A new study published on May 10 in the open access journal open heart suggests that the sex of the drinker and the brewing method may be the key associated with coffee and elevated cholesterol, a known risk factor for heart disease.
The results showed that the gender difference between drinking espresso and cholesterol level was the largest; The difference between drinking coffee and cholesterol was the smallest.
Naturally occurring chemicals in coffee - diterpenes, caffeinol and coffee white fat - raise cholesterol levels in the blood. Brewing methods have an impact, but it is unclear what impact espresso may have and how much.
Therefore, the researchers hope to compare espresso with other brewing methods among adults aged 40 and over (average age 56).
Drawing on data from 21083 participants (11074 women; 10009 men), they responded to the seventh survey of the 2015-16 Tromso study, a long-term demographic study that began in 1974 and involved residents of Tromso, Norway.
Participants were asked how many cups of coffee they drank every day - no, 1-2 cups; 3-5 cups; And six or more cups, and what type of coffee they drink - filtered; Method pressure pot; Espresso from coffee machine, coffee capsule, mocha pot, etc; And instant coffee.
The researchers took blood samples and measured the participants' height and weight. Information was also requested on potential influencing factors: diet and lifestyle, including smoking, alcohol intake and physical activity; Education level; And whether type 2 diabetes has been diagnosed.
On average, women drink less than four cups of coffee a day, while men drink an average of nearly five cups.
Data analysis showed that the association between coffee and serum total cholesterol was different, depending on the brewing method. Except manual brewing, there were significant gender differences in all brewing types.
Drinking 3-5 cups of espresso a day was significantly associated with an increase in serum total cholesterol, especially in men. Compared with those who did not drink, this consumption pattern was associated with a higher serum cholesterol of 0.09 mmol / L in women and 0.16 mmol / L in men.
Drinking six or more cups of hand brewed coffee a day is also associated with elevated cholesterol, and the degree is similar for men and women: women are 0.30mmol/l higher than men, and men are 0.23mmol/l higher than women.
After drinking six or more cups of filtered coffee a day, women's cholesterol was 0.11 mmol / L higher than those who didn't drink filtered coffee, but men didn't.
Although instant coffee was associated with increased cholesterol in men and women, it did not increase with the number of cups consumed compared with those who did not choose coffee powder / granules.
The researchers noted that standardized cup sizes were not used in their study; For example, Norwegians tend to drink espresso in a larger cup than Italians.
Different types of espresso - from coffee machines, capsules or mocha pots - may also contain different levels of key naturally occurring chemicals. They added that there was no clear explanation for the gender difference in cholesterol response to coffee.
"Interestingly, coffee contains more than a thousand different phytochemicals." "The intake of each compound also depends on the type of coffee, the degree of baking, the type of brewing method and the amount consumed," they explained
They added that experimental studies have shown that caffeinol and caffein white fat not only increase total cholesterol, but also have anti-inflammatory effects, protect the liver, and reduce the risk of cancer and diabetes.
"This proves that the compounds contained in coffee may cause multiple mechanisms to operate simultaneously," the researchers stressed.
Moreover, they pointed out: "coffee is the central stimulant most frequently consumed in the world. Due to the large consumption of coffee, even small health effects can have considerable health consequences."