Alzheimer's Disease (AD) is a progressive neurodegenerative disorder that affects millions of people worldwide. In Australia, it’s currently the second leading cause of death and in the US, it’s now the third leading cause of death.
Traditionally, AD has been associated with age-related cognitive decline and memory loss, but emerging research is shedding light on an intriguing sub-class of the disease known as Inhalation Alzheimer's Disease. Two notable medical pioneers, Dr. Dale Brederson, a renowned neuroscientist working in Alzheimer’s disease treatment and prevention, as well as Dr Ritchie Shoemaker, a clinician who has pioneered identifying and treating mould-related illness, have been at the forefront of drawing attention to this under-recognised aspect of AD.
What is Inhalation Alzheimer’s Disease?
Inhalation Alzheimer's Disease is a subtype of AD that is believed to be caused by exposure to airborne toxic substances. Unlike other forms of AD, which are often linked to genetic predisposition and age-related factors, Inhalation Alzheimer's Disease is thought to be triggered by inhaling toxic particles or biotoxins present in the air we breathe.
Repeated, or ongoing exposure to these inhaled substances can lead to forgetfulness, brain fog, difficulty concentrating and recalling information, mood changes and cognitive deficits that often cannot be explained by family history or genetic predisposition to Alzheimer’s disease.
Potential Environmental Toxins
While the exact mechanisms of how inhaled toxins contribute to AD development are yet to be fully understood, some environmental toxins have been implicated in research;
Air Pollution
Several recent Lancet commissions exploring the effects of pollution on health have identified that air pollution is a major contributor to global disease burden. It is estimated that up to 16% of deaths worldwide could be attributed to pollution.
Studies have shown that exposure to air pollution, especially fine particulate matter (such as PM2.5 and NO2) raises risks of cognitive decline and dementia by contributing to hypertension, raised lipids, atherosclerosis, oxidative stress, insulin resistance, endothelial dysfunction, enhanced propensity toward coagulation, inflammation, and stroke. These pollutants can easily be inhaled and reach the brain both directly and indirectly, through the olfactory nerves or via initiation of systemic inflammation.
Heavy Metals
Research shows that risks for Alzheimer’s Disease and Dementia can be attributed to environmental exposure to toxic heavy metals. Exposure to mercury, lead, cadmium and manganese are common due to their widespread presence in the environment. Once someone is exposed to these heavy metals, they can enter our cells and reach the brain, initiating oxidative stress and neuroinflammation, and contributing to cognitive decline.
Volatile Organic Compounds (VOCs) and Solvents
Occupational exposure to these substances is emerging as a catalyst for greater risks of neurological disease. Awareness is growing for the various VOCs, found in products like paints, cleaning agents, and household items, which can be released into the air and inhaled. Organic solvents are widely used in the modern world. They are found in paints, pharmaceuticals, degreasers, adhesives, printing inks, pesticides, cosmetics, and household cleaners.
Chronic, long-term exposure to VOCs and solvents has been associated with cognitive impairment and neuroinflammation. Harm reduction strategies in workplaces are now far more common than was the case in the 1980’s and 90’s, to help mitigate the long-term health impacts when working with these chemicals. However for people of working age in this era, their exposure may have contributed to the rise we’ve seen in recent decades of dementia and Alzheimer’s disease.
One of the most concerning modern-day inhalation exposures that leads to obvious neurological impairment is the deliberate abuse of inhaling butane or lighter fluids to obtain a ‘high’. This potent, acute exposure has a rapidly evident effect on the neurological system which has immediate and long-term risks.
Pesticides
The use of pesticides has increased drastically over the last century. Pesticides and organophosphates are known neurotoxins and numerous studies have shown that those who are at risk of higher exposures, such as agricultural workers and gardeners have a much higher risk of going to to develop Alzheimer’s Disease. Pesticides are ubiquitous in our food supply chains meaning that virtually everyone is being exposed to low-grade pesticides on a daily basis.
