A morning cup of coffee not only boosts alertness but may also make you happier. Drinking coffee has been proven to offer long-term health benefits, including reducing the risk of diabetes, coronary heart disease, and stroke. However, experts remind us that the type of coffee beans, the brewing method, and even the water used can directly affect whether that cup is a "healthy beverage" or a "harmful trap."
Numerous large-scale studies have shown that drinking coffee is beneficial for health, likely related to the antioxidants in coffee beans that help reduce inflammation; the diuretic effect of caffeine also aids in lowering blood pressure. For example, a study published by the American Heart Association in November 2025 indicated that adults who had previously experienced atrial fibrillation reduced their likelihood of recurrence by 39% by drinking one cup of coffee daily. However, coffee consumption can also have some negative effects, such as tooth staining or increased anxiety. Experts offer the following 7 tips for healthy coffee drinking:
1. Drinking Coffee in the Morning Brings Happiness
A UK study suggests that people who drink coffee within the first two and a half hours of the day are happier than those who don't. Professor Anu Realo, head of the Happiness, Culture, and Personality research group at the University of Warwick, explains that this may be because caffeine effectively blocks adenosine, a chemical that induces tiredness in the body, while promoting the release of dopamine, which creates a "sense of well-being," thereby improving mood and enhancing alertness. This effect might also stem from mild caffeine withdrawal; tiredness disappears after a morning cup, making people feel happier and more energetic.
2. Choosing Coffee Beans
Associate Professor Christopher Hendon from the Department of Chemistry at the University of Oregon, a renowned coffee scientist, points out that the two most common types of coffee beans on the market are Robusta and Arabica.
Robusta Beans: Primarily produced in Vietnam, Indonesia, and parts of Africa, they typically have a strong, bitter flavor. Their caffeine content is usually double that of Arabica beans, and they are rich in the antioxidant chlorogenic acid, resulting in higher acidity, which might more easily irritate those with sensitive stomachs. They are generally used in instant coffee.
Arabica Beans: Accounting for 70% of the world market, they are mainly produced in South and Central America. They have complex aromatic layers with fruity or chocolate notes.
Their caffeine content is lower, and acidity is typically lower as well, making them gentler on the stomach. They also contain more trigonelline, an alkaloid with antioxidant, anti-inflammatory, and metabolism-regulating properties beneficial for liver and brain health.
Hendon notes that chlorogenic acid is an acid produced during the roasting process of coffee. It can be broken down by gut bacteria into various potentially beneficial substances, such as caffeic acid, which has anti-inflammatory effects. Roasted coffee is one of the very few ways to ingest chlorogenic acid.
3. Adding Milk Reduces Tooth Staining
Latest research finds that chlorogenic acid in coffee is one of the culprits behind tooth yellowing, and hot coffee is more likely to stain teeth than iced coffee. Hendon reminds us that adding milk can help reduce this issue because the casein in milk binds with acidic substances, preventing them from adhering to tooth enamel.
4. Pay Attention to Consumption Amount
The European Food Safety Authority recommends that adults should not exceed 400mg of caffeine per day, generally equivalent to 3-4 cups. However, natural variations in coffee beans and different brewing methods can lead to vastly different caffeine contents, so it shouldn't be measured simply by "cups."
For example, Espresso, despite its intense flavor, has a very short contact time between hot water and coffee grounds (only about 20-30 seconds), so the actual caffeine extracted is relatively low. A single shot of espresso contains approximately 40-80mg of caffeine. As for filter or drip coffee, the contact time can last several minutes, extracting more caffeine. A 240ml cup of filter coffee can contain as much as 150mg or more of caffeine. However, due to the longer contact time, filter coffee may also contain more beneficial antioxidants. Adults can drink about 5 shots of espresso but only 2-3 cups of filter coffee per day.
5. Pay Attention to Your Body's Reaction
Professor Peter Rogers, a psychologist at the University of Bristol, mentions that he drinks only decaffeinated coffee unless he's on a long drive. Having studied the effects of caffeine on the body, he points out that while caffeine's primary effect is to refresh and sharpen the mind, it has side effects like causing anxiety and raising blood pressure. The blood pressure increase is generally mild and temporary but may be particularly noticeable in those who don't drink coffee regularly. Caffeine raises blood pressure by blocking adenosine and triggering adrenaline production, which causes blood vessels to constrict.
He emphasizes that while coffee can keep you awake, it doesn't actually enhance cognitive ability. The refreshing effect of coffee largely just alleviates "caffeine withdrawal symptoms," such as headaches and fatigue. For some people, excessive caffeine can instead cause anxiety, distraction, rapid heartbeat, and make it harder to concentrate.
6. Freshly Ground Coffee is Better than Instant Coffee
Instant coffee generally undergoes multiple heating or freezing processes (e.g., spray drying) to turn coffee liquid into solid form, which is then broken into granules. Professor Hendon notes that this process may produce more undesirable by-products, such as the carcinogen acrylamide. Although its content is far below safety levels, the overall nutritional value is usually lower than that of freshly ground coffee.
He reminds us that for those who prefer to grind their own beans, storing unground beans in the freezer can maintain freshness. It also makes the beans easier to grind evenly, allowing for a more stable release of flavor.
Professor Realo adds that coffee brings happiness not only due to substances like caffeine but also because of the ritual of brewing, the aroma of coffee, and the sense of anticipation, which are inherently effective for stress relief and mood enhancement.
7. Pay Attention to Water Quality
Professor Hendon states that using hard water to brew coffee affects flavor because high levels of calcium and bicarbonate weaken the natural acidity of coffee. Bottled water is not a good choice either—it's less environmentally friendly and can be harder than tap water, making it even less suitable for brewing coffee. If filtered or soft water isn't available, one can choose coffee beans that are naturally lower in acidity and whose flavor is less affected by water quality.
