Ever wondered which is better, green tea or coffee?
For thousands of years, many people worldwide have turned to extracts of green tea leaves, barks and roots to infuse their hot drinks during morning or night. Similarly, coffee has been cultivated for thousands of years and used for medicinal purposes and as the primary component of hot beverages. Brewed coffee and green tea infusion have been part of man’s diet for millennia.
Several studies have examined the benefits of these two types of drinks. Before deciding which is best suited for you, you must be aware of the benefits of both drinks and their potential side effects.
Brewed coffee, what is the primary ingredient?
Caffeine is one of the main components of coffee . Other constituents of coffee are tannins, fixed oil, proteins and carbohydrates. In the nervous system, caffeine acts as a mild stimulant and is the primary pharmacologically active compound found in coffee . One cup of coffee contains about 75-100 mg of caffeine. According to the European regulatory body on food safety , an intake of 400 mg of caffeine per day does not lead to serious safety concerns for adults who are not pregnant. The same organisation also acknowledged that a habitual intake of 200 mg of caffeine daily for pregnant women does not raise safety issues and concerns.
Extensive studies have been conducted on the benefits of caffeine in the diet. Low-dose consumption of caffeine may result in positive effects in certain groups. For example, a study  examined if athletes who received 3-13 mg/kg body mass of caffeine increased their performance in intensive running or cycling. Results revealed that intake of approximately 2-7 cups of coffee a day, equivalent to 3-13 mg/kg body mass of caffeine, improved cycling and intensive running performance by 20-50%.
Improvement in physical activities following intake of low-dose caffeine is also well documented in the literature. Athletes’ physical and motor capabilities improved with an intake of 3 mg/kg of caffeine compared with 9 mg/kg of caffeine . In a more recent study , low, moderate and high doses of caffeine were examined and compared in terms of caffeine’s effects on prefrontal activities and executive function. Prefrontal activities and executive functions include:
- Focusing one’s attention.
- Planning for the future.
- Managing emotional reactions.
- Anticipating events in one’s environment.
Additional activities involve juggling multiple tasks, remembering instructions and time management, planning and organisation.
Results of the study  demonstrated that intake of low doses of caffeine (3 mg/kg body mass) resulted in improvements in both executive functioning and prefrontal activities. This is equivalent to taking 2 cups of coffee per day. In contrast, the same improvements in executive functioning and prefrontal activities could not be replicated in moderate (6 mg/kg body mass) and high (9 mg/kg body mass) doses of caffeine. Results from this study reinforced earlier findings that lower amounts of caffeine might be more effective in improving cognition and physical performance than higher doses of caffeine.
Drinking coffee as a habit may have many benefits. However, the results are not always favourable and conflict. One study  examined the effectiveness of habitual coffee consumption and cognitive function of 415,530 participants. The same research likewise pooled findings from 300,760 individuals who are coffee drinkers from 10 studies. Results suggested no evidence of the long-term effects of drinking coffee habitually and improvements in memory and global cognition. These findings revealed that coffee might not dramatically improve your memory and cognition in the long term. Nevertheless, the same study did not find any adverse effects in long-term drinking of coffee and global cognition and memory.
What are the other benefits of coffee?
Despite being subjected to debates, the benefits of coffee are extensive. The coffee you brew at home may have different contents from the coffee you buy from a coffee shop. How beans are roasted, the type of beans used, how it is brewed and the amount you grind will all affect the quality and contents of your coffee. Coffee has numerous benefits for one’s health. However, higher doses of caffeine have been attributed to anxiety, restlessness, increased heart rate and insomnia .
Is the benefit due to caffeine or the other compounds present in coffee? Several polyphenols present in coffee have anti-inflammatory and anti-cancer effects. Coffee studies [9, 10] showed that caffeine could potentially interfere with the growth and spread of cancer cells. Additionally, these studies showed that polyphenols could prevent the growth and spread of cancer cells in animal models. Hence, coffee can potentially reduce inflammation, one of the risk factors in cancer development.
