Wednesday, June 3, 2009

Essential Fatty Acids and Children with Autism

What is it?
Essential fatty acids (EFAs) are compounds that cannot be made by the body, but are required for many crucial biochemical processes. There are two groups of EFAs: omega-6 and omega-3. The relative levels of these two groups of EFAs are critical to the health and development of the brain and the body. If the level of omega-6 is much higher than the level of omega-3 in the diet, there can be negative effects on cognition, mood, and behavior. (1-4).

The ideal ratio between these EFAs has been estimated at 2.3:1 omega-6 to 1 omega-3 (5). Most American diets provide too many omega-6 EFAs and not enough omega-3 EFAs, giving a ratio estimated at between 10:1 and 20:1 omega-6 to 1 omega-3. (2-5).

Grains, processed foods, meat, milk, eggs, and corn oil all contain omega-6 EFAs (3, 4); olive oil and walnuts contain high levels of omega-3 EFAs (3). Eggs contain omega-6 and omega-3 EFAs, and eggs labeled omega-3 eggs are from chickens fed a special diet to increase omega-3 concentrations in the eggs. However, the best sources of omega-3 EFAs come from fatty fish such as cod, halibut, mackerel, herring, trout, sardines, and salmon (2-5).

What's it like?
omega-3 EFAs can be added to a child's diet with a fish oil supplement purchased over-the-counter or online at a grocery, drug, or health-food store. The supplement can be taken one or more times every day. Children may find swallowing fish oil capsules difficult; several flavored chewable or custard-like options are available (see Resources). Alternatively, adult-sized gel caps can be squeezed into a small child's mouth or "popped" by an older child.

The recommended dosage of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) for all ages is at least 650 mg/day total (or 0.65 grams/day). Medical supervision is recommended for daily intakes above 3 grams (5, 6). There has been no research on the optimal dose for children with autism. Research on other disorders shows that the best dose of EFAs depends on the disorder, but seems to range from 1-2 grams per day (6, 7). Research on using EFA supplementation to treat autism and related disorders have used doses of omega-3 EFAs at 540-2,320 mg per day (0.5-2.3 grams/day) (8-11). If you choose omega-3 EFA supplements as an alternative therapy, ask your child's pediatrician what dose is appropriate for your child (see Is It Harmful?).

The best source of omega-3 oils for vegan and vegetarian families are flaxseed oils and several types of algae, but the EFAs from these sources are not as useful for the body as those in fish oils (3).

What is the theory behind it?
Some scientists have proposed that autism, dyslexia, attention-deficit/hyperactivity disorder (ADHD) and dyspraxia are a related group of neurodevelopmental disorders that are all caused by problems in the metabolism of EFAs (3, 12). The idea is that, for unknown reasons, the brains and bodies of individuals with autism and related disorders have problems converting the EFAs from foods into the forms that are necessary for many biochemical reactions (7). In addition, omega-3 fatty acids seem to be lower in individuals with autism than in others (9, 13).

Both of the omega-3 fatty acids DHA and EPA have been found to affect many aspects brain function (1, 3). Specifically, changing the amount of DHA and EPA in the diet alters the amounts of certain critical genes in the brain, at least in rats (14). In addition, one study found that giving animals a diet with a ratio of omega-6 to omega-3 EFAs of about 1:4 improved experimental measures of cognition in the animals (1). Finally, mood and behavior problems in humans have been linked to a lack of omega-3 EFAs in the diet (2 , 3 , 12 ).

Does it work?
Currently there are only a few studies of the effectiveness of EFA supplementation as a treatment for autism, and none of these have been well controlled (3, 4, 6, 12). For example, most of the parents of eighteen children with autism who had been given fish oil supplements (Eye-Q at 4-8 capsules/day giving 0.6-1.2 grams/day of EPA and DHA, or Kirunal at 5-10 capsules/day giving 1.2-2.3 grams/day of EPA and DHA) for six months described improvements in overall health, cognition, sleep patterns, social interactions and eye contact (9). Unfortunately, this was not a double-blind study, meaning that it was not certain that this was not just a placebo effect. In another case report, a child diagnosed with autism who had been given 540 mg of the omega-3 fatty acid EPA per day over a four week period experienced a complete elimination of his previous anxiety about everyday events as reported by his parents and clinician. They also described an improvement in his overall quality of life (8).

In a double-blind, placebo-controlled study, 117 children with dyspraxia, a motor disorder frequently associated with cognitive, behavioral and social challenges (12), received fish and evening primrose oil (a source of omega-3 fatty acids) during treatment (10). Significant improvements in reading, spelling, and behavior were reported during the treatment period, and these improvements continued as long as the treatment was underway (10).

Recently a double-blind, placebo-controlled pilot study of 13 children with autism (5-17 years old) was published (11). This study reported reduced hyperactivity and reduced stereotypy (repeated movements like hand-flapping) in children who received 1.5 gm of fish oil per day, as compared to children who received placebo.

Is it harmful?
Studies of EFA supplementation at doses between 540-2,320 mg per day (0.5 - 2.3 grams per day) have not reported any significant side effects (8-11). As long as EFAs are less than 10% of the total dietary intake, they are considered safe (15). However, several scientists have noted that fish oil supplements can contain contaminants such as mercury, hormones, dioxins, and PCBs (2, 4, 15). Thus, when purchasing fish oil supplements, you should purchase those that are purified by molecular distillation and are described as pharmaceutical grade.

The cost of EFA supplementation depends on the quality of the EFAs. A bottle of 90 capsules containing 500-700 mg of EPA and DHA can cost anywhere from $7-40. Fish oil that has been purified and tested for contaminants is recommended (4), though these supplements can be more expensive.

EFA supplements can be purchased at most drug stores and in many online stores.

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