Coffee intake, CVD outcomes, and heart structure
To study the relationship between coffee intake and incident MI, stroke, and death, as well as heart structure, the researchers examined data from the UK Biobank, which recruited 500,000 people aged 40-69 years in 2006-2010 from across the United Kingdom.
They identified 468,629 participants with no signs of heart disease at recruitment and an average age of 56 years, of whom 56% were women.
The participants were divided into three groups based on usual coffee intake: none (22% of participants), light-to-moderate (58%), and high (20%).
Median tea intake was three cups per day overall, four cups per day in noncoffee drinkers, three cups per day in light-to-moderate coffee drinkers, and one cup per day in high coffee drinkers.
Compared to not drinking coffee, light-to-moderate coffee consumption was associated with lower risks for all-cause death (hazard ratio [HR], 0.88; P < .001), CVD death (HR, 0.83; P = .006), and stroke (HR, 0.79; P = .037), over a median follow-up of 11 years, after adjustment for sex; weight; height; smoking status; physical activity; high blood pressure; diabetes; cholesterol level; socioeconomic status; and usual intake of alcohol, meat, tea, fruit, and vegetables.
In the 30,650 participants who had cardiac MRI data, the study found that compared with not drinking coffee, both light-to-moderate and high coffee consumption were associated with significantly increased left and right ventricular end-systolic and end-diastolic volumes, and with greater left ventricular mass (all P < .001).
These differences were small but significant, Dr. Simon stressed, because this was a cohort of healthy patients who did not have CVD (heart failure, MI, stroke, AF) at baseline, although some had hypertension or diabetes.
Press conference chairperson, Steen Dalby Kristensen, MD, professor and cardiologist, Aarhus University Hospital, Denmark, a coffee lover himself, wanted to know if an amount such as two, three, or four cups of coffee was optimal to see these heart benefits, and whether there were differences in benefits seen with drinking different types of coffee.
The analysis did not identify an optimal coffee intake, Dr. Simon said. Compared with not drinking coffee, she continued, drinking instant coffee was associated with a lower risk for all-cause mortality, but not CVD mortality or stroke.
Drinking filtered coffee was associated with lower risks for all three outcomes, but there was no significant difference in risk for MI. Drinking decaffeinated coffee was associated with a lower risk for all-cause and CVD mortality.
“Decaffeinated coffee contains a small amount of caffeine,” Dr. Simon pointed out. “Something other than caffeine might have this protective impact,” she suggested.
The researchers and Dr. Lichtenstein declared having no relevant financial disclosures.
A version of this article first appeared on Medscape.com.