Replacing that daily muffin with a handful or two of nuts may help people with diabetes better control their blood sugar and cholesterol levels, according to a study.

When people with type 2 diabetes replaced some of their usual carbohydrates with about a half-cup of mixed nuts each day, their blood sugar and "bad" cholesterol levels dipped slightly over three months, researchers wrote in the journal Diabetes Care.

By contrast, no such improvements were seen among people who swapped their normal carbs for a daily whole-wheat muffin.

While the findings don't mean that nuts are the key to diabetes control, they can be part of a healthy diet, said Cyril Kendall of the University of Toronto in Canada, one of the researchers involved.

"We should be focusing on overall diet and lifestyle," Kendall told Reuters Health. "They (nuts) have a lot of fat, but we now realise that those fats are healthy ones," he said, referring to the unsaturated fats that have been linked to a lower risk of heart disease and other health benefits.     

Still, nuts are high in calories, and people with diabetes should not simply add a handful to their usual diet but should use them in place of less healthy snacks, Kendall said.

For the study, 117 adults with type 2 diabetes were randomly assigned to one of three groups. One group was given unsalted mixed nuts and told to eat them instead of some of their usual carbs, a second group replaced their normal carbs with "healthy" whole-wheat muffins with no added sugar, and the third group went on a half-nut, half-muffin regimen.

The "full-nut" group ate, on average, about 2 ounces, or a half cup, of nuts per day, totaling roughly 475 calories. After three months, the researchers found, the full-nut group showed a 0.2 percent dip in their average hemoglobin AIC level -- a measure of long-term blood sugar control.

The change was small and "just shy," Kendall said, of what is considered a clinically significant improvement in blood sugar control. But the people in the study were already on diabetes medication and typically had good blood sugar control.

"So we're seeing a benefit over and above what they were achieving with medication," he added. As for cholesterol, the nut group's average LDL cholesterol -- the "bad" kind -- declined from about 97 milligrams per deciliter to 89 mg/dL. An LDL count below 100 mg/dL is generally considered optimal.     

No similar improvements were seen in the other two groups. It wasn't clear why the full-nut group showed better blood sugar and cholesterol levels, but Kendall said he suspects it is largely because of the monounsaturated fats in nuts.

For people who aren't crazy about nuts, there are other sources of monounsaturated fats, such as olive oil and avocados.
 While the study did not look at those foods, Kendall said it might be a wise move to replace some carbs with those fats.

The study was partially funded by the International Tree Nut Council Nutrition Research & Education Foundation and the Peanut Institute, both industry groups.  - Reuters