Eating Nuts Daily Could Help Control Type 2 Diabetes and Prevent Complications, Study Suggests

ScienceDaily (July 12, 2011) — Eating nuts every day could help control Type 2 diabetes and prevent its complications, according to new research from St. Michael's Hospital and the University of Toronto.

Eating nuts every day could help control Type 2 diabetes and prevent its complications, according to new research from St. Michael's Hospital and the University of Toronto. (Credit: © Dmitry Rukhlenko / Fotolia)

In the research, published online by the journal Diabetes Care, a team of researchers led by Dr. David Jenkins (University of Toronto Department of Nutritional Sciences; St. Michael's Hospital Risk Factor Modification Centre) reports that consuming two ounces of nuts daily as a replacement for carbohydrates proved effective at glycemic and serum lipid control for people with Type 2 diabetes.

"Mixed, unsalted, raw, or dry-roasted nuts have benefits for both blood glucose control and blood lipids and may be used as part of a strategy to improve diabetes control without weight gain," said Dr. Jenkins, who also has appointments with St. Michael's Division of Endocrinology and Metabolism and the U of T's Department of Medicine. He also serves as Canada Research Chair in Nutrition and Metabolism.

Jenkins and his colleagues provided three different diet supplements to subjects with Type 2 diabetes. One group was given muffins, one was provided with a mixture of nuts including raw almonds, pistachios, walnuts, pecans, hazelnuts, peanuts, cashews, and macadamias, and one group was given a mixture of muffins and nuts.

Subjects receiving the nut-only supplement reported the greatest improvement in blood glucose control using the glycosylated hemoglobin (HbA1c) test. The nut diet subjects also experienced a reduction in low-density lipoprotein cholesterol (known as LDL, or "bad cholesterol"). The subjects provided the muffin supplement or mixed muffin-and-nut supplement experienced no significant improvement in gylcemic control but those receiving the muffin-nut mixture also significantly lowered their serum LDL levels.

"Those receiving the full dose of nuts reduced their HbA1c [the long-term marker of glycemic control] by two-thirds of what the U.S. Food and Drug Administration recognizes as being clinically meaningful for therapeutic agents. Furthermore, neither in the current study nor in previous reports has nut consumption been associated with weight gain. If anything, nuts appear to be well suited as part of weight-reducing diets," Dr. Jenkins said.

"The study indicates that nuts can provide a specific food option for people with Type 2 diabetes wishing to reduce their carbohydrate intake."

Nuts Good for Some With Diabetes
Study Shows Daily Serving of Nuts Improves Blood Sugar in Type 2 Diabetes
By Bill Hendrick
WebMD Health News
Reviewed by Laura J. Martin, MD

July 8, 2011 -- Eating about 2 ounces of nuts daily in place of carbohydrates may be beneficial to people with type 2 diabetes by lowering bad cholesterol levels and improving blood sugar control, a new study shows.

"There are two important factors in caring for diabetes: blood sugar control and heart health," study researcher Cyril W.C. Kendall, PhD, of the University of Toronto, says in a news release.

Nut Study Design
The study involved 117 people with type 2 diabetes who were randomly assigned to one of three groups. One group's members ate about 2 ounces of mixed nuts daily, another a healthy muffin, and the third half nuts and half muffin.

Researchers say those whose diet included 2 ounces of nuts showed better results after three months in both blood sugar and LDL "bad" cholesterol levels than participants in the other two groups.

The nuts consisted of a mixture of unsalted and mostly raw almonds, pistachios, walnuts, pecans, hazelnuts, peanuts, cashews, and macadamias.

The muffin was concocted to be a healthy whole wheat product, sweetened with apple concentrate but with no sugar added. The muffins had similar protein content to the nuts from the addition of egg white and skim milk powder. Calories from monounsaturated fatty acids (MUFAs) in the nuts were the same as the carbohydrate calories in the muffin, the researchers write.

During the three-month study, participants were asked to maintain their oral diabetes medications.

Blood Sugar Improvement
The main outcome researchers looked for was change in a marker of blood sugar control called HbA1c.

Kendall described the results of the study as "a very exciting and promising finding about the treatment" of type 2 diabetes.

The researchers write that the reduction in the HbA1c level was significantly more in those in the nuts-only group than participants in the other groups.

The reduction of LDL "bad" cholesterol was also significantly greater in those who ate 2 ounces of nuts compared with the group eating muffins.

"We conclude that mixed, unsalted, raw, or dry-roasted nuts have benefits for both blood glucose control and blood lipids and may be used to increase vegetable oil and protein intake in the diets of type 2 diabetic patients as part of a strategy to improve diabetes control without weight gain," the researchers write.

The study is published in the August issue of Diabetes Care.
One of the supporters of the study was the International Tree Nut Council Nutrition Research and Education Foundation, which represents almonds, Brazil nuts, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios, and walnuts, and also the Peanut Institute.

Both Kendall and David J.A. Jenkins, MD, also of the University of Toronto and author of the study, acknowledged receiving honoraria from the Almond Board of California, the International Tree Nut Council Nutrition Research and Education Foundation, and Unilever Canada.

SOURCES: News release, Western Pistachio Association.Jenkins, J. Diabetes Care, August 2011; vol 34.

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