Brain circulation (also called cerebral blood flow or blood flow to the brain) is very important for all aspects of brain function. Your brain depends critically on oxygen, glucose, and other nutrients that the blood brings.
Poor brain circulation causes poor cognitive function (brain fog), fatigue, anxiety/depression, and even HPA axis dysfunction (adrenal fatigue).
The lack of oxygen to the brain (hypoxia) also increases oxidative stress in the brain, which kills brain cells and causes neurodegenerative diseases such as Alzheimer’s.
Ensuring that you have good blood flow to the brain is critical for health and recovery from any chronic disease, but is nearly always neglected by mainstream medicine.
Read this post to learn more about brain circulation and how to improve it.
What Is Brain Circulation? (Blood Flow to the Brain)
Brain circulation, or brain blood flow, is the movement of blood through the network of arteries and veins supplying blood to the brain. The arteries deliver oxygenated blood, glucose, and other nutrients to the brain. The veins carry deoxygenated blood back to the heart, removing carbon dioxide, lactic acid, and other metabolic products.
Why Is Brain Circulation Important?
The brain is the most important organ to receive the blood supply. Although it’s only 2% of your body weight, it consumes 50% of glucose and 20% of the oxygen that is available in the body [R].
In addition, the blood also removes wastes from the brain. Lack of oxygen for merely minutes will start to kill brain cells.
However, during most of the days, when we are upright, the brain is the highest part of the body with the smallest blood vessels that are furthest from the heart. This makes the brain a difficult organ to deliver blood to.
Too little blood flow results in a lack of glucose and oxygen needed to keep neurons metabolically active, a condition known as ischemia. Too much blood flow results in increased intracranial pressure, which causes severe neurological damage in extreme cases.
Therefore, the body has several checks and balances to ensure that the brain receives sufficient blood flow and oxygen [R].
Adults with normal blood pressure get about 50 ml of blood to 100 g of brain tissue per minute, which provides oxygen pressure to the brain at between 60 – 160 mmHg [R].
If the oxygen pressure to the brain falls outside of this range, the brain loses its ability to maintain constant blood flow, so the blood flow strictly depends on the pressure within the arteries (mean arterial pressure) [R].
Causes of Poor Brain Circulation
1) Low or High Blood Pressure
Many SelfHacked clients have very low blood pressure due to low vasopressin (ADH) levels, so low blood flow to the brain is a major concern.
Low blood pressure has been related to a risk of brain atrophy (loss of brain tissue). In a study examining patients with hardening of the arteries, not all patients with lower blood pressure had low blood flow to the brain. However, those with lower blood pressure and less blood flow to the brain were more likely to have brain atrophy [R].
Note: In this study, low blood pressure considered only systolic (the higher number) below 120.
In some people with hypertension, the hypertension is caused by constriction of the blood vessels (vasoconstriction), which also reduces blood flow to the brain. Hormones like vasopressin and angiotensin II constrict the blood vessels and cause these effects [R].
Conversely, drugs that reduce the functions of these hormones, such as angiotensin II inhibitors (many blood pressure drugs) increase blood flow to the brain [R].
High histamine or mast cell activation also causes low blood pressure because histamine is a vasodilator [R].
It is therefore important to maintain healthy blood pressure in order to have good brain circulation.
2) Poor Circulation
Factors that cause poor circulation include:
- Inflammation and infections, such as bacterial meningitis [R].
- Low thyroid is associated with lower brain circulation, which may contribute to depression among these patients [R].
- Low nitric oxide, although too much can be neurotoxic [R].
- Poor blood vessel health, such as from hardening of the arteries, and high blood sugar.
3) Oxidative Stress
Oxidative stress damages the blood vessels. In turn, low brain blood flow also increases oxidative damage in the brain.
When oxidative species attack red blood cells and other components in the blood vessel, these damaged components can clump up and make the blood more viscous. This can impair blood flow [R].
Oxidative stress also results in poor blood vessel health and stiffening of the blood vessels, which results in poor circulation.
Angiotensin II activates NADPH oxidase, which generates ROS in the brain (cerebral) arteries [R].
Acute mental stress, however, increases blood flow to the brain. Levels of blood flow to the brain correlate with the increased heart rate and cortisol levels [R].
Health Problems Linked to Poor Brain Circulation
1) Brain Fog or Poor Cognitive Function
Therefore, increasing brain circulation in certain areas of the brain may improve cognitive deficits [R].
In the Rotterdam Study, a large longitudinal study designed to assess the factors related to dementia and cognitive decline, researchers found that in 1,716 subjects without dementia, increased probability of cognitive decline was related to decreased brain blood flow [R].
Adequate blood flow is crucial to normal cognitive function and preserving circulation in the brain may be important in slowing down and even preventing cognitive decline later in life.
Poor Brain Circulation May Cause Neurodegenerative Diseases
Brain circulation has also been linked to various neurodegenerative diseases and mental disorders.
2) Parkinson’s Disease
Parkinson’s disease patients with dementia display decreased blood flow in certain areas of the brain in comparison to controls [R].
3) Alzheimer’s Disease
Reduced blood flow in key brain regions is one of the earliest signs of Alzheimer’s disease and therapy that increases blood flow to the brain shows some benefits to Alzheimer’s patients [R].
Poor Brain Circulation and Mental Health
Decreased blood flow in the select brain regions has also been shown to occur in patients with late-life depression [R].
Generally, provoking the traumatic experiences in PTSD patients result in increased blood flow to the amygdala (the brain region associated with fear conditioning) and decreased blood flow to other regions of the brain [R, R].
6) OCD and Anxiety Disorder
People with anxiety disorders, OCD, agoraphobia, and PTSD have significantly less brain blood flow than healthy people [R].
