Coffee is one of the world’s most popular drinks. Millions of people start their day with a cup of coffee and rely on caffeine to feel more awake and alert.
Coffee has also been linked to several health benefits in scientific studies, including a lower risk of certain liver diseases, type 2 diabetes, and some heart conditions.
However, anyone who drinks coffee regularly has probably noticed that people react to it very differently. Some people can drink several cups throughout the day and sleep perfectly well at night. Others may feel shaky, anxious, or unable to sleep after only one cup.
Scientists have long wondered why people respond so differently to caffeine. A research team from the University of Toronto has now found that our genes may hold an important part of the answer. Their study suggests that the effects of coffee on health, including kidney health, may depend largely on a person’s genetic makeup.
The research was led by Professor Ahmed El-Sohemy and was published in JAMA Network Open. The findings add to growing evidence that genes influence the way our bodies respond to everyday foods and drinks. They also point toward a future in which dietary advice may become more personalized and tailored to each individual.
At the center of the discovery is a gene called CYP1A2. This gene controls how quickly the body breaks down caffeine. In simple terms, the gene acts like an instruction manual that tells the body how fast it should process caffeine from coffee, tea, energy drinks, and other caffeinated products.
People inherit different versions of this gene. Some individuals carry a version that allows them to break down caffeine very quickly. Their bodies process caffeine efficiently, meaning that the stimulant does not stay in their systems for very long. These people can often drink several cups of coffee each day without experiencing strong effects.
Other people inherit a slower version of the gene. For them, caffeine remains in the body much longer. As a result, they may be more sensitive to coffee and other caffeinated drinks. They may experience symptoms such as nervousness, a racing heart, jitteriness, anxiety, or difficulty sleeping. Some may even feel the effects of caffeine many hours after drinking a single cup of coffee.
The researchers found that these genetic differences may also affect kidney health. The kidneys perform many essential jobs in the body.
They filter waste products from the blood, remove excess fluids, help control blood pressure, and maintain the proper balance of minerals and chemicals in the body. Healthy kidneys are critical for overall health and wellbeing.
According to the study, people who process caffeine slowly may place additional strain on their kidneys if they consume too much coffee over long periods.
Because caffeine stays in their bodies longer, its effects may be stronger and last longer, potentially increasing stress on the body and the kidneys. This finding suggests that the same amount of coffee may have very different effects on different people.
The researchers estimate that about three cups of coffee a day is generally a safe amount for most people. Some individuals may be able to tolerate four cups a day without problems.
However, the ideal amount appears to depend partly on a person’s genes. Interestingly, about half of the population carries the fast-processing version of the CYP1A2 gene, while the other half has the slower version.
Scientists say there is even a genetic test that can determine which version of the gene a person has. Knowing this information may help people make better decisions about their caffeine intake and possibly reduce their risk of certain health problems.
The study also highlights an important shift in nutrition science. For many years, health advice has generally been based on broad recommendations that apply to large groups of people. However, researchers increasingly recognize that individuals can respond very differently to the same foods and drinks because of differences in their genes, lifestyles, and health conditions.
This approach, often called personalized nutrition, aims to provide health recommendations that are better suited to each individual. Rather than assuming that one dietary rule fits everyone, scientists are working toward advice that considers a person’s unique biological characteristics.
Overall, the new findings suggest that coffee is neither completely good nor completely bad. Its effects may depend largely on how each person’s body handles caffeine. Understanding your own sensitivity to caffeine may help you enjoy coffee more safely while also protecting your kidney health and overall wellbeing.
As scientists continue to study the relationship between genetics and nutrition, people may gain increasingly useful tools for making dietary choices that support long-term health.
If you care about nutrition, please read studies about why vitamin K is so important for older people, and this snack food may harm your heart rhythm.
For more health information, please see recent studies about vitamin that may protect you from type 2 diabetes, and results showing this common chemical in food may harm your blood pressure.
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