New Research Connects Omega-3 Levels to Suicide and Self-Harm

By Stacy Cappadona, MS, RD, CSSD, CSCS, TSAC-F, OmegaQuant Science Writer & Reviewer 

Stacy Cappadona is OmegaQuant’s science writer and reviewer. She is a registered dietitian and board-certified specialist in sports dietetics. Stacy has spent most of her career supporting the health and performance of United States military communities, applying evidence-based nutrition strategies to meet the demands of high-stress, high-performance environments. Learn more

 

 

In recent years, mental health has become a major focus of scientific research, as experts try to identify biological factors that may contribute to mental health conditions and behaviors such as suicide and self-harm. Among these potential factors, omega-3 fatty acids have gained attention. Known for their many health benefits, omega-3s are also increasingly recognized for their potential impact on mental well-being.

This article will review the research on omega-3s, how they might help reduce the risk of suicide and self-harm, and what this means for individuals considering nutritional strategies as part of their mental health treatment.

VIDEO: How Omega-3s Help Anxiety

 

Suicide and Self-harm

According to the Centers for Disease Control and Prevention (CDC), suicide is “death caused by injuring oneself with the intent to die.” Suicide has become a serious public health issue, as rates have increased over the last few decades, making it one of the top 8 leading causes of death in 2023 for people aged 10-64 and the second leading cause for those aged 10-34. Some groups experience higher suicide rates than others, with the highest among non-Hispanic American Indian/Alaska Native individuals, followed by non-Hispanic White people. Along with suicide, the prevalence of other mental health behaviors, like self-injury, has increased as well.

Nonsuicidal self-injury, also known as NSSI or self-harm, involves intentionally causing injury to oneself without the intent to die. NSSI includes a variety of behaviors such as cutting, burning, scratching, head banging or hitting, hair pulling, or worsening pre-existing wounds.

Like suicide, reports of self-harm have increased over the past few decades. Although the actual numbers are likely underreported, known rates of nonsuicidal self-injury remain higher among adolescents and young adults compared to older adults. Reported rates range from 7% to 21% for early and older adolescents, with college-aged populations showing rates as high as 38%.

Regarding adolescent NSSI, there seem to be gender differences, with girls being at higher risk than boys. And, like suicide, the occurrence of NSSI is more common among White individuals than non-White individuals, and particularly high among Native American and Latino adolescents.

Suicide and self-harm are rarely caused by a single factor; often multiple elements can increase risks. Factors range from individual risks like illness, financial struggles, or substance use to relationship and societal challenges such as bullying, loss of loved ones, discrimination, or community violence. Although the reasons for suicide and self-harm are complex, increasing evidence suggests that certain nutrients, like omega-3 fatty acids, may serve as protective factors.

VIDEO: Are Omega-3 Levels Related to Aggressive Behavior?

 

Omega-3s’ Role in Brain Health and Mental Well-Being

Omega-3 fatty acids, specifically docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are a class of polyunsaturated fats. They are often considered “essential” fatty acids that must be obtained through direct food sources, primarily fatty fish and marine algae.

Specific to brain health, DHA is present at high levels in the brain, accounting for over 40% of total omega-3 fatty acids in neuronal tissue. At the cellular membrane, DHA helps maintain neuronal membrane fluidity and increases neurotransmitter release, thereby improving neural health and function.

Furthermore, omega-3s have potent anti-inflammatory effects. Through decreasing reactive oxygen species in the brain, omega-3s can provide neuroprotection, increasing the health and longevity of neural cells, which in turn may help improve mental health symptoms and outcomes.

Studies examining the link between omega-3 levels and self-harm or suicide risk have been growing. For example, a 2013 study analyzed DHA concentrations in the postmortem prefrontal cortex of adult depressed suicide victims and controls, with and without cardiovascular disease. The researchers observed a non-significant trend toward lower DHA levels in suicide victims compared to all controls (p=0.06), but the difference was significant when comparing suicide victims to controls without cardiovascular disease (p=0.03).

Similarly, a 2012 study assessed serum omega-3 fatty acid status among US military suicide deaths versus controls. The researchers found that the risk of suicide was 14% higher for each standard deviation decrease in DHA%.

An even earlier study from 2004 also indicated that low omega-3 levels are a risk factor for suicide attempts. These findings contribute to the growing body of evidence connecting low omega-3 levels to the pathology of depression and suicide. And yet, the overall evidence remains mixed.

VIDEO: What is Omega-3 DHA’s Job in the Brain?

 

New Research Examines the Association Between Omega-3 Levels and Self-Harm/Suicidal Ideation

A new study aiming to better understand this connection, examined the relationship between plasma omega-3 fatty acid levels and measures of self-harm in the United Kingdom Biobank (UKBB). The UKBB is a prospective, population-based cohort of over 500,000 individuals aged 40-69 recruited in the UK.

This study used a random subset of 258,012 participants with data on plasma omega-3 levels and self-harm or self-reported self-harm. Researchers conducted a secondary analysis of 80,745 individuals who provided more detailed follow-up responses. The median follow-up time was 13.7 years, and the sample was slightly more female than male, primarily White, with an average age of 56 years.

The researchers measured three different outcomes in this study. First, when assessing the history of thoughts related to self-harm through self-reporting, they found that participants in the highest quintile of DHA levels were 13% less likely to report that life is not worth living compared to those in the lowest quintile.

The second outcome was the history of self-harming behaviors, assessed through both self-reports and medical records. The odds of self-harm were 26-33% lower in the highest quintile of plasma omega-3 levels compared to the lowest quintile.

Finally, the third outcome measured was medical-record-based evidence of future self-harm behaviors that occurred after baseline. The researchers found that those with higher omega-3 fatty acid levels had an 18–26% lower odds of self-harm behaviors compared to those with lower omega-3 levels.

Overall, the researchers found an inverse relationship between plasma omega-3 levels and both past and future measures of self-harm and suicidal ideation. Although they observed positive relationships between DHA, total omega-3s, and non-DHA omega-3s (ALA + EPA + DPA), the connection was stronger with the non-DHA omega-3s.

This study cannot pinpoint which fatty acid (ALA, EPA, or DPA) is responsible, and more research is needed to determine whether a primary omega-3 fatty acid is accountable. Still, this study adds to the body of evidence that higher levels of omega-3s, both DHA and non-DHA, are associated with reduced risks of self-harm and suicidal ideation, highlighting the potential of omega-3 fats to lessen self-harm.

 

Summary

Suicide and nonsuicidal self-harm are serious public health issues affecting people of all ages. Although the reasons behind suicide and self-harm are complex, increasing evidence suggests that omega-3s could be an important nutritional approach to improving mental health outcomes and reducing self-harm behavior. A recent study added to this body of evidence reporting that higher levels of DHA, non-DHA, and total omega-3s are inversely related to suicidal thoughts, history of self-harm, and the risk of future self-harm in a large cohort population.

Although this study suggests a link between omega-3 levels and self-harm risk, more research is needed to understand this relationship better. Still, increasing omega-3 intake appears to be a low-risk, low-cost approach to support mental health outcomes.

If you, or someone you know, is experiencing mental health-related distress, contact the 988 Suicide and Crisis Lifeline. Call or text 988 or visit 988lifeline.org. Trained crisis counselors are available 24/7/365, free and confidential.