We need to keep thinking about what foods contain salicylate from different research analysis when they become available. It can make us rethink the basis of a low salicylate diet. Here I will consider the 2011 work by Wood and team.
How can we summarise what was found? Reading the following information can help you understand why it is so complex. The information is different from the earlier analysis results by Swain, and both analyses are different from what food sensitive people report reactions to. Critics of the diet feel they can query the scientific basis of the low salicylate diet. See my comment after you read the analysis data to help think through why analysis data may not mean as much as reports of those who do have reactions to spices and many other foods.
All researchers have reported that salicylates are present in all herbs and spices. Reports vary on other foods.
Wood’s group collected all the different results from all researchers worldwide and showed the really wide ranges of salicylate in foods.
Their work is available in: A systematic review of salicylates in foods: Estimated daily intake of a Scottish population. Adrian Wood et al Mol Nutr Food Res. 2011 55, S7-S14.
Two ideas are important. The first is that the average amounts of salicylate found in all other studies is not similar to the Australian data figures by Swain in 1985. The second one is that the range of values is surprisingly very great. Regardless of where in the world analysis of compounds such as lactose or gluten are done, the values are similar. But the values for salicylate are not at all similar. One day you could be eating an orange that has a salicylate value of 0.02mgm/kgm and on another day the orange you eat could be 23.90! It is very difficult to make useful tables from these findings.
Here are some examples of median and range values provided –
Values are mg/kg
Pears are 1.46 range of 0.2 – 2.7 This is a big range from 3 analyses
Apples 0.55 range of 0.02 – 5.9 from 5 analyses
These values are in the unexpected direction with pears always presumed very low and apples higher.
Tomatoes 0.36 range of 0.05 – 1.3 from 5 analyses
Tomato soup 0.02 range of 0.05 – 1.3 “
Tomato juice 1.32 only one analysis
Bolognaise sauce 3.2 only one analysis
[it could have some added herbs]
This result where tomato is much lower than apples and pears was unexpected
Salicylates in herbs and spices had very high median values with the range very very high, but inconsistently so.
Paprika 28 range of 2.98 – 2000!
This variation would make a big difference when diluted in food
Thyme 28 range of 12.8 – 1800!
So we can say that all herbs and spices are suspect, that some may tolerated, but to expect an inconsistent outcome.
Tea 1.06 range of 0.4 – 34.5
Coffee 1.8 range of 0.4 – 6.8
Coffee is reported to have higher median value of salicylate content than tea, but weak coffee is better tolerated. Tea has a much wider range of values.
Bananas 0.4 range of 0.3 – 18.6
However just-ripe bananas are rarely reported not tolerated, except in those with high amine sensitivity.
How do these figures relate to the low salicylate diet used in the RPAH handbook? They do not verify the tables provided. This could mean that the salicylate data made in Australia may apply better to Sydney to the fruit analysed around 1980 than world-wide data does. This is a problem as it means that values in different parts of Australia, and in different years may be as wide as the international data, and therefore not able to be used usefully.
Since values provided around 1980 did not correlate with what food sensitive patients found the classification of salicylate-containing foods as low, medium or high in the RPAH booklets has been altered to reflect the clinical findings, such as apples valued as low in the analysis data were redesignated as medium in the booklet tables.
What can we say to the critics?
We can say that salicylate analysis data is important but is not the whole story for food sensitive people. Despite the complexities, we can be sure there are some reaction-producing chemicals in what are termed “high salicylate” foods.
Importantly, those who have bad reactions to herbs and spices also have similar but milder reactions to many fruits and vegetables, teas and mint. After collecting reports carefully on 1200 families, and another 2000 which verified those, I was secure enough to design the Best Guess Food Guide, published in Tolerating Troublesome Foods in 2014. It grades foods as having a low risk of reaction as Risk Rating 1, and those most likely to produce a reaction as RR 10.
Foods up to a RR of 5 are allowed on the Baseline Diet to provide a manageable diet at the beginning of diet investigation. For detail see http://www.foodintolerancepro.com/tolerating-troublesome-foods/
In 1998 when I learned of Venema’s study had shown there was no salicylate except in spices I asked myself if that would mean I would stop believing patients who reported reactions after improving on the baseline diet, or parents who reported their children had adverse reactions, especially hyperactivity or sleep problems which parents can see clearly. What can we conclude from this new data on salicylates in food? We can say that the information that is available at this time is not useful enough to plan a neat diet. It could even be said that it disproves the hypothesis that salicylate has much of a role at all. No, it does not! It just says that the amount of salicylate varies in foods. But we are gradually learning more, such as about the enzymes that metabolise salicylates. And we are beginning to appreciate that other similar compounds such as natural flavours which occur with salicylates may also have an important role.