A diet heavy in animal products and other acidic foods can cause an acid load in the body, resulting in health complications. This includes reduced insulin sensitivity, which can lead to type 2 diabetes, according to the new study.
"We have demonstrated for the first time in a large prospective study that dietary acid load was positively associated with type 2 diabetes risk, independently of other known risk factors for diabetes," the researchers said. "Our results need to be validated in other populations, and may lead to promotion of diets with a low acid load for the prevention of diabetes."
The term animal products refer to meat, eggs and dairy. Greater consumption of fruits and vegetables is believed to lead to a lower acid load, the researchers said.
The study included more than 66 000 women in Europe who were followed for more than 14 years. During that time, nearly 1 400 of the women were diagnosed with type 2 diabetes.
Acid load reduction
Those with diets highest in acidic foods were 56% more likely to develop diabetes than those with diets lowest in acidic foods, according to the study, which was published recently in the journal Diabetologia.
This link between a highly acidic diet and increased risk of diabetes remained even after the researchers adjusted for dietary patterns, meat consumption and intake of fruit, vegetables, coffee and sweetened beverages.
The study did not, however, prove that a highly acidic diet actually causes diabetes.
"A diet rich in animal protein may favour net acid intake, while most fruits and vegetables form alkaline precursors that neutralise the acidity," wrote Dr Guy Fagherazzi and Dr Francoise Clavel-Chapelon, of the Centre for Research in Epidemiology and Population Health at INSERM, in Paris."Contrary to what is generally believed, most fruits such as peaches, apples, pears, bananas and even lemons and oranges actually reduce dietary acid load once the body has processed them."
INSERM is the French equivalent of the US National Institutes of Health.
The US Office of Disease Prevention and Health Promotion outlines ways to prevent type 2 diabetes.