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ADHD: An inflammatory condition

The link between ADHD and obesity.

Just as we appear powerless to reverse the epidemic of childhood obesity, the growing number of children with attention deficit hyperactivity disorder (ADHD) also is escalating. Might the two disorders be linked? I believe the answer is yes, if we look closer at the role of diet in the induction of inflammatory responses.

According to the Centers for Disease Control, greater than 9 percent of children in the United States suffer from ADHD (1). This is approximately half the percentage of children who are obese (2). I suggest that both conditions are related to increased inflammation induced by radical changes in the American diet during the past 40 years. To understand that statement, you first have to understand something about inflammation.

There two types of inflammation. The first type is classical inflammation that hurts. The second type is cellular inflammation that is below the perception of pain. Although this type of inflammation can be measured, it tends to be ignored since there is no associated pain. It is this type of cellular inflammation that causes disruption in the cellular signaling networks in individual cells that are required for the body's organs to run at peak efficiency. If the inflammation is in the fat cells, the result is increased accumulation of body fat. If the inflammation is in the brain cells, the result is increased neurological disorders, including ADHD.

The primary drugs used to treat ADHD are amphetamine derivatives that have the ability to stimulate dopamine receptors in the brain. We also know that children with ADHD have lower levels of long-chain omega-3 fatty acids in the blood compared to control children (3). So what is the connection? It turns out that omega-3 fatty acids in animal studies stimulate increased dopamine production as well as increasing the number of dopamine receptors (4). This begs the question whether or not simply increasing the blood levels of long-chain omega-3 fatty acids in the blood can have a significant positive impact in the treatment of ADHD. The answer is yes, as long as you are taking a therapeutic amount (5,6). If you take a placebo dose of any nutrient, you can expect a placebo result. Outside of these two studies, most others have used essentially placebo level doses of omega-3 fatty acids. The two studies that have indicated that high-dose omega-3 concentrates do demonstrate a statistically significant improvement in behavior in children with ADHD used between 7.5 and 10 grams per day of omega-3 fatty acids (5,6).

Can you give too much of these omega-3 fatty acids? Of course you can. That's why both studies measured the levels of fatty acids in blood required to reach the same level as found in the Japanese population. The reason for the need of high levels of the omega-3 fatty acids to reach a therapeutic level to address ADHD is due to the growing imbalance of omega-6 to omega-3 fatty acids in the American diet.

This is not to say that omega-3 fatty acids are the total answer to treating ADHD, but as long as they remain at deficient levels, the management of ADHD will require far greater drug levels to treat the symptoms. The underlying cause of increased cellular inflammation will remain untreated. This also is why you have to work on the other side of the equation that requires having the children follow an anti-inflammatory diet to reduce the production of pro-inflammatory hormones. Such a diet is one that is very rich in vegetables with limited fruits, adequate in low-fat protein, low in grains and starches, and very low in omega-6 fatty acids found in common vegetable oils and virtually every processed food. The last dietary recommendation may be the most difficult to achieve as omega-6 fatty acids are now the cheapest source of calories in the American diet. Not surprisingly, their intake has dramatically increased as the levels of omega-3 have correspondingly decreased in the American diet. Animal studies are quite clear on the consequences of this growing essential fatty acid imbalance: The offspring become fatter, sicker and dumber with each passing generation (4,7).

Our children now represent the third generation of Americans who have been exposed to these dietary changes that our genes (especially our inflammatory genes) are not prepared to handle (8). ADHD and obesity are simply a consequence of some of the collateral metabolic damage that results from our increasingly pro-inflammatory diet.

1. CDC Mortality and Morbidity Weekly Report 59: 1439-1443 (2010)
2. Ogden Cl et al. JAMA 303: 242-249 (2010)
3. Antalis CJ et al. Prostglandins Leukot Essent Fatty Acids 75: 299-308 (2006)
4. Chalon S et al. Prostglandins Leukot Essent Fatty Acids 75: 259-269 (2006)
5. Sorgi P et al. Nutr J 1: 16 (2007)
6. Germano M et al. Nutr Neurosci 10: 1-9 (2007)
7. Hanbauer I et al. Cardio Psychiatry Neuro 2009: p867041 (2009)
8. Sears B. "Toxic Fat." Thomas Nelson. Nashville, TN (2008)

Dr. Barry Sears is a leading authority on the hormonal effects of food and their effects on inflammation. He is the author of the #1 New York Times best seller "The Zone" and has published more than 30 scientific articles. He is the president of the non-profit Inflammation Research Foundation. For more information on diet-induced inflammation, please go to

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