Polyunsaturated fatty acid status in attention deficit hyperactivity disorder, depression, and Alzheimer's disease: towards an omega-3 index for mental health?

Abstract

Interest in the role of polyunsaturated fatty acids (PUFAs), particularly long-chain (LC) omega-3 (n-3) PUFAs, in mental health is increasing. This review investigates whether n-3 PUFA levels are abnormal in people with three prevalent mental health problems - attention deficit hyperactivity disorder, depression, and dementia. Data sources included PubMed, Web of Science, and bibliographies of papers published in English that describe PUFA levels in the circulation of individuals who have these mental health conditions. Although abnormal blood PUFA levels were reported in a number of studies, weighted comparisons of PUFA status showed no significant differences overall between people with mental health problems and controls. Whether those with low n-3 PUFA status are likely to be more responsive to n-3 PUFA supplementation is not yet resolved. Further studies assessing PUFA levels and mental status with greater uniformity are required in order to clarify the relationship between LC n-3 PUFA status and mental health.

Red blood cell oleic acid levels reflect olive oil intake while omega-3 levels reflect fish intake and the use of omega-3 acid ethyl esters: The Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico–Heart Failure trial

“…A target omega-3 index of 7-8% would have been consistent with subsequent findings linking similar levels with reduced risk for acute coronary syndromes [34], slowed rates of telomere attrition [35], and (using plasma phospholipid EPA+DHA to predict the index) a lower risk for total mortality [36]. Further data are need to better define optimal omega-3 index values for reducing risk for cardiovascular disease (and possibly for neurocognitive/behavioral disorders [37]). …”

Omega-6 fatty acids and greater likelihood of suicide risk and major depression in early pregnancy

“…Both n-3 and n-6 fats cannot be made de novo but must be obtained from diet. Fish is a rich source of both n-3 and n-6 HUFAs and lower intakes have been associated to increased risk for depressive symptoms and suicidal thinking in cross-national and cohort based studies; while the majority of blood based studies indicate that n-3 HUFAs are protective, n-6 HUFAs are associated with increased risk [For review see (3, 4)]. Meta-analyses of randomized controlled trials have reported similar efficacy of n-3 HUFA supplementation as fish oils and pharmaceutical antidepressants in reducing significant depressive symptoms (5, 6).…”

Omega−3 fatty acid and ADHD: Blood level analysis and meta-analytic extension of supplementation trials

“…Furthermore, the importance of long chain polyunsaturated fatty acids (LC-PUFAs), in particular Omega—3 long chain fatty acids, has been highlighted as a promising area of research interest to physical as well as mental health (Milte, Sinn, & Howe, 2009; Sinn & Bryan, 2007; Vaisman et al, 2008; Voigt et al, 2001). It is increasingly recognized that like other mental disorders, ADHD, while heritable, is probably a product of interplay of genetic liability and environmental stressors (Nigg, Nikolas, & Burt, 2010), of which nutrition may be a component.…”