READING:

Can Diet Help Stop Depression and Violence?

JURRIAAN KAMP

Jurriaan Kamp is the author of Because People Matter: Building an Economy That Works for Everyone and Small Change: How Fifty Dollars Can Change the World. He has worked on the staff of the European Parliament; as a freelance newspaper correspondent in India; and as chief economics editor of the NRC Handelsblad, a leading Dutch newspaper. In 1994, Kamp and Hélène de Puy, his wife, started the progressive monthly magazine Ode (now, The Intelligent Optimist), which focuses on solutions to environmental issues and problems facing the human race. Currently, Kamp is president and editor-in-chief of The Intelligent Optimist. As you read the essay that follows, highlight the results of each scientific study that Kamp uses to support the cause-and-effect relationship he proposes.

The best way to curb aggression in prisons? Longer jail terms, maybe, or stricter security measures? How about more sports and exercise? Try fish oil. How can children enhance their learning abilities at school? A well-balanced diet and safe, stimulating classrooms are essential, but fish oil can provide an important extra boost. Is there a simple, natural way to improve mood and ward off depression? Yoga and meditation are great, but—you guessed it—fish oil can also help do the trick. A diet rich in vitamins, minerals, and fatty acids like omega-3 is the basis for physical well-being. Everybody knows that. But research increasingly suggests that these same ingredients are crucial to psychological health too. And that’s a fact a lot of people seem to find hard to swallow.

1

The relationship between nutrition and aggression is a case in point. In 2002, Bernard Gesch, a physiologist at Oxford University, investigated the effects of nutritional supplements on inmates in British prisons. Working with 231 detainees for four months, Gesch gave half the group of men, ages eighteen to twenty-one, multivitamin, mineral, and fatty-acid supplements with meals. The other half received placebos. During the study, Gesch observed that minor infractions of prison rules fell by 26 percent among men given the supplements, while rule-breaking behavior in the placebo group barely budged. The research showed more dramatic results for aggressive behavior. Incidents of violence among the group taking supplements dropped 37 percent, while the behavior of the other prisoners did not change.

2

Gesch’s findings were recently replicated in the Netherlands, where researchers at Radboud University in Nijmegen conducted a similar study for the Dutch National Agency of Correctional Institutions. Of the 221 inmates, ages eighteen to twenty-five, who participated in the Dutch study, 116 were given daily supplements containing vitamins, minerals, and omega-3 for one to three months. The other 105 received placebos. Reports of violence and aggression declined by 34 percent among the group given supplements; at the same time, such reports among the placebo group rose 13 percent.

3

Gesch is quick to emphasize that nutritional supplements are not magic bullets against aggression, and that these studies are just “promising evidence” of the link between nutrition and behavior. “It is not suggested that nutrition is the only explanation of antisocial behavior,” he says, “only that it might form a significant part.” But Gesch is just as quick to emphasize that there is no down side to better nutrition, and in prisons in particular, the cost of an improved diet would be a fraction of the cost of other ways of addressing the problem of violence among inmates. Still, the menu in British prisons hasn’t changed in the five years since Gesch published his results, even though the former chief inspector of prisons in the United Kingdom, Lord Ramsbotham, told the British newspaper the Guardian last year that he is now “absolutely convinced that there is a direct link between diet and antisocial behavior, both that bad diet causes bad behavior and that good diet prevents it.”

4

Yet the effect of nutrition on psychological health and behavior is still controversial, at least in part because it is so hard to study. Our moods, emotions, and actions are influenced by so many factors: everything from our genes to our communities to our personal relationships. How can the role of diet be isolated among all these competing influences? That’s exactly why Gesch conducted his study in prisons. In a prison, there are far fewer variables, since all detainees have the same routine. Do the results of the inmate trials reach beyond the prison walls? Gesch thinks so: “If it works in prisons, it should work in the community and the society at large. If it works in the United Kingdom and in the Netherlands, it should work in the rest of the world.”

