Children should start drinking tea from the age of four to combat obesity, stress and heart disease, a study has found.
Other wider benefits of a daily brew include lowering the risk of stroke among the elderly and acting as a replacement for sugary drinks.
Green tea and more traditional black tea contain compounds such as flavonoid phenolics, L-theanine and caffeine which can aid concentration and cognitive function.
Dr Pamela Mason, who authored the study for the Nutrition and Food Technology journal, analysed the results of 60 different scientific studies into tea and its effect on 'wellness'.
The research found that consuming Camellia sinensis (the plant from which tea is made) throughout life from childhood onwards can improve cardiovascular health and boost the immune system.
Dr Mason said: “Including three cups of black tea daily as part of a healthy lifestyle could help to preserve physical and mental health in childhood, through the teens and adulthood, pregnancy and into old age."
Parents should use tea as a substitute for sweet and sugary drinks for children as young as four, she added.
The study also found that L-theanine, an amino acid unique to tea in the UK diet, helps relaxation, reduces stress and in combination with caffeine influences brain functions such as alertness and concentration.
Flavonoid polyphenols, particularly one called EGCG, the dominant phenolic compound in green tea, boosts nitric oxide levels which lowers blood pressure and is an antioxidant that lowers inflammation which reduces the risk of heart and vascular disease as well as strokes.
Dr Tim Bond, from the Tea Advisory Panel, which independently commissioned the research, added: "We know that tea drinking is a marker of reduced risk of developing cardiovascular disease and dying from a stroke or heart attack but we also understand why.
“Clinical and laboratory studies show that tea polyphenols limit cholesterol absorption in the gut and target receptors which regulate blood cholesterol levels."