Which Nuts are Good for Diabetes?
Many people will seek out healthier food in the new year in the search for improved health, but those with diabetes need to pay constant attention to their diet throughout their lives. This group maintains a tight control of their blood glucose levels, partly by consuming foods which do not cause sharp spikes in glucose. They also need to ensure that they are eating a healthy amount and type of fat. In fact, lower fat diets are typically being recommended to them. This is why nuts are conservatively included in the typical ‘diabetes-friendly diet’. However, research is increasingly proving the benefits of nuts to blood glucose control in people with diabetes. The American Diabetes Association now ranks peanuts and tree nuts as ‘diabetes superfoods’.
The benefits of nuts are not limited to glycaemic control; this food group also improves cardiovascular health. Nut consumption is associated with a reduced risk of cardiovascular disease in people with type 2 diabetes. A higher intake is also generally not associated with being overweight, possibly because they contain both fiber and fat which are digested slowly, contributing to satiety. Most studies examine the effects of walnuts, almonds and hazelnuts, and many studies examine nut intake in general without separating varieties. However, there is some research available on specific types.
One study compared a group of volunteers who were given 30g per day of mixed walnuts, almonds and hazelnuts in addition to receiving healthy diet advice. Everyone in the group had metabolic syndrome, which is a common precursor to type 2 diabetes. This significantly reduced their fasting insulin over the course of 12 weeks, suggesting that these nuts can contribute to improved insulin sensitivity.
People with type 2 diabetes in another study received 10% of their daily energy intake from either olive oil or almonds. The group who ate almonds saw an increase in the concentration of high-density lipoprotein cholesterol in their blood (this is the ‘healthy’ form of cholesterol which is protective against heart disease).
A clinical trial put its volunteers on an energy-restricted but high-fat diet, where fat contributed 43% of the energy. Almonds, cashews, hazelnuts, macadamia, pecans and pistachios contributed to this fat. This was more effective at reducing low-density lipoprotein (‘unhealthy’ cholesterol) than another energy restricted diet with lower fat content.
Patients with diabetes who were given 25g of pistachio nuts twice a day showed decreased blood pressure and fasting blood glucose when compared to another group who received similar snacks without nuts. This also improved markers of chronic inflammation in the volunteers.
Peanuts added to a high glycemic index (GI) meal, such as a bagel and a glass of fruit juice, blunt the blood glucose response immediately following the meal. This may be caused by the slow digestion of the other foods due to their own slow absorption. They have a low available carbohydrate content, with a GI of 14 and a glycemic load of just 1.
Another study gave a large group of people with type 2 diabetes advice to follow the standard ‘diabetic diet’, but also provided 30g per day of cashew nuts to around half of the volunteers. This group saw a greater decrease in blood pressure from baseline levels than the group without cashews, with a rise in high-density lipoprotein.
Although more research is needed before specific nut varieties can be recommended for people with diabetes, there is good evidence that a moderate consumption of nuts as part of a healthy diet is an excellent addition to the diet. They contain complex matrices of vitamins, minerals and fibre in addition to healthy unsaturated fat.
Further reading:
Kendall, C.W., Josse, A.R., Esfahani, A. and Jenkins, D.J., 2010. Nuts, metabolic syndrome and diabetes. British journal of nutrition, 104(4), pp.465-473.
