Although it has been frequently studied, the effects of coffee on health continue to be a debate. Coffee effects on hypertension, for example. One study says good, while the other studies say it is not good.
To resolve this debate, Giuseppe Grosso as nutrition epidemiologist from the University of Catania, Italy and his team studied 127 independent meta-analyzes that investigated the health effects of coffee.
Some of these studies also conducted randomized trials, but the majority used observational methods of coffee and caffeine consumption habits.
The research team from the University of Catania then assessed the strength of studies and conclusions using the scale, from "Convincing" to "Limited".
Published in the Annual Review of Nutrition, the research team said that none of the studies showed evidence at the "Convincing" level.
However, some claim that coffee drinking habits can reduce cancer risk by 2 to 20 percent depending on the type of cancer rated "Allowable".
The study team's findings also found that coffee can reduce the risk of cardiovascular disease by 5 percent, as well as type 2 diabetes and Parkinson's disease by up to 30 percent. People who are used to drinking coffee also have a lower risk of death during the duration of the study.
However, coffee is not always good for everyone. One group that should avoid coffee is pregnant women. Several studies that scored "Allows" found a link between caffeine consumption and an increased risk of miscarriage.
According to Grosso, this is because the fetus has no enzyme to citrate the caffeine. As a result, caffeine accumulates and can cause miscarriage. Grosso also admitted that these findings are "Allowing", but to be safe, he recommends that pregnant women stop or severely limit their coffee consumption.
Well, about the effects of coffee on high blood pressure and often changing cancer, Grosso and the team found that this is likely due to the failure of studies in controlling the subject's smoking habits, a habit that is often done along with consuming coffee.
When the study only looked at non-smoking subjects, the data showed that moderate coffee drinkers were more protected from high blood pressure and cancer.
All the benefits of this coffee, Grosso said, because the phytochemical content that is also found in fruits, vegetables, chocolate, and tea has antioxidant and anti-inflammatory capabilities. Caffeine and phytochemicals also have a positive effect on enzymes that regulate renal function, insulin, glucose metabolism, and DNA repair.
Therefore, Grosso and the team reached the conclusion that coffee can be part of a healthy diet.
However, the key is on the amount consumed. The maximum benefit of coffee can be obtained at a dose of four to five cups of coffee, or about 380 to 475 milligrams of caffeine per day.