Phenols
Phenols are a type of chemical found in food. They can occur naturally in plant foods and can also be man-made and added to processed foods as preservatives or dyes. Natural phenols are in many nutritious foods and can be beneficial, but some people are highly sensitive to these food chemicals, and consuming them can cause many unpleasant symptoms
Quick Facts
Phenols are a type of chemical found in food. They can occur naturally in plant foods and they can be man-made and added to processed foods as preservatives or dyes.
The word phenol may make you think of “polyphenols”, which are antioxidants found in fruits, vegetables and other plant foods. Natural phenols are in many nutritious foods and can be beneficial, but some people are highly sensitive to these food chemicals, and consuming them can cause many unpleasant symptoms ranging from headaches, gastrointestinal problems, sinus/respiratory and skin issues, bedwetting, mood disturbances like aggression, hyperactivity and sleep problems.
Salicylates, amines, and glutamates are all types of phenols.
Our bodies break down phenols by a process called sulfation. An enzyme called phenol sulfurtransferase (PST) is critical to breaking down phenols. Sulfate is a mineral and is essential to the function of the PST enzyme.
Insufficient sulfate can lead to poor sulfation and reactions to phenols. In those with poor sulfation, removing phenols relieves the burden of this biochemical process and relieves symptoms.
The Feingold diet and the Failsafe diet are both aimed at minimizing the intake of phenols. The Feingold diet specifically limits salicylates while the Failsafe diet is more comprehensive and limits all types of phenols.
Symptoms of Phenol Sensitivity
Symptoms are varied and may include:
Red cheeks and ears
Persistent dark circles under eyes
Aggression/irritability
Abdominal pain and diarrhea
Chronic headaches, headbanging/self-injury
Ear infections, asthma, and sinus issues
Hives/rashes, skin conditions like eczema, psoriasis
Bedwetting and urinary incontinence
Those with a history of these symptoms may benefit from a trial of the Failsafe diet.
Foods containing phenols
Amines
Fermented or pickled foods like vinegar, yogurt, kombucha, kefir, sauerkraut, pickles, soy sauce, Worcestershire sauce (see: Fermented Foods)
Wine and beer
Smoked, cured, and aged foods
Cocoa, chocolate
Soy sauce
Monosodium glutamate (MSG)
Soy sauce
Parmesan cheese
Gelatin
Artificial and Natural Additives (about 50)
Colors (FD&C colors, annatto)
Preservatives (sorbates, benzoates, sulfates, nitrates/nitrites, propionates, fermented items)
Flavors (glutamates, disodium guanylate/inosinate, yeast extract, hydrolyzed vegetable protein)
Additional eliminations:
All fragranced products (which contain phthalates) such as personal care products (things like perfumes, cosmetics, air fresheners, scented garbage bags, cleaning products or toiletries, mint-flavored toothpaste and mouthwash, and even essential oils).
Certain medications:
Acetaminophen
NSAIDs and COX-II inhibitors like aspirin and ibuprofen
finding alternatives without phenols [1]
Fresh, unprocessed meat, poultry, fish and dairy products like butter that are minimally processed with no preservatives
Minimally processed grains like rolled oats, plain pasta, plain rice, homemade bread
Celery, cabbage, asparagus, carrots, green beans and white potatoes
Natural oils like olive or avocado oil
Flavorings like garlic, parsley, chives and coconut
Peas, lentils and sunflower seeds
Chemical reactions
The body can respond to foods and/or chemicals in many different ways including allergies and sensitivities. If you suspect a chemical reaction, you can either choose to avoid the chemical or additional testing.
Phenols & Autism in the Research
The following chemicals are types of phenols.