5

Another place improved nutrition seems to be working is in the city of Durham in northeastern England. There, Alex Richardson, a physiologist at Oxford University, conducted a study at twelve local primary schools. The research examined 117 children ages five to twelve, all of whom were of average ability but were underachieving. Instructors suspected dyspraxia, a condition that interferes with coordination and motor skills and is thought to affect at least 5 percent of British children. Possible signs of dyspraxia may include having trouble tying shoelaces or maintaining balance. The condition frequently overlaps with dyslexia and attention deficit hyperactive disorder (ADHD), and is part of a range of conditions that include autistic-spectrum disorders.

6

Half the group of children in Richardson’s study was given an omega-3 supplement for three months; the other half received an olive oil placebo. The results: Children given the omega-3 supplements did substantially better at school than those in the control group. When it came to spelling, for example, the omega-3 group performed twice as well as expected, whereas the control group continued to fall behind.

7

Richardson came to the study of nutrition through neurology. Her interest was sparked by the rapid rise of conditions like ADHD, autism, dyslexia, and dyspraxia. The incidence of these disorders has increased fourfold in the past fifteen to twenty years. “These disorders overlap considerably,” she says, “but a real solution is rarely offered. A dyslexic child is assigned a special teacher. A kid with dyspraxia is sent to a physical therapist. One with ADHD is prescribed Ritalin. And you’ve got to learn to live with autism.” But as Richardson writes in They Are What You Feed Them: “There is always something that can be done. Don’t ever believe it if anyone tells you otherwise.” One of the things that can be done, according to Richardson, is to boost your child’s intake of omega-3.

8

Of course, omega-3 is not the only answer to ADHD, autism, dyslexia, dyspraxia, or other psychological or behavioral disorders, which also include Alzheimer’s disease. Studies like Richardson’s suggest, however, that it may play an important role in stimulating the brain, keeping it healthy, and helping it ward off debilitating conditions.

9

And it looks like we need all the help we can get. Behavioral dysfunctions like ADHD are currently the fastest-growing type of disorder worldwide. Twenty years ago, no one had even heard of ADHD. Today, everyone knows a kid who is taking Ritalin. The World Health Organization (WHO) estimates that the number of people with psychological disorders will double by 2020—and that around that time, depression will surpass heart and vascular disease as the No. 1 most preventable cause of death. The WHO adds that psychological disorders account for four of the ten most common causes of disability and that a quarter of the general population will be affected by them at some point in their lives.

10

So what’s a consumer to do? Eat fish. Working with the U.S. National Institutes of Health (NIH), American physician and psychiatrist Joseph Hibbeln compared data on fish consumption with figures on depression and murder in a large number of countries around the world. Fish are a rich and ready source of omega-3. In countries in which fish consumption is low, Hibbeln found that the likelihood of suffering from depression was up to fifty times greater than in countries where it is high.

11

Some 6.5 percent of New Zealanders suffer from severe depression; these citizens also eat very little fish. In Japan, where fish consumption is high, 0.1 percent of the population suffers from depression. Manic depression (bipolar disorder) is rare in Iceland, which has the highest per capita fish consumption in the world, but is quite common in Brazil and Germany, where people don’t eat as much fish. Hibbeln also found that, on average, the risk of being murdered is thirty times greater in countries where fish consumption is low compared to countries where it is high.

12

Cultural and other factors certainly influence these statistics, but the comparisons are nevertheless illustrative. Overall, in subsequent trials, Hibbeln found that depressive and aggressive feelings diminished by about 50 percent after taking fish-oil capsules for two to four weeks. Based on this and other research, the WHO concluded in a report last year: “Certain dietary choices, including fish consumption, balanced intake of micronutrients, and a good nutritional status overall, also have been associated with reduced rates of violent behavior.”

13

It almost sounds too good to be true, but research is beginning to confirm that vitamins, minerals, and fatty acids can reduce aggression and improve psychological well-being. That could be a simple recipe for a more peaceful world.

14