Coffee is so ubiquitous that we almost forget how it may affect our health. Indeed, more than half (55%) of the US population drinks coffee on a daily basis, at an average of about 2 cups per day, according to recent surveys. Serious coffee drinkers gulp down much more. But what’s all this coffee doing to our health?
For the most part, coffee is good for your health. Caffeine and other compounds in coffee have been shown to help you burn more calories, reduce cellular damage, aid in DNA repair, and provide anti-inflammatory effects. Coffee may even lower the risk of certain types of cancer.
But coffee has its downsides, as well. We all know that too much coffee can cause restlessness, wakefulness, and “the jitters.” In addition, too much coffee during pregnancy (more than 4 cups per day) has been linked with preterm births, low birth weights, and stillbirths. Coffee also raises the risk of bone fractures in women.
So, before you pick up that next cup of joe, read about these other pros and cons of coffee.
Pro: Coffee may lower mortality risk
Moderate coffee drinking (about 3-5 cups per day) was associated with reduced premature death from cardiovascular disease, neurological disease, and suicide, according to results of a large population study in Circulation.
Surprisingly, those reductions aren’t due to the caffeine in those magic beans. Coffee drinkers experienced the same beneficial effects whether they sipped full strength or decaf.
“Bioactive compounds in coffee reduce insulin resistance and systematic inflammation,” said the study’s first author Ming Ding, MD, DSc, Department of Nutrition, T.H. Chan School of Public Health, Harvard University, Cambridge, MA. “That could explain some of our findings. However, more studies are needed to investigate the biological mechanisms producing these effects.”
Con: Drinking coffee raises cholesterol
Drinking coffee—especially unfiltered coffee—significantly contributes to increased levels of total cholesterol, low-density lipoprotein cholesterol (LDL-C), and triglycerides, researchers have reported. The more coffee consumed, the higher the concentrations of LDL-cholesterol and total cholesterol, they found.
In one prospective study, researchers reported that drinking 1 cup of regular coffee per day was associated with about a 2-mg/dL increase in total cholesterol during a 16.7-month period, after adjusting for age and changes in other potential confounders.
However, different methods of brewing appear to result in different concentrations of cholesterol. Using a paper filter usually traps the two compounds in coffee—kahweol and cafestol—that are believed to have lipid-inducing effects. But other methods of brewing, such as boiling or using a French press, result in much more of these cholesterol-raising compounds in your coffee cup.
Pro: Coffee linked to lower risk for diabetes
People who increased their daily coffee consumption (> 1 cup) over 4 years had an 11% lower risk for type 2 diabetes, while those who decreased their daily coffee consumption over the same period of time had a 17% higher risk for type 2 diabetes, Harvard University researchers reported in a 2014 study in Diabetologia.
“Our findings confirm those of previous studies that showed that higher coffee consumption was associated with lower type 2 diabetes risk,” said lead author and research fellow Shilpa Bhupathiraju, PhD, Department of Nutrition, Harvard T.H. Chan School of Public Health. “Most importantly, they provide new evidence that changes in coffee consumption habit can affect type 2 diabetes risk in a relatively short period of time.”
Con: Coffee increases risk of bladder cancer
In a 2015 meta-analysis of observational studies, researchers showed that coffee drinkers were 33% more likely to develop bladder cancer than people who didn’t drink coffee. In addition, the authors found a dose-response relationship: the more coffee a person consumes, the higher their risk for bladder cancer.
Notably, male coffee drinkers and non-smokers with high coffee consumption were even more likely to develop bladder cancer, the researchers reported.