Review Finds Tea Beneficial Against Cardiovascular Disease

by | Dec 20, 2013 | 2013, Antioxidants, Cardiovascular Health, Flavonoids, Whole Foods - General

Written by Greg Arnold, DC, CSCS. A review of tea and cardiovascular disease research showed that those with the highest intake of flavonols from tea (34 mg per day) had a 20% reduced risk of cardiovascular disease compared to the lowest intakes from tea (les than 2 mg per day). 

Cardiovascular diseases, including heart disease and stroke, which are the first and third leading causes of death for both men and women in the United States, account for 1 in 3 of all U.S. deaths. Heart disease and stroke are expected to cost our healthcare system $473 billion in 2009. If all major types of cardiovascular disease were eliminated, U.S. life expectancy would increase by nearly 7 years (1).

Now a new research review (2) suggests that tea consumption may be a way to help fight cardiovascular disease. In the study, researchers analyzed data from 13 studies, 5 of which were reviews of previous studies (called meta-analysis). Among the strongest studies, a 2009 meta-analysis (3) showed green tea consumption to reduce the risk of cardiovascular disease by 28% (p = 0.039), with every cup of tea decreasing risk by an addition 10% (p = 0.000).

When examining flavonol intake (a type of antioxidant plentiful in tea), a 2003 meta-analysis (4) showed those with the highest intake of flavonols from tea (34 mg/day) had a 20% reduced risk of cardiovascular disease compared to the lowest intakes from tea (< 2 mg/day, p < 0.001).  A 2010 meta-analysis (5) showed the highest intakes of flavonols from tea (16-47 mg/day) reduced risk by 20% compared to the lowest flavonol intake (4-14 mg/day, p = 0.05).

When suggesting possible mechanisms for how tea helps protect against cardiovascular disease, the researchers pointed to studies showing both black and green tea to help reduce blood pressure in stroke-prone hypertensive rats at doses equivalent to 1 Liter/day in humans (6). Tea also was found to help maintain healthy blood vessels, which helps control blood pressure, one of the first steps in the process of cardiovascular disease (7, 8).

For the researchers, “the strength of this evidence supports the hypothesis that tea consumption might lower the risk of stroke.”

It must also be noted that caffeine content of an average cup of tea is about 50mg and therefore comes with health risks. The health risks include: gastro-esophageal reflux disease, ulcers, cardiac arrythmias, low-birth weight in pregnancies, and can also lead to dependence and unpleasant withdrawal symptoms. The use of caffeine is higher in psychiatric patients as been linked with specific disorders such as anxiety disorders, sleep disorders and eating disorders, and there is a possible association with schizophrenia (9).

Source: Arab, Lenore, Faraz Khan, and Helen Lam. “Tea consumption and cardiovascular disease risk.” The American journal of clinical nutrition 98.6 (2013): 1651S-1659S.

© 2013 American Society for Nutrition

Posted December 20, 2013.

Greg Arnold is a Chiropractic Physician practicing in Hauppauge, NY.  You can contact Dr. Arnold directly by emailing him at PitchingDoc@msn.com or visiting his web site at www.PitchingDoc.com

References:

  1. “Cardiovascular Disease at a Glance” posted on the CDC website
  2. Lenore A.  Tea consumption and cardiovascular disease risk.  Amer Jou Clin Nutr 2013 doi: 10.3945/ajcn.113.059345
  3. Wang ZM, Zhou B, Wang YS, Gong QY, Wang QM, Yan JJ, Gao W, Wang LS. Black and green tea consumption and the risk of coronary artery disease: a meta-analysis. Am J Clin Nutr 2011;93(3):506–15.
  4. Huxley RR, Neil HA. The relation between dietary flavonol intake and coronary heart disease mortality: a meta-analysis of prospective cohort studies. Eur J Clin Nutr 2003;57:904–8.
  5. Hollman PC, Geelen A, Kromhout D. Dietary flavonol intake may lower stroke risk in men and women. J Nutr 2010;140(3):600–4.
  6. Arab L, Liebeskind DS. Tea, flavonoids and stroke in man and mouse. Arch Biochem Biophys 2010;501(1):31–6.
  7. Alexopoulos N, Vlachopoulos C, Aznaouridis K, Baou K, Vasiliadou C, Pietri P, Xaplanteris P, Stefanadi E, Stefanadis C. The acute effect of green tea consumption on endothelial function in healthy individuals. Working Groups on Epidemiology & Prevention and Cardiac Rehabilitation and Exercise Physiology. Eur Cardiovasc Prev Rehabil 2008;15:300–5.
  8. Tinahones FJ, Rubio MA, Garrido-Sanchez L, Ruiz C, Gordillo E, Cabrerizo L, Cardona F. Green tea reduces LDL oxidability and improves vascular function. J Am Coll Nutr 2008;27:209–13.
  9.   Winston, Anthony P., Elizabeth Hardwick, and Neema Jaberi. “Neuropsychiatric effects of   caffeine.” Advances in Psychiatric treatment 11.6 (2005): 432-439.