While the good news is that we're all living longer - in the west, twice the lifespan of our ancestors 200 years ago - there is a down side: as the ageing world population increases, so will the incidence of age-related diseases. It's predicted that in 20 years, they will be responsible for three quarters of all deaths in the developing world. Chronic diseases such as diabetes, cancer and cardiovascular conditions are more likely to appear. And if you survive all these, there are arthritis and neurological conditions, such as Alzheimer's disease.
Scientists grappling with how to deal with an increasingly elderly population are looking for ways of eradicating these diseases. Hopeful signals are coming from research into antioxidants. The body produces free radicals which can damage cells and, so the theory goes, the cumulative effects of such damage can account for the physical changes and diseases associated with ageing. Antioxidants - which are produced in the body or obtained from some foods and vitamins - mop up free radicals and may help to offset the ageing process and protect against heart disease and cancer. Researchers suggest that damage caused by these free radicals can be minimised by following a diet rich in antioxidants - fruit, vegetables and wholegrains. Others say that such a diet has to be accopanied by a low calorie intake.
Melatonin is another buzzword in the anti-ageing world. It's a hormone produced by the pineal gland and is important is orchestrating our biorhythms and sleep patterns. It can also scavenge free radicals. As we age, melatonin levels decrease. Some studies show that supplements of the hormone boost the immune system, lower blood cholesterol levels and help the body fight cancer and cardiovascular disease. These benefits have not been proven in humans and the safety of melatonin supplements has been questioned.
In the meantime, the quest for eternal youth has opened up a massive market throughout the western world. Every year, 65,000 Britons opt for cosmetic surgery. For those who fight shy of the knife, there are hundreds of "revolutionary" creams claiming to rejuvenate ageing skin.
But dermatologists say that the only way to have young skin is to stay out of the sun. Putting creams on your face 40 years on will add moisture, but otherwise it's a bit like closing the door after the horse has bolted. Good genes help too, but if you don't have them it may be some time before we can acquire them artificially.
"If I'd known I was going to live this long, I'd have taken better care of myself," quipped American jazz pianist Eubie Blake on his 100th birthday, five days before he died. As we face longer and longer lives, that's the big challenge. While the Baluchistani woman doesn't have access to sunblocks and health advice, we do. Photograph by: Steve McCurry.
Antioxidants and melatonin: