- Two studies show that a modest increase in fruits, vegetables, and whole grains can reduce the risk of developing type 2 diabetes.
- The findings aren’t surprising, but they’re more scientific, as they used blood biomarkers rather than questionnaires.
- Dietitians recommend eating these foods, along with limiting intake of processed, sugary foods that can cause blood sugar spikes.
Two new studies offer further evidence that a healthy diet — one that includes fruits, vegetables, and whole grains — can help lower the risk of developing type 2 diabetes.
Both studies found that a modest increase in healthier foods was associated with a lower risk of developing type 2 diabetes.
That increase can be as simple as consuming one or more servings a day of whole grain breakfast cereal or slightly increasing fruit and vegetable intake.
The whole grains study found that those who consumed two or more servings of oatmeal per week had a 21 percent lower risk than those who had less than one serving per week.
Because researchers conducted their analysis based on biomarkers in the blood rather than a dietary questionnaire, the data is more reliable, according to one of the study authors.
“By measuring levels of biomarkers in the blood, we did not have to rely on people’s memory of their intakes of fruit and vegetables, and so we minimized error and bias that comes with recall of foods consumed,” explained Dr. Nita Forouhi of the University of Cambridge’s MRC Epidemiology Unit in England and one of the authors of the fruits and vegetables study.
“Previous research has been limited because we have relied solely on subjective recall of people’s diets, so different studies gave different results, and there was a lack of certainty about the link between consumption of fruit and vegetables for diabetes prevention,” Forouhi told Healthline.
The certainty of the findings helps reinforce the advice you’ll likely hear from any doctor or nutritionist: It’s best to stick to natural foods and avoid processed products.
While the analytical nature of the studies provided more accurate results than a simple questionnaire might, the findings don’t come as much of a surprise to experts.
Two nutritionists interviewed by Healthline said the findings are in line with best-practice advice regarding diet.
“This is a message that we’ve heard for quite some time: that foods that are higher in fiber, such as complex carbohydrates, fruits, vegetables, whole grains, brans, and generally foods that take longer to be digested, don’t cause a spike to our blood sugar level,” explained Sharon Zarabi, RD, CDN, CPT, the bariatric program director at Lenox Hill Hospital in New York.
“We know that processed foods, such as crackers, chips, pretzels, white bread, white rice, and sugary cereals — stuff that many Americans eat every day — unfortunately cause those spikes in blood sugar, and over time can lead to diabetes,” Zarabi told Healthline.
Audrey Koltun, RDN, DCES, a dietitian in the pediatric endocrinology unit at Cohen Children’s Medical Center in New Hyde Park, New York, says that for years, dietitians have been recommending that people increase intake of fruits, vegetables, and whole grains.
“These studies both state they support the findings that increasing whole grains, fruits, and vegetables by even a small amount can help in preventing type 2 diabetes. This is huge,” Koltun told Healthline.
The evidence is clear: Eating healthier foods reduces the risk of developing type 2 diabetes.
That can be difficult for someone who lives in an area without quality food choices. The same is true for lower-income families that perhaps can’t afford higher priced products.
But it can also be tough to correct a poor diet even for a higher income person who lives near stores with a multitude of food options.
“You would think this would be an easy recommendation and everyone would comply. However, that is hardly the case,” said Koltun. “So many people have their favorite foods and are very apprehensive about trying something new. Vegetables can be the hardest food to like.”
Complicating matters is the fact that many foods that are advertised as being healthy are often processed and can cause spikes in blood sugar.
Zarabi points out that many cereal and bread products are advertised as whole wheat, which doesn’t necessarily mean they’re whole grain. These products generally include blended flours with refined white flour as the primary ingredient.
“When we look at a box of Cheerios, many patients think that it’s healthy for them and they’re reducing their risk of diabetes, when in fact they’re actually increasing their risk,” she said. “Number one, most people are not using the recommended serving of three-quarters of a cup of cereal, and number two, if they’re adding a cup of milk, it adds another 12 grams of sugar, and another dose of carbohydrates, into their meal.”
To start moving in a healthier direction, Zarabi encourages starting the day off with a high-protein meal such as eggs, Greek yogurt, and whole grain toast, along with vegetables.
Simply looking at your plate can also yield insights.
“I think it’s always important to look at your plate and make sure it’s colorful,” Zarabi said. “Fruits and vegetables are very colorful, so that’s the easiest way for the eye to see if you’re getting that whole range of fruits and vegetables.”
Other ways to boost the diet include replacing rice with riced cauliflower, and replacing pasta and noodles with pasta made from beans, lentils, chickpeas, or peas.
It’s also important to note that getting nutrients directly from the source will always be preferable to taking supplements.
“It is vital to understand that our research does not promote consuming vitamin pills, but rather it indicates the benefits of consuming fruit and vegetables, which contain not only vitamins but also a range of other healthful components,” explained Forouhi.
Koltun also points this out, saying she finds that people are often more willing to take dietary supplements than simply eating healthy foods.
Finally, while the data supports increasing intake of fruits, veggies, and whole grains, diet is only one part of the puzzle.
“Just eating some whole grains, fruits, and vegetables doesn’t automatically reduce your risk of type 2 diabetes,” said Koltun. “Developing a healthy lifestyle and limiting junk food, fast food, sugar-sweetened beverages, and juice, as well as trying to get some physical activity, is also part of working on type 2 diabetes prevention.”