Attention deficit hyperactivity disorder (ADHD) - an omega-3 deficiency?
GUELPH, ONTARIO, CANADA. The development of an assay for EPA and DHA in red blood cell fatty acids has made possible a number of interesting studies from sudden cardiac death to ADHD. In a just published study from the University of Guelph in Ontario, researchers examined the association between both dietary intake and red blood cell fatty acid status in a group of adolescents diagnosed with ADHD as compared to an age-matched control group. Both groups had similar anthropometric measurements such as weight, height, % fat mass, etc. Both groups consumed equivalent amounts of omega-3 and omega-6 fatty acids but the ADHD group consumed more energy and fat even though they had similar anthropometry. The ADHD children had significantly lower red blood cell levels of DHA and total omega-3 fatty acids, higher omega-6 fatty acids and a lower omega-3 to omega-6 ratio. In addition, this lower omega-3 status correlated with scores obtained with a standard behaviour measurement scale (the Conners' Parent Rating Scale or CPRS). The authors point out that these abnormal fatty acid profiles are also observed in younger ADHD children and again are distinctly different from controls of a similar age. Given that the dietary intakes in this study were similar, the results suggest that there are metabolic differences in fatty acid handling between ADHD adolescents and normal controls. Finally, they provide evidence from other studies that it may be possible to improve behaviour patterns with omega-3 supplements, but the successful studies have used rather large doses (up to 16 g fish oil per day).
Colter, AL, et al. Fatty acid status and behavioural symptoms of Attention Deficit Hyperactivity Disorder in adolescents: A case-control study. Nutrition Journal, Vol. 7, No. 1, February 14, 2008, p. 8 www.nutritionj.com/content/7/1/8

Fish oils may help prevent esophageal cancer
NORWICH, UNITED KINGDOM. Cancer of the esophagus has a poor prognosis and is increasing in frequency. Esophageal cancer is usually preceded by a condition called Barrett's esophagus (BE) in which the normal squamous (scale-like) epithelium in the lower esophagus is replaced with columnar epithelium. About 5% of patients with BE progress to esophageal cancer. BE, in turn, is linked to gastroesophageal reflux disease (GERD) with from 10-20% of GERD patients progressing to BE.

Research has shown that colon cancer is associated with an increased expression of the COX-2 enzyme in the colon and that fish oil can reduce both the COX-2 level and the risk of colon cancer. There is also evidence that the COX-2 enzyme is upregulated in Barrett's esophagus and esophageal cancer. British researchers therefore reasoned that fish oil supplementation might also be beneficial in BE and thus, indirectly, lower the risk of esophageal cancer.

Their clinical trial involved 46 patients with previously diagnosed BE. Twenty-seven of them were assigned to receive 3 EPA (eicosapentaenoic acid) capsules daily providing a total EPA intake of 1.5 grams a day with the remaining 19 patients serving as controls. Before the start of supplementation and at the end of the 6-month trial period, all participants underwent endoscopy during which appropriate biopsy samples were obtained. Analysis of the samples showed a significantly increased concentration of EPA and a significantly decreased level of COX-2 proteins in BE tissue in the supplement group, but not in the control group.

The researchers conclude that regular supplementation with relatively small doses of EPA results in significant incorporation of metabolically active long-chain amoega-3 fatty acids into BE tissue and a concomitant, beneficial decrease in COX-2.
Mehta, SP, et al. Effect of n-3 polyunsaturated fatty acids on Barrett's epithelium in the human lower esophagus. American Journal of Clinical Nutrition, Vol. 87, 2008, pp. 949-56

Fish oils in anger management
NEW YORK, NY. Omega-3 long-chain fatty acid deficiency has been implicated in several psychiatric disorders including depression, suicidal tendencies, and aggressive behaviour. Supplementation with fish oils (EPA and DHA) has been found effective in combating depression and bipolar disease. Now researchers at the New York Harbor Healthcare System report that supplementation with eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), the main components of fish oil, is effective in defusing anger and decreasing hostility.

The double-blind, randomized trial involved 24 patients who had a lifelong history of aggressive behaviour and problems with the law, and had been admitted to substance abuse clinics. The average age of the patients was 51 years, 80% were unemployed, and 60% were either separated, divorced or widowed. Eight patients (4 in the treatment group and 4 in the placebo group) had a history of assaultive behaviour and 7 patients in each group had served jail sentences for various offences. Baseline fish intake was low at 36 grams a day average yielding about 150 mg/day of long-chain omega-3 fatty acids, predominantly EPA and DHA. The researchers made the interesting observation that patients with a history of assaultive behaviour consumed only about half the amount of fish consumed by those who had not exhibited this behaviour.

