what causes type 2 diabetes?

Here’s a simple question: what causes type 2 diabetes? The NHS Choices website lists four risk factors – age, genetics, weight and ethnicity. The amount of sugar in the diet doesn’t get a mention. In fact, both Diabetes UK and the American Diabetes Association say it is a “myth” that sugar causes diabetes.

The Diabetes UK website confidently states: “Though we know sugar doesn’t directly cause type 2 diabetes, you are more likely to get it if you are overweight”. That official line was repeated in the Scientific Advisory Committee on Nutrition’s report on carbohydrates last year – sugar doesn’t cause type 2 diabetes, although it can contribute to weight gain, which is a known risk factor for the condition.

Well, I have been arguing for years that excess sugar in the diet drives metabolic changes independently of weight gain – you can read the evidence for this here and here. And now the mainstream stance has been blown out of the water by some startling new research findings in which the damage sugar does is starkly revealed.

Researchers in California gave obese children and adolescents a nine-day diet in which their usual intake of sugars (added sucrose and fructose) was partly replaced by starches. Total calories and the ratio of carbs, protein and fat consumed remained the same. And the kids continued to eat the foods they enjoyed, such as turkey hot dogs, potato chips, and pizza. After just nine days on this sugar-restricted diet, weight loss was zero but there were dramatic changes in the markers of metabolic syndrome that signal a high risk of type 2 diabetes.

Virtually every aspect of the participants’ metabolic health improved – diastolic blood pressure went down by 5mm, triglycerides by 33 points, LDL-cholesterol (“bad” cholesterol) was down 10 points, and liver function tests improved. Fasting blood glucose went down by five points, and insulin levels were cut by a third. All this after simply limiting sugar intake for just nine days.

Can anybody still believe that sugar doesn’t cause type 2 diabetes?

Dr Robert Lustig, who led the research team, said: “This study definitively shows that sugar is metabolically harmful not because of its calories or its effects on weight; rather sugar is metabolically harmful because it’s sugar”. As I pointed out here, table sugar (sucrose) is made up of two chemically distinct sugars – glucose and fructose – which behave very differently in the body. High consumption of added fructose leads to insulin resistance, type 2 diabetes, high blood pressure, furred up arteries, a fatty liver and excess body fat.

Insulin switches on sugar cravings

When you eat sugar, it triggers cravings for more of the same. Insulin, which is released in response to eating sugar and carbohydrates, normally activates receptors in the brain that tell us when we are full. But too much insulin could also be driving sugar addiction. In another recent study, insulin was found to increase brain levels of dopamine, a neurotransmitter that helps control the brain’s ‘reward and pleasure centres’. Dopamine is a ‘feel good’ chemical – drugs such as cocaine and methamphetamines induce euphoria by hugely increasing dopamine levels.

As the authors of this study point out, what we call a “sugar rush” is probably a “dopamine reward rush”. Their findings suggest that people can get hooked on this feeling, unconsciously choosing high-sugar and high-carb foods that release more insulin and so heighten dopamine release. This overrides the satiety mechanism, encouraging us to eat more than we need and more sugar than is good for us.

Added sugar is the single worst ingredient in the modern diet. In addition to driving the epidemic of type 2 diabetes, it has been shown to cause:

• Heart disease
• Cancer
• Fatty liver disease
• Alzheimer’s disease
• Obesity
• High blood pressure
• Gout
• Frequent colds and infections
• Tooth decay and gum disease
• Irritable bowel syndrome
• And much, much more!

The link between sugar consumption, high blood sugar and heart disease is well established. But it seems that repeated episodes of low blood sugar can also be damaging to the heart. If you have diabetes, medications that drive your blood sugar level too low or raise insulin levels too high could be putting you at increased risk of heart problems. Those are the conclusions of two recent studies that will be the subject of my next blog post.

Wishing you the best of health,

Martin Hum
PhD DHD Nutritionist
for Real Diabetes Truth