A functioning immune system is high on many agendas right now. We want to be sure that we are doing everything we can to protect ourselves and our loved ones from this global pandemic. However, as an immunologist, I’ll let you in on a secret – we don’t really know a lot about this virus and how it operates. Don’t get me wrong; researchers and frontline healthcare workers are learning more, day by day.

However, to pretend that I know the inner workings of this virus and its long-term impacts would be arrogant in the extreme. Therefore, I think the best strategy is to temporarily forget about this pervasive bug and focus on what we do know: that the immune response won’t be effective if it’s too strong or too weak: it needs to be just right.

What many people don’t realise is that for many serious infections, it’s not the invading bacteria or virus that causes the most damage but the immune response to the bug itself. This over-reaction against the invading bug is normally associated with a “cytokine storm”, whereby chemical messengers (cytokines) produced at the site of infection recruit overwhelming numbers of immune cells. For cytokine storms, the end result is often elimination of the infection, accompanied by significant tissue damage in the local area, such as the lung. That is why doctors often use a combination of anti-microbial drugs and steroids to treat serious infections; the steroid will suppress an overly aggressive immune response. We want a primed immune system, ready to respond appropriately to the invading microbe with a healthy resolution (elimination of the infection) and no serious after-effects. Therefore, trying to boost the immune response, especially during infection, might not be the best thing to do, even if you could take supplements or other actions in attempt to do so.

CORONAPHOBIA

Coronaphobia – fear of contracting SARS-CoV-2 or dying from Covid-19 infection – has gathered significant momentum. Multiple scientific studies have reported that at least one third of the public suffer from serious Coronaphobia. Why might this be a problem for the immune response?

Anxiety and stress from real or perceived threats initiate a cascade of events, where stress activation of the autonomic nervous system leads to the production of adrenaline and noradrenaline – neuro-transmitters associated with the fight or flight response. Interestingly, both of these molecules can activate immune cells to produce an anti-bacterial response, while suppressing the antiviral reaction. This is a very important point. It means that stress suppresses (at least temporarily) the immune response to viruses. Why is this the case? At first glance, it doesn’t make sense.

The theory goes like this: we evolved in a world surrounded by dangerous, hungry predators. Most, if not all of these predators had mouths teaming with bacteria that could cause life-threatening infections. So, even if your ancestor survived a bite from a bear and managed to flee the scene, chances are that she would have died from the resultant bacterial infection caused by the bite itself. It is hypothesised that fear, stress and anxiety prepares the body for a bacterial infection, in anticipation of a bite from a predator. Adrenaline and other stress hormones increase our heart rate, blood pressure, dilate the bronchioles of the lung and ready the body to run or fight. Simultaneously, appetite is shut down and digestion is halted. After all, you don’t need to be eating a sandwich when running from a bear – you need all your energy directed to your muscles. The body seems to gamble on the fact that we are more likely to face a bacterial infection than one from a virus, in the case of an attack from a predator. Of course it doesn’t mean that the anti-viral response is completely switched off, just suppressed.

If we fast forward a few thousand years to the present day, when bears have long been extinct, we find that our immune response to stress and anxiety hasn’t changed all that much. By now I’m sure you can see that Coronaphobia in the face of a viral pandemic will not help boost immunity, in fact it can make your immune system less effective.

METAFLAMMATION

Unfortunately, Coronaphobia as well as other fears related to the financial climate are not the only factors at play during this pandemic. Our western lifestyles and industrialised societies also play a role in how we respond to infection. We have moved as a society from infectious diseases (ironically) and malnutrition being the biggest killers of human beings, to illnesses called “diseases of civilisation”. These include heart disease, obesity, diabetes, lung disease and mental illness and certain cancers. Scientists are learning that many of these disease of civilisation are associated with a low rumbling inflammation called metaflammation. This type of inflammation (immune activation) was first observed in diseases that involved metabolism (the production of energy in the body) such as obesity. Researchers combined the words metabolism and inflammation to coin the new term, metaflammation.

Metaflammation is believed to be initiated by agents of human origin called anthropogens (anthropos is Greek for human). These anthropogens include chemicals called endocrine (hormone)-disruptors from plastics, as well as pesticides and other pollutants. Anthropogens are also found in highly processed, high-fat and high-sugar foods. The best example of an anthropogen causing metaflammation is Low-density Lipoprotein (LDL), the so-called bad cholesterol-containing fat. A high-fat western diet that contains LDL, combined with cholesterol, can irritate cells lining our artery walls. This leads to the production of those chemical messengers called cytokines and the recruitment of immune cells to the area. These immune cells eat so much LDL at the site of irritation that they are called “foam cells” (they appear foamy under the microscope). Long story short – this type of metaflammation can continue over decades, eventually causing a blockage and a heart attack if it occurs in arteries feeding the heart.

