Scientific studies have linked the toxins, called advanced glycation end products (AGEs), with inflammation, insulin resistance, diabetes, vascular and kidney disease, and Alzheimer's.

The implication of the new study could lead to a larger food health scare -- and the resulting reaction from manufacturers -- than that surrounding acrylamide, a chemical also produced by a chemical reaction during processing.

The new study by Mount Sinai School of Medicine researchers found that AGE levels are elevated in the blood of healthy people, and even more so in older individuals than in younger people.

"Of particular interest was the finding that a major determinant of the blood levels of AGEs is the amount of AGEs in the diet, not dietary calories, sugar, or fat," the researchers stated.

AGEs are a group of compounds formed from the non-enzymatic reaction of reducing sugars with the free amino groups of proteins. They are also produced when meat products are sterilised and pasteurised.

They are absorbed into the body through the consumption of grilled, fried, or broiled animal products.

Helen Vlassara, the senior study author, said the research meant that processors should put AGE levels on nutrition labels.

People should be given information about their AGE intake and be advised to consider it in the same way they would think about trans fats and salt intake. They should be warned about their AGE levels the way they are about their cholesterol levels or cigarette smoking, he said.

"AGEs are quite deceptive, since they also give our food desirable tastes and smells," he said. "So, consuming high amounts of grilled, broiled, or fried food means consuming significant amounts of AGEs, and AGEs in excess are toxic."

Inflammation and oxidative stress are more common in older age, so the goal of the study was to assess whether AGEs played a significant role in age-related inflammation and oxidative stress by measuring AGE levels in both young and older individuals.

Blood tests on test subjects showed that AGE levels were 35 per cent higher in individuals aged 65 and older compared with those younger than age 45.

The study also showed that in all of the participants, the higher the consumption of foods rich in AGEs, the higher the blood levels of AGEs, and the higher the levels of markers of inflammation.

The study also showed that AGE levels could be very high in young healthy people. High AGE levels found in some healthy adults in the study were on par with AGE levels observed in diabetic patients in their earlier studies, the researchers said.

"The fact that healthy adults had levels similar to those seen in diabetic patients may suggest that early and prolonged exposure to these substances in the diet could accelerate the onset of diseases," Vlassara said.

AGE-rich foods correlates with rising rates of diabetes and heart disease.

"Excessive intake of fried, broiled, and grilled foods can overload the body's natural capacity to remove AGEs so they accumulate in our tissues, and take over the body's own built-in defenses, pushing them toward a state of inflammation," Vlassara said. "Over time, this can precipitate disease or early aging."

He said that once AGEs enter the body, it becomes more difficult to get them out, especially as people age.

Older people have a reduced capacity for removing AGEs from the body, the researchers said, most likely because kidney function slows down as the body ages.

"Although the accumulation of AGEs pose an immediate and significant health threat to the older adult population, they are also an invisible, lingering danger especially for younger people and this needs to be addressed," Vlassara said.

New methods of cooking to reduce AGE intake, particularly steaming, boiling or making stews, can make a difference, he said. Keeping the heat down and maintaining the water content in food reduces AGE levels.

In other studies, the team found that cutting AGE intake in half, but maintaining a diet comprised of the same calories and fat, increased the lifespan of animals when compared with animals fed their usual diet.

The study is published in the April issue of the Journal of Gerontology: Medical Sciences.

In relation to acrylamide, many processors have reacted by changing their manufacturing methods to lessen the amount of cancer-causing chemical in their products.

The chemical is a carcinogen that is created when starchy foods are baked, roasted, fried or toasted. It first hit the headlines in 2002, when scientists at the Swedish Food Administration first reported unexpectedly high levels of acrylamide in carbohydrate-rich foods.

Previous studies have linked the chemical with cancer in laboratory rats.