Findings suggest that taking the bioavailable and safe form of curcumin, theracurmin improves memory performance over an 18-month period in middle-aged and older non-demented adults.
In addition, such a regimen may lead to less plaques and tangle accumulation in the amygdala and hypothalamus brain areas so often seen in patients with Alzheimer's disease.
“Exactly how curcumin exerts its effects is not certain, but it may be due to its ability to reduce brain inflammation, which has been linked to depression," said Dr Gary Small, study author and director of geriatric psychiatry at the University of California, Los Angeles' (UCLA) Longevity Center.
Theracurmin, which contains 90 milligrams (mg) of curcumin, was selected due to its high absorptive properties, made possible by the inclusion of colloidal nanoparticles.
This boost in bioavailability addresses curcumin’s relatively poor solubility and absorption from the gut, optimising its delivery and its metabolites for use in supplement and functional foods.
Theracurmin’s makers, Japan-based Theravalues, join OmniActive Health Technologies and Indena as players in the curcumin market that offer a variety of innovative ways to enhance the pigment’s properties.
While Theravalues rely on its granulation and suspension technology to ensure its product is more stabilised when dispersed in water, OmniActive use a “smart” coating system that allows nutrients to blend with a greater variety of applications and finished products.
Like a host of botanicals, curcumin is looked upon with caution by the European Food and Safety Authority (EFSA).
With no approved health claims for curcumin in the EU at the moment, interested parties are looking to the 17 or so claims on hold for health benefits including anti-inflammation and digestive health.
These applications form part of a 2000+ list of on-hold botanical claims yet to be processed by the authority.
Led by Dr Small, the team began by enrolling 40 adults, who had previously complained of mild memory lapses.
These adults were then allocated to the study group (90mgs of curcumin twice daily for 18 months) or the placebo group.
Both the curcumin and placebo were encapsulated and the colour of the active curcumin capsules did not differ from the placebo capsules.
All subjects underwent cognitive assessments at the start of the study and at six-month intervals.
Curcumin levels in their blood were also noted at the start of the study and after 18 months.
To assess brain health, thirty subjects underwent positron emission tomography (PET) brain scans to record the levels of amyloid and tau in their brains at the start of the study and after 18 months.
Results found that in memory tests, the people taking curcumin improved by 28% over the 18 months accompanied by small improvements in mood.
Analysis of the PET scans suggested that behavioural and cognitive benefits were associated with decreases in plaque and tangle accumulation in brain regions responsible for mood and memory.
"These results suggest that taking this relatively safe form of curcumin could provide meaningful cognitive benefits over the years," said Dr Small, who is also UCLA's Parlow-Solomon professor on aging.
Mechanisms of action
Curcumin’s potent anti-inflammatory and antioxidant effect was put forward as a possible antidote to the brain inflammation and oxidative stress observed in Alzheimer’s disease and major depression.
The team also theorised that curcumin could also disrupt the formation, accumulation, and toxicity of amyloid plaques as well as the interaction with such neurotoxic heavy metals as cadmium and lead.
Interestingly, they thought that curcumin's ability to reduce amyloid accumulation may be “mediated through gut-controlled inflammatory processes in the body, involving multiple pathways, limitation of oxidative damage, and reduction of cholesterol”.
Source: The American Journal of Geriatric Psychiatry
Published online ahead of print, doi: 10.1016/j.jagp.2017.10.010
“Memory and Brain Amyloid and Tau Effects of a Bioavailable Form of Curcumin in Non-Demented Adults: A Double-Blind, Placebo-Controlled 18-Month Trial.”
Authors: Gary W. Small, et al