Curry favour with colorectal cancer
fruit, could reduce the pain of headaches and reduce the risk of
colorectal cancer, says a review from Scotland.
While it seems highly unlikely that such a result will be translated into pushing vindaloo as a functional food, it may see increased use of spices and herbs as functional ingredients in the rapidly expanding functional food market.
According to market analyst, Mintel, the UK functional food market was worth an estimated £1.1bn (€1.6bn) in 2005, having grown 143 per cent since the start of the new millennium.
The potential health benefits of herbs and spices have been consistently researched, with studies of the anti-cancer effects of turmeric from curcumin, and capsaicin from red chilli pepper spending significant time in the spotlight recently.
And the review, authored by the late John Paterson, and his colleagues Gwen Baxter and James Lawrence from Dumfries and Galloway Royal Infirmary, and Professor Garry Duthie from Rowett Research Institute, adds to this by looking at the science behind the potential benefits of dietary salicylic acid.
The health benefits of salicylic acid are not in question because the compound is the metabolite of acetylsaliclylic acid, more commonly known as aspirin. Recent reports have reported that a daily dose of 75-80 mg of aspirin may halve the risk of colorectal cancer.
The question remained, therefore, whether salicylic acid from fruit, vegetables, and herbs and spices such as paprika, curry powder, thyme and oregano, is also available in bioactive quantities from the diet, and if this could impact on colorectal cancer risk.
Colorectal cancer accounts for nine per cent of new cancer cases every year worldwide. The highest incidence rates are in the developed world, while Asia and Africa have the lowest incidence rates, thereby begging the question whether such incidence may be related to dietary salicylic acid intake.
"Possibly," Prof. Duthie told NutraIngredients.com, "but causality is not proven."
"However, [it has been reported that] the plasma concentrations of salicylic acid in Southern Indians are 4 times higher than in Scots, suggesting a higher dietary intake of salicylic acids in India presumably from spices. Rates of colon cancer are low in India," he said.
An article by the Dumfries group (J. Ag. Food. Chem., Vol. 54, pp. 2891-2896) reported that a portion (549g) of a vindaloo style curry contained about 86 grams of total salicylates.
Moreover, an article in the Journal of the American Dietetic Association (1985, Vol. 85, pp. 950-960), reported that curry powder and paprika contain over 2000 milligrams of salicylates per kilogram, although these findings were not repeated in an additional study.
And despite a study from 1996 concluding that amounts of bio-available salicylates in a "normal" diet were too low to have any effect on the risk of diseases, the new review concludes: "It is, therefore, feasible that sufficient salicylates could be obtained from regular consumption of plant-based diets to decrease disease risk by PGHS-2 inhibition… an enzyme implicated in colon cancer pathogenesis."
Prof. Duthie told this website that he was continuing to work with the Dumfries group to further explore the bioavailability of salicylic acid from the diet.
"We are also conducting studies to try to ascertain potential anti-cancer mechanisms of salicylic acid in model systems at the molecular level," he said.
Excessive consumption of salicylic acid-rich vindaloo curries is not recommended, while extreme intake of the pure compound can result in stomach irritation and bleeding, said Prof. Duthie.
"This is one reason Bayer acetylated it to produce aspirin to try to reduce its acidity and minimise side effects," he said.
