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June 23, 2017 by Julia Rucklidge, PhD & Bonnie Kaplan, PhD

Data Shows That Nutrients Reduce Aggression: Why is Policy Not Changing?

A study just published in the Journal of Child and Adolescent Psychopharmacology was a timely reminder that there is ample evidence that nutrients can be used to reduce aggression and violence in children who are prone to such behaviours. The new study reaffirmed what we already know. Actually, the benefit of using nutrients to reduce violence has been known since the 1990s, so this is really nothing new. In fact, we wondered whether it was even worth blogging about it, given that there have already been five randomized controlled trials (RCTs) that have shown nutrients can successfully reduce aggression and violent incidents across a range of populations from delinquent children to adults in prison.1 2 3 4 5

But we decided it is worth talking about this new study as it is a timely reminder of the huge challenge we face in this field: despite study after study after study showing the same thing — that there is a simple, cheap solution to reducing aggression in many people — the message hasn’t carried through to changing policies or treatment approaches. Until that happens and nutrients become part of the mainstream publicly funded approaches to addressing these problems, we need to keep writing.

So what did this new study find? Hambly and colleagues administered a micronutrient treatment for 16 weeks to 32 children aged 4-14 who displayed ongoing violent and aggressive behaviour. Eighty four percent of the children were identified as having “very elevated” aggression. It wasn’t a blinded trial and so everyone knew what the kids were receiving. The nutrients chosen were based on knowledge of biochemistry and the nutrients known to be essential for combating oxidative stress, improving neurotransmitter synthesis and glucose metabolism. More specifically, the researchers identify elevated copper relative to zinc as playing an important role in the expression of aggression. They explain that when there is a deficiency in zinc, copper accumulates, leading to a variety of challenges including hyperactivity, inattention, violence and mood problems.

Prior to the initiation of the treatment, the researchers showed that on average the children had an elevated copper to zinc ratio, confirming their expectation that it would be higher in this group. Interestingly, they also found that reduction in aggression was associated with an improvement in the copper to zinc ratio suggesting that lowering copper relative to zinc may be essential for a clinical response.

The effects on their outcome measures were large — the number of children identified as having “very elevated aggression” shifted from 84% to 32% of the sample. Thirty-five percent were now in the normal range. The rest were now mild to moderate. There were also improvements across all areas of aggression, including verbal and physical. Quality of life improved as did family functioning. They also showed that the longer the kids stayed on the micronutrient treatment, the better the outcome.

And just like many of our studies and those of others using nutrients, there were no identified side effects and a very low dropout (1 participant).

Violence is a huge problem not only in prisons. In Christchurch where Julia lives, there has been an increasing problem of violence towards staff in psychiatric inpatient units. However, rather than address the problem with improving the nutrient intake of these most vulnerable people (no possibility of harm and it might even make things better), the district health board reacted by using sedating drugs and hiring more guards. One would understand reluctance to use nutrients if there was no evidence but there is, so what is holding them back? Based on published research, even starting with reduction of sugar would have a good impact. 6, 7

What do you think: if a drug were shown to reduce aggression with no side effects, would it be ignored?

Not all of our blogs are open for comments, but we are asking that this one be open so that anyone who has constructive suggestions for how to translate the existing data into policy changes can offer their ideas here.


  1. Gesch, B., Hammond, S., Hampson, S., Eves, A., & Crowder, M. J. (2002). Influence of supplementary vitamins, minerals and essential fatty acids on the antisocial behaviour of young adult prisoners. British Journal of Psychiatry, 181, 22-28.
  2. Schoenthaler, S. J., Amos, S., Doraz, W., Kelly, M. A., Muedeking, G., & Wakefield Jr, J. (1997). The effect of randomized vitamin-mineral supplementation on violent and non-violent antisocial behavior among incarcerated juveniles. Journal of Nutritional and Environmental Medicine, 7(4), 343-352.
  3. Schoenthaler, S. J., & Bier, I. D. (2000). The effect of vitamin-mineral supplementation on juvenile delinquency among American schoolchildren: a randomized, double-blind placebo-controlled trial. Journal of Alternative and Complementary Medicine, 6(1), 7-17.
  4. Tammam, J. D., Steinsaltz, D., Bester, D. W., Semb-Andenaes, T., & Stein, J. F. (2015). A randomised double-blind placebo-controlled trial investigating the behavioural effects of vitamin, mineral and n-3 fatty acid supplementation in typically developing adolescent schoolchildren. British Journal of Nutrition, 115(2), 361-373. doi: 10.1017/S0007114515004390.
  5. Zaalberg, A., Nijman, H., Bulten, E., Stroosma, L., & van der Staak, C. (2010). Effects of nutritional supplements on aggression, rule-breaking, and psychopathology among young adult prisoners. Aggressive Behavior, 36(2), 117-126. doi: 10.1002/ab.20335; 10.1002/ab.20335
  6. Schoenthaler, S. J. (1982). The effect of sugar on the treatment and control of antisocial behavior: A double-blind study of an incarcerated juvenile population. International Journal of Biosocial Research, 3(1), 1-9. Solnick, S. J., & Hemenway, D. (2012).
  7. The ‘Twinkie Defense’: the relationship between carbonated non-diet soft drinks and violence perpetration among Boston high school students. Inj Prev, 18(4), 259-263. doi: 10.1136/injuryprev-2011-040117


Bonnie-Kaplan-PhDDr. Bonnie Kaplan, PhD is the fund advisor of the Nutrition & Mental Health Research Fund and a member of the new International Society for Nutritional Psychiatry Research (ISNPR). For many years, she studied developmental disorders in children, especially ADHD and reading disabilities (dyslexia). Dr. Kaplan was part of a team from University of Calgary and University of British Columbia which helped in the search for genes that predispose children to dyslexia. Also, with her students, she investigated the characteristics of adults with ADHD. Such work led her to further investigations of the role of nutrition. Another interest has been the mood symptoms that accompany ADHD and learning difficulties, and the role of micronutrient treatment of mood, aggression and explosive rage. This progression of topics has resulted in a research program focused on the role of nutrition in brain development and in brain function, especially the use of broad spectrum micronutrient treatment for mental disorders.

Dr. Kaplan’s latest published research: A randomised trial of nutrient supplements to minimise psychological stress after a natural disaster. PsychiatryResearch(2015).

One thought on “Data Shows That Nutrients Reduce Aggression: Why is Policy Not Changing?

  1. I would start by editing Aggression in Wikipedia. This entry gets 391 pageviews/day. Then I would move on to Twinkie defense, which gets 355 pageviews/day, and so on.

    I would cite only the most convincing studies (for example, randomized controlled trials vs open label studies).

    Good luck,
    Elizabeth Saenger, PhD

    Pageviews for Aggression:

    Pageviews for Twinkie defense:

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