Research Round-Up: April 2020

Immunity is a hot topic right now and not just because we are approaching the cooler months in the southern hemisphere. With COVID-19 impacting much of the world, people everywhere are more keenly aware of what they can do to best look after their immunity, not only to optimise their own health, but to help protect their friends, colleagues and loved ones around them.

The large volume of content currently being shared on the topic of immunity had us wondering what the recent science said about what does and doesn’t help to support our immune systems. Accordingly, we published two evidenced based articles on the topics of holistic immunity for adults and nutrition to support immunity in kids. We also thought it timely to take a closer look at some of the more specific nutrients that are purported to target immune system support, so have dedicated this month’s entire research round up to all things immunity!

The importance of psychoneuroimmunity during COVID-19

The worldwide outbreak of COVID-19, the latest of the coronavirus infections to spread amongst humans, has been met by a large and widespread reaction of panic and anxiety in individuals subjected to the real or perceived threat of the virus. Our lifestyles and patterns have changed drastically and continue to do so on a daily basis. And while plenty of physical preventative measures for protecting immunity have been shared, recommended and even legally enforced, few have assessed or discussed the biopsychosocial and psychoneuroimmunological factors of this infection.

In a viewpoint published in Brain, Behavior, and Immunity, psychiatrists from China Medical University explore the importance of psychoneuroimmunity, relying on practices of a balanced and healthy lifestyle, as an underlying but quintessential component of immune system function, particularly during our current health climate. As the authors explain, “social distancing and wearing masks might help protect us from pathogen exposure, however these measures also prevent us from expressing compassion and friendliness,” important components of psychoneuroimmunity.

The viewpoint explores the multifaceted impact of the panic spread about the virus on the health of those who have acquired the infection, those who are more susceptible to the virus such as the elderly, those with underlying physical illness, serious mental illness and carers of such populations, as well as the impact on general society due to the dramatic increases of public fears, decreases in social and economic activity and the current state of quarantine, all of which may lead to depression, anxiety, guilt and anger. The emotional side effects in all of these populations contribute to increased stress, which in turn may reduce immunity and compromise recovery.

The authors conclude that while most people lack immunity against this novel virus, and that there is currently no targeted medication yet available, prevention is the best strategy, namely one that reduces pathogen exposure as well as boosts individual immunity. Important for this is a healthy lifestyle, regular exercise, balanced nutrition, quality sleep and a strong connection with families and communities as part of the necessary psychological support your body needs to enhance psychoneuroimmunity.

Kim SW, Su KP. Using psychoneuroimmunity against COVID-19. Brain Behav Immun 2020;PMID 32234338.

Sleep, cellular stress and immunity

Sleep is a universal phenomenon occurring in all species studied so far. For humans, sleep is important to almost every function of existence, and the result of sleep loss impacts our physiological response on both the organismal and cellular levels, suggesting an adaptive role for sleep in the maintenance of overall health. In a review published in Current Opinion in Physiology, researchers from the University of Pennsylvania explored the bidirectional impact of sleep on cellular stress and how the long-term effects of chronic cellular stress impact immunity.

The connection between sleep and the immune response has been investigated for over 40 years. The cellular stress that occurs as a result of sleep loss, impacts and elongates inflammatory processes that alter immunity, susceptibility to infection and recovery.

The review highlights that chronic cellular stress impacting the cellular homeostasis that contributes to DNA damage and disruption of cellular nuclear health. This alteration leads to a cascade of events that negatively impact the adaptive-immune and inflammatory responses, culminating in a destructive state of apoptosis.

The authors of the review conclude that sleep is an important part of the recovery process from acute stress or illness and that a growing body of work demonstrates that improvements in sleep can promote and enhance recovery, survival and the adaptive cellular response that underlies these processes.

Williams JA, Naidoo N. Sleep and cellular health. Curr Opin Physiol 2020;15:104-110.

How 1,3/1,6 beta-glucans affect inflammation and influence immunity

Inflammation is part of the innate immune system response, which protects the body in a rapid and non-specific manner against immunological threats. Emerging evidence currently suggests that yeast derived beta-glucans can aid host defence against pathogens by modulating the inflammatory and antimicrobial activity of neutrophils and macrophages, thereby influencing the outcome of innate immunity.

In a review published in Molecular Nutrition & Food Research, the relationship between supplemented beta-glucans and the immune system was explored. Highlighted was the outcome of pre-clinical work that has decrypted the beta-glucans’ mode of action, known as ‘innate immune training,’ which refers to a newly recognised phenomenon whereby compounds have the capacity to “train” innate immune cells to return a more effective immunological response. This supports the hypothesis that 1,3/1,6 beta-glucans may offer increased immunosurveillance (the process by which cells of the immune system are able to seek and identify foreign pathogens).

Although various human studies have been carried out, the results of these are weaker than those returned from pre-clinical studies. The authors of the review suggested further studies are required to fully elucidate the interaction between beta-glucan supplementation and human immune function.

De Marco Castro E, Calder PC, Roche HM. β-1,3/1,6-glucans and immunity: state of the art and future directions. Mol Nutr Food Res 2020;e1901071:PMID 32223047.