STILLWATER, Okla.—Drinking green tea or supplementing with the extract every day may improve heart health in obese subjects with metabolic syndrome, according to an Oklahoma State University study (doi:10.1016/j.nut.2010.01.015). The study, which was published in Nutrition, found green tea and its extract significantly reduced plasma serum amyloid alpha, an independent cardiovascular disease (CVD) risk factor.
Green tea (Camellia sinensis) has shown to exert cardioprotective benefits in observational studies. The objective of this clinical trial was to assess the effects of green tea on features of metabolic syndrome and inflammation in obese subjects.
Researchers conducted a randomized controlled trial in obese subjects with metabolic syndrome. Thirty-five subjects with a mean age of 42.5 ± 1.7 y and a body mass index (BMI) of 36.1 ± 1.3. For eight weeks, subjects either drank four cups of green tea a day, took two capsules of green tea extract a day, or received no received no treatment (4 cups water/d). Both the beverage and extract groups had similar dosing of epigallocatechin-3-gallate, the active green tea polyphenol. Fasting blood samples were collected at screening, after four weeks and after eight weeks of the study.
Both green tea beverage and extracts significantly reduced plasma serum amyloid alpha versus no treatment (P<0.005).However, green tea beverage or extract supplementation did not significantly alter features of metabolic syndrome or biomarkers of inflammation including adiponectin, C-reactive protein, interleukin-6, interleukin-1?, soluble vascular cell adhesion molecule-1, soluble intercellular adhesion molecule-1, leptin, or leptin:adiponectin ratio.