Despite conflicting research, DHA is widely used to buttress cognitive development and prevent cognitive impairment.
DHA is an omega 3 fatty acid believed to offer a wide variety of health benefits. Similar to other nootropics, it seems particularly capable of promoting brain health through:
- Neuroprotection. The antioxidant and anti-inflammatory activities of DHA as well as its ability to combat brain plaques may collectively empower it to protect neurons from injury and deterioration.
Docosahexaenoic acid (DHA), similar to eicosapentaenoic acid (EPA), is an omega-3 fatty acid that serves as one of the main structural components of the human brain, skin, and retina. It is most widely recognized as an algae and phytoplankton by-product that is accordingly present in fish oil, but it can also be obtained from breast milk.
The essential nature of the omega 3 fatty acids in the brain and body have stirred interest in their use in health and medicine. Along with EPA, DHA is regularly used to help manage numerous conditions, including heart disease, asthma, hay fever, lung disease, lupus, headaches, dermatitis, and arthritis, to name a few.
DHA has been identified as a particularly critical compound for the mental development of infants, which has led to belief in its potential to impart nootropic effects. Its effectiveness as a nootropic for adult mood and cognition is being hotly investigated.
How DHA Might Help the Brain
DHA is a fundamental component of normal neural function, and is believed to play a vital part in neuronal membranes.1 Moreover, supplementation with DHA has been shown to contribute to the structural development and growth of brain tissue through an unclear mechanism.2 3
Attenuate amyloid beta secretion
The formation of toxic amyloid beta (A-β) plaques in the brain is a well-documented cause of memory loss and other cognitive deficits. DHA has been shown to significantly reduce the presence of beta amyloid plaques by:
- Increasing the presence of a sorting protein known as LR11.4
- Stimulating the synthesis of a protein, NPD1, that promotes brain cell survival and suppresses the toxicity of amyloid beta plaques.5
DHA has been shown to confer neuroprotection in numerous instances, in no small part due to its ability to increase antioxidant capacity.6 7 An increased presence of DHA in the brain was found to significantly reduce memory errors by suppressing compounds causing oxidative stress, specifically lipid peroxide and reactive oxygen species.8
DHA Nootropic Benefits & Uses
DHA is most commonly supplied to infants in the first 4 – 6 months of life in order to improve their mental development. Inadequate amounts of DHA in fetuses and infants has been shown to consequence in behavioral, functional, and neurological disorders.9
Low DHA levels have further been associated with cognitive deficits, which is why it is used to prevent disorders of the mind in people with insubstantial DHA, despite lacking consistent clinical backing.10 It has specifically been used to help manage such health conditions as:11
- Attention deficit/hyperactivity disorder (AD/HD). DHA may help children with ADHD be less aggressive, although it does not seem to improve ADHD symptoms per se.
- Depression. DHA may mildly improve mood as well as reduce aggressive behavior.
- Alzheimer’s. The neuroprotective effects of DHA may attenuate memory loss and improve memory-related learning.12 13
- Dyslexia. DHA may improve various aspects of dyslexia.14
Animal research indicates that DHA may:
- Improve memory-related learning in rats17 18
- Improve spatial cognition and focus in rats19
- Prevent learning deficiencies by increasing antioxidant defense in rats20
- Ameliorate spatial cognitive deficits in rats21
- Increase neuroprotection in aged rats affected by low blood supply to the brain22
Clinical studies have presented conflicting findings concerning the impact of DHA on cognitive function. Its impact on mood and cognition seems to be mild, at best.
In this randomized, placebo-controlled investigation, 36 patients with depression were given either a placebo or 2 g of DHA daily for 6 weeks. A slight improvement in ratings of depression (27.8%) compared to the placebo (23.5%) were reported, though the change was not statistically significant.
- The researchers concluded that “this trial failed to show a significant effect of DHA monotherapy in subjects with major depression.”23
In this randomized, double-blind, placebo-controlled investigation, 81 patients with mild to moderate depression were given either a placebo, 1 g of EPA, or 1 g of DHA daily for 12 weeks. The DHA group showed slight improvements in depression compared to the placebo, but only the EPA group demonstrated significant improvements.
- The researchers concluded that “these data suggest greater efficacy of EPA compared to DHA or placebo as an adjunctive treatment in mild-to-moderate depression.”24
In this randomized, placebo-controlled, double-blind investigation, 196 adults with depression were given either a placebo, 1 g of EPA, or 1 g of DHA every day for 8 weeks. All 3 groups experienced significant improvement in depression, with no significant differences among them.
