New research on mice detailed the mechanism by which caffeine appears to be assisted by the heart.

To convince a tea lover to change his mind, he just needs to buy an espresso machine. In a new study, a team of scientists in Germany said they were able to correct one of the common abnormalities in the hearts of mice – a defect linked to age – by giving mice doses of caffeine equivalent to four to five cups of coffee per day for humans. The paper – the latest addition to a growing body of research that supports the health benefits of coffee – describes how the work of caffeine at the molecular level appears to enhance the function of heart cells and protect these cells from damage.
It is still not known whether these results will ultimately be appropriate in relation to humans. However, Joachim Altscheid of the University of Heinrich Heine in Düsseldorf – who led the study with his colleague Judith Hindler – says: “It is clear that this idea The old saying that you should avoid drinking coffee if you have heart problems is no longer a valid idea. ”
Previous research has already reported such results. For example, a 2017 report in the Annual Review of Nutrition – a report analyzing more than 100 studies on coffee and caffeine – found that coffee is associated with a possible decline In the risk of cardiovascular disease, as well as type 2 diabetes and several types of cancers. The new paper, published in June in the journal PLOS Biology, identifies a specific cellular mechanism in which coffee can improve heart health.
The study is based on previous work, in which the world has shown that caffeine increases the functional capacity of cells lining the blood vessels. The drug acts by entering the cells and stimulating them to mitochondria, those structures within cells that burn oxygen by converting glucose into energy. “Mitochondria are power plants in cells,” Hindler says. One of the things that mitochondria rely on to continue their work is a protein known as P27. As Altschmidt and Hindler (as they describe in the present paper) have discovered, caffeine produces its magic effect within the main types of heart cells by increasing the amount of P27 protein in the mitochondria of these cells.
After the researchers induced myocardial infarction in the mice during the trials, the extra stock of P27 protein in the caffeine-containing cells seemed to have prevented the death of damaged myocardial cells. The paper says that the P27 protein of mitochondria also stimulated the formation of cells armed with strong fibers to withstand the mechanical forces, and strengthened the repair of the lining of the blood vessels and internal chambers of the heart. To determine the importance of this protein, scientists have modified genetic engineering in mice to cause a deficiency in its P27 protein. The scientists found that these mice developed disabilities in the function of mitochondria, and these disabilities did not improve with the use of caffeine.
The researchers also studied the potential role of caffeine in correcting one of the common effects of aging in mice and humans: the low respiratory capacity of mitochondria (in this context, the term “breathing” refers to a complex series of biochemical events within this organ).
For the purpose of this part of the experiment, a number of mice – mouse age of 22 months – received a quantity of caffeine in drinking water, equivalent to the daily rate of four to five cups of coffee in humans, for 10 days. According to the study, this was sufficient to increase the mitochondrial respiration of these mice to the levels observed in the six-month-old mice. The analysis showed that older mice had about twice the amount of P27 protein in the mitochondria after taking caffeine for 10 days.
Although these recent findings on the potential health benefits of drinking coffee include only one animal study, tea lovers may seriously feel that they have chosen the wrong side of the equation. According to the National Coffee Association, 64% of Americans aged 18 and above At least one cup of coffee per day, with an average daily consumption of 3.2 cups. Three cups of traditional morning tea contain less than 150 mg of caffeine, compared to about 500 mg in the same amount of brewed coffee. Tea lovers may wonder if they are missing out on a potential health benefit and start drinking coffee.
But Donald Hensrod, medical director of Mayo Clinic ‘s Healthy Life program, answers this question: “Of course not; we need to enjoy life, and if you enjoy drinking tea, continue to enjoy it. All these things are useful; there are health benefits for coffee, black tea and green tea. ” Hensrod points out, however, that there are some problems associated with large doses of caffeine. For example, the amount of caffeine found in more than two cups of coffee a day can interfere with pregnancy and increase the risk of miscarriage. Because the rate of caffeine metabolism varies from person to person, those with low metabolic rate may be more likely to have side effects, such as stomach cramps, insomnia, and palpitations, Hensrod said.