Research suggests that the contribution of genetics to the development of autoimmune disease is approximately a third, or 33%. That means that whilst a third of the predisposing factors for developing an autoimmune condition lie within the genes, the rest is entirely down to factors other than our DNA. Put another way, you can be born with the ‘predisposition’ to autoimmunity – but 66% of the factors which are going to make you develop autoimmune conditions are anything but genetically predetermined.
This might surprise you. Genetic analysis is currently so popular that you could be forgiven for thinking that interpreting genetics would hold the key to revealing the truth of our identities, our characteristics, our traits – and our illnesses. Figures suggest that the reality is far different. So whilst genetics is certainly a part of the manifestation of illness, it is far from the whole story.
You may have heard the phrase “genetics load the gun, the environment pulls the trigger.” This alludes to the fact that our DNA contains all of the information necessary for producing (and reproducing) every single cell in our entire body. But along with these deterministic factors, there are a lot of other variables and things which need to be switched ‘on’ in order to manifest. Much of our genetic code is just a predisposition until circumstances cause it to become ‘expressed’.
The term ‘genetic expression’ indicates what we are coming to understand about the manifestation and/or minimisation of certain parts of ourselves: both of our personality and our biology. Certain genes can be turned ‘on’ and ‘off’.
What turns these switches on or off (i.e. governs whether certain genetic traits or patterns are ‘expressed’) is referred to as the ‘exposome’, i.e. everything external and non-genetic that we go through in life. And yes, we literally mean everything, from food to sleep, stress, emotions, relationships, chemicals, mood, nutrients etc. etc. etc…. for your entire life.
This is the realm of epigenetics – the manipulation of gene expression by factors which are not genetic. If you appreciate that DNA may not malleable, but certain parts of it are able to be influenced in terms of how brightly they shine, it demonstrates why only 33% of autoimmune disease is genetically determined: there is a whole world of ‘triggers’ and ‘activations’ that must happen in life for the genes which predispose to autoimmunity to come into effect in the life.
It gets even more nuanced than this. The exposome that surrounded our ancestors can also influence our own DNA and biochemistry. That means that the environment around the people that made us – from food to toxicity to societal norms and structures – can affect us in the now: this is thought to be how cultural norms affect genetic evolution.
This means that the way your mother and father ate, responded to stress, exercised and dealt with their epigenetic milieu will have, in part, played a role in the activation or repression of some of your genes’ expression.
Then they brought you up – and you went to school – and you lived in a certain community and at a certain socioeconomic level. Everything that you went through factors into the you that you become. Brain frontal cortex development isn’t even complete until age 25, so you literally aren’t even thinking like a fully formed adult until you are a quarter of a century old…
It seems that the elements of biology we believed were ‘fixed’ may actually be far more manipulated and altered than we imagined.
But what does any of this have to do with autoimmunity?
Guilt, Responsibility and Illness
One of the most pervasive and complex parts of any chronic illness, including autoimmune conditions, is the psychological distress that can come along with it. You will read elsewhere on this site how important mindset, perspective and attitude are in the process of attempting to effect change.
This is why we present an understanding of genetics – because understanding the ‘why’ behind any physical suffering or condition is a fundamental step in being able to accept the current situation. The heritability of genetics, coupled with the influences of the exposome of our ancestors, shows us that there is a many things that we could do nothing about that contributed to the evolution of any of our suffering.
But that said, this same understanding of genetics and the influence of the exposome also shows us that our fate is not written in our genetic code because we can, today, change our exposome – and in doing so we have the power to tackle our health conditions head on and really make improvements in our wellbeing.
So what is the genetic cause of autoimmunity?
Well, in truth, chronic illnesses are rarely, if ever, caused by one isolated ‘instigator’ or issue. Chronic illnesses arise due to a multitude of factors, the combination of which is often referred to as a ‘perfect storm’.
This perfect storm of lifestyle conditions may trigger illness, but a genetic predisposition is what determines its downstream impacts. When discussing autoimmunity, these downstream impact revolve around having an immune system which goes into overdrive.