Mycotoxins
One of the biggest emerging factors in inhalation Alzheimer’s presentations is exposure to mycotoxins, typically associated with moulds such as Stachybotrys, Penicillium, or Aspergillus, often present in water-damaged buildings.
Mycotoxins can release spores into the air that can set off a systemic inflammatory response in susceptible individuals which has been collectively termed “Chronic Inflammatory Response Sydrome” (CIRS). This is a multi-system health issue that can affect immunity, hormonal health, cognitive function, pain and mood, all of which have a spill-over effect on the neurological system. This can impact both cognitive and motor functions and lead to persistent neurological damage.
Prevention and Risk Reduction
The discovery of Inhalation Alzheimer's Disease underscores the importance of addressing environmental factors to reduce the risk of AD. While genetic factors are beyond our control, steps can be taken to minimise exposure to potential airborne toxins and to protect our nervous system from the potentially damaging effects of exposures and free radicals.
Be Aware of Indoor and Outdoor Air Quality: Regularly ventilate indoor spaces, use air purifiers, and avoid smoking indoors to reduce exposure to indoor air pollutants. Use suitable safety precautions when dealing with cleaning or gardening chemicals and stay informed about air quality levels in your area and take necessary precautions on days when pollution levels are high.
Promote Green Spaces: Encourage the development and maintenance of green spaces to reduce the impact of air pollution in urban areas. Not only does green space provide a cleansing offset to many environmental pollutants, but humans spending time in green space also benefits the body and mind.
Use Safe Cleaning Products: Opt for natural or eco-friendly cleaning products to reduce exposure to VOCs. The array of chemical cocktails sold to solve cleaning problems can often be solved with simpler, cleaner solutions - including vinegar and bicarb soda.
Choose Organic Produce or Keep a Vege Garden: When possible, select organic fruits and vegetables to minimise exposure to pesticides throughout the food supply. Growing your own produce can also not only provide you with clean, healthy fruits and vegetables but gardening itself is a wonderful mindfulness activity that can benefit mental health.
Consider Antioxidant Intake: Both through diet (colourful fruits and vegetables) and supplements, we can incorporate high antioxidant compounds as a safeguard to our cellular health. A range of potent antioxidant compounds have been shown to be influential on brain and cognitive function such as glutathione, n-acetyl-cysteine, astaxanthin, resveratrol, selenium, quercetin, curcumin, omega-3, vitamin E and brassica.
Nootropics: Many nootropic substances exert their cognitive enhancing effects through antioxidant actions or supporting pathways that serve and protect memory, neuroplasticity and nerve structural integrity. Examples include; Gingko biloba, Bacopa monnieri, phosphatidylcholine, omega-3 fatty acids, vitamin D, medium-chain triglycerides and green tea, to name a few.
Awareness Is The First Step to Change
Inhalation Alzheimer's Disease is a compelling sub-class of AD that deserves greater recognition and research attention. Dr. Ritchie Shoemaker and Dr. Dale Brederson's work has shed light on the potential impact of environmental toxins on brain health and the development of AD and dementia-like illness. While much remains to be understood about this subtype of AD, it serves as a powerful reminder of the importance of our environmental exposures and the impact that the air we breathe every day can have on our long-term brain health.
REFERENCES
Bredesen DE. Inhalational Alzheimer's disease: an unrecognized - and treatable - epidemic. Aging (Albany NY). 2016 Feb;8(2):304-13.
Peters R, et al. Air Pollution and Dementia: A Systematic Review. J Alzheimers Dis. 2019;70(s1):S145-S163.
Bakulski KM, et al. Heavy Metals Exposure and Alzheimer's Disease and Related Dementias. J Alzheimers Dis. 2020;76(4):1215-1242.
Dick FD. Solvent neurotoxicity. Occup Environ Med. 2006 Mar;63(3):221-6.
Yan D, et al. Pesticide exposure and risk of Alzheimer's disease: a systematic review and meta-analysis. Sci Rep. 2016 Sep 1;6:32222.