Heart palpitations when you drink coffee? Maybe it has something to do with your genes.

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Although many recent studies have confirmed that drinking coffee has many benefits, the negative benefits also exist. Is coffee good or bad for you? Scientists have revealed that it has something to do with genes.

There are many people who must have a cup of coffee in the morning to start the day's work; some even drink four or five cups of coffee a day, because that is his source of creativity and energy. Recently, many studies have confirmed that coffee has many benefits to the human body, and the US Dietary guidelines also suggest that eating a moderate amount of coffee every day can help reduce the risk of chronic diseases. Even the World Health Organization withdrew the carcinogenicity of coffee for the first time, downgrading from "possible carcinogens" to "there is not enough evidence to show the risk of cancer." The news made coffee drinkers ecstatic.

But there is still a group of people who can't enjoy the benefits of coffee. They just drink coffee and get palpitations and restlessness. Why is there such a difference? Scientists suggest it has something to do with genes.

Ahmed El-Sohemy, a professor in the Department of Nutrition at the University of Toronto, noticed these differences about a decade ago. He suspects that these differences vary from person to person; he found a specific set of genes, called CYP1A2, that control the enzymes in our bodies and affect how quickly our bodies metabolize caffeine.

He found that one of the variants in this group of genes causes the liver to metabolize caffeine very quickly. If you inherit the "fast variant" chromosome from your parents, it means that the person has a fast metabolic gene; if you inherit the fast variant chromosome from only one of the parents, or if you inherit a slow variant, then the rate of caffeine metabolism will be slower. Elsohimi even pointed out that people with fast metabolic genes metabolize caffeine four times as fast as those with slow metabolism.

Funded by the National Institutes of Health (National Institutes of Health), Elsosimi's team recruited 4, 000 adults, 2, 000 of whom had a previous history of heart disease. They analyzed the subjects' genotypes and their coffee drinking habits. Overall, people who drank more than four cups of coffee a day increased their risk of heart attack by 36%, but if they added in a different variable of genetic variation, they were surprised to observe that only in subjects who slowly metabolized the genome, coffee drinkers (heavy coffee consumption) had a higher risk of heart disease.

In the past, the negative risk of coffee was mainly caused by slow metabolic genes.

Elsohimi shows that these risks do not exist at all if you look at the genome of rapid metabolism. His team pointed out that drinking 1 to 3 cups of coffee a day can even significantly reduce the risk of heart disease in the fast metabolic genome, so coffee can even have a protective effect for this group of people.

El Sohimi believes that these differences are due to the fact that caffeine stays in the slow metabolic genome for a long time and has an effect on the body for a long time. In the fast metabolic genome, caffeine is metabolized quickly, and antioxidants, polyphenols and other healthy substances act quickly without being affected by the side effects of caffeine.

Other studies also support this argument. A group of Italian scientists found in 553 subjects that both heavy coffee drinkers and moderate daily coffee drinkers had significantly higher rates of high blood pressure in the slow metabolic genome, but for the fast metabolic genome, the risk increased only when coffee consumption increased.

In fact, CYP1A2 is not the only gene that dominates caffeine metabolism. Dr. Dr. Marilyn Cornelis, an assistant professor at Northwestern University's Finnberg School of Medicine (Northwestern University Feinberg School of Medicine), points out that her research has further discovered more genes related to caffeine metabolism. She believes that there are still many differences in genetic or environmental factors that affect caffeine metabolism that existing studies have not yet explored.

But at the very least, these studies focusing on the relationship between genes and coffee will help us to better understand the effects of coffee on the human body and health. In the past, some studies have pointed out that coffee has negative effects on breast cancer, ovarian cancer, type 2 diabetes, and even Parkinson's disease. Scientists have begun to study whether this is related to CYP1A2 or other genes.

Whether coffee is good for you or not, maybe it's all meant to be.

Not only negative relationships, but also positive relationships are affected by genes. For example, in the part where coffee improves sports performance, Christopher J. Womack, a professor of muscle dynamics at James Madison University (James Madison University), points out that coffee may be more helpful to endurance athletes with fast metabolic genes. In 2012, Womack and his colleagues found that giving caffeine ingots to a group of iron horse athletes to run 40 kilometers on a bicycle made them slowly metabolize the genome one minute faster, but four minutes faster.

Womack speculates that this may be because the rapid metabolism of caffeine boosts the autonomic nervous system and puts the body in a state of preparation for battle and flight. "in a broad sense, most people are affected by caffeine and enhance their athletic performance, but for some people, the effect of this addition is more significant. And this difference exists in genes. "

Even if you like the smell of coffee, it has something to do with genes.

According to FitnessGenes, an American genetic testing company, about 40% of people have fast metabolic genes, while 45% are half slow and half fast, while 15% are a pair of slow metabolic alleles.

Studies have slowly begun to focus on the interaction between different genotypes and coffee drinking habits. Dan Reardon, founder of the testing company, said what has been observed is that for people with slow metabolic genes, the aging effect of coffee to help wake up can be extended to a few hours, while those with fast metabolic genes can quickly increase alertness as soon as they drink coffee, but the energy quickly fades away. As a result, people with fast metabolic genes may need to drink several cups of coffee.

And the attractiveness of coffee to you is also affected by genes. A 2015 Cornelius study found that eight groups of genetic variants made people more likely to crave coffee, and at least two groups of genotypes were found to give people pleasure from caffeine intake. This shows that some people are born to drink coffee, while others can't feel the aroma of coffee at all.

These studies just give us a better understanding of the effects of coffee, but they don't ask you to rush to the genetic testing center to see if you have those genotypes. Just because the influence of coffee is "inborn", you might as well let your body tell you whether you are fit to drink coffee.

Source: < For Coffee Drinkers, the Buzz May Be in Your Genes >, New York Times