Fish oils and psychosis

Recent evidence published in Archives of General Psychiatry suggests that fish oil supplementation may reduce the risk of transition to psychotic illness in people at very high risk of these disorders.

The use of antipsychotic medication for the prevention of psychotic disorders is controversial. Long-chain omega-3 polyunsaturated fatty acids may be beneficial in a range of psychiatric conditions, including schizophrenia. Given that omega-3 polyunsaturated fatty acids are generally beneficial to health and without clinically relevant adverse effects, their preventive use in psychosis is of considerable interest.

Previous studies have found low levels of omega-3 and omega-6 polyunsaturated fatty acids in people with schizophrenia, and some scientists have suggested that problems with fatty acid metabolism could play a role in the development of the disorder. However, studies looking at the effects of omega-3 polyunsaturated fatty acid supplementation in people with schizophrenia have so far been inconclusive. Types of omega-3 fatty acids are found in oily fish, certain vegetable oils and in fish oil capsules.

A randomized, double-blind, placebo-controlled trial was conducted between 2004 and 2007 in the psychosis detection unit of a large public hospital in Vienna, Austria.

The aim was to determine whether omega-3 polyunsaturated fatty acids reduce the rate of progression to first-episode psychotic disorder in adolescents and young adults aged 13 to 25 years with subthreshold psychosis.

Eighty-one individuals at ultra-high risk of psychotic disorder participated in the trial. These participants had at least one of the following risk factors for psychosis:

• low levels of psychotic symptoms (delusions, hallucinations, suspiciousness, or conceptual disorganisation measured on a standard scale),

• transient psychosis, i.e. lasted less than a week and resolved without antipsychotic medication, or

• having either a schizotypal personality disorder or a first-degree relative (such as a mother, father, sister or brother) who had psychosis, plus the participant experienced a significant reduction in ability to function in the last year.

A 12-week intervention period of 1.2 g per day omega-3 polyunsaturated fatty acids or placebo was followed by a 40-week monitoring period; the total study period was 12 months.

Researchers monitored how much of their supplements the participants took by monitoring the number of pills they had left and by taking blood samples. The placebo pill contained coconut oil (which does not contain omega-3 polyunsaturated fatty acids) and an equivalent amount of vitamin E to the fish oil capsules, plus 1% fish oil to make the taste of the capsules similar.

Seventy-six of 81 participants (93.8%) completed the intervention. By the end of the study (12 months), 2 of 41 individuals (4.9%) in the omega-3 group and 11 of 40 (27.5%) in the placebo group had transitioned to psychotic disorder (P = .007). The difference between the groups in the cumulative risk of progression to full-threshold psychosis was 22.6% (95% confidence interval, 4.8-40.4).

Omega-3 polyunsaturated fatty acids also significantly reduced positive symptoms (P = .01), negative symptoms (P = .02), and general symptoms (P = .01) and improved functioning (P = .002) compared with placebo.

The incidence of adverse effects did not differ between the treatment groups.

The researchers concluded that:

a 12-week intervention with omega-3 significantly reduced the transition rate to psychosis and led to significant symptomatic and functional improvements during the entire follow-up period (12 months)

This small study does seem to suggest that, at least in the short term, fish oil supplementation could prevent young people at high risk from progressing to psychotic illness. However, while the study was robust in its design it was too short to say whether the illnesses were prevented completely or just delayed.

Psychotic illnesses are serious conditions and if fish oils can be confirmed to prevent or delay their development in susceptible individuals this would be a very important finding. However, it will require larger, long-term studies to know if this is the case.

To learn more about the effects of what we eat on our mental health, why not come along to a Cooking for Health course on “Food and Emotions“, taught by nutrition consultant Dr Jane Philpott.

Modern chickens provide more energy from fat than protein

broiler chickensIn 1976, the Royal College of Physicians and the British Cardiac Society in a report on heart disease, recommended eating less fatty red meat and more poultry instead because it was lean. However, the situation has changed since then.

A new paper in the journal Public Health Nutrition describes analysis of chickens sold in 2004-2008 compared to historical data.

Samples were obtained randomly between 2004 and 2008 from UK supermarkets, farm shops and a football club. The amount of chicken fat was estimated by emulsification and chloroform/methanol extraction.

First the content of omega 3 DHA (docosahexaenoic acid) has fallen to less than a third of the value in 1970s. Secondly, the fat content of the chicken carcass has risen; now providing about three times the calories compared to protein. Such chickens are no longer a protein rich food but a fat rich food. Thirdly, the organic chickens we analysed were little better.

The explanation is simple; namely that they are fed largely on cereals and whether organic or not, the cereals contain little omega 3 fatty acids.

The value of the omega 3 DHA is that it is preferentially utilised for the brain and vital organs. Traditionally, chicken meat and hens eggs would have been valuable land sources of omega 3 DHA.

Fully free range chickens would get the omega 3 from the green foods (grass, leaves and small animals that eat plants). However, feed hoppers maintained full 24 hours a day with omega 3 deficient food destroys the incentive of the birds to search for such foods even if they are allowed out of doors.

In addition, the denial of exercise and again 24 hour availability of energy dense and omega 3 deficient food in the broiler system provides exactly the recipe for weight gain which means fat gain. Genetic selection for fast weight gain makes that situation worse. The biochemical analysis of the meat of the birds is not only consistent with the loss of omega 3 and increase in fat, but also the lack of exercise and the selection for fast weight gain which exacerbates the loss of omega 3.

