Coffee is one of the most commonly consumed beverages in the world, with millions of people enjoying the boost they receive from the caffeine in the coffee. A new large-scale lifestyle and health study may have some good news for these people, suggesting that coffee may have a variety of health benefits including lowering risk for diabetes and reducing overall risk for death.
The study was done by a team of researchers from the National Cancer Institute and utilized data from a large-scale genetic study done in Great Britain and referred to as the UK Biobank. The data was gathered by taking blood samples and asking detailed lifestyle and health questions of over half a million people. The Biobank project is part of ongoing research into the relationship between health and genes.
Coffee And Genes
The researchers examined data on subjects who drank coffee, finding out how much coffee and what kind of coffee people drank. The researchers then looked at the biodata to find differences in genes associated with the metabolization of caffeine. Finally, the researchers examined death rates over the ten years the study tracked. The research team found that individuals who drank coffee were noticeably less likely to die over the course of the 10 year period that the researchers tracked than those who didn’t drink coffee.
This effect held true regardless of how much coffee the people drank or what kind of coffee they drank. Even those who drank decaf coffee seems to have a lowered risk of death, suggesting it may not be the caffeine in the coffee that has the beneficial effect. Even the heaviest drinkers of coffee, those who drank more than eight cups of coffee a day, were found to be less likely to die than those who didn’t drink coffee.
There were some facts about the Biobank population that might have made the data nonrepresentative of the population at large. For one thing, most of the people in the population were British and more likely to drink instant coffee than other parts of the world. The coffee drinkers in the biobank dataset were also more likely to be men, white, drinkers of alcohol, and former smokers, according to Erikka Loftfield of the National Cancer Institute, one of the researchers who worked on the study. Loftfield explains:
Participants drinking four or more cups per day, compared with those drinking less coffee and nondrinkers, were more likely to drink instant coffee and be current smokers, whereas participants drinking one to three cups per day were older, more likely to have a university degree, and more likely to report ‘excellent’ health.
Despite these differences, the differences in mortality between the two groups were notable. In the 10 years of follow up to the study non-coffee drinkers were considerably more likely to die than coffee drinkers. This news may bring some relief to those worried that their coffee drinking could be negatively affecting their health. Previous studies had suggested that heavy coffee drinking could be detrimental to one’s health, especially when paired with genetic variations that impact the metabolization of caffeine. A prior study found that those who had a variant of the CYP1A2 gene, which encodes the enzyme responsible for the vast majority of caffeine metabolism, may have had different cardiovascular outcomes associated with coffee drinking. Those who had slower caffeine metabolism had a higher risk of developing hypertension (high blood pressure) or of having a heart attack when compared to their non-drinking counterparts. Those who had faster caffeine metabolisms had a much lower risk of these negative outcomes. Yet the work done by the NCI researchers found no extra risk associated with any genetic variant.
What Of The Health Benefits?
Several possible explanations exist for the health benefits of drinking coffee. Coffee’s benefits could be related to the antioxidant properties of coffee, antioxidants are thought to combat cancer. Coffee could also reduce inflammation within the body, assist the liver in functioning, improve the lining of blood vessels or improve how insulin gets used in the body. There is some suggestion that coffee can lower the risk of diabetes, liver cancer, Parkinson’s disease, and reduce inflammation associated with heart disease or diabetes.
Samantha Heller, a nutritionist from the NYU Langone Medical Center in New York City explains that like many plant foods coffee beans have beneficial compounds like polyphenols, which research suggests have anti-oxidant, anti-cancer, anti-inflammatory and anti-hypertensive properties. Thanks to these compounds those who follow a more plant-based diet tend to have lower rates of diseases like dementia, heart disease, diabetes and certain cancers.
The NCI research team is planning on doing more work on the Biobank data, looking for other possible relationships between coffee and health. The research team wants to examine how the different types of coffee preparation (filtered coffee, pressed coffee, roasted, etc.) impact health. Some studies suggest that unfiltered coffee made in French presses or percolators might lead to damaging levels of cholesterol.
Don’t Start Drinking More Just Yet
The NCI team cautions that because the study was only observational it cannot prove that drinking coffee is responsible for the lowered risk of death and that more research is needed. The research does seem to challenge a previously held idea that coffee was linked with cancer, an idea which recently caused a California judge to issue a mandate that coffee sellers in the state of California would have to post-cancer warnings on their products.
Loftfield also urged caution and said that people shouldn’t dramatically up their intake of coffee over the results. Only a fraction of those involved in the study said that they drank 8 or more cups of coffee a day, only about 10,000 of the 500,000 people tracked, so the data regarding this is much smaller.
Yet while there isn’t enough evidence to suggest that people should start drinking more coffee to live longer, at the very least the study suggests coffee drinkers shouldn’t be worried it is negatively impacting their health, explains Edward Giovannucci, a professor of epidemiology and nutrition at the Harvard T.H. Chan School of Public Health.
“While the evidence may not be strong enough to suggest that [one should start] drinking coffee for health benefits, people drinking coffee should feel reassured of no harm and probably even benefits of coffee,” said Giovannucci.