Tea For Your Health – March 2013
Update for Health Professionals & Media – March 2013
In this issue:
- Fifth International Scientific Symposium on Tea & Human Health Heart Health
- Brain Health
- Weight Management
Fifth International Scientific Symposium on Tea & Human Health
Leading nutrition scientists from around the world convened in Washington, DC to present the latest research supporting the role of tea in benefiting and promoting better health.
In just the past five years alone there have been more than 5,600 scientific studies on tea, forming a substantial body of research on this world wide consumed beverage. The symposium showcased significant scientific advances in tea as it relates to human health.
“There is now an overwhelming body of research from around the world indicating that drinking tea benefits human health,” says Dr. Carol Greenwood, Professor of Nutritional Sciences at the University of Toronto and a Senior Scientist at the Rotman Research Institute at Baycrest.
Dr. Greenwood, an expert on the relationship between diet, nutrition and brain health, went on to say “the compounds in tea appear to impact virtually every cell in the body, resulting in a positive health outcome. Healthier blood vessel linings might be a reason why tea consumption seems associated with so many benefits. The bottom line consensus is that drinking at least a cup of tea a day can contribute significantly to the promotion of public health.”
Flavonoids in tea, among other compounds present in tea leaves, may help ward off inflammation and vascular damage linked to chronic conditions associated with aging.
“Tea is the second most consumed beverage in the world next to water, and about one-third of the weight of a tea leaf is flavonoids. This makes tea a key dietary source of flavonoids” says Louise Roberge, President of the Tea and Herbal Association of Canada.
Researchers are discovering that tea flavonoids may contribute to improved vascular health. Tea supports heart health and healthy blood pressure, and appears to be associated with a reduced risk of cardiovascular disease, including stroke and heart attack.
New research presented by Claudio Ferri, MD, University L’Aquila, Italy, found in 19 normotensive and 19 hypertensive individuals that black tea was able to reduce blood pressure.
In the hypertensive patients, black tea appeared to counteract the negative effects of a high-fat meal on blood pressure and arterial blood flow. Hypertensive subjects were instructed to drink a cup of tea after a meal that contained 0.45 grams fat/lb body weight.
The results suggest that tea prevented the reduction in flow mediated dilation (FMD), the arterial ability to increase blood flow that occurs after a high-fat meal.
“What is healthy for the heart is healthy for the brain” says Dr. Greenwood. We know from the stroke and cardiovascular literature that tea consumption may protect the vasculature and this could explain the reduced stroke risk in tea consumers.
Dr. Lenore Arab’s meta-analysis study suggests that daily consumption of either green or black tea equaling 3 cups per day could prevent the onset of ischemic stroke.
Healthier blood vessels create better blood flow, which means all organs, including the brain benefit. We would anticipate that anything which helps maintain the health of our blood vessels would also help to lower dementia risk, as poor vasculature is a dementia risk factor.
Beyond the ability of flavonoids to help maintain vascular health, there is a body of literature coming from animal studies which suggest that flavonoids may reduce other pathologic events that occur in Alzheimer Disease2 (development of amyloid plaques and neurofibillary tangles).
The interplay between vascular health and Alzheimer diseases is an important area of research.3
Obesity is the largest public health concern in North America and there are few strategies that provide long-term success. Beverages can account for 20% of total calories in a typical Canadian diet.4
Tea is 99.5% water, and without milk and sugar is a zero calorie beverage. Tea is an ideal choice to help consumers meet fluid requirements without adding calories to their diet.
Not only does tea have fewer calories than most beverages but certain compounds in tea, and especially green tea, may help the body burn fat.
Caffeine slightly increases fat-burning, but it could be the combination of caffeine and certain types of flavonoids that increase energy expenditure and fat oxidation. Note that the amount of caffeine from drinking moderate amounts of tea is not dehydrating, and is significantly less than that found in regular coffee.
- Arab et al, Green and Black Tea Consumption and Risk of Stroke, A Meta-Analysis. Stroke, 2009; 40:1786-1792
- Williams et al, Flavonoids, cognition and dementia: Actions, mechanisms, and potential therapeutic utility for Alzheimer disease, Free Radical Biology & Medicine 52, 2012, 35-45
- American Heart Association Scientific Statement, Stroke, 2011, 42:2672-2713
- Garriguet, Beverage consumption of Canadian Adults, Statistics Canada, Health Reports, December 2008
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