DHA Supplementation Alone or in Combination with Other Nutrients Does not Modulate Cerebral Hemodynamics or Cognitive Function in Healthy Older Adults

Abstract

A number of recent trials have demonstrated positive effects of dietary supplementation with the omega-3 polyunsaturated fatty acids (n-3 PUFAs), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) on measures of cognitive function in healthy young and older adults. One potential mechanism by which EPA, and DHA in particular, may exert these effects is via modulation of cerebral hemodynamics. In order to investigate the effects of DHA alone or provided as one component of a multinutrient supplement (also including Gingko biloba, phosphatidylserine and vitamins B9 and B12) on measures of cerebral hemodynamics and cognitive function, 86 healthy older adults aged 50–70 years who reported subjective memory deficits were recruited to take part in a six month daily dietary supplementation trial. Relative changes in the concentration of oxygenated hemoglobin and deoxygenated hemoglobin were assessed using Near Infrared Spectroscopy (NIRS) during the performance of cognitive tasks prior to and following the intervention period. Performance on the cognitive tasks was also assessed. No effect of either active treatment was found for any of the NIRS measures or on the cognitive performance tasks, although the study was limited by a number of factors. Further work should continue to evaluate more holistic approaches to cognitive aging.

Inappropriate nutrients intake is associated with lower functional status and inferior quality of life in older adults with depression

“…The protective effect of fatty acid EPA on the incidence of depression has been a frequent topic of research 44–47. While supplementation attempts have generally not been successful,48 a diet rich in EPA, a primary source of which is fish, is known to have a favorable impact on depression. However, in the present study, more than half of the depression group had not consumed EPA at all during the previous 24 hours.…”

How does high DHA fish oil affect health? A systematic review of evidence

“…For example, in the Childhood Asthma Prevention Study, the effect of dietary omega-3 supplementation and/or house dust mite was studied (Brew et al 2015;Hansell et al 2014;Marks et al 2006;Skilton et al 2012), while in the Nutrition and Health Lifestyle Study, the effect of fish oil supplementation with or without folate was assessed (Campoy et al 2011;Escolano-Margarit et al 2011). In addition, two studies assessed the effects of DHA as one component of a multinutrient supplement on cognition function (Jackson et al 2016;Strike et al 2015); Micallef and Garg (2009) conducted a randomized, double-blind, placebo-controlled study where 60 hyperlipidemic participants were provided with either sunola oil (high-oleic sunflower oil) or n-3 LC-PUFA capsules with or without plant sterols for three weeks; Johnson et al (2008) tested the low dietary intake of DHA and/or foods rich in lutein on cognitive decline in the elderly; Smuts et al (2015) investigated the effects of iron and DHA supplementation, alone or in combination, on physical activity; Meyer et al (2007) tested the benefits of high DHA fish oil supplementation as an adjunct to statin therapy for hyperlipidaemia; and Newens et al (2011) investigated the effect of acute elevation of non-essential fatty acids enriched with either saturated fatty acids (SFA) or SFA plus fish oil on vascular function. Further, a double-blind, randomized, controlled trial run by D'Vaz et al (2012) studied the effect of early postnatal fish oil supplementation on infant cellular immune function at 6 months of age in the context of allergic disease examined.…”

Shining a light on the effects of omega‐3 polyunsaturated fatty acids on the brain: The relationship between cerebral blood flow parameters and cognition

“…When evaluating the neuroimaging data gleaned from intervention studies in older adults, the picture is less clear. To date, no evidence of an effect of n-3 PUFA supplementation on CBF parameters as measured using NIRS has been detected in this population, even following a 6-month intervention [6]. Evidence from the study conducted by Witte et al [8] suggests perhaps that the lack of evidence in favour of modulation of CBF parameters in older adults may be due to the neurological changes that occur during ageing, although this suggestion requires further exploration.…”

“…In contrast, a modulating effect of n-3 PUFAs has not been demonstrated in older adults using NIRS. Recently, Jackson et al [6] conducted a 26-week, randomised, double blind, placebo-controlled intervention study with 3 treatment groups (placebo, 2 g DHA rich fish oil, 2 g DHA rich fish oil with added multinutrients) on a sample of 84 healthy adults (age m = 59.68 years). No effect of either active treatment was found for any of the NIRS outcome measures or on the cognitive performance tasks.…”