Caffeine found in coffee, tea, soft drinks and chocolate, is one of the most consumed drugs in the world. It has an association with increased energy and alertness due to its ability to block adenosine receptors, a chemical that slows down your body. In addition, evidence indicates that caffeine consumption might boost levels of nitric oxide, a gas molecule that increases blood flow.
Nitric oxide is a gas molecule secreted by the inner lining of your blood vessels. It helps the smooth muscle layer of blood vessels to relax and dilate. This improves blood vessel function and increases blood flow to your organs. Moreover, nitric oxide plays other roles in the body, including blood pressure regulation, immune system support and nerve function. Certain cardiovascular disorders, such as congestive heart failure, may disrupt nitric oxide production in the body, according to findings reported in the March 1998 issue of "Pathologie-Biologie."
Increases Nitric Oxide
Scientists at Hiroshima University Graduate School of Biomedical Sciences in Japan investigated the effects of acute caffeine consumption on blood vessel function in healthy young men. Subjects received 300 mg of caffeine or a placebo and then had their forearm blood flow response measured. Scientists observed that those in the caffeine group experienced increased forearm blood flow due to an increase in nitric oxide production compared with those who had a placebo. The findings appeared in the December 2006 issue of the "American Journal of Cardiology."
Researchers from Colombia reviewed the literature regarding the impact of caffeine consumption on vascular health. They discovered that caffeine consumption increases the production of nitric oxide synthase enzyme, which converts the amino acid L-arginine into nitric oxide. In addition, caffeine blocks adenosine receptors, which constrict blood vessels and decrease blood flow, according to research published in the August 2010 issue of "International Journal of Vascular Medicine."
Caffeine seems to promote nitric oxide release in the dosage of 300 mg. Note that higher levels of caffeine, from 500 to 600 mg, can produce a variety of side effects such as nausea and insomnia, according to MayoClinic.com.
- "Pathologie-Biologie"; Role of Endothelial Nitric Oxide in the Regulation of the Vasomotor System; J.B. Michel; March 1998
- "American Journal of Cardiology"; Effects of Acute Administration of Caffeine on Vascular Function; T. Umemura et al.; December 2006
- "International Journal of Vascular Medicine"; Caffeine's Vascular Mechanisms of Action; D. Echerverri et al.; August 2010
- MayoClinic.com: Caffeine: How much is too much?; March 2011