Introduction to Antioxidants: How Specific Supplements Can Enhance Mitochondrial Health in ADHD
- Sara L
- May 19, 2024
- 5 min read
Let us first start with, what are mitochondria?
Mitochondria are found in nearly every cell of the body. They are the tiny power stations located inside cells, producing energy by driving protons (teeny tiny particles) through miniature turbines. This energy allows our cells to carry on doing what they do best (keeping us alive and well). But they can also produce a waste product, in much the same way as a factory does. The waste is something called reactive oxygen species.
Diagram of a cell and its mitochondria
Sometimes mitochondria don't work the way they should. This can be caused by mutations in the DNA, or instruction manual, held in each cell, or in the mitochondria themselves (they have their own DNA!), or by nasties in the external environment such as radiation, chemicals and certain medications.
Mitochondrial dysfunction is the equivalent of a nuclear power station experiencing out of control reactions, and melting down, destroying the neighborhood. In mitochondrial dysfunction, the excessive production of reactive oxygen species overwhelms the safeguards in place, called antioxidants, which are produced to neutralize them. Antioxidants are both naturally produced by our bodies, and can also be found in the food we eat¹. Mitochondrial dysfunction both causes oxidative stress and is also a casualty of any oxidative stress going on².
Under normal circumstances the body does a decent job of neutralizing reactive oxygen species using antioxidants and enzymes to break them down and get rid of them, in the same way that nuclear waste from a power station is chemically treated to make it less dangerous.
However, when there are more reactive oxygen species floating around than the body can handle and get rid of, the oxidative stress damages cells and DNA leading to disease. It can damage the cells in the brain, called neurons, causing chronic and degenerative illness³.
So what is the relationship between mitochondrial dysfunction and ADHD?
Although the exact cause of ADHD is still unclear, ADHD is thought to be exacerbated by oxidative stress and inflammation⁴. It is thought that in ADHD, the mitochondria are not working properly.
If the mitochondria are not working right, they produce too many reactive oxygen species and too little energy, and then cells lack the necessary enzymes and antioxidants to effectively neutralize this waste by-product, leading to further damage of cells and DNA in the body. Numerous studies suggest that oxidative stress contributes to the development of, and the symptoms of ADHD⁵,⁶,⁷
The imbalance of antioxidants and reactive oxygen species in ADHD
Making matters worse, in addition to the oxidative stress experienced in ADHD, children with ADHD may naturally have lower concentrations of something called brain-derived neurotrophin factor (BDNF)⁷ which is essentially brain fertilizer supporting the growth and health of the brain. When this brain fertilizer is low, there can be problems with learning, memory and mood⁸.
Worsening this issue is that any BDNF present in the brain is at risk of being damaged by oxidative stress⁹ as you would see with the mitochondrial dysfunction of ADHD.
So children with ADHD are starting out with lower amounts of this brain fertilizer that is then being destroyed by the oxidative stress present in ADHD. At baseline, the brain as an organ is more susceptible to damage by oxidative stress and, compared to other organs of the body, naturally has lower levels of antioxidants floating around to protect it from this damage⁷.
This results in worse mental health outcomes for children with ADHD, which is potentially why we see so many co-occuring conditions with ADHD. ADHD rarely acts alone. The most commonly co-occurring conditions with ADHD include emotional dysregulation, ODD, sleep disorders, Autism Spectrum Disorders, anxiety, depression, OCD and personality disorders¹⁰.
How does oxidative stress influence neurotransmitters in the brain?
Oxidative stress suppresses the release of dopamine by damaging the cells that produce it, and interfering with how it moves from one place to another in the brain¹¹.
This is important because, in ADHD, symptoms are caused by low dopamine in the brain, which yields behaviors such as reward seeking, risk taking, lack of motivation and issues with concentration and memory.
Overly simplified diagram of oxidative stress on the brain and the neurons that produce dopamine.
Norepinephrine also runs low in the ADHD brain resulting in symptoms such as inattention and lack of interest in one’s surroundings. Norepinephrine is actually protective against oxidative stress and, as an antioxidant, protects the neurons in the brain that produce dopamine¹².
But in an unfortunate twist of fate, as norepinephrine runs low in the ADHD brain, it is unable to effectively combat the reactive oxygen species that are damaging the brain cells that produce dopamine. Furthermore, the chronic oxidative stress occurring over time in ADHD does eventually start to damage and break down any norepinephrine through the oxidative stress¹³ of ADHD.
In studies using rats, methylphenidate (a common ADHD stimulant medication) worsens oxidative stress and causes mitochondrial dysfunction¹⁴,¹⁵,¹⁶. So in ADHD, where you have mitochondrial dysfunction at baseline, adding methylphenidate could theoretically worsen oxidative stress in the brain, increase inflammation, and reduce the brain's ability to neutralize that stress, damaging neurons. However as mentioned previously, these studies have been performed in rats so far and it remains unknown what the long terms effects , if any, are in humans.
As such, stimulant medications remain the 'gold standard' or what should be used to treat children with ADHD if they are able to tolerate stimulant medications. Stimulants are highly effective medications for ADHD. The risk of not treating ADHD could include a worse quality of life overall, with issues related to economic instability (due to poor academic achievement), social struggles (due to issues with social-emotional awareness) and the development of chronic diseases (due to not being able to make healthy life choices), all secondary to the impulsivity and inattention of ADHD. Healthcare providers should absolutely treat ADHD if it is causing problems for the child, with the lowest dose of the most effective medication, whether a stimulant or non stimulant.
What can be done to limit oxidative stress in ADHD?
We could all be doing a better job of supporting both the body and the brain with supplementation, namely with antioxidant supplementation, to provide the brain with what it needs to combat any ADHD- and medication-induced oxidative stress on the neurons. Antioxidants therefore provide a natural protective answer for those taking stimulant medication for ADHD¹⁶. Further examples of additional antioxidants are B12, Vitamin D, Zinc, Magnesium, Omega 3 and Folate.
Conclusions
Mitochondrial dysfunction and oxidative stress are thought to be contributing factors in ADHD.
Oxidative stress can lead to the damage of brain cells and the neurotransmitters important in ADHD, such as dopamine and norepinephrine.
Children with ADHD may have lower levels of brain-derived neurotrophic factor (BDNF), which is important for brain health, making them even more susceptible to the effects of oxidative stress.
Stimulant medications, the current standard treatment for ADHD, may worsen oxidative stress in the brain, highlighting the need for additional treatment approaches to support the brain during medication treatment.
Supplementation with antioxidants may be a helpful strategy to combat oxidative stress in ADHD and potentially mitigate some of the negative effects of stimulant medication.
This site is for general informational purposes only and does not constitute the giving of medical advice. The contents do not constitute the practice of medicine, nursing, or other professional health care services. No provider–patient relationship is formed. Please consult with your child's healthcare provider when considering supplementation for children.
¹⁰DSM-5-TR; Diagnostic and Statistical manual of Mental Disorders. Fifth Edition. American Psychiatric Association. American Psychiatric Association Publishing.
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