Effects of Long Chain Omega-3 Polyunsaturated Fatty Acids on Brain Function in Mildly Hypertensive Older Adults

Abstract

Purported benefits of long chain omega-3 polyunsaturated fatty acid (LCn-3PUFA) for brain function may be attributable, at least in part, to improved cerebral perfusion. A pilot randomised controlled trial was undertaken to investigate effects of taking a DHA-rich fish oil supplement for 20 weeks on cerebrovascular function, mood and cognitive performance. Borderline hypertensives aged 40–85 years with low habitual LCn-3PUFA intake took four capsules/day of EPAX (1600 mg DHA + 400 mg EPA) or placebo (corn oil). Cerebrovascular function was assessed at baseline and after 20 weeks in 38 completers (19 on each supplement) using transcranial Doppler ultrasound of blood flow in the middle cerebral artery at rest and whilst performing a battery of cognitive tasks (neurovascular coupling). The primary outcome, cerebrovascular responsiveness (CVR) to hypercapnia, increased 26% (p = 0.024) in women; there was no change in men. In contrast, neurovascular coupling increased significantly (p = 0.01 for the overall response) in men only; the latter correlated with an increase of EPA in erythrocytes (r = 0.616, p = 0.002). There was no associated improvement of mood or cognition in either men or women. These preliminary observations indicate that LCn-3PUFA supplementation has the potential to enhance blood flow in the brain in response to both hypercapnic and cognitive stimuli. Future studies should examine differential effects of EPA and DHA and take account of the gender differences in responsiveness to supplementation.

Self-Reported Omega-3 Supplement Use Moderates the Association between Age and Exercising Cerebral Blood Flow Velocity in Older Adults

“…To our knowledge, we are the first to report this potential connection between omega-3 supplementation and improved CBF measures during exercise. However, this finding is consistent with randomized controlled trials that have found that omega-3 supplementation can increase CBF during other cerebrovascular challenges such as hypercapnia and cognitive tasks [4,6].…”

“…Future studies that measure changes in CBF would provide evidence for this mechanistic pathway. Importantly, one randomized trial lends credence to this potential mechanism by showing that 20 weeks of omega-3 supplementation increased CBF response to carbon dioxide and cognitive tasks in older adults with borderline hypertension [6]. The current study expands upon these findings by demonstrating preserved exercising CBF velocity with age with omega-3 supplementation, specifically in older adults who are at increased risk for vascular dysfunction.…”

“…More recently, a randomized controlled trial in older adults with mild cognitive impairment showed that omega-3 fatty acid supplementation reduced cognitive and functional decline [5]. While this trial did not explore the mechanisms through which omega-3 consumption improved brain function, a previous study found that fish oil supplementation improved the CBF response to hypercapnia and to cognitive stimuli in older adults with borderline hypertension [6], suggesting that omega-3 may act mechanistically by improving blood flow to the brain. These findings are important since the brain receives 15-20% of cardiac output despite comprising only 2% of body mass [7].…”

“…Lifestyle interventions, including healthy diet and regular physical activity, are important for maintaining optimal brain health [21], partially denoted by maintenance of CBF. Omega-3 fatty acid supplementation has been shown to increase CBF in response to carbon dioxide and during cognitive tasks [4,6]. However, the impact of omega-3 polyunsaturated fatty acid supplementation on CBF during other stimuli relevant to daily life, such as exercise, has yet to be elucidated.…”

The Face of Early Cognitive Decline? Shape and Asymmetry Predict Choice Reaction Time Independent of Age, Diet or Exercise

“…The supplement group did not show any increase in brain volume. Howe, Evans, Kuszewski and Wong [103] administered fish oil supplement in a randomized control trial for 20 weeks in a group of older adults. There was some structural change observed-cerebrovascular responsiveness to hypercapnia, but only in women.…”