South Korean women will soon outlive us all. What's their secret?

Women born in South Korea in 2030 are projected to be the first in the world to have an average life expectancy of above 90, a new study has found.

And six other countries are not very far behind. France, Japan, Australia, Canada, Chile and the UK are all likely to see women’s average life expectancy at birth pass 85 by 2030, according to the research by Imperial College London and the World Health Organization, which looked at future life expectancy in 35 industrialized countries.

The study, published in The Lancet medical journal, predicted that life spans would continue to increase significantly in most of the countries studied.

In the United States, however, life expectancy is set to rise more slowly. This is due to a combination of factors including obesity, high maternal and infant mortality rates, unequal access to healthcare and relatively high homicide rates.

By 2030 lifespans at birth for American men will be comparable to those of Czech men (under 80) and American women will have life expectancy similar to those in Croatia and Mexico (under 85).

A lot of it is to do with how tall people are. The US is the first wealthy country to experience stagnation or even a possible decline in average adult height – a factor that correlates closely with health and longevity.

Kimchi is the new superfood

The study, which uses 21 different models to forecast life expectancy, gives South Korean women born in 2030 a 57% chance of exceeding the age of 90, and a 97% probability they will live to be over 86.

The researchers say South Koreans’ expected longevity is based on the assumption that they will have lower average-body-mass indexes (BMIs) and blood pressure than citizens of other comparable countries.

Their long lifespans could also be down to the South Korean diet, other experts suggest; most notably kimchi, a dish based on fermented vegetables – usually cabbage – which is high in probiotics and vitamins A and B.

Other factors driving rising life expectancies in the countries at the top of the league table include improved nutritional education, advances in economic and social status, lower road-traffic accident rates and high-quality healthcare systems, which improve prevention and survival rates from serious diseases and reduce infant mortality.

Men are catching up

The gap between the average lifespans of men and women is beginning to close in most of the countries studied. Although men continue to have greater lifestyle risk factors, such as smoking and cardiovascular disease, women’s lifestyles are becoming more like men’s and their life expectancy advantage is likely to shrink in every country by 2030.

Notable exceptions are Mexico – where female life expectancy is predicted to increase more than male life expectancy – and Chile, France and Greece, where the two sexes are likely to see similar lifespan gains.

The impact on health and social care

With many people living well into their 80s and even 90s in future, the researchers underline the impact that this increased longevity will have on health and social care services.

They argue that countries will need to go beyond increasing capacity and take into consideration how and where healthcare is delivered.