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Heart disease, stroke, diabetesâ””in recent decades the most widespread of Americansâ”™ chronic diseasesâ””appear to be linked to inflammation and the accumulation of body fat. Several news articles this month reinforce this conclusion by pointing to a common physiologic mechanism connecting these conditions.

Eating too much food, especially the high-fat-high-carb kind, overwhelms the bodyâ”™s ability to store fat, which spills over into other types of cells and brings on the metabolic syndrome of obesity, elevated blood sugar and LDL cholesterol, hypertension, and high risk of cardiovascular disease. The inactivity of modern life makes things worse by making it easier to consume more calories than necessary.

Doctors at UT Southwestern Medical Center have proposed this unified theory of the most prevalent modern diseases. Quoted in ScienceDaily, one of the doctors, Roger Unger, commented:

If one imagines the USA population to be unwitting volunteers in the largest (300 million subjects) and longest (50 years) clinical research project in history, the specific aim of which was to determine if the deleterious effects of sustained caloric surplus in rodents also can occur in humans, the outcome of the project becomes clear — after 50 years of exposure to an inexpensive calorie-dense diet high in fat and carbohydrates, 200 million subjects are overweight and >50 million have metabolic syndrome.

The metabolic syndrome develops because the cells that take up the excess fatâ””muscle, liver and macrophages, a type of immune cellâ””arenâ”™t adapted to storing it and in reaction secrete inflammatory chemicals into the blood. The fat cells, in contrast, serve the storage function well, at least until they reach overcapacity. Thus, the accumulation of body fat actually protects against the metabolic syndrome and the chronic diseases.

A recent article in USA Today reports other research that supports the theory. Medical scientists at UCSF found that macrophages exposed to a lot of saturated fat become inflamed, but if the cells are genetically modified to hold more fat, this doesnâ”™t happen. Another scientist at Columbia University found that macrophages make up only 5% of the cells in the body fat of lean people, but they may comprise 50% of these cells in the fat of obese people.

Another article by the AP reported that a doctor at Albert Einstein College of Medicine gave healthy but overweight volunteers intravenous fatty acids, as might happen when excess fat spills out from fat cells. She found that the subjects became resistant to the action of insulin, the characteristic of the metabolic syndrome that causes elevated blood sugar.

If the theory is correct, the best treatment for diabetes and cardiovascular disease may be to reduce daily calorie intake to match daily calorie need, and to do so by eating less high-fat-high-carb food. That, of course, would be no surprise. But Americans are having a hard time changing their food preferences and adjusting their energy requirements. So if all those excess calories are causing inflammation, which in turn is causing the diseases, why not test the effect of an anti-inflammatory drug?

Researchers at NIH are doing just that, according to the AP report. They will try the anti-inflammatory drug salsalate in several hundred people with type 2 diabetes, as an addition to their usual medication. The drug is related to aspirin but is less harmful to the GI system. Earlier research suggested that salsalate helped lower blood sugar.

Inflammation appears increasingly to play a central role in all the chronic diseases of modern life. It now appears that overeating may be one of the reasons for it.

Tags: CARDIOVASCULAR DISEASES, diabetes, HIGH-CARBOHYDRATE DIET, HIGH-FAT DIET, INFLAMMATION, METABOLIC SYNDROME, OVEREATING

This entry was posted on Thursday, March 18th, 2010 at 11:14 am and is filed under Medicine and Science. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.