Sorry, a weekly curry won’t prevent dementia

    24 May 2016

    A weekly curry could prevent dementia, according to recent headlines. Sadly the evidence isn’t there yet — but it is a genuine area of research.

    The latest study, published in the British Journal of Nutrition, found that a supplement of curcumin, a key chemical in turmeric, appeared to stave off cognitive decline.

    Curcumin is believed to block a protein called beta amyloid, which sticks together and degrades neurons.

    The year-long trial, by researchers at Edith Cowan University in Perth, Australia, involved 96 participants between the ages of 40 and 90, who were given either a curcumin supplement or a placebo three times a day for a year.

    The researchers found that those taking the placebo experienced a decline in mental function after six months that was not observed in those taking the curcumin supplement. Cognitive function was measured with memory and verbal tests.

    Dr Stephanie Rainey-Smith, the study’s lead author, said: ‘Curcumin therapy in animals has produced positive cognitive and behavioural outcomes; results of human trials, however, have been inconsistent.

    ‘In this study, we report the results of a 12-month, randomised, placebo-controlled, double-blind study that investigated the ability of a curcumin formulation to prevent cognitive decline in a population of community-dwelling older adults.

    ‘Our findings suggest that further longitudinal assessment is required to investigate changes in cognitive outcome measures, ideally in conjunction with biological markers of neurodegeneration.’

    Instant analysis
    The methodology in this study — randomised, placebo-controlled, double-blinded — appears to be strong. The group studied was comprised of older adults living in a retirement village; although the results suggest an association in some individuals between taking high doses of turmeric (higher than in a mild curry, for example) and improved performance in cognitive tests taken six months and one year later, it is not clear from the results whether turmeric taken by a wider population at an earlier age could prevent cognitive decline.

    The low number of subjects in this study limits its power and the applicability of the results, so while there may be a suggested association between turmeric intake and avoiding cognitive decline, it does not prove causality. The lay press hasn’t let this lack of causality get in the way of a spicy headline, though.
    Research score: 2/5