This article was originally published in the September 2018 issue of AromaCulture Magazine (www.aromaculture.com) and has been adapted for use here with permission from the publisher.
Nutrition is well known to be an important factor for immune system function. In fact, malnutrition is the leading cause of immunodeficiency worldwide (Chandra, RK, 2007). Although developing a deficiency in a single nutrient is uncommon, clinical studies show that even mild deficiencies can negatively affect immune system function (Chandra, RK, 2007). This may manifest as an increased frequency of colds and flus, genital, and urinary tract infections (Chandra, RK, 2002).
With exception to people in at risk groups, such as the elderly and those in clinical immunocompromised states, eating a varied, whole foods diet is usually simpler and more effective than supplementing to ensure you are getting a rounded variety of nutrients to take care of your immune system (10).
Understanding the Immune System
The immune system is generally divided into two categories: innate, and acquired - sometimes called humoral. The innate immune system is the first line of defence, and consists of the skin, mucosal barriers, enzymes such as those in saliva and stomach acid, and generalized immune cells such as macrophages, leukocytes, natural killer cells (NK cells), and dendritic cells. These are cells that directly kill any foreign pathogens and material that they don’t recognize as part of the body. (Wintergerst ES et al)
If the innate immune system fails to prevent infection, the adaptive immune system steps up (Wintergerst ES et al). These are specialized T and B lymphocytes, named for whether they mature in the thymus gland or the bone marrow (Wintergerst ES et al). These cells make up antibodies, memory cells that recognize past infection and can quickly react to subsequent exposure (Wintergerst ES et al). The adaptive immune system has a more complex system. It uses signalling molecules called cytokines and interleukins which act like hormones to trigger an inflammatory response, reactive oxygen species (ROS) to weaken pathogens, and inflammation (Wintergerst ES et al). All components of the immune system are vulnerable to deficiencies, from barrier integrity, to phagocytosis and antibody production, to the ability to deal with excessive ROS (L.C. Carmen).
In addition to circulating in the lymph and bloodstream, immune cells are also present in the skin and epithelial lining of the gut, lungs, and reproductive tract (Wintergerst ES et al). The gut is in fact considered the largest immune organ in the body, referred to as GALT (gut-associated lymphoid tissue) (Wintergerst ES et al). The health of the gastrointestinal tract itself will affect absorption of nutrients and therefore immune function, but of equal importance is the health of the microbiome (Forchielli ML, Walker WA). The composition of gut bacteria has been shown to influence not only gastric immune cells, but mucosal immune cells at distal sites as well (AJ McDermont, GB Huffnagle) One of the ways a healthy microbiome interacts with the immune system is by producing short-chain fatty acids and other metabolites that induce inflammatory mediators, and help to produce a balanced T-helper response (Forchielli ML, Walker WA).
Nutrients and their effects on the Immune System
It is difficult to study the effects of diet overall on immune health, so most studies are carried out on single nutrients. The nutrients that are known to directly affect the immune system are essential amino acids, folic acid, vitamins A, C, E, B6, B12, zinc, copper, iron, and selenium. (Calder PC, Kew S),(Wintergerst ES),(Maggini S et al)
Innate immunity - barrier integrity
Vitamins A, C, D, E, and zinc are all directly related to skin barrier and epithelial mucous membrane integrity and function (Maggini S et al). For example, vitamin A is involved in gene expression and differentiation of epithelial tissue, therefore regeneration of the tissue is impaired with deficiency, as is its ability to fight extracellular infections. (Wintergerst ES),(Maggini S et al). When there is a deficiency in any of these nutrients, as shown in studies of vitamins A, and D, there will be a higher frequency of infections in the eyes, respiratory tract, and gastrointestinal tract (Maggini S et al). Increasing vitamin A levels in children in developing countries has resulted in fewer deaths from measles, diarrheal disease, acute respiratory infections, malaria, and tuberculosis (Maggini S et al).
Vitamin D in particular is protective to the respiratory tract; we notice this in the winter months when a lack of sunlight causes increased lung infections (Maggini S et al). Alternatively, using cod liver oil or UV exposure during the winter decreases susceptibility to respiratory infections (Maggini S et al). This happens because vitamin D stimulates production of generalized immune cells that are present in the mucous lining of the lungs and respiratory tract (Maggini S et al). It is vital to every part of the immune system, as there are vitamin D receptors on most immune cells (Maggini S et al).
