Approximately 10–20% of older adults worldwide are affected by late-life depression, defined as a major depressive episode after the age of 60.
Curcumin, the main active polyphenolic compound of the curry spice turmeric (Curcuma longa), has been shown to reduce depressive symptoms in individuals suffering from depression and to improve mood. Cox et al. extended the curcumin supplementation and measured outcomes at four and twelve weeks. Again, fatigue was shown to be reduced following four weeks as well as twelve weeks of supplementation. Furthermore, curcumin significantly reduced tension, anger, confusion and total mood disturbance but these effects were only found at 4 weeks of supplementation.
Combining curcumin with other bioactive nutrients has been shown to counteract depressive symptoms has been suggested as a potential strategy to extend the mood-enhancing effects over longer periods due to potential additive or synergistic effects of the combination.
A large body of epidemiological and observational studies shows an inverse association between fish intake and the prevalence of depression and that depressed adults have lower blood and adipose tissue levels of LCn-3 PUFAs.
A team of researchers from the University of Newcastle, Australia, recently reported the combined effects of fish oil and curcumin on systemic and brain blood flow function in overweight middle-aged and older adults.
This team then carried out the current 16 week randomised, double-blind, placebo-controlled trial to: Confirm previously reported mood-enhancing benefits of curcumin and determine whether combining curcumin with fish oil would result in additional, longer-lasting benefits on mood states, subjective memory complaints (SMCs) and quality of life (QoL); and investigate the independent effects of fish oil on mental wellbeing and QoL and whether they are affected by plasma apolipoprotein E4 (APOE4) status (which indicates risk of Alzheimer's disease).
The participants - all overweight or obese middle-aged and older adults - were randomly allocated to one of four treatment groups: FO group: active fish oil capsules (Blackmores Omega Brain: 400 mg EPA and 2000 mg DHA/day) with placebo curcumin capsules (maltodextrin with yellow food colouring); CUR group: active curcumin capsules (Blackmores Brain Active: 800 mg Longvida containing 160 mg curcumin/day) with placebo fish oil capsules (mix of corn and olive oil with 20 mg of fish oil to match odour); FO + CUR group: active fish oil and active curcumin capsules; and PL group: placebo fish oil and placebo curcumin capsules.
Participants were instructed to consume six capsules daily, two fish oil and one curcumin (or matching placebos) in the morning and again in the evening with meals, and to record their supplement intake in an assigned diary, together with any changes in medication intake. They attended the research facility for a total of four visits—two at the beginning and two at the end of the intervention and provided a number of blood samples ad filled in questionnaires in order to gauge mood, memory, general health perception, APOE4, inflammatory markers and Omega-3 status.
The results indicated curcumin supplementation had potential beneficial effects on mood and reduced SMCs. Authors concluded that the improvements in both mood and SMCs are associated with improved QoL. However, they also found that combining curcumin with fish oil did not result in additional benefits.
Fish oil independently improved vigour and total mood disturbance, but only in APOE4 non-carriers. The observation that the mental wellbeing response to fish oil was influenced by APOE4 status should be followed up with studies designed to compare effects of fish oil on mental wellbeing between APOE4 carriers and non-carriers.
Two previous studies have examined the potential of diet or dietary supplements to reduce SMCs. An observational study showed an inverse correlation between adherence to a healthy diet—mix of a Mediterranean diet and Dietary Approaches to Stop Hypertension (DASH) diet—and SMCs in adults aged above 70 years who did not suffer from depression.
A 12 week clinical trial of BrainPower Advanced, a supplement containing a mix of 15 ingredients (Ginkgo biloba extract, green tea extract, l-pyroglutamic acid amongst others), showed improvements in SMCs compared to placebo in older adults (average 67 years).
Further investigation is needed into the long-term effects of reducing SMCs on cognitive function, mood and QoL and explore potential underlying mechanisms. The current report's authors also note thse studies might need to incorporate neuroimaging to more accurately assess SMCs in individuals at baseline.