Almost 1200 years back coffee is introduced into human society. Gradually, it became a popular drink because people experience a brain-boosting effect after drinking this unique flavored beverage. Presently, many of us start and end up of our day with a cup of coffee. It has been found that half of the American population drinks coffee regularly and the individual consumption is almost 5.1 kg/year. [1] However, there are individuals who experience irregular heartbeats after consuming excessive coffee. It is essential to explore the benefits and side effects of coffee drinking, and how much coffee is permissible to avoid adverse effects.
Benefits of Coffee
- Caffeine is the principal ingredient of coffee with psychoactive properties and acts by blocking the adenosine receptor activation. The activation of the adenosine receptor causes drowsiness by releasing an inhibitory neuromodulator, adenosine. Therefore, drinking coffee provides the central nervous system with stimulatory effects.
- Phenolic compounds present in coffee have antioxidant property, which helps to balance the oxidant-antioxidant ratio in the body and assist to normalize metabolic functioning. Intake of such natural antioxidants also improves the antioxidant enzyme functioning in our body.
- Coffee has a preventive effect against multiple chronic conditions. Health researchers reported prolonged coffee drinking can reduce the risk of type 2 diabetes development.
- A scientific journal published a report, in which it is mentioned that coffee has a hepato-preventive effect and provides a protective effect against the development of hepatic injury, liver cirrhosis, and hepatocellular carcinoma in people with higher risk factors.
- Coffee drinking inversely reduces the risk of developing Parkinson’s disease in men. Women also get this benefit who do not expose to postmenopausal estrogen.
- Caffeine has Alzheimer’s disease preventive effect. Regular caffeine drinking through coffee is one of the effective ways to reduce Alzheimer’s disease risk.
- Physical endurance enhancement is significant after drinking coffee beverages.
- The research study evidence shows that the suicidal tendency has also been reduced by 13 percent by increasing the consumption of coffee regularly.
- The cancer risk-reducing effect of coffee is significant, especially in liver cancer and colorectum cancer. However, the exact mechanism of action of coffee against cancer is unknown. [1]
Side Effects of Coffee
Coffee ingestion has some significant side effects. These are as follows:
- Coffee has direct adverse effects on the cardiovascular system. It has been observed that excessive coffee intake can stimulate cardiac functioning and the outcome of this leads to increased heart rate (tachycardia), hypertension (increase blood pressure than normal), and sporadic arrhythmic (abnormal cardiac rhythm) conditions. The sudden changes in cardiac functioning are noticeable immediately after the intake of coffee. Coffee intake can induce arrhythmia and therefore, a doctor usually does not recommend coffee as a beverage for the cardiac patient. Individuals with frequent coffee-drinking habits often have high blood pressure complaints. Cardiac patients have strict restrictions on coffee drinking because it can increase the risk of cardiac arrhythmia. [1]
- Low-density lipoprotein (LDL) and cholesterol level enhancement are the major cause of cardiac disorders because the rise in LDL and cholesterol level influences plaque formation. Plaque can develop in any type of blood vessel and often causes obstruction in the blood vessel by stimulating blood clotting. The clot can be dislodged to another site by circulating through the systemic circulation. This phenomenon is termed thrombo-embolism. Thrombotic complications in the brain, pancreas, and ovary are often associated with cancer. Plaque disruption is one of the major cause of coronary thrombosis and emboli formation and trigger atherosclerosis. [2] Cafestol and kahweol are two diterpenes present in coffee and coffee containing these diterpenes is responsible for increasing cholesterol-level in the blood. [1]
- Calcium is an essential mineral for bone health. But, it has been found that coffee drinking can cause hindrance of calcium absorption in the gastrointestinal tract. Therefore, elderly people who have developed a risk of osteoporosis should avoid 2–3 cups of coffee consumption per day and also require to increase their consumption of vitamin D and calcium supplements for preventing frequent fractures. [1]
- Caffeine, the bioactive compound of coffee can cross the placental barrier and can reach the fetus, which can cause impaired development of the fetus. Caffeine has the potential to cause spontaneous abortion also. Therefore, pregnant women should limit caffeine-containing coffee drinking during the gestation period. [1]
- Restricted intake of coffee is also necessary for children because it has been observed that exceeding the upper limit of caffeine can trigger altered behavior in children. They often have a complaint of anxiety or nervousness with increasing consumption of coffee. [1]
How many cups are right?
Although it is easy to understand how many cups are right for coffee intake, it is difficult to estimate the standard coffee intake per day measured through the cup because the volume of a coffee cup can vary. In the United States, the cup measurement used for nutrition labeling is 240 ml, whereas, 1 Canadian cup = 227.3045 milliliters. [3] In addition, the quantity of coffee intake per day varies depending upon several individual factors including body weight, age, and the physical condition of a particular person. However, the following are some evidence-based recommendations:
- Experts estimated that pregnant women should not intake more than 300 mg/day of coffee during the gestation period. [1]
- Federal Department of Health, Ottawa, Ontario, Canada estimated the upper limit of coffee for children. According to this, the consumption of coffee by children should not exceed 2.5 mg/kg body weight/day. [1]
- Experts also recommended filtered coffee for individuals who have a tendency to develop high serum levels because unfiltered coffee contains a significant amount of diterpenes. However, diterpenes can be removed through a filtration process. Filtered coffee consumption is an alternative option to reduce the risk of elevation of serum cholesterol. [1]
- Caffeine energy drinks become popular beverages in Western countries. Excessive drinking of this beverage causes anxiety, sleep disturbances, and cardiac disorders including tachycardia, jitteriness, and gastrointestinal problems. It has also been reported that excessive intake of this can cause seizures and even death in rare cases. To limit these events, Health Canada recommends the dose of caffeine intake. According to this guideline, the upper intake of caffeine for healthy adults is 400 mg/ day; and for adolescents (more than 13 years of age), the calculation depends upon the body weight of an individual. The calculated value of caffeine is 2.5 mg/kg body weight. [1]
- In the Canadian market, a single serving of energy drinks typically contains 80 mg to 180 mg of caffeine (depending on size). Health Canada allows a maximum limit of caffeine per serving is 180 mg /container and 200mg to 400 mg per liter of the drink. [4]
- It is also important to check the product label of the caffeine-containing drink. Health Canada also advises both quantitative and qualitative statements about the declaration of caffeine required to mention in the product label, which is “Do not consume more than (X) container(s)/serving(s) daily” or “Usage: (X) container(s)/serving(s) maximum daily.” The X may be 1 or 2, which depends on the vitamin and mineral content of the product. [4]
In social activities, coffee drinking is one of the most convenient and safe beverages. It also improves performance and provides a feeling of well-being at the workplace and also in the leisure period.
The restricted intake of coffee provides several health benefits, but if anyone develops habitual addiction and crosses the upper limit, then it can provide an adverse effect. So, it is advisable to keep drinking coffee within the limit.
References
- https://www.sciencedirect.com/science/article/pii/S2213422014000456
- https://www.ncbi.nlm.nih.gov/pubmed/17903843
- https://ipfs.io/ipfs/QmXoypizjW3WknFiJnKLwHCnL72vedxjQkDDP1mXWo6uco/wiki/Cup_(unit).html
- https://www.sciencedirect.com/science/article/pii/S2211335516301450