For people recently diagnosed with type 2 diabetes, eating lots of olive oil, fish and whole grains slows progression of the disease more than restricting fat, according to a new analysis.
In a trial that followed participants for more than eight years, those following a so-called Mediterranean diet went significantly longer before needing diabetes medication and more of them had their diabetes go into remission, compared to those on a low-fat diet.
"There's been lots of epidemiology suggesting that a Mediterranean diet was beneficial with metabolic syndrome and diabetes," Dr Leanne Olansky told Reuters Health.
"But this was a randomized controlled trial, so we know it really was the diet causing the results," she said. "This is the kind of evidence that we use to determine if drugs are effective."
"Everybody thinks of fat as being bad, but this shows that it depends on what kind of fat," said Olansky, an endocrinologist at the Cleveland Clinic who was not involved in the new study.
People diagnosed with diabetes should aim to have a healthy diet, and a Mediterranean diet is a good, healthy option, lead study author Katherine Esposito told Reuters Health in an email.
Cutting calories is important, and cutting fat is an easy way to cut calories, but according to this study, maintaining the right levels of healthy fats is important, she said.
"One of the main aspects of the Mediterranean diet is the percentage of daily fat, which is higher than 30 percent of daily calories, however, the main fat is monounsaturated, usually from olive oil in the Mediterranean basin," said Esposito, of the Diabetes Unit at University Hospital at the Second University of Naples in Italy.
She and her colleagues continued to follow participants in a previous study who had been divided into two groups - one assigned to follow a Mediterranean diet and the other a low-fat diet - when they were first diagnosed with type 2 diabetes.
Both diets were designed to help prevent the disease from getting worse and to keep blood sugar under control without medication for as long as possible.
On both diets, women aimed to consume 1,500 calories per day and men aimed for 1,800 per day. Mediterranean dieters ate lots of vegetables and whole grains and replaced most red meat with poultry and fish. Monthly sessions with nutritionists helped them keep less than half of their calories coming from carbohydrates and at least 30 percent of calories from fat,