|MadSci Network: Biochemistry|
Thank you for your question.
It's a very good one.
In response to your question, salicylates are widely found in fruits and vegetables. In plants, they work as signals to stimulate a response against attacks by insect pests and microbes.
In terms of the specific types of salicylates found, they include salicylic acid and methyl salicylic acid. There is some debate over whether acetylsalycilic acid (aspirin) is present in appreciable amounts. Overall, the highest levels of salicylates have been reported in spices, such as cinammon, oregano, rosemary, and thyme. A study comparing vegetarians to non-vegetarians to people taking low-dose (75-150mg/day) aspirin reported that those taking aspirin excrete the most salicylic acid in their urine (indicating that it reached the bloodstream) followed by vegetarians. Non-vegetarians not taking aspirin had the lowest urinary salicylate output.
The question remains as to whether the salicylates naturally present in plant foods actually have health benefits. Some authors have suggested that Western diets, which tend to be low in fruits and vegetables, are “salicylate-deficient” and that people should consider low-dose aspirin supplementation. Others have indicated that the availability of salicylates from plant foods is low, regardless of the type of diet consumed.
As you can see, there are still a lot of unanswered questions regarding the presence and potential benefits of natural salicylates, but I guess that is the nature of science.
Lawrence JR, Peter R, Baxter GJ, Robson J, Graham AB, Paterson JR.
Urinary excretion of salicyluric and salicylic acids by non-vegetarians, vegetarians, and patients taking low dose aspirin.
J Clin Pathol. 2003 Sep;56(9):651-3.
Janssen PL, Katan MB, van Staveren WA, Hollman PC, Venema DP.
Acetylsalicylate and salicylates in foods.
Cancer Lett. 1997 Mar 19;114(1-2):163-4.
Janssen PL, Hollman PC, Reichman E, Venema DP, van Staveren WA, Katan MB.
Urinary salicylate excretion in subjects eating a variety of diets shows that amounts of bioavailable salicylates in foods are low.
Am J Clin Nutr. 1996 Nov;64(5):743-7.
Dini P. Venema, Peter C. H. Hollman, Karin P. L. T. M. Janssen, and Martijn
Determination of Acetylsalicylic Acid and Salicylic Acid in Foods, Using HPLC with Fluorescence Detection.
J Agr Food Chem 1996;44: 1762 - 1767
Try the links in the MadSci Library for more information on Biochemistry.