What Drinking Coffee Every Day Does to Your Body, According to Nutrition Experts

For coffee lovers, facing the day without that morning cup is an alarming prospect. Whether you're a latte lover or macchiato maven, those all-essential sips provide the fuel you need to erase grogginess and grouchiness. But what does drinking coffee every day actually do to your body? We caught up with nutrition and coffee experts to learn more about the upside of your caffeine quotient—and how to know when that extra dose is too much of a good thing.

Enhances Alertness

Coffee contains several biologically active substances, including caffeine, an alkaloid that sharpens faculties. Caffeine helps to give the brain a little nudge to wake up, says Mandy Enright, MS, RDN, RYT, and author of 30-Minute Weight Loss Cookbook.

"Caffeine is a natural central nervous system stimulant that can help support alertness and reduce feelings of fatigue,” says Stephanie Hoffman, VP of Operations at Bulletproof Coffee and Certified Q-Arabica Grader, with a background in food science and nutrition. Caffeine acts as a stimulant by blocking adenosine, a chemical that signals tiredness in the brain, adds Alyssa Pike, RDN, senior manager, Food Safety & Nutrition, International Food Information Council.

Moderate amounts of caffeine may also improve aspects of cognitive performance such as attention and reaction time, especially when you're already tired, Pike says.

Boosts Brain Health

"There is a reason we can be cranky before having our coffee first thing in the morning—coffee can put people in a better mood," Enright says. 

Some studies suggest that moderate amounts of caffeine also act as a mild antidepressant, helping to reduce the risk and symptoms of depression and improve mental health. "Caffeine can help increase dopamine production to help start your day with a little more positivity," Enright says. Dopamine and serotonin are neurotransmitters in your brain with "reward chemical" capabilities released when you're engaged in an enjoyable activity like eating or learning something new.

Coffee can also fine-tune focus—but it has its limitations. "Caffeine is best for short-term or very specific tasks," Enright says. Some studies indicate that coffee may also protect against neurodegenerative diseases such as Alzheimer's and Parkinson's disease.

Supports Heart Health

A substantial body of research suggests that moderate coffee consumption is associated with a lower risk of several chronic diseases, including cardiovascular disease, Pike says. A regular coffee habit can also shield against stroke. Some findings suggest that people who drink up to three cups a day have healthier hearts in terms of size and function.

Decreases Risk of Type 2 Diabetes

Another perk: Research finds that habitual coffee intake improves insulin sensitivity and reduces the risk of Type 2 diabetes. "While these studies show associations rather than cause-and-effect relationships, the evidence overall suggests coffee can fit into a healthy dietary pattern for many people," Pike says.

Related Stories

8 Reasons Your Coffee Tastes Bitter—and How to Brew It Right, According to Experts

What Eating Oatmeal Every Day Does to Your Body, According to Nutrition Experts

Lowers Risk of Liver Disease

Your coffee habit may benefit your liver, with studies indicating that daily intake improves fat oxidation and lowers the risk of steatosis (fatty liver disease) and cirrhosis.

Battles Inflammation

Caffeine won't treat chronic conditions, but it may help prevent or slow the progression, Enright points out. "Coffee contains high levels of polyphenols, particularly chlorogenic acids (CGAs) that can fight off inflammation that causes many of these chronic diseases."

Polyphenols, found in fruits, vegetables, tea, and coffee, are plant-based compounds with powerful antioxidant and anti-inflammatory properties, and can help prevent cell damage.

"The antioxidants in coffee have been linked to better metabolic health, protect against heart disease, and have neuroprotective properties," Enright says, noting that one review study found strong evidence linking coffee consumption to a lower risk of cognitive decline, stroke, dementia, and some cancers.

Promotes Longevity

Though not exactly the fountain of youth, coffee may bolster longevity and overall lifespan. One study found that people who drank between 1.5 and 3.5 cups daily—even with a spoonful of sugar—were up to 30 percent less likely to die during the study period than abstainers. The study didn’t consider other factors that influence low mortality risk, like exercise or healthy eating habits.

How Much Coffee Should You Drink to Get the Benefits?

How much coffee a day can bestow benefits? "The U.S. FDA and the European Food Safety Authority state that caffeine intakes up to 400 milligrams per day, consumed throughout the day, do not raise safety concerns for healthy adults, except for pregnant women," Pike notes.

That's about four 8-ounce cups of drip coffee—but caffeine content can be all over the map, depending on the source, how it's produced, and brewed, the portion size, cup size, and type of coffee used.

The appropriate amount of coffee can vary from person to person, Hoffman explains. "Individual tolerance differs based on factors like body size, metabolism, medications, and sensitivity to caffeine."

Most coffee drinkers have experienced the pitfalls of a cup too many. "Consuming too much caffeine may lead to unwanted effects such as jitters, anxiety, increased heart rate, sleep disruption, or digestive discomfort," Hoffman says. Paying attention to how your body responds to those cups of coffee can help determine what level of intake works best for you, she adds.