Biologists reckon our bodies could last up to 120 years. We all know about smoking, exercise, diet, etc, but here are some other longevity-boosters. (Sorry, gains aren't cumulative.)

Eat three chocolate bars a month. (Add 1 year) In a study of 7,841 male Harvard graduates, those who ate 1-3 bars a month lived a year longer than those who ate more or none at all. Chocolate contains phenols, antioxidants that appear to help prevent heart disease.

Visit a house of prayer twice a week. (Add 7-14 years) A study reported that white people attending religious services more than once a week lived on average seven years longer than those who didn't. Among black people the figure was 14 years. Such people have lover rates of smoking and drinking, plus helpful factors such as strong social ties.

Don't make mobile phone calls while driving. (Add 1-2 years) Every day 99 years of life are lost when motorists blabbing on their mobiles crash. So each one-minute call shaves an average of 45 seconds off your life.

Ask lots of questions. (Add up to 5 years) Research on 1,200 pensioners for five years found those who were most curious had a 30% better chance of living beyond this period. Higher curiosity levels may mean better adaptation to changes, challenges and stress.

Think positive. (Add 2 years) AIDS patients with pessimistic outlooks, says one study, died on average two years before more positive subjects.

Be eccentric. (Add 5-10 years) A Scottish neuropsychologist studying 1,000 eccentrics (one built to lectern on his roof to preach to his sheep) found they live five to ten years longer than normal people. One reason: they're unencumbered by the usual worries the rest of us fret over.