Thinking about your heart health? Consider pouring yourself a cup of tea - hold the milk and sugar.
A study published in the peer-reviewed European Journal of Preventive Cardiology suggests that people who drink tea three or more times a week may live longer and suffer a lower risk of cardiovascular disease than their non-tea drinking counterparts.
Researchers in China tracked self-reported tea consumption as part of the China-PAR project, monitoring the cardiovascular health of more than 100,000 Chinese adults with no prior history of heart attack, stroke, or cancer.
Overall, they found that, on average, consistent tea drinkers were diagnosed with atherosclerotic cardiovascular disease 1.41 years later and live 1.26 years longer than those who drink tea rarely or not at all. Atherosclerotic cardiovascular disease, or atherosclerosis, is caused by high cholesterol levels, causing plaque to form and arteries to harden and become blocked.
Among these, a subset of 14,081 participants surveyed twice over an average of eight years found a more definitive correlation between tea drinking and cardiovascular health. Individuals who habitually drank tea in both surveys had a 56per cent lower risk of fatal heart disease and stroke and a 29 per cent decreased risk of all-cause death, per the report.
Dongfeng Gu, a professor at the Chinese Academy of Medical Sciences and co-author of the study, said in a statement that tea's "protective effects" affected consistent habitual tea drinkers the most.
"Mechanism studies have suggested that the main bioactive compounds in tea, namely polyphenols, are not stored in the body long-term," he said. "Thus, frequent tea intake over an extended period may be necessary for the cardioprotective effect."
What about tea makes it so heart-healthy?
"Tea is rich in flavonoids, a natural, plant-derived antioxidant that has been shown to reduce inflammation and improve heart and vascular health," said Dr. Benjamin Hirsh, the director of preventive cardiology at Northwell Health's Sandra Atlas Bass Heart Hospital in Manhasset, New York. He is unaffiliated with the study.
The type of tea might make a difference, researchers noted. Green tea was linked with approximately 25 per cent lower rates of heart disease, stroke and death. However, no significant associations were observed for black tea.
This might merely be due to the number of people in the study drinking black tea. Only 8 per cent of those surveyed primarily consumed black tea, while nearly half drank green tea. The study also raises the possibility that the polyphenols in black tea could be deactivated during the fermentation process, and that black tea tends to be consumed with milk - possibly counteracting tea's health benefits.
Since the study only surveyed people in China, these benefits may or may not extend to people of other races or ethnicities, Dr Olujimi Ajijola, a cardiologist at Ronald Reagan UCLA Medical Center, told USA TODAY.
The study also acknowledged that the positive benefits of tea were more robust in men than women. Dr Eugenia Gianos, the director of women's heart health at New York City's Lenox Hill Hospital, said that may be due to the lower levels of habitual tea consumption and the lower risk of atherosclerotic cardiovascular disease in the women surveyed, compared to men. She is unaffiliated with the study.
It may also be attributed, however, to differences between sex, noted Dr Jordan C. Ray, a cardiologist at the Mayo Clinic who is unaffiliated with the study. Atherosclerosis is complex and can be varied by sex hormones and genetic differences, he said.
Ray further cautioned that the consistent tea drinkers in the study tended to be older men who were heavy smokers and heavy drinkers. Age and tobacco use, he said, increase cardiovascular risk, while drinking lowers it.
"Anytime there are population differences you have to ask if the tea is the source of the decreased number of events or (if it's another) common reason," Ray told USA TODAY.
Nevertheless, tea may help reduce inflammation and be a good part of a heart-healthy diet and a steady exercise routine, Ray said, which continue to be the best routines to limit cardiovascular disease.