Unilever is the world’s largest supplier of branded tea. Lipton, Glen and Joko are some of the best-known tea brands found in South Africa. Unilever has a long history of tea research, which includes the effects of tea – often executed in close collaboration with external tea researchers – and our findings are published in numerous papers and peer-reviewed journals.
Tea and Flavonoids:
Flavonoids are a group of plant substances within the polyphenol family. They are not nutrients, yet they are thought to support and promote good health due to special properties shown in-vitro that enable them to reduce inflammation, inhibit cancer cells and maintain vascular function. Examples of individual flavonoids include catechins, which are found mainly in green tea, and quercetin, which is found in onions.
The key dietary sources of flavonoids in Western countries are tea, onions, red wine, chocolate and fruit1. Black tea contributes 60-84% of dietary flavonoids in Western populations2, although green and white teas are more concentrated sources. The level and type of flavonoids in tea varies greatly depending on the type of tea (green, white or black), variety, growing conditions, manufacturing process, and tea preparation habits (eg. brewing time).
Many studies have linked a high intake of flavonoids with healthy living and a reduction in the risk of developing a chronic disease. The most researched areas remain cardiovascular disease and cancer 4, 5, 6, 7, 8, 9. However, there is emerging data on other areas of health such as mental function, weight control and diabetes.
- Erdman JW et al (2007). Flavonoids and heart health: Proceedings of the ILSI North American flavonoids workshop. Journal of Nutrition 137, 178S-375.
- Hertog MG et al (1993). Dietary antioxidant flavonoids and the risk of coronary heart disease: the Zutphen Elderly Study. Lancet 342, 1007-11.
- Astill C et al (2001). Factors affecting the caffeine and polyphenol contents of black and green tea infusions. Journal of Agriculture & Food Chemistry 49,5340-7.
- Peters U et al (2001). Does tea affect cardiovascular disease? A meta-analysis. American Journal of Epidemiology 154, 495-503.
- Huxley PR e Neil HA (2003). The relation between dietary flavanol intake and coronary heart disease mortality: a meta-analysis of prospective cohort studies. European Journal of Clinical Nutrition 57, 904-8.
- Hooper L et al (2008). Flavonoids, Flavanoid-rich foods, and cardiovascular risk: a meta-analysis of randomized controlled trials. American Journal of Clinical Nutrition 88, 38-50.
- Schroeter H et al (2006). (-)-epicatechin mediates beneficial effects of flavanol-rich cocoa on vascular function in humans. Proc Natl Acad Sci USA 103: 1024-1029
- Widlansky ME et al (2007). Acute EGCG supplementation reverses endothelial dysfunction in patients with coronary artery disease. Journal of the American College of Nutrition 26, 95-102.
- Loke WM et al (2008). Pure dietary flavonoids querccetin and (-) epicatechin augment nitric oxide products and reduce endothelin -1 acutely in healthy men. American Journal of Clinical Nutrition 88,1018-25.
- Westerterp- Plantenga MS (2010). Green tea, catechins, caffeine and body-weight regulation. Physiology & behaviour (Epub ahead of print).
- Hughes LA et al (2008). Higher dietary flavones, flavanol, and catechin intakes are associated with less of an increase in BMI over time in women : a longitudinal analysis from the Netherlands Cohort study. American Journal of Clinical Nutrition 88, 1341-52.
- Spencer JPE (2009). Flavonoids and brain health: multiple effects underpinned by common mechanisms. Genes & Nutrition 4, 243-250.
- Nurk E et al (2009). Intake of flavanoid rich wine, tea and chocolate by elderly men and women is associated with better cognitive test performance. Journal of Nutrition 139, 120-7.
- Odegaard AO et al ( 2008). Coffee, tea and incident type 2 diabetes: the Singapore Chinese Health Study. American Journal of Clinical Nutrition 88, 979-85.
- Huxley R et al (2009). Coffee, decaffeinated coffee, and tea consumption in relation to incident type 2 diabetes mellitus. A systematic review with meta-analysis. Archives of Internal Medicine 169, 2053-2063.
- Jing Y et al (2009). Tea consumption and risk of type 2 diabetes: a meta-analysis of cohort studies. Journal General and International Medicine 24, 557-62.