Although laboratory studies do suggest that a compound in turmeric may have anti-cancer properties, claims that meals rich in turmeric could be used in the fight against cancer are not supported by current scientific evidence, concludes a review by the British Nutrition Foundation, published recently in Nutrition Bulletin Magazine. So it’s not time to reach for the golden latte or curry for anything other than an enjoyable meal.
Turmeric and curcumin- the magic ingredient?
The low rates of cancer in India where they traditionally use a lot of turmeric was the reason many believed there could be a link. According to the Indian Food Survey the average consumption of turmeric is 22-29/g/month while in the UK (based on the data of National Nutrition and Dietary Survey reviewed by BNF) it is 2.1 g/month. Whether the lower cancer incidence could be due to other dietary and lifestyle factors or to the increased turmeric consumption remains to be examined, as no large, reliable population-based studies have taken place.
Curcumin is the most well studied compound of turmeric, and the one to which most of the potential health benefits of turmeric are credited. However, the consumption of turmeric is not an accurate measure of the curcumin consumption, as only 3% of turmeric is curcumin. Although, curcumin is safe even when consumed at high quantities, only a small amount gets into the body’s tissues, as it is hard for the body to absorb. Interestingly it is better absorbed when it is consumed with a hot and high in fat meal, like a curry. But no clear evidence or recommendations exist about the daily consumption of turmeric or a recommended daily dosage of curcumin.
In the lab, curcumin has been shown to prevent cancer cell development and growth. Results from animal studies support the evidence on the anti-cancer action of curcumin, where it helped prevent cancers including mouth, bowel (colon), foodpipe, liver and skin cancers. These studies also showed, though, that the absorption of curcumin by the body is very low.
Where does evidence show curcumin could help?
Other applications of curcumin have shown benefit. In patients with cancerous skin lesions, application of curcumin on the skin resulted in relieving symptoms. Curcumin administration by the mouth has been linked with reduced formation of signs of polyps in the colon – a precursor to cancer in some people. Taking curcumin for 10 days before surgery for colon cancer was also related to improved health of patients at the time of surgery, but patients should always consult their doctors before taking any supplements. Limited studies looking at the combined effects of chemotherapy and curcumin show some positive evidence of anti-tumour activity; better-designed clinical trials are necessary to give definite answers.
What does the evidence tell us?
Well-designed, larger human studies are necessary to examine further the therapeutic potential of curcumin and whether turmeric consumption in meals could show similar results.
The role of diet in cancer prevention is unquestionable, however, magic potions created by single food ingredients should always be regarded with some skepticism. Some golden milk may alleviate your child’s sore throat but it will not reduce the nation’s cancer incidence.