Mitochondrial Dysfunction
What is Mitochondrial Dysfunction?
You might have learned “the mitochondria are the powerhouse of the cell” in science class - and that’s absolutely true!
Mitochondria are inside our cells and generate energy for our bodies. Think of them as little energy factories. Mitochondria take the molecules from the foods we eat and turn them into a form of energy that our bodies can use, called ATP.
The brain, muscles, liver, eyes, heart, and gastrointestinal (GI) tract are some of the most energy-hungry organs. They need a lot of ATP to perform their functions. When the mitochondria aren’t working properly, they can’t create enough energy. This is called mitochondrial dysfunction. [1]
There is some evidence to suggest that those with ASD are more likely to have mitochondrial dysfunction. Estimates range from 30-80% of those with ASD may also have mitochondrial dysfunction. [8,9, 20]
It is not clear if mitochondrial impairments cause ASD or if they are merely a feature of the condition. [12]
The symptoms of mitochondrial dysfunction are incredibly varied, which makes this a difficult condition to diagnose. There are a few diagnostic options including:
Genetic sequencing of mitochondrial or nuclear DNA could help determine if the cause is a genetic mutation
Biochemical testing with a urine Organic Acids Test (OAT) from Vibrant America or Great Plains Labs
Signs & Symptoms
Mitochondrial dysfunction can manifest differently even among family members. Symptoms will be based on which organ systems are affected in that particular person.
The organs that are affected most often are those that require the most energy; the heart, brain, muscles, GI tract. Mitochondrial dysfunction has been described in immune and buccal (cheek) cells, fibroblasts, muscle and gastrointestinal tissue and the brains of individuals with ASD. [11]
A combination of signs, symptoms and the results of appropriate tests are considered before giving a diagnosis.
Symptoms of mitochondrial dysfunction include [4]:
Fatigue and muscle weakness
Exercise intolerance
Poor growth or hypotonia (low muscle tone)
Vision and hearing problems
GI issues like reflux, cramping, diarrhea, and/or constipation
Seizures
Developmental delays (speech etc) and autism or autism-like features
If you suspect mitochondrial dysfunction in your child with autism, one of the best actions is to record the signs and symptoms that your child mentions or displays. Record the severity and frequency. Remember that for a non-verbal child, signs may look different than you might expect. For example, head banging may be a sign of a headache. Bending over furniture or otherwise applying pressure to the belly may be a sign of GI pain. Keep a specific and accurate record over a period of weeks or months and discuss your concerns with your healthcare practitioner.
Contributing Factors
Mitochondria are very delicate and so dysfunction can be caused by a number of things including [2]:
Genetic mutations
Environmental stressors like [11]:
Toxins like heavy metals, medications, mold/mycotoxins, and pesticides (like glyphosate) from food, water, or air
Oxidative damage and inflammation illnesses like Lyme disease or viral infections
Ironically, the main source of oxidative damage from free radicals within the cell is mitochondria themselves. As a by-product of their work, mitochondria produce free radicals, also known as reactive oxygen species. The more “helper molecules” (aka antioxidants) available to protect the mitochondria, the better, because as damage accumulates more and more mitochondria are affected and the dysfunction becomes more severe. Research has shown that people with autism have increased oxidative stress and reduced activity of those “helper molecules” which protect against oxidative damage. [3]
Next Steps
Diet
Some research suggests that the high fat/low carb ketogenic diet may be beneficial for those with mitochondrial dysfunction. [6, 14, 21] However, this diet may be challenging for children with autism who are often picky eaters and prefer carbohydrate-rich foods.
Nutritional ketosis may be beneficial by inducing mitohormesis, which causes an increase in mitochondrial capacity and self-produced antioxidant defense. [15]
If you decide to trial a ketogenic diet, do it with the guidance of a healthcare provider
Antioxidant foods may be beneficial including:
Co-enzyme Q10 - meat, poultry, fish, and nuts
Selenium - brazil nuts, yellowfin tuna, sardines, ham and shrimp
Manganese - mussels, hazelnuts, pecans, brown rice, chickpeas, spinach and pineapple
Vitamin A - beef liver, sweet potato, spinach, pumpkin and carrots
Vitamin C - red peppers, oranges, grapefruit, kiwi, broccoli and strawberries
Vitamin E - wheat germ, sunflower seeds, almonds, hazelnuts, peanuts
Glutathione - sulfur-rich foods are the building blocks of glutathione and these include garlic, onions, and cruciferous veggies like broccoli, cabbage, kale, and cauliflower
Foods containing B vitamins - meat, poultry, fish, eggs, dairy, nutritional yeast, chickpeas, leafy greens, sunflower seeds, avocado, and whole grains
Carnitine-rich foods may be beneficial as well. Carnitine levels are highest in animal foods like beef, chicken, fish, and milk.
Supplements
Supplementation is often focused on providing micronutrients that the mitochondria need to perform their tasks, as well as antioxidants to reduce oxidative stress and damage.