Innate immunity - generalized immune cells
As with the previous section, vitamins A, C, D, E, and zinc, with the inclusion of copper and iron have important roles in the function and production of the various generalized immune cells and phagocytosis (Wintergerst ES),(Maggini S et al). There are a significant number of vitamin D receptors on monocytes, macrophages, and thymus tissue, suggesting a vital role of vitamin D in immune system function and immune cell production and maturation (Maggini S et al),11 Although vitamin D stimulates production of monocytes, antimicrobial peptides, NK cells, and neutrophils in the lungs (Maggini S et al), it appears to have an immunomodulatory role on the innate immune system - particularly on monocytes and antigen-presenting cells (Barbara Prieti et al). This has important implications in autoimmune diseases, which are vulnerable to an overactive immune system (Barbara Prieti et al).
Iron influences cell differentiation and growth, including immune cells, however, an overabundance of iron can actually feed the pathogen, so supplementation should only be used in iron-deficient states. (Maggini S et al)
All nutrients mentioned in this article except for vitamin C and iron are used in antibody production, while B6, selenium, copper, and zinc have a direct impact on it (Wintergerst ES),(Maggini S et al). The latter nutrients also have a direct impact in particular on B-cell proliferation; these particularly good with extracellular pathogens (Maggini S et al).
Vitamin D again is an important nutrient in adaptive immune system function. Vitamin D enhances calcium and phosphate absorption and promotes mineralisation of bone. Because immune cells originate in the bone marrow, healthy bones will produce healthy immune cells. During active infections, both T and B lymphocytes upregulate vitamin D receptors, and there is evidence that calcitriol acts in a suppressive way on B cells in the same way that T-suppressor cells work, which can again have important implications in autoimmunity. (Barbara Prieti et al)
Vitamins B6, B12, and Folate work together in protein synthesis. A deficiency in any of these three vitamins results in decreased T-lymphocyte maturation and proliferation, as well as antibody and cytokine production. Selenium activates the expression of genes that code for cytokines and various other proteins involved in the immune response. (Maggini S et al)
ROS are a normal byproduct of immune system function. They are created during inflammation and are used to kill bacteria and pathogens, but every cell in the body is vulnerable to oxidative stress. Vitamin C is an effective antioxidant that scavenges free radicals therefore controlling oxidative stress, and regulating inflammation. Vitamin C is rapidly used up during infection, as high concentrations of ROS can impair immune response even though they are used in immune response. Studies show that increased vitamin C intake can significantly reduce the duration and severity of cold and flu symptoms, though will not prevent infection in the first place. (Maggini S et al)
Healthy Dietary Sources
Now that we know which specific nutrients are important for the immune system and why, if you are noticing in yourself or in your clients a potential immune deficiency, through looking at their diet we can find what they may be missing. We often hear about the importance of eating a “varied, whole foods diet”. But what does eating whole foods mean? Unprocessed whole grains are grains with the outer shell, or hull, included. Whole grains have substantially more minerals, vitamins, and other nutrients compared to refined, hulled grains.13 When comparing vegetables, some studies have found that organically grown plants contain up to 90% more minerals than conventionally grown.13
Similarly to conventionally grown plants, farmed fish contain less healthy fats and are more susceptible to infection, even when organically fed, than wild fish do.13 The same can be said for grass-fed beef over grain fed, the former having a higher fatty-acid content, and a higher content of omega 3 precursors (Cynthia A. Daley et al).
It appears that by simply changing to organic whole foods, with grass-fed beef or wild fish, you can already start to increase your nutrient profile, though this is not always possible for every demographic. Here, we can generally stick to locally sourced food, and think about which foods contain the highest levels of the immune-specific nutrients. This information is easily found online, but as a general rule, there are high levels of minerals and B vitamins in dark green, leafy vegetables, while orange and red pigments are rich in Vitamin A (Dieticians of Canada, 2018). Of course, in all cases it is important to remember to take care of your gut health.
