Q) My son has been diagnosed with attention-deficit/hyperactivity disorder (ADHD), and I've been advised to supplement his diet with essential fatty acids (EFAs). What sort of dose should he be taking, and are there any dangers of long-term supplementation with EFAs? Also, can he get the same benefits from dietary sources of EFAs?-K.G., via e-mail
A) Given the litany of side-effects associated with prescribed drugs for ADHD (see WDDTY vol 11 no 11), taking the nutritional route to treat your son's disorder is certainly a wise choice. Omega-3 and -6 fats are known as 'polyunsaturated fatty acids' (PUFAs). They are essential because they cannot be synthesized by the human body and so must be supplied via dietary sources. Fish and seafood are the main sources of omega-3s, particularly the crucial ones for the eye and brain-eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Green vegetables, certain nuts and oils are the dietary sources of the beneficial omega-6s. But even if the diet contains sufficient amounts of PUFAs, the body may not be efficient at metabolizing them as it should.
Indeed, children with ADHD have lower amounts of vital long-chain (LC) PUFAs-such as arachidonic acid (AA), DHA and EPA-in their circulation, even when intake of their precursors, linoleic acid (LA) and alpha-linolenic acid (ALA), is adequate (Am J Clin Nutr, 1995; 62: 761-8). Moreover, the Western diet is typically lacking in LC PUFAs, particularly omega-3s (Lipids, 2004; 39: 1215-22).
Supplementing with omega-3s helps children with ADHD (Int Rev Psychiatry, 2006; 18: 155-72), and EPA is particularly relevant (Pediatrics, 2005; 115: 1360-6). Ratios of about 12:1 omega-3 to omega-6 and 3:1 EPA to DHA are especially effective. In one 30-week Australian trial, 132 ADHD children, aged seven to 12, were given a supplement called eye qTM (Equazen), comprising 400 mg of fish oil and 100 mg of evening primrose oil, with positive results (J Dev Behav Pediatr, 2007; 28: 82-91). The effective daily dose was six capsules, which provided 558 mg of EPA, 174 mg of DHA and 60 mg of omega-6 gamma-linolenic acid (GLA).
Another study, the Oxford-Durham Trial, reported that 40 per cent of 117 children with learning/behavioural problems who took eye q made dramatic improvements in reading and spelling (Pediatrics, 2005; 115: 1360-6).
As for the effects of long-term EFA supplementation, so far, it appears to be safe. Nevertheless, in the Australian study described above, two parents commented that their children felt a little sick after taking the supplements and one boy suffered a nosebleed, possibly due to the blood-thinning effect of PUFAs (J Dev Behav Pediatr, 2007; 28: 82-91).
More serious problems can occur, however, if mega-doses of EFAs are taken. In a small-scale Italian study of 40 healthy individuals given either a placebo or increasing doses of EPA and DHA, after six months, those taking the highest doses of the fish oils were more susceptible to oxidative damage to red blood cells (Am J Clin Nutr, 1996; 64: 297-304). Another small US study had similar findings (J Nutr, 1991; 121: 484-91).
This is worrying as oxidative stress can lead to various diseases, including atherosclerosis, emphysema and cancer (J Nutr, 1991; 121: 484-91). However, the dosages were extremely high (4100 mg/day of EPA and 3600 mg/day of DHA in the Italian study; 1680 mg/day of EPA and 720 mg/day of DHA in the American study). So, provided that you stick to a low dose-for example, six 500-mg capsules of fish oil each day for 12 weeks, then reduce the dose to only two or three capsules per day-there's unlikely to be any problems.
Also, many supplements include the antioxidant vitamin E to counteract the damaging free-radical effects of fish-oil supplementation-eye q, for instance, contains 1.8 mg of vitamin E per capsule. However, you may wish to boost this dosage as studies suggest that 200 mg/day (around 100 IU) is effective (Am J Clin Nutr, 1993; 58: 98-102). Those who also have diabetes should add garlic or pectin to their regime to mitigate any changes in glucose control due to fish-oil supplementation (J Diabetes Compl, 1996; 10: 280-7).
As well as Equazen's eye q, other brands worth trying are BioCare and VeryWise Nutrition. These companies use a new process that increases the absorption of omega-3s. Pre-emulsification of fish oil prior to ingestion significantly increases the body's uptake of EPA and DHA (Nutr J, 2007; 6: 4). The process is used in products such as OmegaWise and BrainWise by VeryWise Nutrition, and BioCare's LipoCell and OmegaBerry.
As for your last question, it may be possible to obtain all of the brain-boosting omega-3s from diet alone. If your son likes fish, two portions of oily fish (salmon, mackerel, herring, sardines, albacore tuna and black cod) provides 2-3 g of LC-PUFAs, equivalent to three or four 1000-mg fish-oil capsules. But, bear in mind that these sources may contain high levels of toxic mercury as well as other contaminants (see WDDTY vol 17 no 10).
High-grade fish-oil supplements, however, have usually had all pollutants removed. A survey by the UK's Food Standards Agency (FSA) found that, out of 100 samples of fish-oil supplements, only nine had detectable levels of mercury, but none over legal limits (see www.food.gov.uk).
Another source of omega-3 is plant oils such as flaxseed (linseed) and hempseed. However, the omega-3s in plants are found in the form of ALA, which needs to be converted into EPA and DHA in the body before it can be utilized. The downside of this is that some people are genetically unable to make this conversion, and others may simply lack the necessary co-nutrients in their diet.
If you do wish to use these sources, make sure your son limits his intake of saturated and trans fats, and also has adequate levels of vitamins B3, B6 and C, magnesium and zinc in his diet.