- The researchers concluded that “neither EPA-enriched nor DHA-enriched n-3 was superior to placebo for the treatment of MDD.”25
In this placebo-controlled, double-blind investigation, 40 children with attention-deficit/hyperactivity disorder (AD/HD) were given either a placebo or fish oil rich foods containing 3.6 g of DHA per week (or ~0.51 g per day) for 2 months. No significant differences between the groups were found, except for slight improvements in short-term memory and continuous performance in the placebo compared to DHA.
- The researchers concluded that “DHA supplementation did not improve AD/HD-related symptoms.”26
In this randomized, placebo-controlled, double-blind investigation, 60 children with AD/HD were given either a placebo or 345 mg of DHA every day for 4 months. No statistically important improvements in subjective (child behavior) or objective (attention, clarity, memory) AD/HD symptoms were found.
- The researchers concluded that “4-month period of DHA supplementation (345 mg/d) does not decrease symptoms of ADHD.”27
In this randomized, double-blind, placebo-controlled investigation, 485 elderly adults were given either a placebo or 900 mg of algal DHA for 6 months. The DHA group presented significantly fewer learning errors and positive effects on verbal recognition memory compared to the placebo group.
- The researchers concluded that “data reveal a potentially beneficial role for DHA in preventing or ameliorating cognitive decline and cardiovascular disease in the aged.”28
In this randomized, double-blind, placebo-controlled investigation, 485 adults over the age of 55 years were given either a placebo or 900 mg of DHA for 24 weeks. DHA supplementation resulted in significantly fewer learning errors and improve verbal recognition memory, but not working memory or executive functions of the mind compared to the placebo. DHA presented no serious adverse side effects.
- The researchers concluded that “DHA improved learning and memory function in ARCD and is a beneficial supplement that supports cognitive health with aging.”29
- Successful clinical research studies have used from 345 mg – 2 g of DHA per day.
- Typical supplements range from 250 – 500 mg of pure DHA per day.
- Capsules, tablets, or softgels
- DHA supplements can be from a marine (fish oil), plant, or algal source
Supplements in Review Says
- DHA 72 – 312 mg as a nootropic.
DHA is essential for cognitive development and may offer additional nootropic benefits. DHA has demonstrated considerable potential in enhancing various facets of mood, memory, and cognitive function, but its application in clinical trials has thus far turned out conflictive outcomes.
Adequate DHA dosing depends on total omega-3 fatty acid consumption. Medical professionals generally recommend consuming no more than 1000 mg of omega 3 fatty acids (500 mg EPA + 500 mg DHA) per day. So, those who regularly consume fish and algae should take care not to use high doses of DHA. We suggest starting at a low dose of 72 – 312 mg.
- Wainwright P. Nutrition and behaviour: the role of n-3 fatty acids in cognitive function. Br J Nutr. 2000;83:337-9. ↩
- Cheruku SR, et al. Higher maternal plasma docosahexaenoic acid during pregnancy is associated with more mature neonatal sleep-state patterning. Am J Clin Nutr. 2002;76:608-13. ↩
- Salem M Jr, et al. Mechanisms of action of docosahexaenoic acid in the nervous system. Lipids. 2001 Sep;36(9):945-59. ↩
- Qui-Lan Ma, et al. Omega-3 Fatty Acid Docosahexaenoic Acid Increases SorLA/LR11, a Sorting Protein with Reduced Expression in Sporadic Alzheimer’s Disease (AD): Relevance to AD Prevention. J Neurosci. 2007 Dec 26; 27(52):14299-307. ↩
- Lukiw WJ, et al. A role for docosahexaenoic acid–derived neuroprotectin D1 in neural cell survival and Alzheimer disease. J Clin Invest. 2005 Oct 1;115(10):2774-83. ↩
- Hong SH, et al. Docosahexaenoic acid confers enduring neuroprotection in experimental stroke. J Neurol Sci. 2014 Mar 15;338(1-2):135-41. ↩
- Jin M, et al. Dietary DHA/EPA ratio affected tissue fatty acid profiles, antioxidant capacity, hematological characteristics and expression of lipid-related genes but not growth in juvenile black seabream (Acanthopagrus schlegelii). PLoS One. 2017 Apr 21;12(4):e0176216. ↩
