Slurp away! By Dr Kenneth Ng
Photo: belchonock / www.123rf.com
Most people are aware that wine has been shown to be beneficial in protecting against heart disease. And as tea and coffee are consumed in greater quantities than wine, researchers have been investigating if they are beneficial too.
Tea has its origins in China and has been enjoyed for the last 4,000 years. It has been found to contain catechins, caffeine, theanine, saponins and vitamins. The main therapeutic effects come from the catechins, which are polyphenols and have a strong antioxidant effect. Theanine, an amino acid, gives the tea its full- bodied taste and has a relaxing effect.
Coffee is widely seen as a stimulant. Its major components include caffeine, antioxidants and diterpenes, which are found in the oil of the bean. Coffee cultivation began in 15th-century Arabia. Today, many people have to start their mornings with a dose of caffeine.
Caffeine has been associated with higher blood pressure, abnormal heart rhythms and increased vascular resistance, all of which are not good for the body. But there is little information on how tea and coffee relate to heart events like stroke, heart attacks and cholesterol plaque formation in the heart arteries. Researchers from Johns Hopkins Hospital and the National Institutes of Health in the United States embarked on a study of 6,814 men and women to determine that.
LOWER RISK OF HEART DISEASE
In their findings published last year, they reported that drinking tea regularly led to a lower risk of heart disease. Around 51 per cent of the participants drank at least one cup of coffee a day. Only 13 per cent of them took at least one cup of tea a day.
At the start, the coffee drinkers were found to have a higher amount of calcium build-up in their heart arteries than most of the tea drinkers. The researchers followed up the study participants for an average of 11 years. They found that regular coffee consumption had a neutral effect on calcium build-up in the heart arteries. In contrast, drinking one or more cups of tea daily on a regular basis decelerated the build-up of cholesterol in the heart arteries.
Overall, the regular tea drinkers experienced a 29 per cent drop in heart-related events. Regular coffee drinkers did not experience any change in heart-related events but those who drank coffee occasionally saw a 28 per cent rise in heart-related events.
In conclusion, the study found that regular tea consumption can lead to fewer heart-related events, such as heart attacks and stroke. Coffee, however, did not have such a beneficial effect. Diterpenes in coffee have been found to raise LDL, or bad cholesterol, levels. But, depending on the preparation method, there may not be enough of it in our cup of coffee to make a difference. Nevertheless, the consolation for coffee-lovers is that drinking coffee regularly does not lead to a spike in heart-related events.
Often, patients who have coronary heart disease or high blood pressure worry about whether it is safe for them to continue drinking coffee. They fear that the caffeine in the beverage could further stress their heart. The study results show that it is safe to continue having your daily cup of coffee.
As for regular tea drinkers, they have reason to celebrate, though the reason tea is better for the heart remains unclear. I believe that tea has much stronger antioxidant properties due to the presence of polyphenols, which are also found in wine. Whatever the underlying cause, I would like to propose a toast to tea drinkers for choosing a superior beverage.
Dr Kenneth Ng is a consultant cardiologist at Novena Heart Centre. A version of this article appeared in the print edition of The Straits Times on January 24, 2017, with the headline ‘Coffee or tea: Which is better for the heart?‘.