Most people think dementia is simply part of getting older.
It isn't.
Research now suggests that the disease process behind Alzheimer's disease and many other forms of dementia can begin 20–30 years before symptoms appear. By the time memory loss develops, significant brain damage has often already occurred.
The question isn't simply:
"What causes dementia?"
The better question is:
"What allows the brain to become damaged in the first place?"
Modern research points to several major contributors.
Remarkably, nitric oxide influences almost every one of them.
Reduced Blood Flow to the Brain
Your brain represents only around 2% of your body weight, yet it consumes approximately 20% of your oxygen supply.
Every thought, memory and movement depends on a continuous delivery of oxygen and glucose.
Nitric oxide is the body's primary molecule for relaxing blood vessels and maintaining cerebral blood flow.
When nitric oxide production declines, blood vessels become stiffer, circulation falls, oxygen delivery declines and waste products accumulate.
Many researchers now believe chronic cerebral hypoperfusion is one of the earliest events in Alzheimer's disease.
Damage to the Brain's Blood Vessels
For decades Alzheimer's disease was viewed primarily as a disease of amyloid plaques.
Today, many scientists recognise that vascular health plays an equally important role.
Healthy blood vessels depend on healthy endothelial cells.
The most important molecule produced by these cells is nitric oxide.
Nitric oxide helps maintain vessel flexibility, reduces inflammation, prevents clot formation and improves oxygen delivery.
As endothelial function declines with age, dementia risk rises alongside cardiovascular disease. This helps explain why hypertension, diabetes, obesity, high cholesterol and insulin resistance all increase dementia risk—they damage the endothelium and reduce nitric oxide bioavailability.
Chronic Inflammation
Inflammation is now recognised as one of the major drivers of neurodegeneration.
Activated immune cells within the brain release inflammatory chemicals that slowly damage neurons over many years.
Healthy endothelial nitric oxide helps regulate inflammation throughout the vascular system.
When nitric oxide levels fall, inflammatory signalling increases and the blood-brain barrier becomes more vulnerable, allowing harmful substances greater access to brain tissue.
Mitochondrial Failure
Every brain cell contains thousands of mitochondria.
These tiny energy factories produce the ATP required for thinking, learning and memory.
Healthy physiological nitric oxide signalling supports mitochondrial efficiency and cellular energy production.
Too little nitric oxide reduces energy availability.
Too much inflammatory nitric oxide, produced during chronic immune activation, can damage mitochondria.
The goal isn't simply more nitric oxide. It is maintaining healthy nitric oxide balance.
Poor Clearance of Amyloid
Beta-amyloid plaques remain one of the hallmark features of Alzheimer's disease.
Emerging evidence suggests poor clearance may be just as important as excessive production.
Healthy nitric oxide supports cerebral perfusion, glymphatic waste clearance and the enzymatic removal of beta-amyloid.
Reduced nitric oxide has been associated with impaired clearance and greater plaque accumulation in experimental studies.
Loss of Brain Cell Communication
Learning and memory rely on billions of neurons communicating with one another.
Nitric oxide acts as a signalling molecule involved in long-term potentiation, synaptic plasticity and memory formation.
Reduced nitric oxide signalling has been linked with impaired learning and cognitive decline.
Why Cardiovascular Disease and Dementia Often Occur Together
One of the biggest breakthroughs in dementia research is the growing recognition that the brain and cardiovascular system are inseparable.
Many of the strongest dementia risk factors are also classic cardiovascular risk factors, including high blood pressure, insulin resistance, type 2 diabetes, smoking, physical inactivity, elevated LDL cholesterol, obesity and poor oral microbiome health.
Every one of these conditions is associated with reduced nitric oxide availability and endothelial dysfunction.
This is why many experts now describe Alzheimer's disease as having a significant vascular component. Protecting your blood vessels may be one of the most effective ways to protect your brain.
Can Medicinal Mushrooms Help Protect the Brain?
While nitric oxide supports the vascular system that nourishes the brain, medicinal mushrooms may provide another layer of protection by targeting inflammation, oxidative stress and neuronal health.
One of the most promising is Lion's Mane (Hericium erinaceus). Human studies suggest it may stimulate the production of nerve growth factor (NGF), helping support the growth, repair and survival of brain cells. Clinical trials have shown improvements in cognitive function in older adults with mild cognitive impairment.
Reishi contains powerful triterpenes and polysaccharides that possess antioxidant and anti-inflammatory properties, while Cordyceps supports mitochondrial function and cellular energy production. Other mushrooms including Turkey Tail, Shiitake and Maitake contain beta-glucans that help regulate immune function and may reduce the chronic inflammation associated with cognitive decline.
Although medicinal mushrooms are not a treatment for dementia, combining them with strategies that optimise nitric oxide may help support multiple pathways involved in healthy brain ageing. All these medicinal mushooms are ingredients in the BOOST 3.
Nitric Oxide May Be One of the Brain's Most Important Protective Molecules
Nitric oxide is not a treatment for dementia.
