Caffeine, a key component in coffee, increases alertness, focus, metabolism, and fat-burning rate. However, it can temporarily raise blood pressure and heart rate, even in people without hypertension.

Caffeine blocks adenosine, a molecule that increases drowsiness. By blocking adenosine receptors, caffeine promotes alertness. However, adenosine also affects cardiovascular health. Caffeine's adenosine-blocking activity can constrict blood vessels, leading to increased blood pressure.

Caffeine stimulates the adrenal glands to release adrenaline, a hormone that increases heart rate and constricts blood vessels, causing high blood pressure. These effects are more pronounced with regular, high caffeine intake. Moderate coffee consumption doesn't cause long-term vascular problems.

Coffee is rich in antioxidants. Oxidative stress and inflammation prevent blood vessel lining cells from dilating normally. When blood vessels can't dilate properly, blood pressure can rise. Coffee's antioxidants may prevent oxidative stress and inflammation, improving vascular function.

According to the American Heart Association (AHA), about 400 mg of caffeine daily (about 4 to 5 cups of brewed coffee) is safe for healthy adults. However, those with a history of hypertension may need to limit their intake. They should also monitor their body's response to different types and amounts of coffee. Cold brew coffee can contain more caffeine, depending on brewing time and the coffee-to-water ratio.

Sugar reduces coffee's bitterness, but it's unhealthy, potentially causing weight gain, obesity, type 2 diabetes, cardiovascular disease, and dental problems. It's advisable to drink coffee without added sugar or use healthier sweeteners like herbs to reduce calories. Be mindful of other caffeine sources like tea, soda, energy drinks, or supplements. Consuming these could exceed the recommended 400 mg of caffeine per day.

For optimal health, consult a doctor or nutritionist for guidance on blood pressure management and a suitable diet.

Le Nguyen (According to Eating Well)