An apple a day may keep you-know-who away, but a healthy intake of fruit will also keep your first chronic disease away too.
In the first study of its kind, a group of international scientists have examined the role of a healthy diet in delaying the onset of multiple chronic diseases such as diabetes, heart disease and high blood pressure.
They found people who consumed a diet high in fruit, vegetables and certain grains had a lower risk of developing not just one but multiple chronic conditions.
More specifically, they found study participants who consumed the most fruit took longer to develop their first chronic disease, while people who ate the most vegetables extended the time between the onset of their first and second chronic illness.
"Those findings are in line with current food guides recommendations on fruits and vegetables and whole grain cereals," the researchers said.
While the benefits of diet on health have been known for decades, Zumin Shi, a researcher involved in the study, said previous studies focused on the link between nutrition and a single disease.
Dr Shi, from the University of Adelaide, said he and his colleagues studied more than 1000 Chinese people over five years, observing the link between diet and 11 chronic diseases.
“We looked at the transition [people go through] from one disease to multiple diseases in association with their food intake,” he said.
The study also isolated the role of nutrition from other risk factors, such as smoking or a lack of physical exercise, that contribute to chronic disease risk.
The group, who have published their results in the journal Clinical Nutrition, found participants who consumed whole grains also had lower rates of chronic disease.
Dr Shi said grains other than rice and wheat such as oats, corn, sorghum, rye, barley, millet and quinoa were less likely to be refined and therefore likely to contain more dietary fibre, which reduced the risk of cardiovascular disease, diabetes and colourectal cancer.
"Rice intake was significantly lower in the healthy group,” he said.
Dr Shi said as it was common for people to have multiple diseases at the same time, which may or may not be related to each other, it was important to consider that dietary advice to prevent one disease may have effects on other conditions.
In their Chinese participants they found high rates of anaemia and diabetes, but the measures required to prevent each condition were conflicting, he said. “To prevent anaemia [people] need iron, but high iron was not good for people with diabetes,” Dr Shi said.