The Last Word
Michael Mosley on turmeric
Tumeric has now become incredibly trendy, thanks to claims that it can improve everything from allergies to depression.
When it’s fresh, turmeric looks a little bit like ginger root (in fact, they belong to the same family), but when it’s ground down you get a distinctive yellowy-orange powder that’s very popular in South Asian cuisine. There are at least 200 different compounds in turmeric, but there’s one that scientists are particularly interested in. It’s called curcumin. Thousands of papers have been published looking at turmeric and curcumin in the lab, and some have had promising results. But the tests have mainly been done in mice, using unrealistically high doses.
Yet there have been some exciting human studies too. There was, for example, one with the delightful title, Curry Consumption And Cognitive
Function In The Elderly. In this study, the scientists looked at just over 1,000 Asian subjects, between the ages of 60 and 93, and compared their levels of curry consumption with their cognitive performance, as measured by their Mini-Mental State Examination (MMSE) score. The researchers found that those who consumed curry ‘occasionally’ or ‘often’ had significantly better cognitive scores than those who ‘never’ or ‘rarely’ consumed curry. For the BBC series
Trust Me, I’m A Doctor we also did a turmeric experiment. We recruited nearly 100 volunteers who rarely ate curry and divided them into three groups. We asked one group to consume a teaspoon of turmeric every day for six weeks, ideally mixed in with their food. Another group swallowed a supplement containing the same amount of turmeric, and a third group took a placebo pill.
To see what effect the turmeric had, we used a novel test developed at University College London by Prof Martin Widschwendter. His test looks at methylation, which is a process by which changes happen to the DNA of cells. It is a bit like a dimmer switch that can turn the activity of a gene up or down. To see if eating turmeric made any difference to genes, we got him to test our volunteers’ blood before and after the experiment. So what did he find?
“We didn’t see any changes in the group taking the placebo. The supplement group also didn’t also show any difference,” he says.
“But the group who mixed turmeric powder into their food – there we saw quite substantial changes,” he continues. “It was really exciting, to be honest. We found one particular gene which showed the biggest difference. And what’s interesting is that we know this particular gene is involved in three specific diseases: depression, asthma and eczema, and cancer… so this is a really striking finding.”
But why did we see changes only in those eating turmeric, not in those taking the same amount as a supplement? Dr Kirsten Brandt, a senior lecturer at Newcastle University who helped run the experiment, thinks it may have something to do with the way the turmeric was consumed. “It could be that adding fat or heating it up makes the active ingredients more soluble, which would make it easier for us to absorb the turmeric,” she says.
There is more research that needs to be done, including repeating this experiment to see if these findings can be confirmed. But I’m already experimenting with adding it to tea and my morning omelette.