Bisphenol A (BPA) and Autism
BPA exposure has a great potential to impact human brain development and possibly contributes to the increasing prevalence of human neurodevelopmental and behavioral disorders. [5]
BPA and BPS exert remarkably similar effects, raising the likelihood that the substitute chemical is potentially as harmful as its predecessor. [6]
BPA can be considered a risk factor for the onset of several cognitive and behavioral disturbances, memory, and learning. There is also evidence that BPA is a risk factor for the development of certain neurodegenerative diseases. The cellular and molecular mechanisms that underlie the neurological effects of exposure to BPA include neuroendocrine disruption, mitochondrial, epigenetic and inflammatory effects. [7]
There is evidence supporting the etiological link between exposure to environmental toxicants, including BPA, and the development of ASD.[8]
New findings add to the growing literature suggesting a common mechanism for BPA misregulation of cell–cell communication, and this may lead to associated social and cognitive behavioral impairments.[9]
In utero exposure of pregnant rats to BPA decreased the neuronal viability and the neuronal density in the hippocampus and impaired learning/memory only in the male offspring while the females were not affected. [10]
BPA may act as an environmental risk factor for autism in genetically susceptible children by inducing oxidative stress and mitochondrial dysfunction.[11]
The major pathway for BPA metabolism and excretion is via glucuronidation. The glucuronidation pathway makes a large variety of substances more water-soluble allowing for their subsequent elimination from the body upon urination. We found glucuronidation to be decreased in the ASD group suggesting that the glucuronidation pathway was compromised in at least some children with ASD. [12]
Severe autism was associated with low sulfate levels while mild symptoms were associated with higher levels of sulfate. The results suggest that sulfate may be helpful in reducing both the incidence and severity of autism. [13]
Propionates/propionic acid (phenol preservative) & Autism
Irritability, restlessness, inattention and sleep disturbance in some children may be caused by a preservative in healthy foods consumed daily. [2]
Increased propionic acid (PPA) exposure in humans, animal models and cell lines elicit diverse behavioural and biochemical changes consistent with inborn errors of metabolism, mitochondrial disorders and autism spectrum disorders (ASD). In this study, PPA treatment showed altered social and locomotor behaviour without changes in learning and memory. Brief systemic administration of propionic acid produced behavioural and dynamic brain ultrastructural changes, providing further validation of the PPA model of ASD. [3]
The data supports a significant role for propionic acid in modulating hNSC patterning leading to gliosis, disturbed neural-circuitry, and inflammatory response as seen in ASD.[4]
Acetaminophen (medication) & Autism
The use of acetaminophen in babies and young children may be much more strongly associated with autism than its use during pregnancy, perhaps because of well-known deficiencies in the metabolic breakdown of pharmaceuticals during early development. [14]
References
[1] Tacanow.org. Accessed September 12, 2021. https://tacanow.org/wp-content/uploads/2020/12/Possible-Treatment-Options-for-Phenol-and-Salicylate-Sensitivities.pdf
[2] Dengate S, Ruben A. Controlled trial of cumulative behavioural effects of a common bread preservative. J Paediatr Child Health. 2002;38(4):373-6.
[3] Lobzhanidze G, Japaridze N, Lordkipanidze T, Rzayev F, MacFabe D, Zhvania M. Behavioural and brain ultrastructural changes following the systemic administration of propionic acid in adolescent male rats. Further development of a rodent model of autism. Int J Dev Neurosci. 2020;80(2):139-56.
[4] Abdelli LS, Samsam A, Naser SA. Propionic Acid Induces Gliosis and Neuro-inflammation through Modulation of PTEN/AKT Pathway in Autism Spectrum Disorder. Sci Rep. 2019;9(1):8824.
[5] Preciados M, Yoo C, Roy D. Estrogenic Endocrine Disrupting Chemicals Influencing NRF1 Regulated Gene Networks in the Development of Complex Human Brain Diseases. Int J Mol Sci. 2016;17(12):E2086.
[6]Mao J, Jain A, Denslow ND, et al. Bisphenol A and bisphenol S disruptions of the mouse placenta and potential effects on the placenta-brain axis. Proc Natl Acad Sci U S A. 2020;117(9):4642-52.
[7] Rebolledo-Solleiro D, Castillo Flores LY, Solleiro-Villavicencio H. Impact of BPA on behavior, neurodevelopment and neurodegeneratio. Front Biosci (Landmark Ed). 2021;26:363-400.
[8] Ye BS, Leung AOW, Wong MH. The association of environmental toxicants and autism spectrum disorders in children. Environ Pollut. 2017;227:234-42.
[9] Henriksen AD, Andrade A, Harris EP, Rissman EF, Wolstenholme JT. Bisphenol a Exposure in Utero Disrupts Hypothalamic Gene Expression Particularly Genes Suspected in Autism Spectrum Disorders and Neuron and Hormone Signaling. Int J Mol Sci. 2020;21(9):E3129.
[10] Thongkorn S, Kanlayaprasit S, Panjabud P, et al. Sex differences in the effects of prenatal bisphenol A exposure on autism-related genes and their relationships with the hippocampus functions. Sci Rep. 2021;11(1):1241.
[11] Kaur K, Chauhan V, Gu F, Chauhan A. Bisphenol A induces oxidative stress and mitochondrial dysfunction in lymphoblasts from children with autism and unaffected siblings. Free Radic Biol Med. 2014;76:25-33.
[12] Stein TP, Schluter MD, Steer RA, Guo L, Ming X. Bisphenol A Exposure in Children With Autism Spectrum Disorders. Autism Res. 2015;8(3):272-83.
[13] Williams RJ. Sulfate Deficiency as a Risk Factor for Autism. J Autism Dev Disord. 2020;50(1):153-61.
[14] Parker W, Hornik CD, Bilbo S, et al. The role of oxidative stress, inflammation and acetaminophen exposure from birth to early childhood in the induction of autism. J Int Med Res. 2017;45(2):407-38.
[15] Autismrecoverysystem.com. Accessed September 12, 2021. https://autismrecoverysystem.com/wp-content/uploads/2017/05/Phenol-Sensitivity-1.pdf
Author
Brittyn Coleman, MS, RDN/LD, CLT
