New threats, powerful defense
We’re living in times when our trust that the healthcare system can offer us fast and reliable solutions for any pathology is waning. We’re facing antibiotic-resistant bacteria and an alphabet soup of new viral epidemics--SARS, MERS, H1N1, Zika, Bird and Swine flus, and now COVID-19--with no pre-existing therapies or readiness, prompting us to seek solutions elsewhere. Panic and hoarding are understandable, but not very protective behaviors.
Fortunately, drugs and vaccines are not our only defense against microbes. Like all species we, too, have evolved in a world full of microbes and developed our own innate defenses against them. Even when medical and pharmaceutical treatments are available, they are largely dependent on the strength of the body’s own functions in order to be successful.
Instead of emptying store shelves, let’s arm ourselves with a few facts about the power of the immune system so that we can do our best to support it in ourselves and in our loved ones.
The immune system - another miracle at work
We are continuously exposed to pathogens, ie microbes that have the capacity to cause us harm. They evolved long before plants and animals did, and because of this all species in existence have evolved with defensive strategies against potential infections. This is what we refer to as our immune system. The immune system is spread throughout the body and involves many types of cells, organs, proteins, and tissues all working together to keep us safe from harm. One of its crucial features is that it can distinguish our own tissue from foreign tissue — self from non-self. An antigen is any substance that can spark an immune response. In many cases, an antigen is a bacterium, fungus, virus, toxin, or other foreign body, but it can also be one of our own cells that is faulty or dead.
White blood cells of various types play a central role in recognizing, remembering and destroying these foreign invaders. Certain types of white blood cells make antibodies, which mark particles as foreign invaders, while other types of white blood cells kill and engulf the invader, and dispose of it.
Most of the time our immune system works so well that we don’t even notice it. We are not aware of the cancer cell it destroyed, the cold virus it killed so that we didn’t get sick, or the balance it’s striking between protecting us from non-self particles while sparing our own cells. But like any system, its delicate balance can be affected by many aspects of our lifestyle.
What impacts the immune system?
Immune system function varies over the course of life, with newborn babies depending on antibody protection through nursing, many lifestyle factors common among adults taxing the immune system and many, although not all, people over the age of 65 experiencing some immune dysregulation that makes them less able to respond to immune challenges. This also manifests as a decreased ability to create antibodies and a resulting diminished response to vaccination in older adults.
Medications such as cortisone, other immunosuppressant medications, chronic stress, malnutrition, loneliness, overexertion, a sedentary lifestyle, overuse of alcohol and poor sleep and irregular sleep/wakefulness cycles (aka circadian rhythm dysregulation) are some of the more common factors that can tax this powerful system and prevent it from effectively defending us from pathogens.
Can you “boost” your immune system?
The answer is generally “no”, but more importantly, you wouldn’t want to. An overactive immune system means feeling inflamed, unwell, allergic or experiencing an autoimmune reaction. What you do want, however, is to make sure your immune system functions properly.
The effects of nutrition on your immune system
Not unlike other bodily functions, the immune system is dependent on certain nutrients. While few individuals in the developed world are dying of hunger, lifespan and quality of life may for many be affected by poor nutrition. It has been estimated that 35% of those aged 50 years or older in Europe, USA and Canada have a demonstrable deficiency of one or more micronutrients . Children may suffer from vitamin and mineral deficiencies due to selective eating habits or lack of sunshine, and the elderly tend to eat less food, but still require the same amounts of micronutrients (and even more protein than younger individuals), which can make for a tricky equation to solve.
Micronutrients that are especially important for immune system function include:
- vitamin A -crucial to immune function throughout the body, and contributes to the maintenance of the barrier created by the epithelial lining in the respiratory and gastrointestinal tracts. (Note that beta carotene is not the same thing as vitamin A.)
- vitamin D - like vitamin A, it is involved in many areas of immune function, and deficiency can increase the risk of infection, especially respiratory tract infections.
- vitamin E - has a potent anti-oxidant effect and is also involved in immune function. Deficiency has been shown to increase risk of influenza infections in the elderly.
- the mineral Zinc is especially important because it maintains the activity of more than 300 enzymes, including in white blood cells, such as phagocytes and natural killer (NK) cells. Even marginal zinc deficiency is known to result in atrophy of the thymus gland and can increase the risk of infection.
- B vitamins - deficiency in B6, B12 and folic acid impairs immune function and immune response.
- vitamin C - supplementation with vitamin C reduces the duration and severity of common cold symptoms in deficient adults. In those under physical stress (e.g., at work, during sports, and under extreme temperatures) or in cases where vitamin C levels are slightly below recommended levels, vitamin C supplementation reduces common cold incidence.
- Iron and Selenium
Please note, however, that healthy eating habits and supplementation can only support normal immune system function by supplying it with the building blocks it needs to function. You can not build some kind of super immunity by supplying your body with higher than physiologically necessary amounts of these nutrients, or any other interventions either, just like, while sleep deprivation can make you more susceptible to infections, sleeping more than necessary won’t increase your resistance to infections.
Inflammation and aging seem to go had in hand, leading to the concept of inflammaging, an imbalance between inflammatory and anti-inflammatory networks contributing to common age-related changes, including immunosenescence, or the aging of the immune system, which, as mentioned, contributes to the increased susceptibility of many older individuals to infectious disease. Anti-inflammatory nutritional interventions can therefore be useful. Fortunately, the aging of the immune system is quite malleable, and affected by both lifestyle choices and medications.
In patients with diabetes the immune system is suppressed by the elevated blood sugar levels. Metformin is a drug commonly used to counteract this phenomenon. The herbal compound Berberine has similar effects, leading to speculation that it could help non-diabetics keep blood sugar levels at ideal levels and thus support the immune system.
Physical activity exerts an anti-inflammaging effect via several mechanisms. Studies have also shown that individuals who perform regular exercise appear to be at a reduced risk of mortality from infections. Exercise also tends to raise Human High Density Lipoprotein (HDL) levels (levels of what many like to call “good cholesterol”). HDL has both anti-inflammatory and anti-oxidative effects.
Other ways of attenuating inflammaging include avoiding caloric excess and eating a nutritious diet. Diets like the Mediterranean diet or other personalized diets with nutritional supplementation with micronutrients and limonene have been shown to both decrease inflammation and improve immune responses.
Anyone wishing to improve their body’s resistance to infection and illness, whether chronic or acute, can benefit from first and foremost supporting their body’s basic functions by ensuring sufficient levels of nutrients through both diet and supplementation, as well as observing other healthy habits and practices that allow the body to function optimally.
Even when a vaccine exists for a particular disease, it is the person’s own immune system that creates the antibodies, and a weak immune system is less able to do so, leading to an antibody response after vaccination of only 17–53% among the elderly.
Regular sleep/wake cycles supported primarily by appropriate exposure to light and darkness, supporting sleep, which I’ve written about here, movement, spending time in nature and avoiding loneliness and stress are all powerful tools. Older individuals need to be especially mindful of taking good care of their immune systems, and this includes taking steps to reduce inflammaging. Exercise regularly, move often, give yourself reasons to laugh even more often, eat well and supplement wisely.
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