A number of supplements have been studied including:
L-Carnitine (aka acetyl-l-carnitine)[13,20]
Ubiquinol or CoQ10 [13]
B vitamins [13]
Selenium [13]
N-acetyl cysteine (NAC) [23]
Antioxidants like alpha-lipoic acid and resveratrol [7, 13, 17]
Butyrate-producing probiotics containing strains of Firmicutes [22]
Lifestyle
Support healthy sleep habits
This could mean turning off electronics a few hours before bed, giving your child a bath, using essential oils, gentle massage, dimming the lights and keeping noise to a minimum, using a weighted blanket, using white noise or calming music, or just having a calming and consistent bedtime schedule and routine.
See more about sleep in the Sleep Issues note
Reduce exposure to toxins
This could mean choosing organic food when possible, using a water filtration system or air purifier, taking a close look at personal care and household products for parabens or phthalates, evaluating your home for common sources of heavy metals or mold.
See more about reducing toxin exposure in the Toxic Load note
Exercise
This can be difficult if the person often feels tired or weak but even gentle exercise can strengthen the muscles, cause them to grow, and signal the production of new mitochondria. Sweating as a result of physical activity is also a way to remove toxins from the body.
Avoid unnecessary use of medications that damage mitochondria
These include aspirin, acetaminophen, antibiotics, NSAIDs, statins [1]
DISCLAIMER: Before starting any supplement or medication, always consult with your healthcare provider to ensure it is a good fit for your child. Dosage can vary based on age, weight, gender, and current diet.
Mitochondrial Dysfunction & Autism in the Research
Causes
Mitochondrial disease (MD) is often diagnosed alongside ASD and is thought to be acquired rather than genetic in origin. The short-chain fatty acids, especially propionic acid, which are increased in ASD-associated gut microbes might contribute to mitochondrial dysfunction. [8]
Several environmental factors, including toxicants, microbiome metabolites, and an oxidized microenvironment are shown to modulate mitochondrial function in ASD tissues. [11]
The mitochondrial physiology of the GI tract in children with ASD may be different than neurotypical children, with some change in mitochondrial function particularly prominent in the cecum.[16]
ASD can often occur with other medical comorbidities (i.e., sleep disorders, sensory abnormalities, epilepsy, gastrointestinal disturbances). This relationship is generally correlated with low mtDNA content and/or putative pathogenic mtDNA variants, demonstrating the strong involvement of the mtDNA in the complex phenotypes that coexist in ASD. [19]
Data suggest that impaired mitochondrial bioenergetics and mitochondrial fragmentation may contribute to the etiology of ASD and that these alterations can be reversed with ketogenic diet treatment.[21]
Inflammation
Proinflammatory cytokines released by activated immune cells stimulate reactive oxygen species production and lead to impaired mitochondrial function. Oxidative stress, as a result of mitochondrial dysfunction and dysregulation of endogenous antioxidant mechanisms, causes inhibition of mitophagy and accumulation of impaired mitochondria, which further trigger inflammation. [14]
Males and females respond differently to immune system activation during the embryonic period, with females being more resistant. Gender-specific immunological abnormalities related to cytokine levels have also been reported, showing a different immune profile in men and women with ASD. The explanation is related to estrogen, which can modulate cytokine expression.[17]
Recent data show that chronic neuroinflammation accumulates the undesirable effects of microglial activation, associated with the secretion of inflammatory mediators, which enhance inflammation. Inflammatory mediators produced by activated microglia and infiltrated immune cells trigger intracellular processes that can alter mitochondrial activity, ultimately leading to neurodegeneration. [17]
Treatment
Treatments commonly used to treat mitochondrial disease have been found to improve both core and associated ASD symptoms. [5]
Data suggest that butyrate can enhance mitochondrial function in the context of physiological stress and/or mitochondrial dysfunction, and may be an important metabolite that can help rescue energy metabolism during disease states. [10]
Adequate nutrient levels are essential for mitochondrial function as several specific micronutrients play crucial roles in energy metabolism and ATP production. B vitamins and lipoic acid are essential in the tricarboxylic acid cycle, while selenium, α-tocopherol, Coenzyme Q10, caffeine, and melatonin are suggested to boost the electron transfer system function. Carnitine is essential for fatty acid beta-oxidation. Selenium is involved in mitochondrial biogenesis. [13]
Given the beneficial effects of a ketogenic diet on epilepsy and increased mitochondrial function, its use has the potential to ameliorate some of the ASD-associated symptoms. [14]
Dietary supplements that promote mitochondrial biogenesis and inhibit the production of oxidative stress have been used to treat autism patients. Supplementation with antioxidants has been found to not only inhibit cognitive decline but also improve behavioral symptoms in autism. [18]
Three clinical trials have reported that carnitine supplementation improves symptoms in ASD. [20]
NAC has been demonstrated to work on multiple pathways that have been implicated in various psychiatric and neurological disorders – oxidative stress, mitochondrial dysfunction, inflammatory mediators, neurotransmission, and neural plasticity. [23]
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[1] Pizzorno J. Mitochondria-Fundamental to Life and Health. Integr Med (Encinitas). 2014;13(2):8-15.