- Hashimoto M, et al. Chronic administration of docosahexaenoic acid ameliorates the impairment of spatial cognition learning ability in amyloid beta-infused rats. J Nutr. 2005 Mar;135(3):549-55. ↩
- Dijck-Brouwer DA, et al. Lower fetal status of docosahexaenoic acid, arachidonic acid and essential fatty acids is associated with less favorable neonatal neurological condition. Prostaglandins Leukot Essent Fatty Acids 2005;72:21-8. ↩
- Moriguchi T, et al. Behavioral deficits associated with dietary induction of decreased brain docosahexaenoic acid concentration. J Neurochem. 2000;75:2563-73. ↩
- Kidd PM. Omega-3 DHA and EPA for cognition, behavior, and mood: clinical findings and structural-functional synergies with cell membrane phospholipids. Altern Med Rev. 2007 Sep;12(3):207-27. ↩
- Lim GP, et al. A diet enriched with the omega-3 fatty acid docosahexaenoic acid reduces amyloid burden in an aged Alzheimer mouse model. J Neurosci. 2005;25:3032–40. ↩
- Hooijmans CR, et al. Changes in cerebral blood volume and amyloid pathology in aged Alzheimer APP/PS1 mice on a docosahexaenoic acid (DHA) diet or cholesterol enriched Typical Western Diet (TWD). Neurobiol Dis. 2007;28:16-29. ↩
- Stordy BJ. Dark adaptation, motor skills, docosahexaenoic acid, and dyslexia. Am J Clin Nutr 2000;71:323S-6S. ↩
- Eady TN, et al. Docosahexaenoic acid complexed to albumin provides neuroprotection after experimental stroke in aged rats. Neurobiol Dis. 2014 Feb;62:1-7. ↩
- Eady TN, et al. Docosahexaenoic acid complexed to human albumin in experimental stroke: neuroprotective efficacy with a wide therapeutic window. Exp Transl Stroke Med. 2012 Sep 14;4(1):19. ↩
- Gamoh S, et al. Chronic administration of docosahexaenoic acid improves reference memory-related learning ability in young rats. Neuroscience. 1999;93:237-41. ↩
- Gamoh S, et al. Chronic administration of docosahexaenoic acid improves the performance of radial arm maze task in aged rats. Clin Exp Pharmacol Physiol. 2001 Apr;28(4):266-70. ↩
- Tanabe Y, et al. Improvement of spatial cognition with dietary docosahexaenoic acid is associated with an increase in Fos expression in rat CA1 hippocampus. Clin Exp Pharmacol Physiol. 2004 Oct;31(10):700-3. ↩
- Hashimoto M, et al. Docosahexaenoic acid provides protection from impairment of learning ability in Alzheimer’s disease model rats. J Neurochem. 2002 Jun;81(5):1084-91. ↩
- Okada M, et al. The chronic administration of docosahexaenoic acid reduces the spatial cognitive deficit following transient forebrain ischemia in rats. Neuroscience. 1996 Mar;71(1):17-25. ↩
- Belayev L, et al. Robust docosahexaenoic acid-mediated neuroprotection in a rat model of transient, focal cerebral ischemia. Stroke. 2009 Sep;40(9):3121-6. ↩
- Marangell LB, et al. A double-blind, placebo-controlled study of the omega-3 fatty acid docosahexaenoic acid in the treatment of major depression. Am J Psychiatry. 2003;160:996-8. ↩
- Mozaffari-Khosravi H, et al. Eicosapentaenoic acid versus docosahexaenoic acid in mild-to-moderate depression: a randomized, double-blind, placebo-controlled trial. Eur Neuropsychopharmacol. 2013 Jul;23(7):636-44. ↩
- Mischoulon D, et al. A double-blind, randomized controlled clinical trial comparing eicosapentaenoic acid versus docosahexaenoic acid for depression. J Clin Psychiatry. 2015 Jan;76(1):54-61. ↩
- Hirayama S, et al. Effect of docosahexaenoic acid-containing food administration on symptoms of attention-deficit/hyperactivity disorder – a placebo-controlled double-blind study. Eur J Clin Nutr. 2004;58:467-73. ↩
- Voigt RG, et al. A randomized, double-blind, placebo-controlled trial of docosahexaenoic acid supplementation in children with attention-deficit/hyperactivity disorder. J Pediatr. 2001;139:189-96. ↩
- Yurko-Maro K, et al. Cognitive and cardiovascular benefits of docosahexaenoic acid in aging and cognitive decline. Curr Alzheimer Res. 2010 May;7(3):190-6. ↩
- Yurko-Mauro K, et al. Beneficial effects of docosahexaenoic acid on cognition in age-related cognitive decline. Alzheimers Dement. 2010 Nov;6(6):456-64. ↩