What are phenols and salicylates?
Phenols are natural chemicals that are present in varying quantities in almost all foods, especially fruits, vegetables, and herbs. Salicylates are one type of phenol used by plants to protect themselves from harm such as diseases, insects, and certain kinds of bacteria. In terms of their chemical structure, these natural salicylates are very similar to acetylsalicylic acid (Aspirin), which is how they first came to be studied in the context of physical and behavioural effects.
In the 1960s, while researching the effects of Aspirin on children, Dr. Benjamin Feingold began to uncover a link between natural salicylates, food colouring, dyes, and additives and symptoms such as hyperactivity. The Feingold diet which you may have heard of was developed based on this research on dietary chemicals.
You will sometimes hear “phenols” and “salicylates” used interchangeably. It is impossible to completely eliminate phenols from the diet, but it is possible to avoid salicylates to a large degree, which will in turn lessen the burden of phenols on the body.
Which foods are high in salicylates?
Foods high in salicylates include (but are not limited to):
-Grapes (red & purple)
Artificial colourings, flavourings, preservatives and additives should also be avoided… but these should be avoided anyways.
What are the signs of salicylate intolerance?
Common signs of salicylate intolerance include:
-Reddened ears & cheeks/facial flushing
A child with a salicylate intolerance may experience some or all of these symptoms, and might experience symptoms not listed. Salicylates stimulate the central nervous system and can act quickly, so reactions are often (but not always) seen within 30-60 minutes of eating an offending food. Sometimes, this involves an extreme emotional high followed by an extreme low.
If you suspect that your child has a salicylate sensitivity, it is important to observe patterns. When are they experiencing which kinds of symptoms? If you do eliminate high salicylate foods, what changes do you notice? If you reintroduce a high salicylate food, what do you see?
Note that there are other dietary considerations to start with before diving into the avoidance of salicylates. Dr. Gannage’s diet pyramid for autism (found HERE) provides an overview.
Why are children with autism more sensitive to salicylates?
All phenols, including salicylates, are broken down in the body through a process called sulfation. Many children with autism have difficulty with this process, and there are a number of reasons why. Children with autism are often deficient in PST, the enzyme that metabolizes phenols and salicylates, as well as sulfate, a tool without which the enzyme PST cannot do its job (1).
Leaky gut is a common cause of salicylate intolerance. Existing intestinal damage will lead an individual have a higher concentration of phenols and salicylates in the bloodstream than normal, which can lead to an intolerance, especially when combined with a deficiency in the PST enzyme. Leaky gut itself can be caused or worsened by a sulfate deficiency, as sulfate is required both in the process of digestion and for the ongoing maintenance of the gut lining.
A child with autism may also have a sulfate deficiency because of mitochondrial dysfunction or an impairment in the methylation cycle (read more here).
How can we support a child with a salicylate sensitivity?
Avoiding high salicylate foods is, of course, key. But we cannot completely eliminate phenols. In order to support the breakdown of other phenols remaining in the diet, enzyme supplementation may be recommended. Epsom salt baths are an effective way to increase levels of sulfate as it is best absorbed through the skin. Finally, we want to address possible causes of impaired sulfation including supporting the methylation cycle (read more here) and addressing leaky gut.
To book a consultation with Dr. Gannage for your child with Autism Spectrum Disorder, click here.
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