Written by Jessica Patella, ND. In a study with 56 obese participants, those given green tea extract had significant improvements in blood pressure, cholesterol, triglycerides, blood sugar, and inflammatory markers.
Obesity leads to imbalances in the body, including hypertension (high blood pressure) and an increased risk for a cardiovascular event, such as a heart attack (1). Research has shown that inflammation in the body seems to be the underlying factor for these imbalances or side effects of obesity (2). Recently, green tea extract has been gaining popularity for its anti-inflammatory and antioxidant properties (3). Research has shown the anti-inflammatory properties of green tea extract may reduce the side effects of obesity (1).
Recent research included 56 obese participants with hypertension (28 men, 28 women). The participants were randomly assigned to receive either one capsule of green tea extract (379mg) or one capsule of placebo (cellulose) per day for 3 months (1). All participants were instructed to maintain their normal eating habits and exercise patterns.
After the 3-month trial, there were significant changes in systolic blood pressure, diastolic blood pressure, total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides, glucose, insulin and inflammatory markers (TNF-alpha, CRP) in participants taking the green tea extract (see table for results) (1). There were no significant changes in participants taking the placebo (1).
Function Significance Before Taking GTE After 3 Months of GTE
Systolic Blood Pressure (mmHG) 0.004 145 +/- 10 141 +/- 8
Diastolic Blood Pressure (mmHG) <0.001 88 +/- 4 84 +/- 3
Total Cholesterol (mmol/L 5.4 +/- 1.0 5.0 +/- 0.9
LDL (mmol/L) 3.5 +/- 1.0 3.1 +/- 0.9
HDL (mmol/L) 1.2 +/- 0.2 1.4 +/- 0.3
Triglycerides (mmol/L) 1.4 +/- 0.6 1.1 +/- 0.5
Glucose (mmol/L) 5.5 +/- 0.4 5.3 +/- 0.3
Insulin (microIU/ml) 32.0 +/- 4.3 28.7 +/- 3.1
TNF-alpha (ng/L) 5.5 +/- 1.8 4.7 +/- 1.6
CRP (mg/L) 3.4 +/- 2.2 2.5 +/- 1.1
In conclusion, green tea extract shows a positive effect on blood pressure, cholesterol levels, blood glucose and insulin levels, as well as inflammatory markers in obese hypertensive participants (1). This was the first clinical trial performed on obese hypertensive patients and future research should include more people over a longer period of time. It would be remiss not to state that a change in diet and exercise should be considered to address the underlying cause of obesity. Green Tea Extract (GTE) varies in caffeine content as does coffee, tea, and chocolate. GTE averages about 18 mg caffeine per 379 mg capsule (4) which is about twice the caffeine in a cup of decaf coffee and half the caffeine in a cup of tea or a dark chocolate candy bar and one fourth the caffeine in a cup of coffee. See the article on some of the harmful effects of caffeine:
http://www.naturalhealthresearch.org/?p=2592#more-2592
Jessica Patella, ND, is a naturopathic physician specializing in nutrition and homeopathic medicine and offers a holistic approach to health.
Source: Bogdanski, Pawel, et al. “Green tea extract reduces blood pressure, inflammatory biomarkers, and oxidative stress and improves parameters associated with insulin resistance in obese, hypertensive patients.” Nutrition research 32.6 (2012): 421-427.
© 2012 Elsevier Inc. Published by Elsevier Inc. All rights reserved.
Posted July 10, 2012.
References:
- Bogdanski P, et al, Green tea extract reduces blood pressure, inflammatory biomarkers, and oxidative stress and improves parameters associated with insulin resistance in obese hypertensive patients, Nutr Res (2012), doi:10.1016/j.nutres.2012.05.007.
- Mehta S, Farmer J. Obesity and inflammation: a new look at an old problem. Curr Atheroscler Rep 2007;9:134–8.
- Dona M, et al. Neutrophil restraint by green tea: inhibition of inflammation, associated angiogenesis, and pulmonary fibrosis. J Immunol 2003;170:4335–41.
- Communication from Carrie O’Halloran, Now Foods.
