By: Andrew Scholey, Katherine Cox
Compounds that increase the activity of certain neurotransmitters (chemical signalling molecules) or the delivery of the basic energy substrates (glucose and oxygen) to the brain have the potential to improve aspects of cognitive function. Those that, like curcumin, decrease inflammation and oxidative stress may have longer-term benefits for the ageing brain.
Indeed, there is converging evidence from both human population and animal studies that curcumin may help prevent age-related cognitive decline.
One study of around 1000 Singaporeans found that those who ate more curry had higher scores on a broad measure of cognitive ability.
While such findings need to be interpreted with caution, they suggest that some component of curry may contribute to the effect. The possible role of curcumin as the key ingredient is supported by numerous animal and test tube studies which show that the compound possesses a host of properties, including many relevant to brain function.
Our placebo-controlled, double-blind study examined the effects of 80mg of the lipid-conjugated curcumin in a cohort of healthy older people. For full transparency, note the study was funded by a grant from the company that makes the extract – though it had no input into the design, interpretation or publication of the study.
We randomly allocated 60 participants (with mean age 69 years) to receive curcumin capsules (the intervention) or a matching placebo (a dummy). Neither group knew whether they were receiving curcumin or a placebo.
The volunteers underwent a training day to familiarise themselves with the computerised cognitive and mood tests. Then they undertook the tests before taking the capsule, then one and three hours after a single dose. They underwent testing at the same three time points following 28 days on curcumin or placebo.
We found that, compared with the placebo group, those in the curcumin group performed better on working memory tasks one hour after the first dose. This effect disappeared by the third hour, by which time blood levels of curcumin would have dropped.
After 28 days, the participants’ working memory was still significantly better than those in the placebo group. Those taking curcumin were also significantly less fatigued at the 28-day assessment.
Sitting computerised cognitive tests for any length of time has negative effects on mood for people in their 60s and 70s. It makes them significantly less alert, content and calm, while increasing stress and fatigue. These mood effects were significantly reduced in the curcumin group, suggesting they were protected to some degree against mental workload stress.
These are early results from a single trial but are encouraging and merit further exploration. We are conducting a replication study, which includes additional measures such as brain imaging to try to better understand the effects of curcumin as a cognitive and mood enhancer.
In the absence of effective new pharmaceutical interventions to treat cognitive decline, it is important that we continue to explore the potential for bioactives like curcumin, and other nutritional interventions, to improve mental function.
To continue reading, please click Mellow yellow? The mood and brain benefits of curcumin from turmeric.
Andrew Scholey is Professor and Director of the Centre for Human Psychopharmacology, Swinburne University of Technology; Katherine Cox is a PhD Candidate, Centre for Human Psychopharmacology, Swinburne University of Technology. As noted in the article, a study mentioned was funded by a grant from a company that makes a curcumin extract. For a full disclosure of various funding received by the article authors, see the original article here.