Two new studies are being presented this week that highlight the health benefits of a diet that includes nuts and seeds. The research is being presented at the 2010 Experimental Biology meeting and focuses primarily on the nutritional qualities of tree nuts, such as pistachios.

The first study focuses on the correlation between snacking on nuts and long-term blood sugar control in type 2 diabetes. Researchers from the Department of Nutritional Sciences at the University of Toronto found that the addition of 75 grams of nuts to the diet, or a little more than 2.5 ounces, significantly lowered HbA1c, which is a measurement of average blood sugar levels over the course of the previous three months. The polyunsaturated fat also helped to control blood lipids, such as total cholesterol and LDL cholesterol, both of which are significant factors in the development of heart disease in people with type 2 diabetes.

The second study used data from the National Health and Nutrition Examination Survey (NHANES) to find that those who snacked on nuts had an overall higher quality of diet and nutrient intake and had lower prevalence of health risks, including less obesity, hypertension, and metabolic syndrome. The reasons are likely related to the vitamin and mineral content of nuts, including fiber, vitamin E, magnesium, and potassium. Snacking on nuts may also replace less healthy snack options such as salty chips or sweet treats.

In addition to pistachios, other tree nuts include almonds, brazil nuts, cashews, chestnuts, filbert/hazelnuts, macadamia nuts, pecans, pine nuts, and walnuts.

The thing to be mindful of when it comes to snacking on nuts is that it only takes a small amount for health and nutrition benefits — too many will add too many calories to your diet, leading to possible weight gain that could counteract the positive influence. Of all of the tree nuts, pistachios offer the fewest calories in a portion size. A one ounce serving consists of 49 nuts and only 160 calories. Compare that to 10 macadamia nuts that contribute 200 calories or 6 Brazil nuts that contain 190 calories. The next two lowest in calories per serving are almonds and cashews.

Almonds contain the most fiber per serving at 4 grams. Fiber is beneficial for protection against both heart disease and diabetes, as well as may offer protection against colon cancer. Fiber can help lower cholesterol by binding with cholesterol in the intestine so it is not absorbed. Higher fiber foods also take longer to digest, so they do not contribute as much to blood sugar spikes as other snack foods may.

Tree nuts also contain phytochemicals and antioxidants that may help reduce the heart disease, cancer and other chronic disease. Almonds, hazelnuts, pecans and pistachios have the highest amounts of flavonoids, which may have anti-inflammatory and anti-tumor activity.