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Higher levels of omega-3 in your blood lower the risk of developing mental diseases

Higher levels of omega-3 in your blood lower the risk of developing mental diseasesOily fish and fish oil supplements contain EPA and DHA, two types of omega-3 fatty acids that are important for our brain, nervous system, and mental health throughout life. According to a new Irish study, young adults with higher blood levels of omega-3 are less likely to develop depression and anxiety. The researchers see a huge therapeutic potential in advising people to increase their omega-3 intake from oily fish or supplements. The problem is that modern diets contain far too little omega-3 and too much omega-6, which contributes to the increased rate of mental illness.

Omega-3 and omega-6 are fatty acids that are involved in numerous biochemical processes that affect our nervous system, immune system, and a variety of other functions. The brain contains large concentrations of both fatty acids but we must eat them in the proper ratio. We primarily get omega-3 from oily fish, whereas omega-6 is found in plant oils. Our diets have changed, however, and today, many people get far too little omega-3 and far too much omega-6 and that has a negative impact on their physical and mental health.

  • The intake of omega-3 fatty acids from fish and shellfish has fallen drastically
  • The intake of omega-6 fatty acids has gone up tremendously
  • This is because of our high intake of plant oils made from corn, sunflower, and safflower, and because we eat margarine, fried foods, ready meals, and junk-food.

Fish oil and its potential for preventing mental disorders

The new study was headed by scientists at RCI University of Medicine and Health Sciences in Dublin and had more than 3,800 participants in the age group 17-24 years. These people were already participants of a larger study (Bristol’s Children of the 90’s) and were being examined for mental disorders like depression and anxiety. The scientists also took blood samples to measure levels of omega-6 fatty aids that cause inflammation in the body and omega-3 fatty acids that have the opposite effect and are effective inflammation inhibitors.
The study only suggested a minor relation between fatty acids and mental imbalances in the 17-yearolds. Nonetheless, the researchers observed that 24-yearolds with mental disorders such as depression and anxiety had too much omega-6 and too little omega-3 in comparison with participants that did not suffer from these problems.
The scientists could also see that the 24-yearolds with mental disorders had lower levels of the omega-3 fatty acid called DHA (docosahexaenoic acid) compared with 24-yearolds without mental disease. DHA is typically found in oily fish and fish oil supplements. It is a very long-chained fatty acid that is particularly important for the brain and central nervous system.
Also, when scientists followed a group of 2,700 people for some time, they discovered that youngsters at the age of 17 years who had higher concentrations of DHA in their blood had a 56 percent lower risk of developing mental disease around the age of 24 years. This shows that DHA lowers younger people’s future risk of developing mental disorders.
The researches also factored in such things as gender, BMI, smoking habits, and social conditions that did not affect the results of the study.
According to the scientists, increasing your intake of omega-3 fatty acids from oily fish may prevent young people from developing mental disorders later in life.
The study also raises the question if too much omega-6 from plant oils contributes to the developing of mental disease. The study is published in the journal Translational Psychiatry.

Fish oil supplements have already shown therapeutical potential in mental disease

Although the University of Dublin scientists call for additional studies to confirm their findings, their study does support earlier research. It has been found that children and adults with depression, ADHD, autism, Alzheimer’s disease, and dementia often have lower levels of DHA in their blood. Also, it has been found that high-dosed supplements of omega-3 have a positive effect on mental disorders. For the record, EPA (eicosapentaenoic acid), the other omega-3 fatty acid, counteracts the inflammatory processes that often are involved in depression and Alzheimer’s disease.

EPA’s and DHA’s role in the brain and nervous system

  • Development of the brain, central nervous system, and eyes
  • Supports the neuronal synapses that exchange information between neurons
  • Increases the blood flow and thereby the ability to solve cognitively challenging tasks
  • Helps form more neurotransmitters – including dopamine and serotonin that are important for a good mood.
  • Counteracts inflammation that is seen with depression and Alzheimer’s disease

How much omega-3 do we need?

Normally, it is possible to get enough omega-3 by following the official dietary guidelines that recommend 2-300 grams of fish per week, preferably oily fish from clean waters. People who dislike the taste of fish or simply don’t eat enough fish can choose to take a supplement. Normally, one gram of omega-3 per day is enough but for those with inflammatory conditions, it normally takes 3-4 times as much. Fish oil based on free fatty acids is absorbed better in the digestive system. Also, make sure that the peroxide value and content of environmental toxins in the fish oil supplement are within the safe threshold levels.

  • It normally takes around a month before you notice an optimal effect of omega-3 fatty acids in the brain and nervous system
  • Similarly, it takes approximately the same amount of time for the effect to wane if you discontinue your use of fish oil supplements


Emily Henderson. Adolescents with higher levels of omega-3 fatty acids less likely to develop psychotic disorder. News Medical Life Sciences, Jun 1 2021

James J. Dicolantonio and James H. O´Keefe. The Importance of Marine Omega-3s for Brain Development and the Prevention and treatment of Behavior, Mood, and Other Brain Disorders. Nutrients. 2020

Carisha S. Thesing et al. Omega-3 and omega-6 fatty acid levels in depressive and anxiety disorders. Psychoneuroendocrinology. 2018

Robert M. Carney et al: Baseline Blood Levels of Omega-3 and Depression Remission: A Secondary Analysis of Data From a Placebo-Controlled Trial of Omega-3 Supplements. Journal of Clinical Psychiatry. 2016

Rapaport MH et al. Inflammation as a predictive biomarker for response to omega-3 fatty acids in major depressive disorder: a proof-of-concept study. Molecular Psychiatry 2015

Nutrition insight. Neuroimaging Highlights Role of Omega-3 in preventing Cognitive decline. 2017

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