Quercetin, an isoflavone with a multitude of health improving properties, has been shown to protect your brain from some of the causes of chronic neural degeneration, called neural protection. This neuroprotection includes boosting the health of your arteries that feed the brain, enhancing mitochondrial functions to maintain good energy production to the brain, reduction in ROS, and anti-inflammatory properties,

Quercetin is found in many foods including apples and onions. However, most people don’t ingest enough quercetin to give themselves the power of quercetin to improve their brain health. Thus, supplementation is recommended. With adequate levels of quercetin in your blood, you may be able to protect your brain from chronic damage that could lead to chronic medical diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), and other degenerative brain diseases you might get as you get older.

Feed Your Brain the Right Stuff

Arterial health is probably one of the most important things you can do to keep your brain healthiest. Poor arterial health, formation of cholesterol plaques with the arteries (atherosclerosis), development of inflammation within the endothelium, scarring, and hardening of the arteries (arteriosclerosis), is associated with brain health. Heart disease is associated with brain disease.[1] After all, if you improve the flow of blood to the brain you get better brain function.

Prevention thus first starts with ensuring a healthy heart. This includes making sure you are eating the right diet, such as a Keto-Mediterranean Diet. Exercising improves circulation to all body parts, including your brain, and exercising around 20 minutes a day is probably the most important thing you can do for your brain. Reducing stress and getting enough sleep are important too. Another beneficial action you can do is to make sure you ingest adequate amounts of quercetin.

How Alzheimer’s Disease Develops

There are many theories regarding how chronic degeneration of the brain occurs resulting in Alzheimer’s disease (AD), or Parkinson’s disease (PD), or other degenerative diseases. With AD, the process starts in your 40’s to 60’s, twenty years before you see the actual symptoms of AD. Most experts have concluded that AD starts with oxidative stress to the cells, particularly to the mitochondria of each cell.  This mitochondrial damage triggers and immune response from the immune cells near the brain cells (called microglia) and when this response is severe, inflammation occurs. Inflammation then causes destruction of neural cells, forming inflammatory tangles, and deposition of beta-amyloid on the nerve cells. When this progresses to a severe state over many years, Alzheimer’s disease is diagnosed. Preventing these from happening years before AD develops is key to prevention of AD.

Reduce Oxidative Stress to the Brain

The neuroprotective effects of Quercetin begins with reducing ROS. Constant excitatory electrical stimulation of the nerves cells through normal thought processes is considered to be the cause of oxidative stress (ROS) to the brain’s mitochondria, the powerhouses of neural cells, their mitochondria.[2]

Quercetin protects brain cells from the oxidative damage seen by the repeated excitatory electrical impulses and thus oxidative damage to the mitochondria of the nerve cells.[3] It increases expression of a natural cellular defense against such mitochondrial damage called the Nrf2 system, which help prevent brain cell death.[4] In addition, quercetin’s anti-oxidant and anti-inflammatory actions reduce toxicity of the dangerous and abnormal beta-amyloid proteins onto the nerve cell walls, which are thought to produce the symptoms of memory loss and dementia.[5]

Moreover the damage to the nerves through these processes results in destruction of the brain structure seem in dementia diseases such as AD and Parkinson’s disease.[6] Quercetin has been found to prevent brain cell death in animal models of Parkinson’s disease.[7]  It preserves vital brain cell function and limits brain cell death that would otherwise produce neurodegenerative diseases.[8]

Increase in Mitochondria in Brain Cells

Studies also demonstrated increased formation of mitochondria in brain cells with administration of quercetin in animal studies.[9] An increase in brain mitochondria increases energy to the brain cells with accompanying increase if brain function. Along with a decrease in ROS, this could confer protective effects of the brain from developing Alzheimer’s disease and other chronic neurodegenerative diseases, of which mitochondrial dysfunction are hallmarks.

Summary

Quercetin can help protect the brain from developing Alzheimer’s disease. It does this through many pathways, including decreasing ROS damage to mitochondria, increasing the number of mitochondria, and decreasing inflammation. Start early and make sure you are getting adequate amounts of quercetin, either through your diet or by taking supplements.

 

These statements have not been evaluated by the Food and Drug Administration (FDA). Any products are not intended to diagnose, treat, cure, or prevent any disease.
References:

[1] Sabia, S, et al. Association of ideal cardiovascular health at age 50 with incidence of dementia: 25-year follow-up of Whitehall II cohort study. BMJ 2019; 366 doi: https://doi.org/10.1136/bmj.l4414

[2] Dorszewska J. Cell biology of normal brain aging: synaptic plasticity-cell death. Aging Clin Exp Res. 2013 Apr;25(1):25-34. doi.org/10.1007/s40520-013-0004-2

[3] Silva, B., Oliveira, P.J., Dias, A. et al. Quercetin, kaempferol and biapigenin fromhypericum perforatum are neuroprotective against excitotoxic insults. neurotox res 13, 265–279 (2008). https://doi.org/10.1007/BF03033510

[4] Arredondo F, Echeverry C, Abin-Carriquiry JA, et al. After cellular internalization, quercetin causes Nrf2 nuclear translocation, increases glutathione levels, and prevents neuronal death against an oxidative insult. Free Radic Biol Med. 2010 Sep 1;49(5):738-47. doi.org/10.1016/j.freeradbiomed.2010.05.020

[5] Shi C, Zhao L, Zhu B, et al. Protective effects of Ginkgo biloba extract (EGb761) and its constituents quercetin and ginkgolide B against beta-amyloid peptide-induced toxicity in SH-SY5Y cells. Chem Biol Interact. 2009 Sep 14;181(1):115-23. doi.org/10.1016/j.cbi.2009.05.010

[6] Week GL, McGann-Gramling K, Hauss-Wegrzyniak B, et al. Attenuation of chronic neuroinflammation by a nitric oxide-releasing derivative of the antioxidant ferulic acid. J Neurochem. 2004 Apr;89(2):484-93.

[7] Karuppagounder SS, Madathil SK, Pandey M, Haobam R, Rajamma U, Mohanakumar KP. Quercetin up-regulates mitochondrial complex-I activity to protect against programmed cell death in rotenone model of Parkinson’s disease in rats. Neuroscience. 2013 Apr 16;236:136-48.

[8] Bournival J, Plouffe M, Renaud J, Provencher C, Martinoli MG. Quercetin and sesamin protect dopaminergic cells from MPP+-induced neuroinflammation in a microglial (N9)-neuronal (PC12) coculture system. Oxid Med Cell Longev. 2012;2012:921941.

[9] Op cit. Davis, m, et al. doi.org/10.1152/ajpregu.90925.2008