The gender of the drinker and the brewing method could be key to coffee’s link with elevated cholesterol levels, according to a new study published in the open-access journal Open Heart.
Researchers reported that espresso drinks showed the widest difference between genders in cholesterol levels. Coffee made with a plunger (cafetière) showed the narrowest difference between genders.
Researchers from UiT The Arctic University of Norway studied data from 13,889 participants (7,167 women and 6,722 men) responding in 2015 and 2016 to the seventh survey of the Tromso Study, a long-term population study launched in 1974 involving residents of the Norwegian city of Tromsø.
Scientists asked participants how many cups of coffee they drank each day. They also asked what type of brew they drank: filtered; plunger (cafetière); espresso from a coffee machine, pods, mocha pots, and instant.
Subjects were 40 and older, with an average age of 56.
Blood samples were collected and physical information was gathered, including height and weight, diet and lifestyle, including whether the participants smoked, how much alcohol they drank, and how much they exercised. They also recorded participants’ education level attainment and whether they’d been diagnosed with type 2 diabetes.
Women drank an average of just under four cups of coffee per day, while men consumed nearly five on average.
Data analysis showed an association between coffee and serum total cholesterol that varied, depending on how the coffee was made. “Significant” gender differences were discovered for all brew types, except coffee made with a bar plunger.
“Coffee is the most frequently consumed central stimulant worldwide,” the study authors wrote. “Because of the high consumption of coffee, even small health effects can have considerable health consequences.”
The study’s details
The researchers pointed out that naturally occurring chemicals in coffee, such as diterpenes, cafestol, and kahweol, raise levels of cholesterol in the blood.
Brewing method matters, but it’s not clear what impact espresso coffee might have, and in what quantities.
Ingesting three to five cups of espresso per day was significantly associated with increased serum total cholesterol, particularly among men.
Compared with people drinking none, that pattern of consumption was associated with 0.16 mmol/l (millimoles per litre) higher serum cholesterol among men, versus 0.09 mmol/l among women.
Six or more cups of plunger coffee per day was also associated with raised cholesterol in both men and women: 0.30 mmol/l higher among women versus 0.23 mmol/l higher among men.
Six or more cups of filtered coffee every day was associated with 0.11 mmol/l higher cholesterol among the women, but not among the men, when compared with those not drinking filtered coffee.
Instant coffee was associated with an increase in cholesterol in both genders, although it didn’t rise in tandem with the number of cups drank, compared with those who didn’t drink the instant.