3-5 cups of coffee a day linked to longer life
By Our reporter
For most people, moderate coffee intake offers health benefits, including decreased mortality and decreased risk for some diseases like cardiovascular disease, and type 2 diabetes.
There are still factors to consider, such as caffeine intake during pregnancy, decaffeinated drinks, and more research is needed.
A review published in Nutrients discusses much of these questions and the currently available information on coffee, including how it decreases mortality risk and risk for several diseases.
It also discusses coffee’s impact on well-being, the possible mechanisms responsible for its effects, coffee additives, areas of concern, and future research.
The review notes that many cohort studies show that drinking coffee is linked to decreased mortality rates. One particular study found that drinking at least 2 cups of coffee a day was linked with a 10–15% lower risk of overall mortality.
A 2019 meta-analysis found the association was nonlinear, with the lowest all-cause mortality risk at drinking three and a half cups of coffee daily.
Decaf and caffeinated coffee may both decrease mortality risk. The mortality reduction may also be true for all coffee types.
Next, the review discussed cause-specific morbidity and mortality. Drinking three to five cups of coffee daily may decrease the risk for cardiovascular disease by around 15%. Evidence also supports that coffee likely doesn’t increase risk for cancer and may help decrease the risk for some cancer types, like endometrial cancer.
Coffee might also decrease the risk of injuries and accidents. The authors note that coffee increases alertness and contributes to higher mobility.
It may decrease risk for chronic respiratory problems and respiratory disease mortality. Coffee may decrease risk for type 2 diabetes, and this likely applies to decaf and regular coffee.
For people with diabetes, one meta-analysis found that coffee may decrease risk for cardiovascular events, cardiovascular mortality, and overall mortality.
Coffee may benefit the liver, but the impact is likely not as substantial as experts previously thought. It may also decrease the risk of kidney problems such as chronic kidney disease.
Drinking coffee may decrease the risk of cognitive disorders by 25%, and this is a non-linear relationship. Regular coffee and caffeine consumption may also decrease the risk for Parkinson’s disease and its progression.
3 to 5 cups of coffee a day
Finally, the authors cite a large umbrella review which concluded that coffee is overall linked to benefits over harm, with likely the most benefit from drinking three to four cups a day.
Researchers further discussed some well-being outcomes. Coffee may help with hydration, although in some instances it may increase urine output. Coffee with caffeine may enhance exercise performance, mental acuity, and senses like vision. It may also help with the return of bowel function in some instances after bowel surgery.
Some data also suggests that coffee may decrease the risk for depressive symptoms and perceived stress.
Coffee’s health benefits and caveats
The authors suggest that coffee helps balance glucose, such as how caffeinated coffee may help improve glucose tolerance. Caffeinated coffee may help increase people’s activity levels, contributing to benefits like lower body mass index.
People who consume caffeine, including in coffee, before exercise may experience an uptick in fat oxidation. It may contribute to better lung function for some people; smoking may mask benefits.
The review notes that the lung benefit could be related to the caffeine metabolites paraxanthine and theophylline. Finally, it may help reduce inflammation and immune response.
Do additives in coffee cause any harm?
Next is the question of coffee additives. Some research suggests that adding sugar might cancel out coffee’s benefits. One study suggests that adding sugar to coffee may increase the risk of depression.
Another suggests that sugar may counteract the possible benefits of regular and decaf coffee on weight gain. However, this study found that adding cream or coffee whitener was not linked to greater weight gain.
Decreased mortality risk might stay for small amounts of sugar and fat, but adding more may cancel it out. Some evidence supports that the health benefits may stay, even if coffee is sweetened.
Finally, there are the possible drawbacks of coffee. Consuming coffee may contribute to getting less sleep, but the timing of drinking it may help avoid this. While coffee might lead to short-term blood pressure spikes, research supports that there isn’t a long-term risk and that it might help lower blood pressure.
Similarly, the data support that moderate caffeine and coffee intake likely doesn’t increase risk for abnormal heart rhythms. One trial studying high caffeine doses suggests caffeine doesn’t induce arrhythmias.
There are possible confounding factors in some research on drinking coffee during pregnancy. Some trials have not found a link between coffee and caffeine and “poor pregnancy outcomes.”
The review authors suggest that in pregnancy, there may be a need to limit caffeine, but drinking less than 200 milligrams a day likely doesn’t have a big impact.
Finally, researchers suggest that excessive use of coffee may cause anxiety and panic attacks, especially in people who struggle with panic disorder. They note that consuming a lot of coffee or caffeine can lead to symptoms like high heart rate and palpitations, similar to what occurs in anxiety attacks. They suggest that caffeine and coffee intake should be individualised.
