Telomeres are the endcaps on chromosomes, and telomeric shortening is thought to govern the number of times a cell can divide. Ruth Chan and a team of Hong Kong-based researchers studied  976 Chinese men and 1,030 Chinese women, ages 65+, surveying their dietary habits via a food questionnaire. Overall, only tea consumption was associated with telomere length. The highest intakes of Chinese tea (black or green), at three cups or 750 millilitres per day, was associated with telomeres that were 4.6 kilobases longer than people who drank an average of a quarter of a cup a day.  The researchers calculated that this average difference in the telomere length corresponds to "approximately a difference of 5 years of life," and comment that "the antioxidative properties of tea and its constituent nutrients may protect telomeres from oxidative damage in the normal ageing process."