[2] Niyazov DM, Kahler SG, Frye RE. Primary Mitochondrial Disease and Secondary Mitochondrial Dysfunction: Importance of Distinction for Diagnosis and Treatment. Mol Syndromol. 2016;7(3):122-37.
[3] Griffiths KK, Levy RJ. Evidence of Mitochondrial Dysfunction in Autism: Biochemical Links, Genetic-Based Associations, and Non-Energy-Related Mechanisms. Oxid Med Cell Longev. 2017;2017:4314025.
[4] 1. Mitochondrial Diseases: Causes, Symptoms, Diagnosis & Treatment. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/15612-mitochondrial-diseases. Published 2018. Accessed June 27, 2021.
[5] Frye RE, Rossignol DA. Treatments for biomedical abnormalities associated with autism spectrum disorder. Front Pediatr. 2014;2:66.
[6] 2. Studies Show Efficacy of Keto for Mitochondrial Disorder. Charlie Foundation. https://charliefoundation.org/am-i-a-candidate/keto-for-mitochondrial-disorder/. Accessed June 27, 2021.
[7] Rose S, Niyazov DM, Rossignol DA, Goldenthal M, Kahler SG, Frye RE. Clinical and Molecular Characteristics of Mitochondrial Dysfunction in Autism Spectrum Disorder. Mol Diagn Ther. 2018;22(5):571-93.
[8] Rosenfeld CS. Microbiome Disturbances and Autism Spectrum Disorders. Drug Metab Dispos. 2015;43(10):1557-71.
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[10] Rose S, Bennuri SC, Davis JE, et al. Butyrate enhances mitochondrial function during oxidative stress in cell lines from boys with autism. Transl Psychiatry. 2018;8(1):42.
[11] Rose S, Niyazov DM, Rossignol DA, Goldenthal M, Kahler SG, Frye RE. Clinical and Molecular Characteristics of Mitochondrial Dysfunction in Autism Spectrum Disorder. Mol Diagn Ther. 2018;22(5):571-93.
[12] Griffiths KK, Levy RJ. Evidence of Mitochondrial Dysfunction in Autism: Biochemical Links, Genetic-Based Associations, and Non-Energy-Related Mechanisms. Oxid Med Cell Longev. 2017;2017:4314025.
[13] Wesselink E, Koekkoek WAC, Grefte S, Witkamp RF, van Zanten ARH. Feeding mitochondria: Potential role of nutritional components to improve critical illness convalescence. Clin Nutr. 2019;38(3):982-95.
[14] Napoli E, Dueñas N, Giulivi C. Potential therapeutic use of the ketogenic diet in autism spectrum disorders. Front Pediatr. 2014;2:69.
[15] Miller VJ, Villamena FA, Volek JS. Nutritional Ketosis and Mitohormesis: Potential Implications for Mitochondrial Function and Human Health. J Nutr Metab. 2018;2018:5157645.
[16] Rose S, Bennuri SC, Murray KF, Buie T, Winter H, Frye RE. Mitochondrial dysfunction in the gastrointestinal mucosa of children with autism: A blinded case-control study. PLoS One. 2017;12(10):e0186377.
[17]Gevezova M, Sarafian V, Anderson G, Maes M. Inflammation and Mitochondrial Dysfunction in Autism Spectrum Disorder. CNS Neurol Disord Drug Targets. 2020;19(5):320-33.
[18] Chidambaram SB, Bhat A, Mahalakshmi AM, et al. Protein Nutrition in Autism. Adv Neurobiol. 2020;24:573-86.
[19] Citrigno L, Muglia M, Qualtieri A, et al. The Mitochondrial Dysfunction Hypothesis in Autism Spectrum Disorders: Current Status and Future Perspectives. Int J Mol Sci. 2020;21(16):E5785.
[20] Frye RE, Vassall S, Kaur G, Lewis C, Karim M, Rossignol D. Emerging biomarkers in autism spectrum disorder: a systematic review. Ann Transl Med. 2019;7(23):792.
[21] Ahn Y, Sabouny R, Villa BR, et al. Aberrant Mitochondrial Morphology and Function in the BTBR Mouse Model of Autism Is Improved by Two Weeks of Ketogenic Diet. Int J Mol Sci. 2020;21(9):E3266.
[22] Louis P, Flint HJ. Formation of propionate and butyrate by the human colonic microbiota. Environ Microbiol. 2017;19(1):29-41.
[23 ]Deepmala J, Slattery N, Kumar L, et al. Clinical trials of N-acetylcysteine in psychiatry and neurology: A systematic review. Neurosci Biobehav Rev. 2015;55:294-321.