Western governments are drastically underestimating how long their citizens are likely to live, according to a new article in the journal "Science".

Two scientists from Cambridge and Rostock argue that life expectancy will go on increasing indefinitely. By comparing differences in life expectancy between the world's wealthier countries, they conclude that as early as 2070, female life expectancy in the US could be as high as 101 years.

The official US forecast for 2070 is only 83.9 years.

Forum Response: Help the Aged

A spokeswoman for Help the Aged told ePolitix.com: "It is encouraging that the essential issues of life expectancy and health are being examined. However it is vital that in assessing the implications of this new demographic, we do not once again assume that older people are a burden on society. Ageism is the last thing we need in an ageing society.

"The increase in life expectancy is one of the greatest triumphs of the last hundred years - it provides many opportunities, but is also a clear challenge to society's continuing devaluing of older people. People are living longer and birth rates are falling - this is our new reality.

"We need to plan not panic, and prioritise: Boosting health levels at all ages; combating poverty and providing for an affordable older age; challenging age discrimination; and employing and retaining older workers."