pattern: people who consumed more caffeinated coffee tended to have a lower risk of dementia compared to those who drank little or none. 

The most noticeable benefit appeared at moderate intake levels — about two to three cups of coffee per day. At that level, participants showed lower rates of dementia and slightly better cognitive performance measures. 

“We also compared people with different genetic predispositions to developing dementia and saw the same results — meaning coffee or caffeine is likely equally beneficial for people with high and low genetic risk of developing dementia,” lead author Yu Zhang said in the news release. 

Interestingly, the same wasn’t true for decaffeinated coffee, which showed no meaningful association with dementia risk. Tea showed similar trends to caffeinated coffee, suggesting caffeine itself may play a role.

Still, researchers emphasize that the effect was modest, and coffee alone isn’t a guaranteed way to protect your brain. Instead, it may be just one piece of a much larger puzzle when it comes to maintaining cognitive health over time. 

If nothing else, this study offers a reassuring takeaway for coffee drinkers: your daily habit might be doing a little more than just helping you power through the morning.

If you’ve ever contemplated whether or not you should have that second – or third – cup of coffee, the results from a new study might convince you to do just that. 

A new study recently published in the Endocrine Society’s Journal of Clinical Endocrinology & Metabolism found that healthy adults who consume 200-300 mg of caffeine every day – or two to three cups of coffee – could lower their risk of cardiometabolic multimorbidity.

According to the researchers, cardiometabolic multimorbidity occurs when patients are diagnosed with more than one cardiometabolic disease such as type 2 diabetes, coronary heart disease, or stroke.  

“Consuming three cups of coffee, or 200-300 mg of caffeine, per day might help to reduce the risk of developing cardiometabolic multimorbidity in individuals without any cardiometabolic disease,” said researcher Dr. Chaofu Ke. “The findings highlight that promoting moderate amounts of coffee or caffeine intake as a dietary habit to healthy people might have far-reaching benefits for the prevention of cardiometabolic multimorbidity.” 

The benefits of coffee

For the study, the researchers analyzed data from approximately 360,000 participants enrolled in the U.K. Biobank. The participants answered questionnaires about their daily caffeine intake, and the researchers analyzed their health records. None of the participants had a history of cardiometabolic issues when the study began. 

Overall, coffee drinkers proved to have a lower risk of cardiometabolic multimorbidity. 

Those who drank three cups per day had a 48% lower risk of cardiometabolic multimorbidity compared to those who drank no coffee and those who drank less than 100 mg of caffeine per day. Similarly, those who had 200-300 mg of caffeine per day had an over 40% lower risk of developing cardiometabolic multimorbidity. 

The researchers explained that this study marks the first time it’s been proven that coffee, tea, or caffeine intake can lower the risk of cardiometabolic multimorbidity – not just individual cardiometabolic diseases. 

Additionally, they noted that while any cardiometabolic disease increases the risk of morbidity, cardiometabolic multimorbidity increases the risk of death from any cause by as much as seven times. 

Previous studies have already shown that there are some health benefits associated with drinking coffee. Now, a new study conducted by researchers from Johns Hopkins Medicine has discovered an additional health benefit connected to the beverage. 

According to their findings, coffee drinkers may have a lower risk of developing acute kidney injuries (AKIs) when compared to non-coffee drinkers. 

“We already know that drinking coffee on a regular basis has been associated with the prevention of chronic and degenerative diseases including type 2 diabetes, cardiovascular disease, and liver disease,” said researcher Dr. Chirag Parikh. “We can now add a possible reduction in AKI risk to the growing list of health benefits for caffeine.” 

Benefits of drinking coffee

For the study, the researchers analyzed data from over 14,200 participants between the ages of 45 and 64 who were enrolled in the Atherosclerosis Risk in Communities Study. Participants were surveyed seven times over the course of two and a half decades to determine how many cups of coffee they typically drank each day; the team then tracked the participants’ health outcomes over the course of the study. 

The team identified a link between coffee consumption and a lower risk of AKIs. Drinking any amount of coffee was associated with a 15% lower risk of kidney injuries. When the team accounted for health factors that may make AKIs more likely -- such as diabetes status, high blood pressure, and high body mass index scores (BMI) -- coffee drinkers still had an 11% lower risk of kidney injuries. 

“We suspect that the reason for coffee’s impact on AKI risk may be that either biologically active compounds combined with caffeine or just the caffeine itself improves perfusion and oxygen utilization within the kidneys,” said Dr. Parikh. “Good kidney function and tolerance to AKIs is dependent on a steady blood supply and oxygen.” 

The team plans to do more work in this area to understand how different caffeinated beverages affect consumers’ kidney health and to get a better idea of the precise ways that coffee affects AKIs. 

“Caffeine has been postulated to inhibit the production of molecules that cause chemical imbalances and the use of too much oxygen in the kidneys,” Dr. Parikh said. “Perhaps caffeine helps the kidneys maintain a more stable system.” 

A new study conducted by researchers from the American College of Cardiology discovered good news for avid coffee drinkers. Their work showed that drinking two to three cups of coffee every day may be linked with a lower risk of heart disease and a greater chance of longer life. 

“Because coffee can quicken heart rate, some people worry that drinking it could trigger or worsen certain heart issues. This is where general medical advice to stop drinking coffee may come from. But our data suggest that daily coffee intake shouldn’t be discouraged, but rather included as a part of a healthy diet for people with and without heart disease," said researcher Dr. Peter M. Kistler.

"We found coffee drinking had either a neutral effect – meaning that it did no harm – or was associated with benefits to heart health.” 

Heart health benefits

For the first part of the study, the researchers analyzed 10 years' worth of data from over 382,000 people enrolled in the U.K. Biobank. Participants answered questions about how much coffee they drank on a daily basis, and the researchers compared that with their incidence of heart disease, including heart attack and stroke, arrhythmias, and coronary artery disease. None of the participants had a history of heart disease when the study began. 

The study showed that regularly drinking two to three cups of coffee per day was linked to a lower risk of heart disease. Participants who fell into this group were 10% to 15% less likely to develop heart failure, coronary heart disease, heart disease-related death, or arrhythmia. Additionally, one cup of coffee per day was linked with a lower risk of stroke. 

In a second study, the researchers analyzed data from nearly 35,000 people who had a history of heart disease to understand how coffee affected their health outcomes. Their work showed that drinking coffee didn’t worsen heart problems, and participants had a lower mortality risk when they drank two to three cups per day. 

Experts say there are many ways that coffee can promote better heart health. They point out that the compounds found in coffee may work to reduce inflammation, boost metabolism, improve insulin sensitivity, and reduce oxidative stress. 

“There is a whole range of mechanisms through which coffee may reduce mortality and have these favorable effects on cardiovascular disease,” Kistler said. “Coffee drinkers should feel reassured that they can continue to enjoy coffee even if they have heart disease. Coffee is the most common cognitive enhancer – it wakes you up, makes you mentally sharper, and it’s a very important component of many people’s daily lives.”