Cancer is now the deadliest in rich countries

Cancer has become the leading cause of death in rich countries, surpassing heart disease, according to the results of two landmark global surveys of a decade on health trends released Tuesday.

The data show that heart disease remains the leading cause of death among middle-aged adults, accounting for more than 40% of deaths.

It is estimated that cancer has caused nearly 17.7 million deaths in 2017. But in the richest countries, cancer now kills more people than heart disease, according to two studies published in the medical journal 'The Lancet' .

"The world is witnessing a new epidemiological transition between different categories of noncommunicable diseases, with cardiovascular disease no longer being the leading cause of death in high-income countries," said Gilles Deganais, professor emeritus at the University of Montreal. 39 Laval University, Quebec.

His team's study showed that cancer was the second leading cause of death in the world in 2017, with just over a quarter (26%) of deaths.

Deganais said that as heart disease rates drop globally, cancer could become the leading cause of death in the world "a few decades from now".

The study followed more than 160,000 adults, in high-income, middle-income and low-income countries. He determined that people in the poorest countries were on average 2.5 times more likely to die of heart disease than those in richer countries.

In contrast, he found that non-infectious diseases such as cancer and pneumonia were less common in low-income countries than in rich countries.

A second study, also conducted by Canadian researchers, on data from patients in 21 countries, found that so-called "modifiable risk factors" accounted for 70% of heart disease cases worldwide.

These included diet, behavior and socio-economic factors, they said. Metabolic risk factors – high cholesterol, obesity or diabetes – are responsible for more than 40% of heart disease and were by far the major determinant of the disease in the richest countries.

But there was also a strong link between heart disease in developing countries and household air pollution, poor nutrition and low levels of education.

"A shift in tactics is needed to mitigate the disproportionate impact of cardiovascular disease in low- and middle-income countries," said Salim Yusuf, a professor of medicine at McMaster University.

"Governments in these countries need to start investing more of their gross domestic product in the prevention and management of noncommunicable diseases, including cardiovascular diseases, rather than focusing primarily on infectious diseases."