Currently, autoimmunity is believed to be the result of the immune system malfunctioning in one of two ways (or possibly both):
Either the immune system is hyper-sensitised and attacks too readily, perveiving anything and everything is a threat and thus engaging in pre-emptive strikes, during which the self tissue is mistaken for enemy tissue and becomes damaged,
The immune system does not have the correct regulatory measures to turn itself off after an initial, appropriate, attack to a legitimate ‘antigen’. This means that inflammatory cytokines and killer immune cells are constantly being released as if a threat were still present, despite it being long gone. The net effect is permanent inflammation and the system issues that result.
WHICH GENES AFFECT AUTOIMMUNITY?
Some of the genetic Single Nucleotide Polymorphisms (or SNPs) which govern the way the immune system responds, and the way the immune suppression system acts, have been identified. To understand this you need to understand that the immune system is built to create antibodies to enemy invaders all the time. It does this by a complex network of cells and complexes which are permanently scanning for foreign bodies, designing antibodies for anything vaguely suspicious and then pulling back after an attack, or after realising that an attack was unwarranted.
In the maelstrom of activity of a perfectly functioning immune system, even healthy individuals continually make so-called ‘auto-antibodies’ – or antibodies that can attack ‘self tissue’. These are kept in check by a regulatory system which either reformulates those auto-antibodies prior to release (after recognising that they would attack ‘self) or removes these auto-antibodies from circulation if they are discovered.
This regulation, reformulation, recall system has to be built by our genes – and there are SNPs which can affect and interfere with the whole, complex workings of immunity.
B cells (a type of immune cell created in the bone marrow) must be ‘checked’ prior to their release – like immunological quality control. Some of the most simple SNPs affecting immunity change this checking process so that instead of faulty B cells being reformulated they are released into circulation, creating unintended inflammatory and immune responses.
One of the most complex, beautiful and intriguing parts of how our immune system works is coded by the Human Leukocyte Antigen (HLA) genes. These affect what is known as the major histocompatibility complex (MHC). The MHC governs the “presenting” of antigens to the adaptive immune system, the part of our immune system that learns what’s threatening to us as we go through life. SNPs in the HLA genes can affect what gets presented by the MHC to the adaptive immune system as a threat. This means that the immune system is taught by faulty HLA/MHC presentation to react to things that aren’t actually damaging – even some ‘self tissue’.
Mutations within the HLA-B coding have been linked to excess sensitivity (and reactivity) to some external products such as foodstuffs, toxins, chemicals or moulds. The number attached to the end of the HLA is correlated with the particular products your immune system will respond to – with HLA-B27 linked to autoimmunity, and several others linked to mould sensitivity, and two other HLAs, DQ2 and DQ8, being tied to the presence of coeliac disease.
Lastly, moving beyond the SNP-determined regulation of autoantibodies and HLA coding, our genes can also affect the strength and nature of our inflammatory responses themselves, not just what we react to. How many immune cells you make, where they are located, how much inflammatory material each cell contains and how easy it is to ‘set them off’ are all, in part, influenced by genetics.
Not one of these SNPs is categorically causative of autoimmune conditions. And, as with all genetic components, it is the epigenetics (everything mentioned in the first few paragraphs here) that will trigger the expression of these genes and the manifestation of extremes of illness as a result.
What the above-highlighted genetic factors do suggest is that if you have the wiring for autoimmunity or immune sensitivity then it is a deep part of you which must be accepted for what it is.
It doesn’t however, have to rule and dominate your life.
Just as epigenetic factors such as diet, lifestyle, stress, lack of sleep, emotional conflict and socio-economic struggles are able to trigger off the manifestation of autoimmunity, these same epigenetic factors are able to regulate the immune system, even when it is in a state of reactivity and self-attack.
Understanding the science of autoimmunity provides the backdrop to accepting the genesis of any autoimmune condition – but it also provides us with the understanding of the pieces of our exposome we can manipulate in order to reverse autoimmunity and place any health crises caused by it into remission.
In many cases this is perfectly possible, but it requires a foundational understanding and compassion. Any autoimmune condition is a perfectly reasonable response from an immune system that has, for some reason, spiralled out of hand. In attempting to keep us safe, our immune system has developed an overzealous response. More on this can be found in out AIP Mindset page.
But with this backdrop in mind, the rest of our AIP section will help you to understand the exposome manipulations which will down-regulate, re-educate and re-balance your immune system. But if you want to know the science behind immuno-modulation using nutritional manipulation, read on…