Turmeric seems to be everywhere these days; in high street coffee shops (turmeric latte anybody?), as a ‘superfood’ in popular diets, in the recipes of celebrity bloggers and in media headlines with claims of miraculous health benefits.
We know turmeric has been used for centuries, particularly in South Asia, for both cooking and alternative (e.g. Aryuveidic) medicinal purposes. Over a number of years, numerous articles have appeared claiming that turmeric is a cure for much, from minor ailments like heartburn to serious diseases like diabetes, depression, Alzheimer’s, and even cancer.
But is there any science to support this?
Firstly, it’s important to mention that when we talk about turmeric, what we may really be referring to is curcumin. This is commonly considered to be the bioactive component in turmeric, and the compound that has been most studied. But only about 3% of turmeric powder is curcumin, and when we eat it, not much of that curcumin is even absorbed into our body.
Research in animals is not equivalent to research in humans
Research in animals, mainly rats, and in lab work (like cell cultures in a dish) have shown that curcumin, typically in extremely high doses, may have anti-inflammatory and antioxidant properties, and has shown potential to inhibit the development of several types of cancer. These effects sound promising, but may not be applicable to humans. As one of the lead academics in turmeric research, Dr. Bharat Aggarwal, Professor of Medicine at the University of Texas has said “If rats and mice were perfect indicators of a treatment’s effectiveness, every disease would be gone by now.”
Animal studies must always be followed by clinical studies in humans before any recommendations can be made. And there is little reliable evidence to support the use of turmeric for any health condition because very few limited clinical trials have been conducted. An example of such a study was a phase 2 clinical trial in the US that looked at the impact of 2g and 4g curcumin a day on potential colorectal cancer biomarkers in 44 smokers for 30 days. The researchers reported a significant effect in one of the biomarkers in the treatment with 4g curcumin, with no reduction at 2g. Yet 4g curcumin would be well over 100g turmeric powder daily, and a typical curry recipe uses 1 teaspoon (around 3g) for 4 people!
Dietary patterns rather than single foods are important when looking at cancer prevention
We also need to look at the quality of the diet as a whole, for example, does it include plenty of fruit and veg and fibre? And also levels of obesity and physical activity. These factors are likely to be far more important than curcumin on its own when it comes to health and disease risk.
There is no reason not to encourage the use of turmeric in cooking, but it is not a miracle food. As readers of this blog are reminded on many occasions – headlines that purport miracle cures for foods should be regarded with scepticism. No single food is going to magically transform us into healthy people, even if there is some credible evidence of its beneficial properties. Turmeric clearly has some interesting properties, but the current popular claims go far beyond the actual evidence.
