Why Drink Tea?
- Nutritional Value
- Anti-oxidants and free radicals
- Cognitive Impairment/Memory Loss
- Tea & Weight Loss
There is a long held belief that caffeinated drinks such as tea have diuretic properties and thus have an adverse effect on hydration, potentially promoting dehydration in the drinker. Tea consumption does not produce a diuretic effect unless the amount of tea consumed at one sitting contained more than 300mg of caffeine. This is equivalent to six or seven cups of tea at one sitting. - Single servings of caffeine at doses exceeding 300mg may have a diuretic effect. - However, a tolerance to caffeine develops so in the unlikely event of there being any diuretic effect, this effect is diminished in people who regularly drink tea. As tea is 99% water it can make a contribution to daily fluid requirements.
“There doesn’t seem to be a downside to tea,” says American Dietetic Association spokeswoman Katherine Tallmadge, MA, RD, LD. Taken without milk or sugar, tea contains no calories and the addition of semi-skimmed milk adds approximately 13 calories to a cup, making tea a healthy alternative to most soft drinks and beverages. Tea is known to be a natural source of fluoride, potassium, manganese and vitamin B2.
It is well known that fruit and vegetables are good sources of antioxidants; however what is less well known is the presence of antioxidants in tea. Tea is known to be a valuable source of anti-oxidants, which assist in fighting free radicals within the body. The major group of antioxidants in tea are flavonoids that appear to be digested, absorbed and metabolised by the body. Green teas contain more of the simple flavonoids called catechins, whilst the oxidisation that the leaves undergo to make black tea converts these simple flavonoids to the more complex varieties called theaflavins and thearubigins. Studies have found that antioxidants in tea, especially green tea, may interfere with the growth of bladder, breast, lung, stomach, pancreatic, and colorectal cancers; prevent clogging of the arteries, burn fat, counteract oxidative stress on the brain, reduce risk of neurological disorders like Alzheimer’s and Parkinson’s diseases, reduce risk of stroke, and improve cholesterol levels.
In 2010 researchers studying dementia, cognitive decline and Alzheimer’s disease found that people who consumed tea had significantly less cognitive decline than non-tea drinkers. Study participants who drank tea 5-10 times/year, 1-3 times/month, 1-4 times/week, and 5+ times/week had average annual rates of decline 17%, 32%, 37%, and 26% lower, respectively, than non-tea drinkers. Coffee consumption did not show any effect except at the very highest level of consumption, where it was associated with significantly decreased decline of 20 percent. The study used data on more than 4,800 men and women aged 65 and older from the Cardiovascular Health Study to examine change in cognitive function over time. Study participants were followed for up to 14 years for naturally-occurring cognitive decline.
Tea, particularly green, has recently been linked with weight loss in adults. This link has arisen from the basis that tea is thought to have a metabolizing effect upon body fats and therefore prove beneficial to weight loss as part of a weight loss program.
There is also a suggestion that green tea consumption can increase endurance in exercise by improving fat metabolism