Zero cost Covid-19 prevention
Hypertension, diabetes-2 and renal failure & heart disease are top covid-19 co-morbidities.
https://www.statista...ients-in-italy/
It seems there are two free of charge substances that can prevent illness from development. It is worth to note, that people with proper homoeostasis are fairly immune to SARS-CoV-2 (children, young people and healthy individuals below 50 and over 50).
Oxygen. (Breathing)
Depleting CO2 from blood is leading to blood pH level elevation. I suspect homoeostatic balance is being knocked out of balance, which triggers physiological reactions to bring homoeostasis back to equilibrium.
Slow breathing exercises decrease BP.
Example exercises.
1) Hyperventilation
(For example: lay down, take 20 fluent, but fast and deep breaths; exhale and stay without air for ~20s or as long as comfortable; inhale and keep breath for 10-20s, as long as comfortable.)
2) Slow breathing
Slowly inhale for minimum 5s, then slowly exhale for min 5 s. Repeat 10 times.
Breathing-control lowers blood pressure.
https://www.ncbi.nlm...pubmed/11319675
Effect of alternate nostril breathing exercise on blood pressure, heart rate, and rate pressure product among patients with hypertension in JIPMER, Puducherry
https://www.ncbi.nlm...les/PMC6691618/
Hypertension can be reduced by following simple alternate nostril breathing regularly.
Slow breathing had a stronger effect than fast breathing. BP decreased longitudinally over a 3-month period with both interventions. S/L ratio, 30:15 ratio, E/I ratio, and BP response in the hand grip and cold pressor test showed significant change only in patients practicing the slow-breathing exercise.
https://www.ncbi.nlm...pubmed/19534616
Collectively, these findings provide compelling evidence for the upregulation of ACE2, the vasoprotective enzyme of RAS, by acute regional hypoxia in HSPCs.
https://www.fasebj.o...upplement.695.6
Breathing exercises impact BP, blood pH, but also ACE/ACE2 dynamics. ACE2 is regarded as a key enzyme in the process of infection.
"ACE2 is also critical in protecting people during various types of lung injury," notes Ordovas-Montanes. "When ACE2 comes up, that's usually a productive response. But since the virus uses ACE2 as a target, we speculate that it might be exploiting that normal protective response."
https://medicalxpres...t-defenses.html
Hydroxychloroquine accumulation in human organelles also raise their pH, which inhibits antigen processing, prevents the alpha and beta chains of the major histocompatibility complex (MHC) class II from dimerizing, inhibits antigen presentation of the cell, and reduces the inflammatory response.[...]
https://www.drugbank.ca/drugs/DB01611
While reduced CO2 blood level and elevated O2 level increase blood pH, I don't know whether it has an impact on inner structures pH, like organelles mentioned above. (Requires further research).
To summarize, air & proper breathing exercises might be regarded as a free and effective way to improve immune system.
Water. Cold exposure.
(To be continued)