As millions of people across the globe kickstart their mornings with a cup of coffee, new research is sparking a conversation about the health benefits—and potential risks—of caffeine consumption.
A large-scale study conducted in the UK in September revealed that moderate caffeine intake from coffee or tea may lower the risk of developing several cardiometabolic diseases, such as heart disease, stroke, and diabetes. Additionally, a January study found that consuming coffee in the morning was linked to a reduced risk of cardiovascular disease and premature death.
While these findings are encouraging, many are left wondering: What exactly are the health benefits of coffee? How much is too much? And should certain individuals be cautious about their caffeine intake? To help shed light on these questions, CNN spoke with Dr. Leana Wen, an emergency physician and CNN wellness expert. Dr. Wen, who also serves as an adjunct associate professor at George Washington University, offered her insights.
The Science Behind Coffee’s Health Benefits
Dr. Wen emphasized that the evidence supporting coffee’s health benefits is robust. Numerous studies over the years have found that moderate coffee consumption is associated with a reduced risk of various health conditions, including heart disease, diabetes, certain cancers, and even dementia.
While the exact mechanisms behind these benefits remain unclear, Dr. Wen explained that several factors could contribute. Coffee contains antioxidants and anti-inflammatory compounds that may help reduce cancer risks. Additionally, substances in coffee might assist the body in using insulin more effectively, aiding in blood sugar regulation. Other components of coffee may also play a role in better cholesterol processing.
However, more research is needed to pinpoint the specific elements of coffee responsible for these health benefits.
How Much Coffee Is Beneficial?
According to Dr. Wen, most studies suggest that moderate coffee consumption—defined as between two to four cups per day—provides the greatest health benefits. A UK study conducted in 2024, for instance, found that individuals who drank three cups of coffee daily had a 48% lower risk of developing cardiometabolic diseases compared to those who drank little or no coffee.
Another significant 2022 study reported that individuals who consumed two to three cups of coffee per day had the most substantial decrease in early mortality. Interestingly, this study also highlighted that ground coffee was more effective in reducing mortality risk (by 27%) than instant coffee (11%).
When Does Coffee Become Harmful?
Despite the numerous health benefits associated with moderate coffee intake, Dr. Wen noted that excessive caffeine consumption could lead to side effects such as heart palpitations, anxiety, and sleep disturbances. The US Food and Drug Administration (FDA) states that up to 400 milligrams of caffeine per day—about the amount in four 8-ounce cups of brewed coffee—is generally safe for most adults.
While many people exceed this amount without experiencing negative effects, individuals who struggle with sleep or other health issues should be mindful of their caffeine intake, as it could exacerbate these problems.
Caffeine in Other Beverages
Caffeine isn’t exclusive to coffee. Dr. Wen explained that different beverages contain varying amounts of caffeine. For example, a 1-ounce shot of espresso contains about 60-70 milligrams of caffeine, while a cup of black tea generally contains 40-50 milligrams, though it can have up to 90 milligrams. Green and white teas typically contain less caffeine. Sodas also contain caffeine, ranging from 3 milligrams to 70 milligrams per 12-ounce serving.
One area of concern is energy drinks, which can have as much as 200-300 milligrams of caffeine in a single serving. Dr. Wen cautioned that these drinks often contain high levels of sugar and other chemicals, which can negate any potential health benefits from caffeine.
Who Should Be Cautious About Coffee?
Some individuals should take special care with their caffeine consumption. The American Academy of Pediatrics recommends that children under the age of 12 avoid caffeine entirely, and that those aged 12 to 18 limit their intake to no more than 100 milligrams per day.
Pregnant women should also exercise caution, with the American College of Obstetricians and Gynecologists advising that caffeine intake should be limited to less than 200 milligrams per day to avoid risks such as miscarriage or preterm birth. Breastfeeding women can typically consume up to 300 milligrams per day without adverse effects, according to the US Centers for Disease Control and Prevention.
People with underlying heart conditions or those taking medications that make them more sensitive to caffeine—such as certain thyroid or antidepressant medications—should also be cautious. Additionally, individuals with sleep problems may benefit from limiting caffeine consumption to the morning hours.
Can Tea or Other Drinks Provide the Same Benefits?
For those who aren’t coffee drinkers, Dr. Wen explained that it remains unclear whether tea or other caffeinated beverages provide the same health benefits. While some studies suggest that tea can reduce mortality rates and lower the risk of certain diseases, it’s not yet known whether these benefits are derived from the caffeine in tea or from other compounds.
Dr. Wen cautioned that the benefits associated with caffeine from coffee or tea likely do not extend to energy drinks or sodas, which often contain high levels of sugar and other unhealthy additives.
The Bottom Line
In conclusion, Dr. Wen emphasized that moderate coffee consumption can offer health benefits for many adults, but it’s important to be mindful of your total caffeine intake. While coffee is not essential for good health, those who enjoy it may reap rewards when consumed in moderation. However, certain groups—such as children, pregnant women, and those with certain medical conditions—should limit or avoid caffeine altogether. As always, individuals with specific health concerns should consult their healthcare provider for personalized advice.
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