I've written a lot about the health benefits of plant-based diets, and anyone who has come to the office for a consultation knows that we spend a lot of time discussing the need to at least move in a more plant-based direction in order to improve heart health.
At this point in time, the evidence is very clear that healthy plant-based diets can improve cardiovascular health, and the science behind these benefits makes sense. Between higher intake of antioxidants, fiber and plant proteins, and generally lower intake of saturated fat and heme iron, there are numerous mechanisms by which this dietary pattern can improve our health.
But can plant-based diets actually change our behavior?
There is actually a fascinating story suggesting that they might.
An Unusual Experiment in a California Prison
In the late 1990s, a man named Terry Moreland, a Seventh-day Adventist and CEO of a private prison corporation called Maranatha Corrections, took over the operation of a prison in Adelanto, California, approximately 120 miles northeast of Los Angeles.
The prison was called the Victor Valley Medium Community Correctional Facility, and it housed several hundred inmates.
The really interesting thing is that when Mooreland bid on the rights to this prison, it was under the condition that the inmates would go vegan if his offer were accepted!
After taking control of the prison, Moreland introduced a type of rehabilitation program for the inmates called NEW START, which like included Bible studies, occupational training, counseling, and anger management. Curiously (and importantly for this blog), the program also included transitioning the inmates to a vegan diet.
Inmates were given the opportunity to participate in this program or remain in a more traditional prison environment.
Now, you might imagine that prisoners wouldn't be particularly enthusiastic about going vegan. But according to a contemporary report published in 2002, approximately 50–60% of the inmates chose to participate!
And what happened next was pretty remarkable.
Doug Anglen, the prison's director of food services at the time, reported that violent incidents dramatically reduced on the "vegan side” or the prison, and occurred overwhelmingly on the nonvegetarian side of the facility.
In a report, Mr. Anglen said that "when there is a violent outbreak, 90% of the time it's on the non-vegetarian side of the facility."
“There is a noticeable difference in the personalities of the vegetarian inmates. They smile more, are fully racially integrated, attend religious classes and anger management classes eagerly," he reported at the time. "Within 10 days the vegan inmates express improvement in how they feel."
There were also reports of improvements in more traditional health measures. Some inmates reportedly lost excess weight, experienced improvements in diabetes control, noticed improvements in skin conditions, and described having more energy.
And more importantly for society at large, there may have been a lasting effect, even AFTER the inmates were released from prison, as stories about the Victor Valley prison have included some truly extraordinary claims.
One frequently repeated statistic is that fewer than 2% of inmates participating in NEWSTART program returned to prison after their release, compared with recidivism rates reportedly as high as 70–80% among those who didn't participate.
Think about that for a moment.
If true, this would represent an almost unbelievable improvement in one of the most difficult problems facing our criminal justice system.
Now, while this comparison is widely reported, there is actually no independently published scientific study or official correctional evaluation confirming these remarkable recidivism statistics.
The original reports appear to have come from individuals involved in operating the program, which can easily lead to bias. This was not a randomized, controlled experiment. And the two groups were likely very different: inmates who volunteer for bible study/anger management/vegan diets are undoubtedly quite different than those who do not. So even if the reported improvements were accurate, we really can’t know that the vegan diet component was responsible.
But that doesn't mean we should dismiss the entire story.
Because there actually is scientific evidence suggesting that nutrition can influence human behavior.
In 2002, researchers published a study in the British Journal of Psychiatry examining the relationship between nutrition and antisocial behavior among prisoners in England.
Unlike the California prison experience, this actually was a randomized, double-blind, placebo-controlled trial.
The researchers enrolled 231 young adult prisoners and randomly assigned them to receive either nutritional supplements (vitamins, minerals, and essential fatty acids) or placebo.
At the end of the experiment, the researchers found that prisoners receiving the nutritional supplements committed 26.3% fewer disciplinary offenses than those receiving placebo.
Is this proof that vegan diets work similarly? No. But it does support the concept that what we eat may influence not only our physical health but also our behavior.
With any research results, we are obligated to ask: Does this result make sense, or could it be the result of random chance or bias?
In this case there actually are several possible biologic mechanisms.
Vitamins, minerals, and essential fatty acids are involved in neurotransmitter production, neuronal membrane function, and numerous other processes that influence mood, cognition, and behavior. Deficiencies in certain nutrients could theoretically affect emotional regulation, impulse control, and even aggression.
There's also an interesting hormonal connection.
A protein called sex hormone-binding globulin, or SHBG, binds circulating sex hormones, including testosterone, and helps regulate how much hormone is biologically available. And observational research has suggested that there are relationships between the levels of these hormones and aggressive behavior.
Interestingly, a study comparing vegan and omnivorous men found that the vegan men had approximately 23% higher SHBG levels (and higher SHBG may be associated with lower androgen availability and less aggressive behavior).
Could this provide a mechanism by which plant-based diets influence aggression?
Possibly. But it's important not to jump to conclusions: Hormones may influence certain aspects of behavior, but human aggression is complex and not likely to be explained by a single hormone or blood protein.
Most importantly, no study has demonstrated that a vegan diet reduces aggression because it increases SHBG.
I think the story of the Victor Valley prison is fascinating, even if some of the more dramatic claims haven't been scientifically substantiated.
At this point in time, we have a lot of evidence that diets emphasizing vegetables, fruits, whole grains, legumes, nuts, and other minimally processed plant foods can improve cardiovascular health, lower LDL cholesterol, improve blood pressure, and reduce the risk of chronic disease.
That alone is reason enough to encourage people to eat more plants.
But the possibility that nutrition might also influence mood, emotional regulation, and even aggressive behavior adds another fascinating dimension to the discussion.
Does that mean eating more vegetables will make us kinder, calmer, and less likely to commit crimes? Maybe. Maybe not. But it also isn’t hard to believe that improving the nutritional quality of our diets has benefits that extend beyond our hearts, arteries, and waistlines
At Wisconsin Cardiology Associates, we counsel our patients to aim for a healthy, plant-based diet, emphasizing fruits, vegetables, beans, lentils, whole grains and nuts. Have questions about the best way you can prevent heart disease? Call us and make an appointment for a consultation.
