It’s no secret that coffee is an extremely popular beverage all around the world. Some people drink coffee because they like the taste, others drink it because they claim it helps them focus, and others still say the caffeine boost helps them stay awake. We picked this topic because since the start of the pandemic one of our co-authors has significantly increased their consumption of coffee.
Which has led us to ask the question, is coffee actually good for you? Is there such a thing as too much coffee? If so, how much coffee is too much? Today, we’re taking a break from COVID-19 to delve into the nutritional science behind one of the world’s favorite caffeinated beverages.
Introduction
There is a plethora of conflicting information on the internet about coffee and caffeine in terms of effects on the human body. What many of these sources have in common though is that the discussion often focuses on one of the molecules found in coffee - caffeine. Gender, weight, health status, and many other factors affect how your body responds to this stimulant.
To answer today’s questions about coffee (and the caffeine found in coffee), we’re going to discuss a paper that reviewed hundreds of other coffee-related studies and a recent study that analyzed the long-term impacts of coffee in over 300,000 people.
Coffee, Caffeine, and Health Outcomes: An Umbrella Review
In 2017, a group of scientists set out to look at all of the data generated from more than 100 different scientific studies looking at the impacts of coffee on long term health and answer once and for all, is coffee bad for you? They found that coffee - when drunk in moderation - was linked to a decreased risk of several types of cancer, cardiovascular disease, Parkinson’s disease, type-2 diabetes, and depression. This is because other components (not caffeine) of coffee such as antioxidants are widely suggested to be beneficial to human health. Coffee also seems to change the microbes that live in your gut. Coffee drinkers have an increased proportion of bacteria that reduce gut inflammation and that have been suggested to lower the risk of Parkinson's disease.
Sounds like a miracle drink, right? Not quite. They also found that caffeine was linked to a temporary increase in blood-pressure, which usually decreased shortly after the coffee/caffeine was consumed. They concluded that people who would be particularly sensitive to an increase in blood-pressure - in even short term - and pregnant women were likely among the only groups of people on whom coffee (more specifically caffeine) would have a negative impact.
Unfortunately, because this study analyzed a lot of data collected independently and under different conditions, the authors of this first study weren’t able to offer a recommendation of how much coffee is too much. Because of course, even a commonly ingested stimulant like caffeine, when ingested in excess can have major negative impacts.
Luckily, a recent study was designed to address this.
They found that coffee was linked to a decreased risk of several types of cancer, cardiovascular disease, Parkinson’s disease, type-2 diabetes, and depression.
Long-term coffee consumption, caffeine metabolism genetics, and risk of cardiovascular disease: a prospective analysis of up to 347,077 individuals and 8368 cases
This second paper had a very specific goal - the authors wanted to see if genetics could link cardiovascular disease and caffeine consumed by drinking coffee. The researchers looked at the genetics of more than 300,000 people and their daily coffee habits. Using statistical tests they determined that there was no link between a person's genetics and an increased risk of cardiovascular disease caused by caffeine consumption.
Instead, they concluded that people who drank more than 6 cups of coffee per day had a 22% more chance of developing cardiovascular disease compared to people who only drank 1-2 cups per day. What’s even more interesting is that when the researchers compared non-coffee drinkers and decaffeinated coffee drinkers to the 1-2 cuppers, two former groups also had a higher risk of cardiovascular disease (11% increase for nondrinkers and 7% for decaf drinkers).
Drinking more than 6 cups of coffee per day increases your risk for heart disease, while drinking 1-2 cups per day doesn't seem to increase your risk at all.
Of course, the risk of cardiovascular disease depends on many, many other factors such as lifestyle, diet, and genetics. The good news is that if you’re drinking 1-2 cups of caffeinated coffee per day, you may be lowering your risk of developing this disease.
Take home message
Today’s post is short and to the point - coffee when consumed in moderation is actually good for you! Sadly, there IS such a thing as too much coffee but if you're drinking 1-2 cups a day, you may be lowering your risk for a number of diseases.
This year has been hard, but at least we have coffee.
References:
Grosso, et al.Coffee, Caffeine, and Health Outcomes: An Umbrella Review. Annual Review of Nutrition. 2017 https://doi.org/10.1146/annurev-nutr-071816-064941
Zhu & Hypponen. Long-term coffee consumption, caffeine metabolism genetics, and risk of cardiovascular disease: a prospective analysis of up to 347,077 individuals and 8368 cases. Am J Clin Nutr. 2019 DOI: 10.1093/ajcn/nqy297
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