Today I found this interesting article on the National Library of Medicine. It is worth reading. I wish every doctor would read it.

NO is one of the most important signaling molecules in our body, and loss of NO function is one of the earliest indicators or markers of disease. Clinical studies provide evidence that insufficient NO production is associated with all major cardiovascular risk factors, such as hyperlipidemia, diabetes, hypertension, smoking and severity of atherosclerosis, and also has a profound predictive value for disease progression including cardiovascular and Alzheimers disease. Thirty plus years after its discovery and over 13 years since a Nobel Prize was awarded for its discovery, there have been no hallmark therapeutic breakthroughs or even NO based diagnostics.
It appears that the inability to produce sufficient NO under the right preclinical conditions enhances the risk for a number of diseases that plague the older population. If true, then there exist an opportunity to intervene early during this process, implement strategies to restore NO homeostasis, and, perhaps, delay or prevent the onset and progression of certain diseases. This gradual loss of NO activity with age can be sped up or slowed down based on individual lifestyle and diet.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3390088/