Study under review: Dietary nitrate provides sustained blood pressure lowering in hypertensive patients: a randomized, phase 2, double-blind, placebocontrolled study
“Eat your greens” is very reasonable advice for improving health, but it is also vague, especially for people following a reductionist approach to their food. We know that carotenoids are beneficial and are found in yellow-red foods, anthocyanins are found in the red-blue spectrum, and copious other polyphenolics are found in fruits and veggies. Greens, however? What could explain the benefits found in these veggies?
It turns out that the leafy greens, even humble lettuce, are great sources of the small nitrogen-containing molecule nitrate. Nitrate (NO3-) forms the starting step for one of the major ways the body can get nitric oxide, a small yet potent signalling molecule that relaxes blood vessels and improves blood flow. Strangely, the route for nitric oxide production from veggie consumption involves saliva, as seen in Figure 1. After nitrate is ingested, the intestines digest the compound and then it’s secreted into saliva, where various mouth bacteria digest the nitrate (NO3-) into nitrite (NO2-) for eventual reabsorption in the digestive tract on an as-needed basis. Nitrite is then converted into nitric oxide throughout the body’s tissues by a wide variety of compounds.
This pathway from nitrate, to nitrite, and finally to nitric oxide can be a major player in reducing blood pressure. This process doesn’t require the nitric oxide synthesizing enzyme found in blood vessels, which is known as endothelial nitric oxide synthase (eNOS). While eNOS also plays a major role in reducing blood pressure, its role in regard to health is preventative, and it works best when maintained, rather than being forced to work harder. eNOS regulation is generally not modulated by supplements. While problems with eNOS would likely increase blood pressure, providing a dietary supplement of the amino acid that eNOS uses (L-arginine) would be a very unreliable way to improve circulation.
Due to its potency, reliability, and safety, nitrate from beetroot juice was tested in this clinical trial. It had already been investigated as a single dose treatment in previous trials. This is the first trial to examine a sustained usage of this supplement and its effects on hypertensive subjects of all ages, regardless of medication.
Nitric oxide (NO) relaxes blood vessels and can reduce blood pressure. It is synthesized in a couple of ways in the body. One of those ways uses nitrate (NO3-) from food sources.
Other Articles in Issue #05 (March 2015)
Can you go too nutty over pistachios?
These researchers expected nutrient-packed pistachios to boost endurance, but found surprising results.
An under-discussed weakness of biomedical research is the lack of focus on women.
D-Serine: The anti-ketamine?
An amino acid called D-serine affects the NMDA receptor, and may help improve mood in healthy people.
Fish oil or snake oil?
Most people wouldn’t take rancid fish oil, yet it’s fairly likely to happen.
A regimented nutrition strategy for marathoners
Some marathon runners go by “feel” when it comes to fluid and carb intake, which may worsen performance.
Fighting back against food allergies with fish oil
Fish oil may help combat food allergies, as tested in this animal study looking at peanut and whey allergy.
Metabolic chamber of secrets: effects of protein on metabolism when overeating
This tightly-controlled metabolic chamber study explored how protein affects energy expenditure during overfeeding.
One meal, two meal, three meal, more?
While there’s been a lot of research on meal frequency and dieting, no one has summarized all the data until now.
- Interview: Dr. Shawn J. Green, PhD
Interview: Adel Moussa
This soon-to-be NERD reviewer is interviewed about all things nutrition research.