Though our bodies come under daily attack from viruses and bacteria, it is in winter that the diseases associated with them become common, affecting people of all ages. So now is a good time to ensure every element of your defence system is supported with the right nutrients. Here’s a brief overview …
What makes up our defence system?
To appreciate how each nutrient can support the immune system, it is first important to understand how the body defends itself against pathogens.
An immediate, non-specific defence system known as innate immunity.
The elements of this type of immunity are:
- phagocytes (macrophages, polynuclear neutrophils, dendritic cells),
- Natural Killer (NK) lymphocytes which rapidly detect viruses and secrete pro-inflammatory cytokines,
- epithelial cells covering all the exterior surfaces of the body and lining the outside of organs (skin, lungs, stomach, intestines).
Their objective? To form a first physical barrier against infectious agents. ‘= -[0p ;…………. N n nn
At a respiratory level, for example, we see the secretion of specific proteins: cytokines, secretory IgA, lactoferrin, lysozyme, phospholipase A2, glutathione and other proteases.
In the gastrointestinal tract, it is primarily the microbiota and intestinal epithelial cells that are essential to the maturation of the immune system: development of the lymphoid structures and secretion of IgA, antimicrobial peptides or chemokines which lead to the recruitment of components of innate immunity (macrophages, neutrophils) and acquired immunity (T and B lymphocytes).
A specific defence system known as adaptive immunity found only in vertebrates.
Should the mechanisms of innate immunity prove inadequate, the ‘second line of defence’ moves systemically into action almost 96 hours later.
- This comprises T lymphocytes: CD4+ (T helper cells type 1 and 2 (Th1 and Th2)) and CD8+ (cytotoxic), which secrete numerous cytokines and are part of cell-mediated immunity.
- And B lymphocytes which play a major role in producing antibodies (immunoglobulins). They make up humoral immunity.
The natural substances which provide effective overall and specific support for the immune system can be divided into three categories:
- Vitamin C found at high levels in leukocytes. It supports immune defences by stimulating Natural Killer cell and T lymphocyte activity, protecting immune cells from oxidation, increasing polynuclear phagocytosis and stimulating interferon production. Studies have shown that taking 500mg-1g of vitamin C a day from the onset of a cold reduces its symptoms and duration. It also promotes absorption of iron, a mineral which can be lacking in certain individuals such as children, adolescents and active women.
- Vitamin D3 is essential as it plays a key role in the synthesis of anti-microbial substances. Without it, the T lymphocytes responsible for destroying viruses and bacteria, cannot bind to this circulating vitamin and launch their defence process.
- Tocopherols (broadly vitamin E) improve lymphocyte reproduction, and may boost phagocytosis and cell-mediated immunity. They therefore complement and act in synergy with vitamin C.
- Vitamin B12 (methylcobalamine) also boosts NK cell and T lymphocyte activity.
An essential element: zinc
We now know that simple zinc deficiencies can disrupt the function of our immune defences; indeed, zinc is essential for the healthy function of T and B lymphocytes, neutrophils, NK cells and macrophages. As a co-factor of thymulin, zinc is necessary for the differentiation and maturation of lymphocytes.
It is now also recognised as being essential to the integrity of the body’s barriers – the skin, and the digestive and respiratory mucosa.
Given that the body cannot produce zinc reserves and that around 10mg is lost each day through perspiration and excretion, intake is not always sufficient to fully compensate for this loss. Studies show that daily supplementation may reduce the incidence of colds and shorten their duration.
is the most popular immune-stimulant in Japan. Extracted from mushroom mycelia, it improves immune response via a number of mechanisms: it induces proliferation of macrophages and NK cells, increasing their activity by more than 300%, it stimulates and increases production of beneficial cytokines: tumour necrosis factor (TNF-alpha), interferon-gamma, and interleukins 1 and 12 (IL-1, IL-12), and it inhibits certain immunosuppressive cytokines and improves the balance between T-helper cells (Th1 and Th2).
, which is concentrated in the eyes, nose and mouth, is a glycoprotein with immune-stimulant, anti-viral, anti-bacterial and anti-fungal properties. It naturally stimulates the growth of bifidobacteria (friendly gut flora), NK cells and neutrophil activity.
(ParActin®), more commonly known as Indian echinacea, is an immune system-booster, and a powerful anti-viral and anti-inflammatory agent for the upper respiratory tract. Its use in traditional Chinese and Ayurvedic medicine for treating fever and respiratory infections has been supported by clinical trials. Supplementation is therefore recommended for reducing the symptoms and duration of colds, sinusitis, bronchitis and pharyngitis, to be taken as soon as symptoms appear.
Anti-ageing substances which also act on the immune system
- AC-11 : extends the life of lymphocytes, as shown in a human study.
- Astragaloside IV and extracts of astragalus promote reactivation of resting immune cells. They stimulate macrophages and immunoglobulin production and promote regeneration of T lymphocytes and activation of NK cells. They induce endogenous production of interferon and maximise its effect on viral infections.
- Cycloastragenol is an excellent immune-stimulant. It increases T lymphocyte proliferation.
- Epitalon : Taking this peptide has been shown to potentially activate proliferation of T lymphocytes in the thymus and production of interferon-gamma.
And also …
- Chlorella is a monocellular, green, fresh water algae, known for its high chlorophyll content and detox action, which may also have a role in immunity through stimulation of T lymphocyte and macrophage activity, and through increasing interferon levels.
- Reishi boosts the activity of T lymphocytes and other crucial immune factors. It increases the number and function of all cell lines responsible for antigenic response, particularly NK, and promotes the specialisation and activation of dendritic cells and macrophages which help the body react to viral threats by supporting antibody production by B lymphocytes.
- Goji berry extract improves lymphocyte and NK cell activity.
- Shilajit is a bituminous substance that increases lymphocytes, activates macrophages and NK cells and stimulates cytokines.
- Ashwagandha enhances the ability of macrophages to destroy pathogens.
- Ginseng panax modulates the immune system by increasing phagocytosis, NK cell activity and production of interferon.
- Fucoidan, extracted from Laminaria japonica, is a sulphated polysaccharide that can boost the immune system, helping it to defend against viruses more effectively.
- Reduced L-glutathione , or its more stable and active form: S-acetyl-glutathione, provides effective support to antigen-presenting cells (macrophages for example) and thus influences the response of Th1/Th2 cytokines.
- Beta-(1.3/1.6)-glucans are also polysaccharides recognised as being immune-modulators.
It is worth noting that an immune system in tip-top condition not only ensures an infection-free winter, but more importantly, provides wider and significant protection against the growth of tumour cells.