Chocolate for Diabetes

Type-2 Diabetes, Hyperglycemia, Insulin Resistance, Glucose Intolerance, Blood Pressure, Weight Control

One of the most promising areas related to the healing properties of chocolate is diabetes. There has been an explosion of diagnoses of type 2 diabetes in recent years, and it is well known that the majority of diabetes-related deaths result from cardiovascular conditions such as atherosclerosis, infarction, stroke and peripheral vascular disease.

But diabetes' effects go beyond the heart. Micro blood vessel damage is caused by elevated blood sugar (an oxidant) linking with blood vessel proteins (collagen), which ultimately causes scarring and blood vessel blockage. This damage is what causes neuropathy (pain in the nerves) and edema (water in the tissues) in extremities, which can lead to ulcerations and amputations. It also causes kidney damage (nephropathy) and even blindness (retinopathy).

Researchers from Italy have recently reported that oxidative stress is the underlying cause of insulin resistance, glucose intolerance and diabetes. The researchers note that oxidative stress - mostly a result of increased calories, an increase in foods high in saturated fats and other "unhealthy" components, and an increasing lack of exercise among the population - is lessened by lifestyle changes including overall dietary habits, reducing calorie intake and increasing physical activity.

In addition, the previously described Kuna Indians from Panama have been studied for the possible health benefits from their high cocoa consumption. Several studies show that the Kuna experience far lower rates of deaths due to diabetes and related conditions than mainland Panamanians (or most other populations around the globe). Of course, the biggest difference in the diet is the significant amount of cocoa beverage the Kuna drink (about 5 cups a day on average). This points to the distinct possibility that the polyphenols in cocoa do have an anti-diabetic effect on the body.

So how does chocolate help prevent or reverse a diabetic state? A recent study from the University of L’Aquila in Italy and Tufts University suggests that flavanols present in chocolate can protect the cardio-vaseular system and can improve the utilization of insulin in diabetic patients. The findings indicate that flavanols can lower blood pressure and lower overall blood fat levels. The researchers state, "Our findings support a potentially beneficial action of chocolate flavanols on blood pressure, vaso-relaxation and insulin sensitivity, and suggest further research in this area."

The Italian researchers from the previously discussed study also discovered in separate research that even short-term administration of dark chocolate can result in a significant improvement in insulin sensitivity, as well as a decrease in blood pressure, a common condition found in type 2 diabetics. The researchers attribute the results to the apparent ability of flavanols to fight free radicals and increase the availability of nitric oxide.

A healthy body, when exposed to increased blood sugars, releases insulin to push the sugars into the cells so they will be used as fuel for energy. In diabetes, either the body does not make enough insulin to push the sugars in, or the body becomes resistant to the insulin resulting in elevated blood sugar, which is very oxidizing. High blood sugar causes all of the serious side effects of diabetes. The afore-mentioned study shows that cocoa flavonoids make the body more sensitive to insulin, thus reducing blood sugar levels. In those individuals with little insulin (type I diabetes) in their body, the flavonoids tend to help use what is available more effectively. Flavonoids also help type 2 diabetics by decreasing insulin resistance, thus lowering blood sugar.

An editorial appearing in the same journal in which this study was published commented on the results, calling them "of particular interest." Cesar Fraga also went on to discuss the mechanisms by which cocoa polyphenols/flavanols may help increase glucose metabolism and lower high blood pressure. He mentions the beneficial increase in nitric oxide production, which is supported by other studies. He also suggests that cell-signaling in turn enhances the production/availability of nitric oxide.

Grasa also goes on to state that other flavanol-containing foods, such as green tea and various other fruits/vegetables, have shown similar effects on vascular health and blood pressure regulation.

In addition, a recent article in the Journal of Nutrition discusses the protection that cocoa polyphenols can provide against postprandial (after-meal) oxidative stress. The authors explain that nutritional oxidative stress occurs because there is an imbalance between the body's pro-oxidant load and its anti-oxidant defense. This is a consequence of excessive intake of free radicals or of inadequate supply of the body with anti-oxidants. This imbalance contributes, of course, to a higher risk of cardiovascular problems.

The authors then proceed to explain that stress that occurs shortly after eating can be minimized by the ingestion of dietary polyphenols, specifically from cocoa products. The authors go on to explain that the health of blood vessels is improved by polyphenols and flavonoids and that their protection comes not only because of their anti-oxidant properties, but also from their ability to act as signaling molecules, an important aspect discussed earlier.

And there's more to this as well. Emerging research suggests that damage to the cells' mitochondria, which occurs from repeated "attacks" by free radicals, contributes to the nerve pain (neuropathy) common to diabetics. Taken in context, it is feasible that cocoa's powerful anti-oxidant capabilities could then prevent or relieve the nerve pain so many diabetics suffer from.

Flavonoids can limit the damage done by diabetes from kidney disease, eye disease, peripheral vascular disease, and even heart disease by improving blood vessel wall function and improving overall cardio-vascular health.

Finally, another recent study from Japan found that mice fed cocoa liquor (high in proanthocyanidins) could prevent the rise of blood glucose in mice with diabetes. For three weeks, the diabetic mice were fed a high-proanthocyanidin diet, while a control group was fed a diet with no proanthocyanidins. The results showed that the cocoa-fed mice showed lower levels of blood glucose than the control group, and the researchers stated that “The intake of food or drink produced from cacao beans might be beneficial in preventing the onset of type-2 diabetes."

Summary Points

• Rates of Type-2 Diabetes have exploded in the last decade, and it is known that the majority of diabetes-related deaths result from cardio-vascular conditions such as atherosclerosis, infarction, stroke and peripheral artery disease.
• Diabetes causes other various undesired effects, most notably oxidative damage from overexposure to glucose and insulin in the blood.
• Studies suggest that cocoa flavanols can protect the cardiovascular system from oxidative stress (free radical damage).
• Studies also show that flavanols help normalize the utilization of insulin, as well as improve cardio symptoms related to diabetes.

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Science Spotlight: Diabetes and Vascular Function

Diabetes is closely linked with symptoms of other conditions, including heart disease. A recent study by a German research team investigated the effects of cocoa flavanols on blood flow in human volunteers. Their findings were very positive, showing that “diets rich in flavanols reverse vascular dysfunction in diabetes, highlighting therapeutic potentials in cardiovascular disease.”