It is true that in people who do not have diabetes, eating a high-carbohydrate diet probably does little harm – although there are some who believe that a switch from fat to carbohydrate in the diet has driven the current surge in obesity levels.
But in type 2 diabetes, a high-carbohydrate diet puts increased stress on the ß cells and will worsen insulin resistance. In fact, the only pathway the body has for getting rid of excess glucose – when liver and muscle stores are full – is to convert glucose into fat in the liver, then export this fat via VLDL/triglycerides to adipose tissue.
And this is a process driven by high insulin levels. In short, if you have type 2 diabetes and you eat a high-carbohydrate diet, you will push up blood glucose levels and blood insulin levels. You will also create hypertriglyceridaemia and, due to protein transfer from HDL to VLDL, a low HDL level. Which is the exact metabolic state now known to be associated with CHD – metabolic syndrome, or syndrome X.
You will probably also create non-alcoholic steatohepatitis (NASH), as the liver fills with fat generated from glucose. If, on the other hand, you eat fat, this cannot have any impact on blood glucose levels. While glucose can be converted to fat, fat cannot be converted back to glucose.
A high- fat diet also has no impact on raising insulin levels, as absorption of fat into adipose tissue requires only a low background insulin level. A high-fat diet will not raise VLDL levels or lower HDL levels either. In short, a high-fat diet is theoretically perfect for people with type 2 diabetes. But a high-fat diet raises LDL levels, doesn’t it? We are repeatedly told this, but it doesn’t happen to be true.
Here, for example, is a quote from Dr William Castelli, director of the Framingham study, one of the longest-running and most widely quoted studies in the world. ‘In Framingham, Massachusetts, the more saturated fat one ate, the more cholesterol one ate, the more calories one ate, the lower people’s serum cholesterol’ – by which he means LDL2.
From a Pulse article by Dr. Malcolm Kendrick