Nitrate supplementation may help breathing and lung clearance in the elderly

Dietary nitrate is readily available for humans and could be used, under proper supervision, to improve respiratory muscle dysfunction that contributes to shortness of breath and morbidity in the elderly.

The researchers gave sodium nitrate to old mice in their drinking water daily for 14 days. The control group received regular water. Diaphragm muscle contractile function cannot be assessed directly in live animals or humans. Thus, they tested diaphragm function in muscle tissues under controlled conditions for muscle stimulation and oxygenation.

The main limitations are that mouse and human diaphragm have different percentages of fast and slow muscle cells. Mouse diaphragm consists of 90% fast muscle cells; the human diaphragm consists of 25-50% fast muscle cells depending on several factors that include and age and sex.

Dietary nitrate seems to exert a greater impact on the contractile function of fast muscle cells. Thus, the benefits to the human diaphragm may not as pronounced as was observed in mice. They also only tested male mice, and the benefits for females is unknown.

Leonardo Ferreira, senior author on the study said:

"Our findings are especially important in light of the current COVID-19 pandemic as they suggest that, if replicated in humans, dietary nitrate is useful to improve respiratory muscle dysfunction that contributes to difficulty in weaning patients from mechanical ventilation."