Metaflammation often goes undetected by tests carried out in regular hospital laboratories. The chemical messengers produced by an infection can be 500 times the normal concentration in the blood, while those produced by metaflammation might only be five or six times above normal. Hence, metaflammation is a low, rumbling process, often occurring under the radar. Metaflammation can also cause issues with the good bacteria that live in our gut; this is bad news for our mental health and mood stability. The bottom line: our western lifestyle, diets and industrialised societies are filled with agents called anthropogens that can lead to a dysfunctional immune response called metaflammation. Not the best defence against a marauding viral infection.

THE SOLUTION

For solutions to these issues, we turn to those who live the longest – denizens of the earth’s “blue zones”. Over 20 years ago, scientists and National Geographic investigated five geographical locations where people lived longer than their compatriots from other parts of the same country. In some cases, there were ten times more centenarians (those who live to 100 or older) in these areas, when compared to equivalent regions. These so-called blue zones include: Loma Linda (California, US), Okinawa (Japan), Northern Sardinia (Italy), Ikaria (Greece) and the Nicoya peninsula (Costa Rica). Remember that infections are the biggest killers of those over 75 years, not just Covid-19, but many other types of infection. Sadly, as we age, we lose our immune memory to viruses and bacteria; our immune systems call also become more dysfunctional.

What can we assume about those who live to 100 years and older? They have either found the elixir of life, won the genetic lottery or are engaged in lifestyle practices that keep their immune systems healthy and balanced. Although genetics might play a part, the fact that citizens of the blue zones come from diverse geographical areas and different ethnic groups, indicates that other factors are at play.

So, what have all they got in common? It turns out that lifestyle practices associated with blue zone living includes: a predominantly plant-based diet, natural daily movement, a sense of belonging, purpose and meaning, as well as close family and social ties.

THE BENEFIT OF A PLANT-BASED DIET

You don’t have to become fully vegetarian or vegan – simply reduce your meat and fish intake. Many processed meats especially, contain anthropogens that can encourage metaflammation. Try skipping meat for a few days during the week and enjoy the Sunday roast all the more at the weekend. Interestingly, blue zone living is also associated with daily intake of nuts and beans. A handful of nuts each day (if you can tolerate them) will provide you with immune-balancing nutrients such as zinc. Speaking of zinc, you shouldn’t really need food supplements with a balanced diet of whole, healthy food. A balanced diet will also help to maintain normal gut flora – bugs that reside in your gut, which contribute greatly to your physical and mental health (check out the Alimentary Pharmabiotic Centre in Cork).

NATURAL MOVEMENT

Inhabitants of the blue zones seem to walk everywhere, regardless of age. They aren’t usually members of local gyms or exercise classes. Natural movement and regular, daily activities such as household chores, tending a small garden, carrying shopping home and taking stairs rather than lifts is recommended. Walking really seems to be key, so try to get out at least twice daily for a decent walk. If you can, get a dog; those longing eyes will guilt you into natural movement, no matter the weather. The science shows that exercise is one of the most effective ways to boost mental and physical health and doesn’t have to cost you an arm and a leg.

CULTIVATING A SENSE OF BELONGING AND MEANING

The Japanese call it Ikigai, roughly translated as “the reason why I get up in the morning”. The Austrian psychiatrist and developer of Logotherapy (psychotherapy through cultivating meaning), Viktor Frankl, saw this firsthand during his horrific experience in the concentration camp, Auschwitz. He noticed that those prisoners who had something to hold onto, whether it was a physical person, place or an abstract concept, tended to survive longer. We all need purpose and meaning; part of this involves other people, therefore, cultivating relationships is important for overall health.

LIMITING ANXIETY

At the newly formed RCSI Centre for Positive Psychology and Health, we recommend using tried and tested techniques to promote mental health and limit anxiety, such as developing a growth mindset (see the work of Carol Dweck), understanding your signature strengths, and meditation. We have studied Attention-based Training, based on mantra meditation, which has been shown to effectively reduce stress, anxiety and burnout while simultaneously balancing the immune response. This simple practice targets the source of anxiety – the thinking process itself. We also recommend regular psychotherapy that helps develop self-awareness and allows you to work out your fears and worries with an impartial professional. All of these practices, when taken together will help you to cultivate and sustain an immune system that’s just right.

Dan Buettner and the Blue Zone (www.bluezones.com) initiative have provided some very readable and accessible summaries of the blue zones. Meditations and information on Positive Psychology can found at www.rcsi.com/positivepsychology.