Cardiovascular Health & Nitric Oxide

17th Apr 2024 News Primary care

It can be very satisfying when a simple, easy-to-do nutrition tip reaps measurable rewards, and I see time and again how regular inclusion of purple pigmented plant foods like beets and blueberries can lower cardiovascular risk – by lowering blood pressure.

How do they do that? – by increasing our innate nitric oxide which is a critical signalling molecule that gets released from the lining of blood vessels, and helps vasodilate arteries. It acts a bit like a smooth Teflon coating, so the higher the levels of nitric oxide being released, the more it will repel cholesterol particles from sticking to the artery wall.

Please do not confuse with ‘sodium nitrates’ which are a commonly used preservative in processed meats like bacon, cold cuts, and hot dogs. These will NOT benefit your cardiovascular system.

There’s an enzyme (endothelial nitric oxide synthase) that is responsible for releasing nitric oxide, but sadly as we get older, enzymes have a tendency to slow down, meaning the nitric oxide protection in the blood vessels can become less efficient. We do have another way to achieve it though – a back-up system – via saliva! Your mum was so wise when she reminded you to chew your food thoroughly. There are however two or three caveats to this back-up system.

Oral Microbiome

The dietary nitrates in green leafy vegetables, dark berries and beets, need a healthy oral microbiome to supply nitrate reducing bacteria in the saliva, to mix with them and break them down. As you chew and swallow the food mixed with saliva they become nitrites in the process. Stomach acid then converts the nitrites to nitric oxide. So the first caveat is the need for a healthy oral microbiome – because nitrate-reducing bacteria can get easily destroyed by regular use of antiseptic, or antibacterial mouthwash.

Stomach Acid

The second caveat is the need for healthy levels of stomach acid, needed to break down proteins, which are required by enzymes. And stomach acid can get greatly reduced by over-the-counter antacids or a class of drugs called proton-pump-inhibitors. When proteins aren’t getting broken down well, we are limiting the ability of our body to manufacture those all important enzymes, required to catalyse all sorts of actions – not just nitric oxide release.

UVA Sunlight

The third caveat is sunlight. Fortunately the awareness of the pluripotent role of vitamin D means people are finally realising that moderate, careful exposure to sunlight is essential to health. And when UVA rays hit your skin, nitric oxide gets liberated from the blood vessels. That initial gentle rosy tint is the blood capillaries close to the surface dilating with the nitric oxide release. It goes without saying I am not advocating the prolonged exposure that leads to burning.

Exercise

Of course writing a piece on lowering cardiovascular risk would not be complete without mentioning exercise. Because exercise actually up-regulates the production of those all important enzymes, needed to catalyse the nitric oxide release. It’s called ‘reactive hyperemia’ when the demands of exercise increases your heart rate which then pumps more blood – and glucose and oxygen – to the exercising muscles. When greater volumes of pumped blood cross the glycocalyx, it causes more nitric oxide to be released from the endothelium. It produces a knock-on effect, you start upgrading the production of those enzymes (a feedback loop response), so in case there’s a repeat – and we exert ourselves again – we’re even better prepared.

So, nitric oxide production is essential for overall health because it enables blood, and therefore nutrients and oxygen, to travel to every part of your body effectively and efficiently. Dark pigmented plant foods, a healthy oral microbiome, good levels of stomach acid, sunlight and exercise – and you’ll be keeping your vascular system healthy, enabling youthful flexibility which is the ultimate strategy for anti-aging!

References

Dyakova E et al., (2015) Physical exercise associated with Nitric Oxide production: signalling pathways and significance in health and disease. Front Cell Dev Biol 3:19 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4382985