Here are 7 useful facts about coffee.
Studies carried out on animals or derived from cell cultures have shown that coffee optimizes the action of insulin, so it could be beneficial for diabetics. Coffee consumption would also prevent bowel cancer. In seniors, it improves memory and reduces the risk of Alzheimer’s. Coffee is often used against headaches and migraines. This is due to the fact that it improves blood circulation, and thereby the irrigation of the organs. It also enhances cardiac activity. Coffee contains a high amount of phenols and polyphenols, substances with an antioxidant effect that help repair damaged cells.
In a large English study, a team of international researchers came to the conclusion that drinking several cups of coffee a day was likely to prevent diseases such as certain cancers as well as cardiovascular diseases. A consumption of 4 to 5 cups of coffee per day led to the best results on health, that is to say lowered the risk of suffering from diseases as much as possible.
The ideal dose of coffee is 3 to 4 cups a day for an adult. It can be lower (1 to 2 coffees) in people who are very sensitive to caffeine and who tend to get nervous when drinking too much coffee. In addition, as the dose of caffeine contained in each type of coffee is not always the same, care must be taken not to exceed 400 mg of caffeine per day. In case of abuse, certain effects such as nausea, anxiety or irritation may occur.
Note that caffeine works better on a rested body than on a tired body. It blocks receptors for adenosine, a substance found in the brain, to allow other substances like dopamine to work better. It is therefore more appropriate to drink coffee when the body is rested, after a nap or a good night’s sleep for example.
There are two main types of coffee: Arabica and Robusta. Robusta is the resistant and wild variety that contains the most caffeine. Arabica is a more delicate variety and requires much more care when planting, but its coffee is known to be tastier and more fragrant.
Pregnant women should reduce their coffee intake to no more than 200mg per day. Studies of a negative impact of caffeine in the event of pregnancy on the health of the child are not yet conclusive, as noted by the American magazine Prevention in September 2019. In other words, the risk for the child in cases of moderate caffeine consumption by the mother would be non-existent or minimal. We do know, however, that caffeine can cross the placenta. As a precautionary measure, pregnant women are advised not to drink more than 200 mg of caffeine per day (the equivalent of a 350 ml American coffee or a large espresso).
Children and other people
Coffee is a source of hyperactivity and sleep disorders in children. For people who have heart rhythm disorders, it is advisable to seek the advice of the doctor, even if a moderate consumption of caffeine remains without danger. For adolescents, beware of the fashion for energy drinks which contain large doses of caffeine.
It would be wrong to believe that caffeine acts immediately. This only has an effect on the body after about 30 to 40 minutes, the time it is absorbed to spread through the body. It will then be necessary to wait several hours before it is completely eliminated. Note that in some people, caffeine can act faster, but not immediately. However, a psychological effect cannot be excluded.
Caffeine does not have the same effect on all individuals, its action depends on the reactivity of the organism. It is for this reason that it can cause insomnia in some people while it will rather promote sleep in others.
Coffee is not classified as a drug, but it is nevertheless addictive. If the body is accustomed to caffeine, certain withdrawal disorders may appear. This is how some people get irritable, complain of headaches, or have trouble concentrating when they don’t drink their usual dose of coffee. In principle, these disorders do not persist in the event of abstinence for more than 10 days, but it is possible that a small period of slight depression occurs during the stop. A part of the population (about half) has no sensitivity to caffeine.
Grosso G: Coffee, Caffeine, and Health Outcomes: An Umbrella Review. Annual Review of Nutrition. 2017 Aug 21;37:131-156. doi: 10.1146/annurev-nutr-071816-064941.