The yellow spice contains curcumin, a chemical thought to block rogue proteins called beta amyloid, which clump together and destroy neurons.

Scientists at Edith Cowan University in Perth studied 96 participants aged between 40 and 90 over 12 months.

Some were given a daily placebo, while others were administered curcumin pills.

In tests of verbal and memory skills, those taking the dummy pill suffered a decline in mental function after just six months that was not observed in those who took curcumin.