A just published study comparing the American diabetes association (ADA) diet with a hunter gatherer (paleolithic or paleo) diet, shows far better blood glucose control and improved insulin sensitivity on the paleo diet.
Twenty-five patients with type 2 diabetes (50-69 years) were randomly assigned to the paleo (n=14) or ADA diet (n=10). They ate a ramp-up diet for 7 days then the test diet for 14 days.
The Paleo diet consisted of meat, fish, poultry, eggs, fruit, vegetables, tree nuts, canola oil, mayonnaise and honey. Foods excluded were dairy products, legumes, cereals, grains, potatoes and products containing potassium chloride. Some foods were not typically hunter- gatherer food: mayonnaise, carrot juice and domestic meat, but contained the general nutritional characteristics of pre-agricultural foods. The diets were divided into three meals and three snacks, all prepared by the research centre kitchen staff.
The diets contained enough calories so patients lost no more than 3 lbs, if they did calories were increased.
The primary outcomes for this study were change in insulin sensitivity and improvements in lipid profiles (total cholesterol, triglycerides and high-density lipoprotein (HDL) cholesterol). Blood pressure was also measured.
Here is the actual breakdown of diet eaten for the 14 day test period. What is interesting is the the diets were matched for calories and macro-nutrients. Notable is the carbohydrate content for both diets. Not at all low – carbs are around 400 grams per day. Previous studies of paleo diets compared to standard diets were naturally lower in carbohydrates, so this study adjusted for that.
Results: Table from paper
There were statistically significant reductions in total cholesterol, HDL cholesterol and low-density lipoprotein (LDL) cholesterol on the Paleo diet . The total cholesterol, HDL cholesterol and LDL cholesterol trended downward on the ADA diet, but only the decline in HDL cholesterol reached statistical significance. The triglycerides trended downward to a greater degree on the Paleo diet than on the ADA diet.
Changes in Insulin resistance
Fructosamine, a marker of blood glucose control reduced by 34umol/l in the paleo group and only 3umol/l in the ADA group. Insulin resistance (IR) improved more in the paleo group, and those with the worse IR at the start improved the most.
The diets were very similar except the source of carbohydrates in the paleo diet was different —from fruits, vegetables and honey. The ADA group ate rice, bread and pasta as recommended. There was a significant difference in fibre content of the diets —about 35 g/2500 kcal in the paleo diet vs 12 g/2500 kcal in the ADA diet. It is possible the fibre slowed the post-prandial glucose rise and that this was the main driver improving overall glucose control.
There has been criticism that the ADA diet should have been high in whole grain carbohydrates with more fibre. However people following ADA diet recommendations would typically choose similar grains to those provided in this study. The paleo diet is naturally high in fibre when choosing the recommended fruit and vegetables.
Another reason the paleo diet may be more successful than the ADA diet is the type of carbohydrate; fruit and vegetables have starch contained in cells, as opposed to granular starch. This has a beneficial effect on gut bacteria, and recent studies show gut bacteria type is linked to type 2 diabetes.
If you have type 2 diabetes, simply switching to a paleo diet of meat, fish, poultry, eggs, fruit, vegetables, tree nuts, olive oil, avocado, and even a bit of honey, and eating as many vegetables as you can manage is your best bet to manage it.