That Dwight Demar is able to sit in front of us, sober, calm, and employed, is "a miracle," he declares in the cadences of a prayer-meeting sinner. He has been rocking his 1.88m bulk to and fro while delivering a confessional account of his past into the middle distance. He wants us to know what has saved him after 20 years on the streets.
"My dome is working. They gave me some kind of pill and I changed. Me, myself and I, I changed," he said.
Demar has been in and out of prison so many times he has lost count of his convictions.
"Being drunk, being disorderly, trespass, assault and battery; you name it, I did it. How many times I been in jail? I don't know, I was locked up so much it was my second home," he said.
Demar has been taking part in a clinical trial at the US government's National Institutes for Health (NIH), near Washington. The study is investigating the effects of omega-3 fatty acid supplements on the brain, and the pills that have effected Demar's "miracle" are doses of fish oil.
The results emerging from this study are at the cutting edge of the debate on crime and punishment. In Britain more people are incarcerated than ever before. Nearly 80,000 people are now in its prisons, which reached their capacity this week.
But the new research calls into question the very basis of criminal justice and the notion of culpability. It suggests that individuals may not always be responsible for their aggression. Taken together with a study in a high-security prison for young offenders in the UK, it shows that violent behavior may be attributable at least in part to nutritional deficiencies.
The UK prison trial at Aylesbury jail showed that when young men there were fed multivitamins, minerals and essential fatty acids, the number of violent offences they committed in the prison fell by 37 percent.
Although no one is suggesting that poor diet alone can account for complex social problems, the UK's former chief inspector of prisons Lord Ramsbotham says 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."
The Dutch government is currently conducting a large trial to see if nutritional supplements have the same effect on its prison population. And this week, new claims were made that fish oil had improved behavior and reduced aggression among children with some of the most severe behavioral difficulties in the UK.
For the clinician in charge of the US study, Joseph Hibbeln, the results of his trial are not a miracle, but simply what you might predict if you understand the biochemistry of the brain and the biophysics of the brain cell membrane. His hypothesis is that modern industrialized diets may be changing the very architecture and functioning of the brain.
We are suffering, he believes, from widespread diseases of deficiency. Just as vitamin C deficiency causes scurvy, deficiency in the essential fats the brain needs and the nutrients needed to metabolize those fats is causing of a host of mental problems from depression to aggression.
Not all experts agree, but if he is right, the consequences are as serious as they could be. The pandemic of violence in Western societies may be related to what we eat or fail to eat. Junk food may not only be making us sick, but mad and bad too.