Plant-based diets may positively influence mental health. Vegetarians, in both cross-sectional and interventional studies, appear to have fewer symptoms of depression, anxiety, stress, and mood disturbance than omnivores, perhaps because of less need for medical treatment or because of the significantly lower intake of arachidonic acid (see also here), which is found in particularly high levels in chicken and eggs. The genetic manipulation of chickens by the poultry industry may also have negative public mental health impacts. Chicken has been linked to a variety of neurological and psychiatric conditions. Toxoplasma brain parasites from meat have been linked to schizophrenia and bi-polar disorder.
While our physical and mental health may be significantly enhanced and protected by a plant-based diet, awareness of food additives, vitamin B12 deficiency and the toxicity of certain plant foods is essential. Green tea and exercise may both have positive effects on mood, whereas artificial colors may increase impulsivity, inattentiveness and hyperactivity in children and eating licorice has been linked to rule breaking, aggression, attention, speech and visual-spatial ability problems in children whose mothers ate more licorice during pregnancy. Vitamin B-12 is one of the two vitamins not made by plants. Vitamin B-12 deficiency have been linked to cases of psychosis, suicidal depression, and cognitive decline, occurring in unsupplemented vegan diets. Thankfully there are safe, cheap, convenient sources.
Dr. Greger covers mental health in his full-length presentation, Uprooting the Leading Causes of Death, where he explores the role diet may play in preventing, treating, and even reversing our top 15 killers.
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