By Madyson Smith, Student Pharmacist and Karen Kier, Pharmacist
On behalf of the ONU HealthWise team

In September 1988, the Swedish rock duo Roxette released their second album Look Sharp! which contained the single “Listen to Your Heart.” The song hit number 1 in the United States and Canada.  The duo of Marie Fredriksson and Per Gessle are the second most successful Swedish band after ABBA. 

The American Heart Association (AHA) is listening and looking out for our hearts. On July 20, 2026, an AHA press release reviewed the scientific evidence from a published article in the medical journal Circulation. The evidence-based article was titled Caffeine and Cardiovascular Disease: A Scientific Statement from the American Heart Association. The publication was a joint effort of various AHA Councils of experts, including the Council on Lifestyle and Cardiometabolic Health, the Council on Clinical Cardiology and the Stroke Council. 

Did you know the majority of Americans consume caffeine every day? It is one of the most commonly used stimulant substances.  Caffeine is a natural stimulant for the brain. It helps to improve alertness and focus while reducing fatigue. Caffeine is in the class of chemicals known as methylxanthines, and this includes theobromine found in chocolate and theophylline found in tea and is used to treat asthma. 

An 8-ounce cup of coffee contains between 75- 165 mg of caffeine depending on how it is brewed. Black tea contains about 45- 50 mg of caffeine compared to green tea, with 25mg in a cup. Sodas or pop range at 40- 55 mg. Chocolate milk provides about 5- 6 mg, while 1 ounce of a dark chocolate candy bar provides 20- 24 mg. Energy drinks can contain 40- 69 mg per ounce, which is 3-4 times higher per ounce than coffee. You do not want to exceed 400mg of caffeine per day. 

When reading labels of supplements, nonprescription products and food sources, look for some hidden caffeine sources labeled as guarana, kola nut, yerba mate, green coffee bean extract, kombucha and matcha. 

In the AHA paper, they describe the benefits of up to five 8-ounce cups of coffee a day with no more than 400 mg of caffeine in total. The report indicates a potential benefit in reducing heart disease, including reducing type 2 diabetes, stroke and heart failure.  Interestingly, caffeine showed a J-shaped curve when evaluating blood pressure (hypertension). This means that at 1-3 cups of coffee a day, blood pressure may be elevated, but with 4-5 cups per day, blood pressure was lower. The J-shape describes as the line is going down, then blood pressure goes up, but when the J makes the curve, then blood pressure goes down. This means that at 3-4 eight-ounce cups, blood pressure starts to reduce. One theory as to why this might be happening is that caffeine has some diuretic effect, causing excess water to be eliminated and thereby reducing blood pressure. 

The publication indicated that black coffee with no cream, sugar, or other sweeteners can help reduce bad cholesterol, the development of type 2 diabetes, stroke, and heart failure. The authors are quick to point out that we need even more evidence to continue to prove a benefit to the heart. 

Another important consideration is how coffee is prepared.  Coffee contains a chemical known as cafestol, and this increases bad LDL cholesterol, which is not good for the heart.  Cafestol is removed by filters when brewing. Methods of serving coffee that do not use filters allow cafestol to exist, including espresso, French press, Turkish coffee and boiled coffee.  

In addition, our genetics determine how our bodies handle caffeine.  The liver contains various cytochrome enzymes referred to as CYP, and they are responsible for metabolizing various substances, including medications and caffeine.  The CYP1A2 enzyme works on caffeine. Your genetics related to CYP1A2 determine how quickly your body eliminates caffeine.  Some individuals are ultra-rapid metabolizers of caffeine, and their body eliminates it very quickly.  Hence, some people can drink several cups of coffee and go right to sleep.  Other individuals are poor metabolizers, and caffeine stays in their blood longer. These individuals are more prone to the jitteriness of caffeine. 

Caffeine may have some important heart benefits, but it may affect sleep for some. Sleep is essential for good heart health. Another study published in Sleep Medicine Reviews evaluated the impact of caffeine on sleep. They found caffeine consumption reduced total sleep time by 45 minutes and decreased sleep efficiency. The researchers looked into how many hours before bed you should stop consuming caffeine. The researchers’ recommendations found that coffee should be consumed at least 8.8 hours before bedtime. Based on the article, you should consume caffeine as early in the day as you can to help avoid disrupting your sleep patterns. 

The balance of the heart benefit and sleep may be difficult to accomplish based on the research.  So, listen to your heart and monitor your sleep!