Can daily coffee use increase your lifespan? Here's what the latest research says.

You've probably heard of the many benefits of drinking coffee. There is no shortage of research studies attesting to the benefits of one (or two or three) cups of joe every day. Some of the studied benefits include reduction of risk of:

• Parkinson's disease
• Type 2 diabetes
• Heart disease
• Prostate cancer
• Melanoma
• Depression and suicide
• Cirrhosis of the liver
• Liver cancer

But did you know that coffee can also increase your lifespan? That's what scientists behind a new research study announced recently.

So, what's so special about coffee? How is it able to reduce our risk of dying from so many diseases? Let's dive in.

What we know about coffee

Coffee is actually a complex mixture of over 1,000 different chemicals. It can pose a challenge for scientists to nail down which of these constituents provide the health benefits of coffee. In fact, coffee has had a checkered past. Some of its many chemicals have been identified as possible carcinogens—in 1991, the World Health Organization actually included coffee on a list of possible carcinogens. However, coffee was subsequently exonerated and removed from that infamous list.

Coffee is thought to be beneficial through the following mechanisms:

• Anti-inflammatory
• Reduced insulin resistance
• High amounts of antioxidants that can prevent or delay cell damage
• Lignans, which disrupt growth and spread of cancer cells
• Chlorogenic acid, which lowers blood sugar levels

What does the research show?

The newest study in the Annals of Internal Medicine analyzed coffee consumption habits from more than 170,000 people in the United Kingdom ages 37 to 73 and followed them for an average of seven years. Researchers found that those who drank between 1.5 to 3.5 cups of coffee per day were 16 to 21% less likely to die from all-cause, cancer-related and cardiovascular disease-related mortality during the study period than non-coffee drinkers.

But this is not the first study to look at the reduction in mortality from regular daily coffee use. A study published in 2015 in the journal Circulation tracked more than 200,000 participants for 30 years. Those who drank 3 to 5 cups of coffee a day were 15% less likely to die from all causes of mortality including cardiovascular disease, Parkinson's disease and suicide. A more recent study in 2018 tracked over 500,000 participants across 10 years. Compared to non-coffee drinkers, participants who downed 6 to 7 cups daily had a 16% lower risk of early death.

In all studies, the benefit was enjoyed by those who drank both caffeinated and decaffeinated coffee—again, suggesting the benefit is from the myriad of bioactive substances in coffee as opposed to caffeine.

Association does not necessarily mean causation

The key takeaway from all these studies is that the data demonstrates an association between daily coffee consumption and a reduced risk of dying. But we should remember that a correlation between two things—in this case, coffee and decreased mortality—does not necessarily mean there's a direct causation. What we don't really know is how much of the reduction in mortality is from the coffee itself, despite its known myriad of benefits and this strong association.

There are many other so-called confounders that could influence this data. However, what I like about this new study is that researchers accounted for possible confounders by controlling for factors like smoking, presence of chronic medical problems, socioeconomic status and diet.

This new study is consistent with findings from a 2019 meta-analysis—which is one of the strongest evidence-based research studies that can be done. This meta-analysis examined 40 different studies that included 3.8 million participants. Researchers found that moderate coffee consumption (2 to 4 cups/day) was associated with reduced all-cause mortality compared to those who do not drink coffee. This benefit was observed irrespective of age, weight, alcohol or smoking use as well as the amount of caffeine present in the coffee.

But we must bear in mind that coffee drinking study participants could have many other lifestyle factors contributing to reduced mortality such as a healthier diet or regular exercise routine. For example, researchers hypothesize that regular coffee drinkers will more likely opt for a cup of coffee vs a more sugar-heavy caffeine boost from an energy drink or soda.

The bottom line is that the new study is consistent with multiple studies showing a strong association between moderate daily coffee consumption (more than 1 cup/day) and reduction in death from many causes. If you already drink coffee daily—caffeinated or decaffeinated—great! However, it's no substitution for daily exercise and a healthy diet! If you get your caffeine from energy drinks or soda, consider switching to a cup of joe—but opt against adding a lot of sugar or whipped cream to your coffee or you might reduce the benefit.