A high habitual intake of nitrates through green leafy vegetables or beetroot is well-known to enhance NO bioavailability – NO is a potent molecule in cell signaling which can enhance vasodilation, blood vessel health, blood pressure reductions, and improved cardiovascular function.
 
Emerging research suggests that nitrates may also have the ability to enhance muscle function, a key indicator of health especially among aging populations, due to increased blood flow to exercising skeletal muscle. For this reason, nitrate was classified in 2018 by the International Olympic Committee as an ergogenic aid for athletes.
 
While most clinical trials on nitrates involved short-term, high-dose supplementation, fewer studies have analyzed the impact of habitual nitrate supplementation. Additionally, few studies on nitrate supplementation have evaluated potential benefits that might occur independently of an exercise intervention. However, a recent study which recruited 3,759 men and women between the ages of 25 and 85 who participated in the Australian Diabetes, Obesity, and Lifestyle Study (AusDiab) revealed that, based on food frequency questionnaires, nitrate intake (about 81% of which was derived from vegetables) was significantly associated with an increased knee extension strength (KES) and the 8-ft-timed-up-and-go tests (8ft-TUG), key parameters in lower limb function.
 
Specifically, individuals in the highest tertile of nitrate intake had 11% stronger KES, and lower odds for a slow 8ft-TUG compared with those in the lowest tertile, and physical activity didn’t influence the relationship between nitrate intake and muscle function.
 
“This work highlights the potential benefits of higher habitual dietary nitrate, predominantly from vegetables, to support muscle function in adults across the lifespan, independently of physical activity levels. The aforementioned relation reached a plateau at nitrate intakes of about 90 mg/d, suggesting that moderate intakes of nitrate may be sufficient to maximize benefits for muscle strength and physical function,” the researchers concluded.
 
Nitrate ingestion has been shown in research to modulate the function of skeletal muscle, and the authors of the study attributed some known mechanisms of action to the benefits observed in this epidemiological survey. It is specifically linked to reductions in ATP cost of muscle force production, and improvements in blood flow to the muscle – furthermore, nitrate intake’s benefits to blood pressure regulation and vascular function could be another mechanism of action responsible for improved lower limb function.