Image of Marc Sim, Ph.D.

Nitrate supplements have been shown to improve muscle and vascular function, but a new study shows that the same benefits can be had from consuming a small daily serving of leafy green vegetables.

Investigators looked at associations between dietary nitrate intake and muscle function in a cohort of more than 3,700 men and women, and to see whether that relationship might be dependent on physical activity levels. 

Participants received at least two food-frequency questionnaires over a 12-year study period. Muscle function was quantified by knee extension strength and the 8-ft-timed-up-and-go, or 8ft-TUG, test at the end of the study period. Overall physical activity was assessed by questionnaire. 

The median total nitrate intake was 65 mg per day, with 81% of the nutrient coming from vegetables, the authors reported. Participants who had the highest levels of nitrate intake (median intake of 91 mg per day) had stronger and faster performance on the two tests, respectively, when compared with individuals in the group with lowest intake (median intake: 47 mg per day). 

Similarly, those who ate more foods with nitrates also were less likely to have relatively weak and slow measurements on the tests when compared with those who consumed the least of these foods.

Poor muscle function is tied to a greater risk of falls and fractures, and making nitrate intake from vegetables a daily habit could be an effective way to promote lower-limb muscle strength and physical function in men and women, the authors concluded. They also recommended vegetables over supplements to get the benefits of additional vitamins and minerals these foods provide.

“We should be eating a variety of vegetables every day, with at least one of those servings being leafy greens to gain a range of positive health benefits for the musculoskeletal and cardiovascular system,” Sim said. “With around one in three Australians aged over 65 suffering a fall each year, it’s important to find ways of preventing these events and their potentially serious consequences.”

Notably, the physical activity levels of the participants did not affect the study results, Sim added. But he proposes that exercise be combined with diet to further optimize muscle function.

The study was published Wednesday in the Journal of Nutrition.