Millions of adults die every year from bugs and toxins in what they eat, according to new World Health Organization data that shows food-borne diseases are far more deadly than the U.N. agency previously estimated.

The research faults unsafe food for 1.2 million deaths per year in people over the age of five in Southeast Asia and Africa -- three times more adult deaths than the Geneva-based WHO had thought occurred in the whole world.

"It is a picture that we have never had before," WHO Food Safety Director Jorgen Schlundt said in an interview. "We now have documentation of a significant burden outside the less than five group, that is major new information."

Ailments linked to contaminated food and water have long been seen as a major threat to young children, who can dehydrate quickly. But the Danish veterinarian and microbiologist said the risks to older populations had been grossly underestimated.

Older children and the elderly are especially vulnerable to severe illness from major food- and water-borne diseases such as salmonella, listeria, E. coli, Hepatitis A and cholera.

Food safety experts are now seeking to measure the burden of such afflictions in people over the age of five in the Arab world, Latin America and elsewhere in Asia including China.

And already, Schlundt said, health officials are recognizing the need to confront the most dangerous types of contamination in their industrial regulations and trade standards.

"Literally millions are dying every year and we know that a lot of these could be prevented," he told Reuters. "There is a realization that instead of doing what we did in the past, in the future we should really focus on where the problems are."

MODERN FOOD PRODUCTION

Many of the contaminants that have made headlines in recent years in the United States, such as salmonella and E. coli, also exist in poorer countries but are not monitored as carefully there, according to Schlundt.

Health authorities in developed countries are now much more able to document food safety risks because of tests that can quickly connect disparate cases of illness to tainted foods such as lettuce, peppers, spinach and beef.

But the WHO expert said that some ailments have also become more prevalent in the food system alongside the globalization of the food supply and the rise of modern food production methods, which can propagate ailments quickly and on a large scale.

"There are certain pathogens that have increased over the last 20 or 30 years. Some problems clearly have moved and become bigger because of the ways that we produce," he said.

Simple steps can cut the levels of chemicals and toxins in foods, such as avoiding conditions where mold can grow, Schlundt said. Farming techniques can also root out microorganisms from the food chain and parasites can be wiped out by targeting their hosts and transmission patterns, he said.

Because it is now clear that some foods are more vulnerable to certain food-borne ailments than others, health officials are well-placed to focus their energies on monitoring areas posing the highest potential disease risk, according to Schlundt.

Another vital part of the food-borne disease fight is having consumers take precautions in the way they prepare foods, and ensuring patients and health workers take symptoms such as diarrhea seriously as a risk across population groups.

"Many of the deaths that we see in developing countries, if they had been treated at the right time, they would not have died," Schlundt said.