Cerebral Blood Flow Is Crucial For Cognitive Performance
How to think about optimal vascular function.
Posted Nov 13, 2019
If CBF ceases to function properly, cognitive functions decline.
“Cerebral blood flow (CBF) is an important factor that maintains brain function, and a prolonged insufficiency causes degeneration and irreversible impairment of brain function.” 
Vasodilation is when blood vessels open up, which improves CBF and generally reduces blood pressure.
Magnetic Resonance Imaging and functional MRI are revolutionary methods of studying the human brain. Many of the studies referred to in this article use these methods, which measure changes in CBF within the different structures of the brain.
CBF can be measured in specific regions of the brain, or globally, in the entire brain. This article concerns global CBF.
Many of the interventions are aimed at improving vasodilation, which in turn (often, though not always) increases CBF.
How to avoid a CBF shortfall
- Schisandra, Resveratrol, Curcumin with Piperine, or Citrulline Malate
Science: It is unclear whether exercise improves CBF intradaily , with some evidence suggesting an increase and some a decrease in CBF . But it certainly helps prevent cerebrovascular diseases in the long-term.
“These results suggest that regular exercise is associated with a delay in onset of dementia and Alzheimer disease, further supporting its value for elderly persons.” 
It makes sense to me (based on experience and my understanding of the underlying mechanisms), that CBF impairments can be prevented in the long-term by exercise. But it could also be that exercise helps prevent dementia and stroke through factors such as blood pressure and cholesterol.
Whether or not exercise increases CBF (understudied), it is great for you, and your brain.
Schisandra [Selfhacked][Examine], Resveratrol [Selfhacked][Examine], Curcumin with Piperine [Selfhacked][Examine] or Citrulline Malate [Selfhacked][Examine]
Science: All of these work by increasing Nitric Oxide in the body, which improves blood flow through vasodilation.
Thanks to its adaptogenic properties, Schisandra can be useful to preserve proper cognitive function under exposure to stress.
Schisandra helps increase Nitric Oxide in the body and nervous system, leading to vasodilation. 
My assessment is that Schisandra has no risk for addiction and that there’s only a low risk for side-effects.
Resveratrol works by a mechanism called hormesis, which entails that a low dose gives more benefits and fewer side-effects than no dose or a high dose.
It has even been found that slightly higher doses than optimal of Resveratrol can be detrimental for health.
“Low doses resveratrol protect health from different types of diseases, while high doses resveratrol can be detrimental for health.” 
One study found that Resveratrol can improve cerebrovascular function, and preserve cognitive functions in post-menopausal women, who have a heightened risk for cognitive decline. 
My assessment is that Resveratrol has no risk for addiction and that there’s only a low risk for side-effects.
Brain ischemia is a condition of impaired CBF. Ischemic strokes account for approximately 87% of all strokes. In experiments with animal models of brain ischemia, researchers concluded that Curcumin has a potential benefit in the treatment and prevention of ischemic strokes. 
Another study on mice also showed Curcumin has positive effects on CBF.
“The present study clearly demonstrates the beneficial effects of curcumin, the dietary staple of India, on CBF, memory and oxidative stress which can be exploited for dementia associated with age related vascular and neurodegenerative disorders.” 
Piperine increases curcumin blood absorption by 2,000 percent. 
Citrulline Malate has the potential to improve blood flow (by increasing Nitric Oxide ) but has no nootropic effects, unless you’re lacking CBF, in which case it probably does.
My assessment is that neither Curcumin with Piperine or Citrulline Malate has any risk for addiction and that there’s only a low risk for side-effects for both of them.
My use: I take .5–5g Schisandra every now and then if I am stressed. I experience significantly lower levels of stress and higher levels of relaxation. Schisandra amps up my creativity, probably thanks to its relaxing effects. It potently improves my attention span and patience. Schisandra works very well for me; it slightly enhances my mood and is great for mitigating anxiousness and stress induced by Caffeine or other stimulating nootropics. If I take too much (6+ grams) I can become drowsy and lose my edge/motivation.
I’ve only used (200mg) (Trans-)Resveratrol once. It didn’t give me any side-effects, but a slight boost in (subjective) energy levels. I plan on experimenting with it more in the future.
I use 300mg Curcumin with 3mg Piperine every morning. From this, I don’t feel much in the short-term, only a slight boost in the frequency of flow states when reading or listening to an audiobook while walking. I haven’t had any side-effects either. In the long-term, I feel a slight anti-depressant effect. The main reason I take it is because of the general health benefits.
I use 3g Citrulline Malate as part of my pre-workout supplement stack and feel like it gives me a slight bump in energy and motivation, without any side-effects.
Science: Vinpocetine potently improves blood flow in the entire body.
“Vinpocetine has been widely used in the treatment of ischaemic cerebrovascular diseases and dementias of vascular type.” […] The authors found a significant improvement of cognitive functions after a 12-week long oral vinpocetine therapy using psychometric tests. […] patients with mild cognitive impairment judged the improvement higher.” 
My assessment is that Vinpocetine has no risk for addiction and a moderate risk for side-effects.
My use: It gives me mental clarity if I use it at doses of 10–20mg, which enhances my cognition. When I experimented with Vinpocetine, it made me stressed, which is why I no longer use it. I don’t know the mechanism of this side-effect yet, but it came back three times. I use all the above mentioned less risky biohacks for maintaining CBF and have no symptoms of poor brain circulation.
I believe the risks of using Vinpocetine outweigh the rewards for me. It works very reliably for vasodilation though, so if you have a problem with CBF it might be helpful for you.
Unless you know you have problems with CBF, there’s little reason for you to optimize it. However, you may have poor CBF without recognizing it.
Symptoms include, but are not limited to: brain fog, dizziness, and confusion.
If you suspect you may lack blood flow to the brain, you may want to try one of the nootropics, and see what results you get from the intervention.
I think Vinpocetine is best for the purpose of self-diagnosing poor CBF, though long-term treatment should preferrably be done with one of the other nootropics.
This blog post is not a substitute for professional medical advice, diagnosis or treatment.
This blog post was originally published at nootralize.com.
 (2016). Cerebral Blood Flow. ScienceDirect
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 Eric B. Larson et al. (2006). Exercise Is Associated with Reduced Risk for Incident Dementia among Persons 65 Years of Age and Older. Annals of Internal Medicine.
 Panossian AG et al. (1999). Effects of heavy physical exercise and adaptogens on nitric oxide content in human saliva. Phytomedicine : international journal of phytotherapy and phytopharmacology.
 Subhendu Mukherjee et al. (2010). Dose-Dependency of Resveratrol in Providing Health Benefits. Dose-Response.
 Evans HM et al. (2017). Effects of Resveratrol on Cognitive Performance, Mood and Cerebrovascular Function in Post-Menopausal Women; A 14-Week Randomised Placebo-Controlled Intervention Trial. Nutrients.
 Glaura Fernandes Teixeira de Alcântara et al. (2017). Curcumin reverses neurochemical, histological and immuno-histochemical alterations in the model of global brain ischemia. Journal of Traditional and Complementary Medicine.
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