The study participants were randomly assigned to receive placebo capsules (soybean oil) or 5 fish oil capsules a day providing a total of 2250 mg/day of EPA and 500 mg of DHA. All capsules contained vitamin E as an antioxidant and lemon oil to mask their taste. At the end of the 3-month supplementation period, the anger score in the group of patients given fish oil had dropped by over 50% and this improvement persisted for another 3 months after ceasing supplementation. The anger score for those given the placebo did not change. The researchers speculate that the beneficial effects of fish oils may be due to their ability to improve membrane fluidity and increase brain levels of serotonin. They suggest that fish oil supplementation should be considered in treatment protocols for patients displaying aggressive behaviours.
Buydens-Branchey, L and Branchey, M. Long-chain n-3 polyunsaturated fatty acids decrease feelings of anger in substance abusers. Psychiatry Research, Vol. 157, 2008, pp. 95-104

Fatty acid profile affects birth weight
AMSTERDAM, THE NETHERLANDS. Infants born with low birth weight and those who are small for their gestational age (SGA) are at increased risk for being sickly and even dying as infants. Long-term they are at increased risk for metabolic and cardiovascular diseases. Adequate maternal nutrition has repeatedly been shown to be essential for optimum fetal growth, but it is not clear exactly which nutrients are most important. Dutch researchers now weigh in with a study aimed at determining the effects of common fatty acids on birth weight and SGA.

The study involved 3704 pairs of mothers and newborn infants enrolled in the Amsterdam Born Children and their Development (ABCD) study. All mothers completed food frequency questionnaires and gave blood samples around week 12 of their pregnancy. Analysis of the phospholipid phase of blood plasma revealed that mothers with low concentrations of omega-3 fatty acids and the omega-6 fatty acid, DGLA (dihomo-gamma-linolenic acid or eicosatetraenoic acid) gave birth to infants with significantly lower birth weights. Women with high levels of other omega-6 fatty acids and the main trans-fatty acid found in the diet, elaidic acid, also gave birth to infants with lower birth weights. Similar associations were found for SGA.

After adjusting for possible confounding variables, the researchers conclude that low maternal plasma concentrations of eicosatetraenoic acid, eicosapentaenoic acid (EPA) and DGLA, and high concentrations of arachidonic acid are associated with reduced fetal growth, lower birth weight, and a 40-50% increase in risk of SGA. They suggest that the established beneficial effect of fish oil supplementation (EPA and DHA) on pregnancy duration, in combination with their own results, points to the importance of fatty acid supplementation as a preventive option at all phases of pregnancy.
van Eijsden, M, et al. Maternal n-3, n-6, and trans fatty acid profile early in pregnancy and term birth weight: a prospective cohort study. American Journal of Clinical Nutrition, Vol. 87, 2008, pp. 887-95

Fish oils and arrhythmias
PITTSBURGH, PENNSYLVANIA. Researchers at the National Institutes of Health and 10 major US hospitals and universities provide an excellent summary of the current knowledge regarding the benefits of omega-3 fatty acids in the prevention of cardiac arrhythmias. There is overwhelming evidence that an adequate intake of the long-chain omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is highly protective against sudden cardiac death (SCD), which is caused by ventricular arrhythmias in 80-90% of cases. A high blood level of EPA and DHA was associated with an 81-90% reduction in SCD in a group of healthy people without known coronary heart disease. As little as 1 gram a day of EPA and DHA (found in oily fish and fish oils) has also been found to be highly protective against SCD in patients having suffered a pervious heart attack. The American Heart Association now recommends that all adults consume fish, preferably fatty, at least twice a week, and that patients with coronary heart disease consume 1 gram a day of EPA and DHA combined.

The effect of oily fish consumption or fish oil supplementation on atrial fibrillation is less clear. One study involving 4815 men and women 65 years or older (mean age of 73 years) found that consumption of baked or broiled fish was associated with a significantly reduced risk (31%) of developing AF over a 12-year follow-up period. In contrast, a study involving 48,000 much younger people (mean age of 56 years) found an increased risk (34%) of AF with increased fish consumption over a 5.7-year follow-up period. A randomized trial of fish oil supplementation (850 mg EPA+DHA) prior to bypass surgery found that 15% of patients randomized to fish oil developed post- procedure AF as compared to 33.3% in the control group.

The researchers suggest that the reason for the discrepancy between the results of the trial involving older people and the one involving younger people could well be that fish oils tend to increase parasympathetic (vagal) tone and this could be detrimental in younger people, while it may be beneficial in older people where sympathetic (adrenergic) tone tends to dominate. Older people would also be more likely to have systemic inflammation and atrial fibrosis which may be reduced by a high intake of long-chain omega-3 fatty acids.

Dietary supplementation with long-chain omega-3 fatty acids (fish oils) is known to change the composition of lipid membranes toward greater fluidity. There is also evidence that fish oil supplementation inhibits a number of sodium, potassium and calcium channels in a beneficial way and reduces the production of pro-inflammatory thromboxanes – all actions that could reduce the incidence of cardiac arrhythmias.
London, B, et al. Omega-3 fatty acids and cardiac arrhythmias: Prior studies and recommendations for future research. Circulation, Vol. 116, September 2, 2007, pp. 320-35