Review highlights: green tea for high blood pressure and cholesterol

One in three US deaths results from cardiovascular disease (1). Major risk factors include high blood pressure and high cholesterol (“dyslipidemia”) (2). A new study (3) suggests green tea may help maintain normal blood pressure and appropriate blood lipid levels.

Researchers analyzed 20 trials involving 1536 participants and found “a significant reduction in systolic blood pressure, the upper reading measured during heart-muscle contraction, favouring green tea.” Specifically, intake up to 200 mg daily, described as five to six cups, significantly reduced systolic pressure by 1.94 mmHg. The best blood-pressure results appeared after at least 12 weeks of use.

Green tea intake up to 200 mg daily for at least 12 weeks also significantly reduced total cholesterol and
LDL
cholesterol. No effect was observed on
HDL.

Explaining blood-pressure effects, researchers cited laboratory work identifying green tea antioxidants acting similarly to antihypertensive medicines known as inhibitors of
ACE (Angiotensin Converting Enzyme inhibitor
) (4,5). For blood lipids, they cited animal studies in which green tea extracts inhibited intestinal fat absorption and increased the sensitivity of
LDL
receptors in the liver (
6,7).

Green tea significantly reduced systolic pressure, total cholesterol and
LDL
cholesterol, although the effect on systolic pressure was described as small and the effect on total and
LDL
cholesterol as modest.

Further independent long-term clinical trials to assess green tea’s effects are therefore warranted.