Can drinking green Tea daily reduce the risk of heart disease and stroke?

CLAIM:

Drinking green tea every day may help reduce the risk of heart disease and stroke. The post claims that the catechins and antioxidants present in green tea support cardiovascular health, improve circulation, protect cells from oxidative stress, and contribute to overall long-term wellness when consumed regularly as part of a healthy lifestyle.

FACT:

Current evidence suggests that regular green tea consumption may support heart health and is associated with a lower risk of cardiovascular disease, stroke, and certain cardiovascular risk factors such as high cholesterol and blood pressure. However, the evidence does not conclusively prove that green tea directly prevents heart disease, and its potential benefits should be viewed as part of an overall healthy lifestyle that includes a balanced diet, regular exercise, adequate sleep, and appropriate medical care.

Remember the green tea craze? The advertisements that convinced many of us to swap our regular cup of tea for green tea in the hope of losing weight and improving our health? Years later, green tea remains a popular choice for its reputation of being healthy, with social media posts frequently highlighting its potential benefits. 

In a recent Instagram post by ‘NutriZenage’, a page with nearly 1.79 lakh followers, claims about green tea helping reduce the risk of heart disease and stroke have started gaining attention online. 

The post mentions that, “Drinking green tea daily may reduce heart disease risk and stroke risk a research said.”

The caption of the post highlights green tea's long history of consumption and its rich concentration of beneficial plant compounds. According to the caption, “Green tea has been enjoyed for thousands of years, not only for its refreshing taste but also for its rich concentration of beneficial plant compounds.” 

It further states that green tea contains catechins, which are described as “powerful antioxidants” that have been widely studied for their potential role in supporting cardiovascular health and protecting cells from oxidative stress. The post suggests that regular consumption of green tea, when combined with a healthy lifestyle, “may be associated with improved heart health, healthy circulation, and overall wellness.” 

Describing green tea as “one of the world's most celebrated natural beverages,” the caption concludes that it brings together “tradition, science, and wellness in every cup” and offers “everyday support for a healthier life.” 

Can drinking green tea daily reduce the risk of heart disease?

Research on green tea and heart health has produced encouraging findings. Several studies have linked regular green tea consumption with a lower risk of cardiovascular disease and improvements in cholesterol and blood pressure levels, although lifestyle factors such as a balanced diet, regular exercise, adequate sleep, and avoiding smoking also play an important role in heart health.  

One of the largest and most frequently cited studies on the topic is a 2006 prospective cohort study conducted in Japan, known as the Ohsaki National Health Insurance Cohort Study. Researchers followed 40,530 adults aged 40–79 years who had no history of stroke, coronary heart disease, or cancer at the start of the study. 

Over the follow-up period, the researchers found that green tea consumption was associated with lower mortality from cardiovascular disease. The association appeared strongest among women and was particularly notable for stroke-related deaths. According to the study, “Green tea consumption is associated with reduced mortality due to all causes and due to cardiovascular disease but not with reduced mortality due to cancer.” 

While observational studies can reveal long-term trends, researchers have also examined whether green tea influences known cardiovascular risk factors. A 2013 review analysed 11 randomised controlled trials involving 821 participants and evaluated the effects of green and black tea on cardiovascular health. 

Although none of the studies measured actual heart attacks, strokes, or cardiovascular deaths, researchers found that green tea consumption was associated with reductions in total cholesterol, LDL ("bad") cholesterol, and blood pressure. However, the authors urged caution, noting that only a small number of trials contributed to the findings and that longer-term, high-quality studies were still needed. 

The review concluded that, “The limited evidence suggests that tea has favourable effects on CVD risk factors, but due to the small number of trials contributing to each analysis, the results should be treated with some caution.” 

Evidence from individual population studies has also pointed in a similar direction. A 2016 Chinese study involving 628 participants examined the relationship between green tea consumption and coronary heart disease (CHD). Researchers observed that male green tea drinkers had lower rates of hyperlipidaemia, lower total cholesterol levels, and lower diastolic blood pressure compared with non-drinkers. 

After adjusting for other factors, the study found that green tea consumption was associated with a lower risk of CHD among men. The researchers reported a dose-response relationship, with greater reductions in risk seen among those who consumed green tea more frequently and over longer periods. Among women, drinking at least three cups per day was associated with a reduced CHD risk, although the relationship was less consistent. 

