The food we eat can influence our mood, our thinking, and our behavior. We have evidence of this link from various types of research studies - animal research, in vitro experiments, epidemiological studies, and even clinical trials. Some of the most common mental illness conditions include depressive disorders, anxiety, dementia or substance abuse. What does current research have to say about the link between diet and mental health?
To help illustrate the important role of nutrition in mental health, we will start with what happens before birth.
History shows that during times of famine, such as during World War II, there were excessive cases of nervous system abnormalities, including neural tube defects, an increased risk of adult schizophrenia, antisocial personality disorders, and various symptoms of mental illness that do not fall under a specific diagnosis. 1
If an iodine deficiency exists during pregnancy, proper growth and development of the brain and central nervous system is hindered. Severe mental impairment can result, such as cretinism. However, other consequences of iodine deficiency include a loss of intelligence in children and reduced academic performance. 2
Even low birth weight and prematurity has been linked to increased risk for schizophrenia, antisocial personality disorders, and neurodevelopmental disorders. 5
During Childhood & Adolescence
Conditions such as autism spectrum disorder, attention-deficit hyperactivity disorder, mood disorders, anxiety disorders, and other behavioral problems are currently under extensive research for their link to diet. Some links have already been found. For example, omega-3 polyunsaturated fatty acid supplementation has shown a beneficial influence on symptoms related to ADHD. 3
During Old Age
To further illustrate the role of diet and nutrition in mental health, consider some evidence of how diet reduces risk of mental health problems later in life.
The Mediterranean diet (high in vegetables, fruits, legumes, nuts, cereals, olive oil; moderate in dairy, meat, poultry, and fish; low in saturated fat) is associated with less cognitive decline in old age and less risk of Alzheimer's disease. 4
We often discuss the potent effects of antioxidants on the EF blog. Oxidative damage to DNA may be reduced or prevented with the aid of antioxidants from various minerals, vitamins, and herbal extracts. Research suggests that a common thread in many mental health conditions (including Alzheimer's disease, anxiety disorders, dementia, depression, schizophrenia, and attention deficit disorder is oxidative stress. 6,7
Nutrition's role in mental health is a growing area of research. Although we definitely need more research, a link between food and mental health is evident. In the next article of this Nutriton & Mental Health series, we will take a closer look at the role of several specific nutrients in maintaining proper mental health. Stay tuned!
1. Nutrition & Dietetics 2015; 72: 2–7
2. Hynes KL, Otahal P, Hay I, Burgess JR. Mild iodine deﬁciency during pregnancy is associated with reduced educational outcomes in the offspring: 9-year follow-up of the gestational iodine cohort. J Clin Endocrinol Metab 2013; 98: 1954–62.
3. Sinn N, Milte C, Howe PRC. Oiling the brain: a review of randomized controlled trials of omega-3 fatty acids in psychopathology across the lifespan. Nutrients 2010; 2: 128–70.
4. Feart C, Samieri C, Rondeau V et al. Adherence to a Mediterranean diet, cognitive decline, and risk of dementia. JAMA 2009; 302: 638–48.
5. Heaney R. Long-latency deficiency diseases: Insights from calcium and vitamin D. Am J Clin Nutr 2003;78:912-9
6.Ng F, Berk M, Dean O, Bush AI. Oxidative stress in psychiatric disorders: evidence base and therapeutic implications. Int J Neuropsychopharmacol 2008;11:851-76.
7. Tsuboi H, Shimoi K, Kinae N, Oguni I, Hori R, Kobayashi F. Depressive symptoms are independently correlated with lipid peroxidation in a female population: comparison with vitamins and carotenoids. J Psychosom Res 2004;56:53-8. 38.