There are a few overlaps, and many differences between Herbalists and Naturopaths. It can sometimes be difficult and confusing to choose the right health care provider when faced with a growing number of alternative and integrative practitioners available. The following is a brief(ish) overview of the differences between these two common health care modalities.
The most extensively trained of the alternative health professions tend to be Naturopaths, as they receive a similar degree of training as Medical Doctors and hold the title of “Dr.” or “ND”. They are able to diagnose, prescribe pharmaceuticals, and order blood tests, x-rays, and other scans. Because of this, they are required to write a licensing exam and in BC are covered by many medical benefits plans.
Naturopaths are trained in a variety of modalities including acupuncture, homeopathy, and botanicals, though, aren't specialists in these areas. Their training will spend a few months on each subject rather than the years covered by specialists in any of those modalities,
While naturopaths dabble in herbal arts, Herbalists are the specialists in botanicals. They are extensively trained in Herbalism, which includes modern science of medicine and herbs, as well as herbal traditional use and philosophy. There is an emphasis on holistic care, not absent in naturopathy, which means that diet and lifestyle habits are of just as much (if not more) importance as the herbs that are used.
Why See an Herbalist Over a Naturopath?
Naturopaths are very good at diagnosis, though unless they seek training outside of their naturopathic training, generally have a minimal or very basic understanding of herbal medicine. This is because although they are trained in it, they get merely a few months of training whereas herbalists will have years.
Although every Naturopath practices in their own unique way, many will have an emphasis on supplement use and ‘nutraceuticals’ (that is, concentrated extracts of herbs). This is different than how herbalists practice, as herbalists tend to use whole herb preparations and (many) feel the whole herb extract is preferable for a variety of reasons both scientific and philosophical.
Many people will see a Naturopath initially for a diagnosis, and to explore treatment options, and after switch to an herbalist to pursue long (or shorter) term herbal treatment. They may also choose to see both a Naturopath and an Herbalist as they can work together very effectively.
Herbalists are really good at choosing the herbs that are right for the individual, as they are versed in a far wider variety of herbs then most Naturopaths and have a far deeper understanding of the breadth of activity in each herb. They also have a good understanding of the way that herbs interact with each other, and with pharmaceuticals, and supplements. This is important as herb/drug/nutrient interactions can alter desired effects or even be dangerous. When pursuing herbal treatment for any reason, it can be far more beneficial to work with an Herbalist than with a Naturopath.
Why Use Herbs at all?
Many are safe to use long term and work wonderfully alongside conventional (or otherwise) treatments.
Conventional medicine (pharmaceuticals) really excel at dealing with acute conditions and symptom management - despite what various blogs and articles tell you, you aren’t going to find an herb that takes a headache away as quickly as Tylenol does. Though If you suffer from chronic pain for example, daily use of Tylenol can quickly deteriorate the health of your liver. There are many herbs that taken daily over the course of weeks or months will manage your pain, often to the point of not having to take harsh pharmaceuticals at all. (That being said, stronger herbs are available to deal with severe pain when necessary and appropriate). If you feel most comfortable using conventional medicine, herbs work really well alongside pharmaceuticals to negate the damaging effects they can have on your liver and kidneys and protect against other side effects.
They give us tools that conventional medicine simply doesn't have
Unlike conventional medicine, herbs truly shine when it comes to treating chronic conditions. Herbs are slower acting and have a cumulative effect, meaning they work best when taken daily over time, but they give us many options for resolving long standing issues over simply treating the symptoms. Although they take time to produce an effect, when used properly herbs usually aren’t a life sentence; as they work to restore balance in the system where the problem is stemming from.
Aside from treating chronic conditions, there are many safe (and delicious) options for treating more acute conditions such as helping to resolve a flu more quickly, or using sedative herbs to get to sleep. Herbal medicine has a lot of tools for things that conventional medicine simply doesn’t. You can’t go to your doctor with the complaint of “I just don’t feel that great” and expect to get much help aside from eating better and getting more sleep (and that’s if your doctor is especially progressive). There are herbs that are able to help your body to better deal with stress, heal more quickly after surgery, or lift your spirits.
It’s impossible to list the variety of conditions that herbal medicine is used for - so if you’re wondering if you can benefit, the answer is yes - even if it’s not curable, your quality of life can certainly be effected (for the better).