Reduced Brain Circulation Causes Fatigue
7) Exercise-Induced Fatigue and General Fatigue
It is normal to become fatigued after exercise or physical exertion. Part of the fatigue is explained by the reduction of blood flow to the brain.
During exercise, increased breathing (hyperventilation) reduced the amount of carbon dioxide in the arteries. This restricts the blood flow to the brain. The reduction of available oxygen to the brain contributes to fatigue [R].
Hypoxia induces an increase in nitric oxide and adenosine in the brain [R].
The increased adenosine levels in the brain may cause drowsiness.
8) Chronic Fatigue Syndrome
Chronic fatigue syndrome patients have less blood flow to the brain than healthy people [R].
9) Traumatic Brain Injuries
Lack of oxygen in the brain tissue (ischemia) is observed in ~30% of people with traumatic brain injuries [R].
Lifestyle Changes That Increase Brain Circulation
1) Moderate Intensity Exercise Increases Brain Circulation
Conversely, high-intensity exercise actually decreases blood flow to the brain, as blood is redistributed throughout the body to reduce body temperature.
2) Cold Exposure to the Hands, Feet, or Face
Cold water increases circulation in the brain.
Submerging the face in cold water triggers a reflex and causes the heart rate to decrease, non-vital blood vessels to constrict, blood vessels in the heart and brain to dilate, and blood pressure to increase [R].
3) Sun Exposure
Sun exposure increases nitric oxide, which dilates the blood vessels and lowers the blood pressure [R].
This might explain why sun exposure improves alertness and brain function.
4) Whole Body Vibration
Whole body vibration therapy increases blood flow throughout the body in humans [R].
In rats, prolonged whole body vibration therapy increased blood flow to the brain [R].
5) Inversion Therapy
By gravity, inversion therapy should increase blood flow to the brain.
6) Caffeine Restriction
While the brain does compensate for this by increasing adenosine receptors during daily caffeine use, research shows this compensation does not completely counteract the decrease in blood flow [R].
To mitigate the effects of caffeine on brain circulation, it is advisable to take periodic breaks from caffeine consumption.
Supplements That Directly Increase Brain Circulation
7) Ginkgo Biloba
A systematic review and meta-analysis found that the herb improved cognitive function and daily living activities in dementia patients [R].
Ibudilast is commonly used in Japan to treat patients with stroke. It improves brain blood flow by dilating blood vessels and prevents platelet aggregation by inhibiting PDE4 [R].
Citrulline, a precursor of arginine, increases nitric oxide concentrations in the blood and restores damaged blood vessels.
Treatment with citrulline prevents the decrease in brain circulation, death of brain cells, and capillary loss following blood supply impairment to the brain. Citrulline improves cognitive dysfunction and memory in rats with brain damage [R, R].
Carnitine is a natural compound found in many animals, plants, and organisms.
Moreover, acetyl-L-carnitine improves energy status, decreases oxidative stress, and prevents cell death in brain injuries [R].
Resveratrol works by dilating blood vessels in the brain, thus increasing brain circulation [R].
14) NAC (N-Acetyl Cysteine)
In rats, NAC opens up blockages caused by a stroke in arteries and blood vessels [R].
15) Nitrate-Rich Foods
Nitrate-rich foods include beets, leafy greens (like spinach and arugula), celery, and carrots.
Dietary nitrates are converted into nitric oxide in the body. Research shows that nitrates derived from vegetables increase brain blood flow in response to cognitively-demanding tasks and improve cognitive performance [R].
In a pilot study, nitrate-rich beet juice increased nitric oxide concentration in the blood, decreased blood pressure, and improved cognitive functions [R].
16) Bacopa Increases Blood Flow to the Brain
In rats, bacopa increases brain blood flow independent of blood pressure [R].
Supplements That Protect the Brain from Suboptimal Circulation
Anthocyanins protect against brain disorders that result from a reduction in blood flow to the brain.
They reduce neuronal damage caused by inadequate blood supply in rats. Anthocyanins prevent the production of proteins that trigger cell death and suppress tumors (p-JNK and p53 transmission pathways) [R].
An extract containing anthocyanins protects brain circulation and blood vessel function following brain damage [R].
Astragalus is commonly used in traditional Chinese medicine. In a rat study, Astragalus prevented brain cell death, reduced the size of brain injuries, and improved brain function in brain injuries caused by reduced circulation [R].
Brain injuries caused by insufficient blood supply often cause inflammation and swelling. One of the major components of Astragalus alleviates these symptoms through anti-inflammatory effects [R].
Phosphatidylcholines are the main component of all cell membranes. Good sources of phosphatidylcholine are eggs, dairy, soybeans, red meat, whole grains, and cruciferous vegetables (like arugula and Brussel sprouts).
Lecithin, a collection of phospholipids that usually include phosphatidylcholine, may protect neurons from damage caused by lack of blood flow in the brain [R].
Diseases That Adversely Affect Brain Circulation
Cerebrovascular diseases affect the vessels of the brain that result from insufficient blood flow to brain cells and include:
- Stroke: An abrupt interruption of constant blood flow to the brain, causing loss of neurological function. A stroke can be caused by a blockage in a blood vessel (ischemic) or bleeding in the brain (hemorrhagic)
- Stenosis: Abnormal narrowing of the blood vessels, usually caused by hardening of the arteries
- An aneurysm: Bulge in the wall of an artery that pools with blood
Cerebrovascular diseases have many different causes, including hardening of the arteries, lodging of a blood clot or foreign material in the blood vessels (embolism), or high blood pressure. Therefore, any lifestyle or dietary intervention that improves these factors improves blood flow in the brain.
Increasing brain circulation may not guarantee that cognitive functions such as memory or attention will be improved, despite correlations between brain circulation and cognitive function.