Cancer has surpassed heart disease as the leading cause of death among people aged 35 to 70 in rich countries, according to a study published Tuesday in British medical journal The Lancet.

Globally, however, cardiovascular disease remains the main cause of death among middle-aged adults, accounting for 40 per cent of all deaths, compared with 26 per cent for cancer.

The Prospective Urban and Rural Epidemiological study (PURE) followed 162,534 men and women aged 35 to 70 in 21 countries on all continents except Australia.

The findings backed up a larger 2017 study that found that cancer was now causing more deaths than heart disease among people aged 50 to 69 in high-income countries, the authors said.

Deaths from cardiovascular disease were two-and-a-half times more common in low-income than in high-income countries, even though the risk factors were greater in the latter, they found.

‘Rates of hospital admission and of medication use were inversely associated with death, suggesting that lower health-care availability or accessibility might be contributing factors to higher mortality in the poorer countries,’ the authors said.

Governments in lower- and middle-income countries should invest more in preventing and managing non-communicable diseases, including cardiovascular disease, ‘rather than focussing largely on infectious diseases,’ lead investigator Salim Yusuf said.