Numerous studies have shown the negative effects of psychological stress on the human body, including triggering headaches, fatigue, loss of libido, sleep problems, and lowered immunity.1,2 It has also been found that levels of nitric oxide - a compound produced by the epithelial and immune cells - as well as lung function in asthmatics substantially decrease during stressful periods.3
Known as a highly nutritious vegetable, beetroot is a rich source of nitrate, which is converted into nitric oxide in the body, increasing blood flow and helping improve oxygen levels. The aim of this study was to investigate whether beetroot supplementation can be beneficial in protecting against cold symptoms in stressful life periods.
This study was conducted at the Department of Psychology at the Southern Methodist University in Dallas, Texas (USA). Researchers recruited 76 undergraduate students who were approaching final exams, 16 of them diagnosed with asthma.
Participants were randomly assigned to two groups: one receiving a 70 mL beetroot juice drink (0.4 - 0.5 mg nitrate) daily for a week during the finals and the control group receiving no beetroot juice.
Assessments of stress, cold symptoms, and exhaled nitric oxide were performed before, during, and after the study.
The primary results of this study showed a significant decrease in reported cold symptoms during and after final exams in participants receiving beetroot juice. Symptom reduction was strongly associated with higher levels of exhaled nitric oxide.
Moreover, students diagnosed with asthma have demonstrated the most pronounced improvements in cold symptoms.
What Does this Mean?
The results of this study demonstrate protective benefits of beetroot juice supplementation on stress-induced cold symptoms, leading the way to a safe and natural way of boosting one's immunity in times of psychological stress.
These findings are also good news for asthma sufferers since respiratory infections due to common cold can exacerbate asthma symptoms, potentially putting people's life in danger and increasing school or work absenteeism.
Additionally, because of nitric oxide's known vasodilatory effects, beet juice supplementation can also lead to blood vessel relaxation, lowered blood pressure, improved blood flow, and a stronger heart, which, in turn, may lead to substantial stress reduction.
- Physiology & Behavior, Beetroot juice supplementation for the prevention of cold symptoms associated with stress: A proof-of-concept study, 2019
- Mayo Clinic. (2019). Stress management. Retrieved November 13, 2019 from https://www.mayoclinic.org/healthy-lifestyle/stress-management/in-depth/stress-symptoms/art-20050987
- American Psychological Association. (n.d.). Stress effects on the body. Retrieved November 13, 2019 from https://www.apa.org/helpcenter/stress-body
- Annals of the American Thoracic Society. (2015). Exhaled Nitric Oxide Decreases during Academic Examination Stress in Asthma. Retrieved November 13, 2019 from https://www.atsjournals.org/doi/full/10.1513/AnnalsATS.201504-213OC