Nor is it the only factor involved.
However, healthy nitric oxide signalling supports many of the biological systems that protect the brain throughout life.
It helps maintain healthy cerebral blood flow, oxygen and glucose delivery, endothelial function, mitochondrial energy production, blood-brain barrier integrity, synaptic plasticity, amyloid clearance and a healthy inflammatory balance.
Rather than targeting a single aspect of dementia, nitric oxide influences multiple upstream processes that help keep brain cells functioning normally.
Can You Measure Your Nitric Oxide Levels?
Unlike cholesterol or blood sugar, very few people have ever measured their nitric oxide levels.
Today, simple saliva nitric oxide test strips allow you to estimate your body's nitric oxide production in less than a minute. These strips measure salivary nitrite, which reflects your body's ability to convert dietary nitrates into nitric oxide through the oral microbiome.
Although they don't directly measure nitric oxide inside the blood vessels, they provide a practical way to monitor one of the body's primary nitric oxide production pathways.
Low readings may indicate reduced nitric oxide production due to ageing, poor oral bacteria, low vegetable intake, smoking, lack of exercise or frequent use of antibacterial mouthwash.
Regular testing can help you monitor how lifestyle changes such as increasing leafy green vegetables, exercising regularly, improving oral health and optimising your diet influence your nitric oxide levels over time.
As the saying goes, you can't improve what you don't measure. Measuring your nitric oxide levels may become just as valuable as monitoring your blood pressure, cholesterol or blood sugar when it comes to protecting both your cardiovascular system and your brain.
The Bottom Line
Dementia is unlikely to be caused by one single factor.
It develops through decades of vascular dysfunction, impaired circulation, chronic inflammation, mitochondrial decline and reduced communication between brain cells.
Nitric oxide sits at the centre of many of these processes.
Alongside a healthy diet, regular exercise, quality sleep and emerging nutritional strategies such as medicinal mushrooms, optimising nitric oxide production may be one of the most important foundations for preserving brain function as we age.
The encouraging news is that nitric oxide levels are highly modifiable. Through nitrate-rich vegetables, regular physical activity, good oral microbiome health and other healthy lifestyle practices, many people can improve nitric oxide production and support the systems that help keep both the brain and cardiovascular system functioning for decades to come.
References
- Livingston G, Huntley J, Liu KY, et al. Dementia prevention, intervention, and care: 2024 report of the Lancet Standing Commission. The Lancet. 2024.
https://pubmed.ncbi.nlm.nih.gov/39096926/ - Iadecola C. The Pathobiology of Vascular Dementia. Neuron. 2013.
https://pubmed.ncbi.nlm.nih.gov/24357508/ - Toda N, Ayajiki K, Okamura T. Cerebral Blood Flow Regulation by Nitric Oxide. Pharmacological Reviews.2009.
https://pubmed.ncbi.nlm.nih.gov/19767882/ - Faraci FM, Brian JE. Nitric Oxide and the Cerebral Circulation. Stroke. 1994.
https://pubmed.ncbi.nlm.nih.gov/7529644/ - Austin SA, Katusic ZS. Loss of Endothelial Nitric Oxide Promotes Amyloidogenic Processing of Amyloid Precursor Protein. Proceedings of the National Academy of Sciences (PNAS). 2011.
https://pubmed.ncbi.nlm.nih.gov/21127294/ - Austin SA, Santhanam AV, Katusic ZS. Endothelial Nitric Oxide Deficiency Promotes Alzheimer's Disease Pathology. Journal of Cerebral Blood Flow & Metabolism. 2018.
https://pubmed.ncbi.nlm.nih.gov/28760945/ - Toda N, Okamura T. The Pharmacology of Nitric Oxide in the Peripheral Nervous System and Brain.Pharmacological Reviews. 2023.
https://pubmed.ncbi.nlm.nih.gov/37019299/ - Wang R, et al. Nitric Oxide Synthase Pathway in Vascular Dementia. Frontiers in Aging Neuroscience. 2021.
https://pmc.ncbi.nlm.nih.gov/articles/PMC8123648/ - Mori K, et al. Improving Cognitive Function in Mild Cognitive Impairment with Hericium erinaceus (Lion's Mane): A Double-Blind Placebo-Controlled Trial. Phytotherapy Research. 2009.
https://pubmed.ncbi.nlm.nih.gov/18844328/ - Saitsu Y, et al. Effects of Hericium erinaceus on Cognitive Function: A Randomised Double-Blind Placebo-Controlled Trial. Biomedical Research. 2019.
https://pubmed.ncbi.nlm.nih.gov/31413233/ - Ryu S, et al. Effects of Lion's Mane Mushroom Supplementation on Cognitive Function and Mood: A Randomised Controlled Trial. Nutrients. 2023.
https://pubmed.ncbi.nlm.nih.gov/38004235/ - Gorelick PB, et al. Vascular Contributions to Cognitive Impairment and Dementia. Stroke. 2011.
https://pubmed.ncbi.nlm.nih.gov/21778438/