Coffee contains about three times more caffeine than tea, which can lead to stronger side effects. However, both beverages contain compounds that may help fight inflammation. Before choosing which drink suits you best, it’s important to understand the potential benefits and side effects of each.
Health Benefits of Coffee
Caffeine is the main active compound in coffee, along with tannins, vegetable oils, proteins, and carbohydrates. A single cup of coffee contains roughly 75–100 mg of caffeine. According to the European Food Safety Authority, consuming up to 400 mg of caffeine per day is considered safe for healthy adults (except for pregnant women).
Low doses of caffeine can have positive effects on certain groups. Drinking about two cups of coffee a day—roughly 3 mg of caffeine per kilogram of body weight—has been shown to improve cycling and running performance by 20–50%. Low caffeine intake also improves concentration, planning, emotional regulation, and anticipation of events. However, when caffeine intake increases to 6–9 mg, these effects are not observed. Thus, a moderate amount of coffee can enhance both cognitive and physical performance.
Despite ongoing debate, coffee offers significant health benefits. The bean type, roasting, brewing, and preparation all affect its quality and caffeine content. High doses of caffeine, however, can cause anxiety, restlessness, increased heart rate, and insomnia.
According to Longevity.technology, certain polyphenols in coffee exhibit anti-inflammatory and anti-cancer properties. Analyses also suggest that caffeine may inhibit the growth and spread of cancer cells.
Health Benefits of Green Tea
Like coffee, green tea contains caffeine but in much smaller amounts—about the caffeine of three cups of tea equals that of one cup of coffee. Because high doses of caffeine can lead to side effects such as trembling, anxiety, and insomnia, it’s best to limit coffee to 1–2 cups a day. Green tea can be a good alternative for those seeking less caffeine.
Although caffeine levels differ, both green tea and coffee are excellent sources of polyphenols—powerful antioxidants. The body naturally produces free radicals, which at high levels can damage cells and increase the risk of disease. Free radicals can also result from exposure to cigarette smoke, industrial chemicals, and air pollution. Antioxidants such as polyphenols neutralize these free radicals and protect cells.
Green tea leaves are especially rich in the polyphenol Epigallocatechin Gallate (EGCG), which has anti-cancer, anti-inflammatory, and antioxidant properties. In coffee, the key polyphenol is Chlorogenic Acid (CGA), which also exhibits antioxidant, anti-inflammatory, and anti-cancer effects. CGA plays an important role in regulating lipid and glucose metabolism and in preventing cardiovascular disease, diabetes, fatty liver, and obesity.
Effects on Weight Loss
The combination of EGCG and caffeine in green tea speeds up lipid metabolism and aids in weight loss. One study found that consuming 80–300 mg of caffeine or at least two cups of tea per day for 12 weeks, along with 100–460 mg of EGCG, significantly reduced body weight and fat.
Similarly, CGA in coffee has been shown to promote weight loss. Visceral fat—linked to heart disease and the risk of cardiac arrest—also decreases after drinking coffee high in CGA.
Choosing between coffee and green tea for weight loss depends largely on personal preference. Both have been shown in animal studies and clinical trials to reduce waist circumference, visceral fat, and body weight. However, if you are concerned about the higher caffeine content in coffee, green tea may be the better option.