Saturday, December 4, 2010

Research Update: Carbohydrates And Inflammation

Carbohydrate Nutrition And Inflammatory Disease Mortality In Older Adults
Buyken, AE et al.
American Journal of Clinical Nutrition 92:634-43 2010.

Objective: To examine whether dietary glycemic index, dietary fiber, and carbohydrate containing food groups were associated with mortality attributable to inflammatory disease.  These diseases include diabetes, Alzheimer’s, Parkinson’s, infectious disease, respiratory diseases, immunologic diseases, digestive diseases and others.

Study Population: 1,400 postmenopausal women and 1,245 men aged 49 or older.  This was an Australian cohort that was followed for 13 years.  By the end of follow up, 84 women had died and 86 men had died.

Results:  Women with the highest dietary glycemic index had a 2.9 fold increased risk of death from inflammatory diseases.  Increasing intake of foods high in sugar or refined starches also independently predicted a greater risk of death from inflammatory diseases.

In men, increasing consumption of fruit and fruit fiber decreased risk of death from inflammatory disease.

Comment:  This study is interesting for a variety of reasons:

#1- I’ve seen literature suggesting that a diet rich in high glycemic carbohydrates increases C - reactive protein (a marker of body wide inflammation), but this is the first study I’ve seen that looks at death caused by inflammation.

#2- A tripling of the risk of death in a 13 year period for women with the highest glycemic index is a very significant finding with a huge public health relevance considering the high glycemic nature of the current American diet. 

#3- The fact that the results were not the same for men was interesting.  It’s not the first time that I’ve seen the effects of glycemic index attenuated in men.  The authors mention that the reason for this may be that men have a higher antioxidant status than women until age 75.

Take Home Message:  The explanation for these results may stem from the hyperglycemia (high blood sugar) that results from chronic consumption of high glycemic carbohydrates.   This may result in an overproduction of free radicals and a greater release of inflammatory cytokines.  

If you read my book or work with me privately, you already know how heavily influenced my nutritional recommendations are by the glycemic index and glycemic load.  This is further evidence to avoid refined carbohydrate containing foods such as white bread, pasta, white rice and most importantly, sugar.

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