What are the benefits of green tea?
Similar to coffee, green tea also contains caffeine. However, the caffeine content is lower compared with coffee. For every cup of coffee, you need three cups of green tea to take the same amount of caffeine. Since high doses of caffeine may lead to side effects such as tremors, anxiety and sleeping problems, it is best to drink fewer cups of coffee daily. Preferably, consume only 1-2 cups a day. Green tea may be a better alternative as this has less caffeine content than coffee.
Although green tea and coffee do not have the same caffeine content, both are excellent sources of polyphenols. Polyphenols are compounds that are potent antioxidants. Our body releases free radicals as part of normal body processes. Sometimes, free radicals are formed following exposure to cigarette smoking, ozone, x-rays, industrial chemicals and air pollutants .
Antioxidants such as polyphenols neutralise free radicals by inhibiting their effects on cells, which include cellular damage . Oxidative stress also hastens the aging process . Hence, you can enjoy a cup of brewed coffee or infusions of green tea if you want to drink a beverage rich in antioxidants.
The polyphenol most abundant in green tea leaves includes Epigallocatechin (EGCG), which is known to have anti-cancer, anti-inflammatory and antioxidant properties . Meanwhile, the primary polyphenol in coffee is a compound named chlorogenic acid (CGA) . Like EGCG, CGA also has antioxidant, anti-inflammatory and anti-cancer activities . In addition, it has been shown to play critical roles in lipid and glucose metabolism regulation . It can help manage cardiovascular disease, diabetes, hepatic steatosis and obesity.
When deciding between green tea and coffee, you can take either coffee or green tea if you want to reap both beverages’ antioxidant and anti-inflammatory properties.
Does drinking green tea or coffee help me lose weight?
When combining EGCG and caffeine, both can help speed up lipid metabolism and help you lose weight. A study  reported that an intake of 80-300 mg of caffeine or 2-7 cups of coffee per day for 12 weeks, along with intake of 100-460 mg of EGCG, resulted in significant weight and body fat reduction.
Meanwhile, CGA contained in coffee has also been reported to have weight loss effects. A clinical trial  that masked the experimental and control groups and the study’s investigators revealed that patients who drank coffee containing high contents of CGA experienced significant weight loss. Significantly, visceral and abdominal fats, which are excellent predictors of cardiovascular disease and risk of cardiac arrest, are also reduced after drinking coffee high in CGA. The control group only received 35 mg of CGA in coffee for 12 weeks.
Findings in the clinical trial  showed that body mass index was significantly reduced in the experimental group compared with the control group. The results are crucial since none of the participants in the study reported any adverse events. However, it is unclear if the intake of coffee high in CGA as weight loss treatment is safe in the long term. To date, only short-term studies lasting 12 weeks were carried out to determine the safety of coffee for weight loss treatment.
While both green tea and coffee are effective in helping individuals who are overweight or obese lose weight, there is still a need to establish the safety of both beverages in the long term.
Choosing between coffee or green tea for weight loss will depend on your taste and preference for a beverage. Both are effective in animal studies and clinical trials in reducing waist circumference, visceral and abdominal fats and weight. However, if you are concerned about the level of caffeine present in coffee, you can switch to green tea and enjoy its antioxidant and anti-inflammatory properties.
Always consult your doctor if you are planning to drink coffee or green tea as a supplement for losing weight. Inform your doctor if you have any side effects following green tea or coffee intake. When taking either or both supplements, remember that these supplements may interact with medications you might be taking. Hence, it is safe to talk to your doctor if you take other supplements and over-the-counter drugs.
Finally, natural compounds from coffee beans and green tea extracts serve as good sources of antioxidants and caffeine. In addition, they have many benefits that can help you achieve optimal health. Hence, choose the most appropriate drink for you- it can be brewed, aromatic coffee or green tea extract infusions.