January and its cold temperatures has truly settled in and with the current situation here in the UK, it’s absolutely normal to experience periods of stress! If you didn’t know already, stress has recently been linked to common cold symptoms by impacting the body’s immune system through reducing the body’s ability to produce nitric oxide. The fact is that nitric oxide acts as a first line of epithelial defence (outer lining of blood vessels) to help defend against pathogens.
Worry not as beetroot juice is a natural source of dietary nitrate that has been shown to increase nitric oxide production in the body. Researchers therefore tested whether beetroot juice could help protect against cold symptoms in students during their exam finals week – a period associated with causing psychological stress.
In a proof-of-concept study (Ritz et al, 2019), 76 students, 16 with asthma, were recruited from a US University. Students were randomly assigned to seven daily doses of beetroot juice supplementation (Beet It Sport shot) beginning the day before their final exams, or a control group that received no beetroot juice supplementation. Throughout the week students completed stress ratings, a cold symptom questionnaire and exhaled nitric oxide measurements were taken.
Now for the results…compared to control, students who consumed the concentrated beetroot juice reported reduced symptoms of cold and sickness during and after their final exams. In addition, those with asthma showed the greatest benefits and increased exhaled NO levels was associated with reduced symptoms of cold and sickness.
Cold symptom severity and sickness ratings for beetroot intervention and no beetroot control groups, taken from Ritz et al (2019).
Cold symptom severity and sickness ratings averaged for during and following exam stress for asthma and healthy participant groups, taken from Ritz et al (2019).
“Our study of the beetroot juice supplement is just a modest start, but it is based on a well-documented biological mechanism. The global threat from the current virus will not be the last one, and it takes months or years to develop vaccines. In the meantime, we should find ways to strengthen our immune defenses more nonspecifically against a broad range of pathogens, and beetroot juice may be a good partner in this fight.” – Professor Thomas Ritz, Southern Methodist University