As the omega 3 DHA is important for the brain, its growth and function, it is worth asking how much would it cost to get the same amount of DHA from a 1Kg chicken today. You would need to eat about 4 chickens at a cost of £12 which at the same time would be associated with 5,000 calories of fat. Not a good idea.

Many scientists consider that the rise in mental ill health is due to the loss of omega 3 fatty acids DHA and EPA in the diet.

The answer is to eat more plant-based foods, including nuts, seeds, whole grains and vegetables like avocado.

If you have not yet transitioned to a fully plant-based diet, you can replace chicken and beef in your diet with oily fish such as mackerel and sardines.

For more information about the effect of diet on health, plant-based diets, recipes and tips please sign up for my free newsletter and visit my website.

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Obesity in children

Overweight and obesity among children is widely regarded as being even more serious than it is among adults, with a very rapid rise in prevalence in the last two decades. Child obesity is likely to continue into adulthood, and many of the problems linked to obesity are more severe if the obesity has been present for a long period. Adults with the highest risk of diabetes, cardiovascular disorders, liver malfunction and orthopaedic dysfunction, are likely to have the most extreme levels of obesity and to have been obese since childhood[i].


Projections of child obesity based on trends from the 1980s and 1990s indicate that the annual increase in child obesity prevalence is itself increasing[ii]. By the year 2010, some 26 million school children in the EU are expected to be overweight, of which 6 million will be obese. The numbers of overweight children will rise by some 1.3 million per year, of which the numbers of obese children will rise by over 0.3 million per year.

At a conservative estimate, over a million obese children in the EU are likely to show a range of indicators for cardiovascular disease, including high blood pressure and raised blood cholesterol levels, and to have three or more indicators of the metabolic syndrome[iii]. Over 1.4 million children could have early stages of liver disorder.

The costs of childhood obesity have not been estimated but should include lost educational opportunity. A study of children’s quality of life found the psychological effects of severe obesity to be equivalent to a diagnosis of cancer[iv].

Behaviour, learning and mental health problems in children are rising as fast as rates of obesity and diabetes. Food affects brains as well as bodies, and early malnourishment can have devastating effects on both. Conversely, improving nutrition can help reduce antisocial behaviour as well as symptoms of ADHD, dyslexia, depression and related conditions[v].

The only pan-European estimates of children’s food consumption patterns are from self-reported surveys of health behaviours of children aged 11-15 years[vi]. The most recent (for 2001-2002) found:

  • In virtually all countries fewer than 50 per cent of children ate vegetables every day. On average, 30 per cent of children said they ate vegetables daily, but the children in countries once famous for their Mediterranean diets reported lower than average levels, especially Spain, where vegetables were typically eaten daily by only 12 per cent of children.
  • In virtually all countries fewer than 50 per cent of children ate fruit every day. On average, 30 per cent of boys and 37 per cent of girls reported eating fruit daily, but in sixteen countries only 25 per cent of children were eating fruit more than once a week. Lowest levels of consumption were reported among children in Northern European countries.
  • Soft drinks and confectionery were consumed daily by about 30 per cent of children (over 40 per cent in some countries).

According to the last National Diet and Nutrition Survey in the UK[vii]:

  • 92 per cent of children consume more saturated fat than is recommended
  • 86 per cent consume too much sugar
  • 72 per cent consume too much salt
  • 96 per cent do not consume enough fruit and vegetables

Governments are trying to improve children’s diets, but young people’s exposure to marketing pressures in our time-poor, anxiety-ridden, media-driven society is at an all-time high.

Widespread action is needed to reverse current trends – and we all need to take responsibility for what we are feeding young bodies and minds.

In a Cooking for Health class focused on Healthy Cooking for Your Children, we look at:

  • The best and the worst food for children
  • Easy steps to free your child from food traps
  • Simple, child-friendly recipes
  • Practical tips to help your child make the best food choices

The class involves 100% hands-on practical cooking in a small, supervised group, combined with teaching of up-to-date information and research findings on the effects of diet on health. Clear, easy-to-follow presentations and handouts are provided with plenty of opportunity for questions and discussion.


[i] Policy options for responding to obesity. Summary report of the EC-funded project to map the view of stakeholders involved in tackling obesity – the PorGrow project. Dr Tim Lobstein and Professor Erik Millstone.

[ii] Jackson-Leach R, Lobstein T. Estimated burden of paediatric obesity and co-morbidities in Europe. Part 1. The increase in the prevalence of child obesity in Europe is itself increasing. Int J Pediatric Obesit 2006;1:26-32.

[iii] Lobstein T, Jackson-Leach R. Estimated burden of paediatric obesity and co-morbidities in Europe. Part 2. Numbers of children with indicators of obesity-related disease. Int J Pediatric Obesity 2006;1:33-41.

[iv] Schwimmer JB, Burwinkle TM, Varni JW. Health-related quality of life of severely obese children and adolescents. J Am Med Ass 2003;289:1813-9.

[v] Richardson, A. They Are What You Feed Them. Harper Thorsons (5 Jun 2006)

[vi] HBSC. Young people’s health in context: Health Behaviour in School-aged Children 2001/2002. Health Policy for Children and Adolescents 4. C Currie et al (eds) Copenhagen: WHO Regional Office for Europe, 2004.

[vii] Gregory, J. et al. National Diet and Nutrition Survey: Young People Aged 4-18 years (The Stationery Office, 2000)