The authors concluded that “there exist a negative association between CHD risk with the frequency, amount and time of green tea consumption in the male population.” 

Looking beyond individual studies, a 2016 meta-analysis combined data from nine studies involving over 2.59 lakh participants to evaluate the relationship between green tea consumption and cardiovascular and ischemic diseases. The researchers found that individuals who did not consume green tea had a higher risk of cardiovascular disease, intracerebral haemorrhage, and cerebral infarction compared with those who drank green tea.

Moderate green tea intake was also associated with lower risks of myocardial infarction and stroke. According to the authors, “Our meta-analysis provides evidence that consumption of green tea is associated with favourable outcomes with respect to risk of cardiovascular and ischemic related diseases.” 

More recent research has continued to support a potential cardiovascular benefit. A 2023 meta-analysis of seven prospective cohort studies involving over 7.72 lakh participants and 9,211 coronary heart disease cases found a nonlinear relationship between green tea consumption and CHD risk. 

Compared with non-consumers, individuals who drank one to four cups of green tea per day generally had a lower risk of coronary heart disease, with the strongest associations observed at low-to-moderate intake levels. However, the researchers also stressed that additional studies are needed before definitive conclusions can be drawn. 

The authors concluded that green tea consumption “may be associated with a reduced risk of CHD, especially among those with low-to-moderate consumption.” 

Researchers have also explored potential biological mechanisms that could explain these associations. A 2023 meta-analysis of 55 randomised controlled trials found that green tea extract supplementation significantly improved several cardiometabolic risk factors. Participants experienced reductions in total cholesterol, LDL cholesterol, fasting blood sugar, HbA1c, and diastolic blood pressure, while HDL ("good") cholesterol increased modestly. 

The researchers noted that these findings “support previous evidence showing the health benefits of green tea supplementation on cardiometabolic risk factors.” 

What experts say

Dr (Prof) Tarun Kumar, Associate Director and Head at Medanta Moolchand Heart Centre, said that green tea contains several bioactive compounds that may contribute to overall health, particularly when consumed as part of a healthy lifestyle. 

According to him, one of the key components of green tea is a group of polyphenols known as catechins, which act as antioxidants. These compounds help neutralise free radicals - unstable molecules that can damage cells, promote inflammation, and weaken the body's natural defence mechanisms. 

“Catechins help fight these free radicals. They protect your cellular structure, prevent cellular injury, reduce inflammation, and even help protect DNA,” he explained. 

Dr Kumar noted that green tea also contains L-theanine, an amino acid that can cross the blood-brain barrier and may promote a sense of calmness while helping reduce stress and anxiety. In addition, caffeine and other plant compounds present in green tea may contribute to improved focus, memory, and reaction time. 

He further explained that flavonoids found in green tea may help relax blood vessels and support vascular health. “All these things are benefits. They add to the benefits once a person engages in other lifestyle modifications,” he said. 

Discussing cardiovascular health specifically, Dr Kumar said that several studies have linked regular green tea consumption with a lower risk of stroke and improvements in cholesterol levels. “In one of the studies, they've shown that daily two to four cups of green tea reduces the stroke risk by 24 per cent,” he said. 

He added that green tea may help lower total cholesterol and LDL ("bad") cholesterol, improve insulin sensitivity, and contribute to favourable metabolic changes. According to him, these effects collectively create what he described as a “good bioenvironment” within the body. 

However, he stressed that green tea should not be viewed as a standalone solution for preventing heart disease. “If you are having underlying diabetes or hypertension, you need to control that also because all these things are additive,” he said. 

While Dr Kumar said that regular green tea consumption can be beneficial, he emphasised that its effects are best understood as part of a broader healthy lifestyle. “Health benefits from different modalities are additive. Drinking green tea is a dietary modification, but exercise, walking, yoga, meditation, taking prescribed medications, and regular health check-ups all work together,” he said. 

He concluded that green tea may offer supportive cardiovascular and metabolic benefits, but “only green tea won't help you normalise all those things.” Rather, it should be considered one component of an overall approach to maintaining good health. 

This story is done in collaboration with First Check, which is the health journalism vertical of DataLEADS