Our genetic code is the basic template that we come into this world with. Some genes you can’t change, however you can maximise your genetic potential by exposing yourself to environmental stimuli that force adaptations. Other genes you can manipulate depending on your diet and lifestyle.
Yes, there are certain genetic mutations in genes that can either guarantee that something is going to happen to us, such as genetic diseases/defects (which is quite rare) or make it more likely that we’re going to have a problem in a certain area of physiology or function.
However, within the last few decades, our understanding of how our genes effect our health have developed significantly.
Epigenetics is the study of changes in gene expression that don’t involve changes to the underlying genes themselves but can be passed on to one or more generations. What we know now is that epigenetics is probably much more of a determinant of our health than genes themselves because genetics account for 10% or less of disease, and the remaining 90% is controlled by our gene expression and how our genes interact with environmental factors (i.e. diet, lifestyle, environment).
That brings us to the exposome. The exposome is the sum total of all of our non-genetic exposures that we experience from the moment of conception to the end our life. This could be our mother and father’s health at the time of our conception (i.e. the quality/DNA of the sperm and the egg, which is influenced by our parent’s diet, lifestyle and environmental exposures) and our mother’s health during pregnancy/breast feeding. This is why preconception and pregnancy nutrition for males and females are so important for fertility and the health of babies.
It also includes things like our diet, lifestyle, mindset, external environment and socio-economic class. Then our internal environment (which is affected by our external exposures), includes our microbiome, nutrient status (excess or deficiency), detoxification mechanisms, hormone balance, infection exposure, immune deregulation (e.g. chronic inflammation/oxidative stress).
The whole interplay between our genes and epigenetics and the exposome is what really drives health and disease. It is worth mentioning that some genetic predispositions are more profound and stronger in some people compared to others. Which means that in some people, it may take less accumulation of environmental triggers (e.g. diet and lifestyle habits) that put you at risk for a particular disease, in order for these genes to be expressed.
There are certain environmental exposures that are more closely linked to certain types of diseases/health issues based on how they effect the body and what systems (e.g. smoking and lung cancer). There are also certain groups (based on age, gender and ethnicity) of people more at risk of developing disease, especially in conjunction with certain types and amounts of environmental exposures. However, everyone is different, meaning two people can have the same type and amount of environmental exposures, but result in two different diseases/health issues OR, one gets a disease and the other doesn’t. This is due genetic predispositions manifesting uniquely from person to person in response to environmental triggers.
Furthermore, the degree (i.e. severity of symptoms and damage to body tissues) in which disease causing environmental exposures affect our health and if they will affect our health, largely depends on our genetic predispositions and the type/amount of exposures that accumulate over time (i.e. certain environmental exposures are more dangerous to the body than others and having high exposure over extended periods of time increases disease risk).
It also depends on something called metabolic reserve. Our metabolic reserve is largely dependent on our diet and lifestyle. If we have a good diet and lifestyle, for an extended period of time, our cells function better and are more resilient to stressors because having a good diet and lifestyle means that the bodies cells have been provided with nutrients to function properly, as well as decreased the inflammatory load on cells. Poor diet and lifestyle factors can cause inflammation in the body and years of inflammation damages cellular function and depletes the body of resources. This can increase the risk of disease as inflammation can “activate” genetic predispositions towards certain diseases. Poor diet and lifestyle habits are environmental exposures that increase disease risk. The worse the diet and lifestyle, the increased disease risk.
However, having a low metabolic reserve from poor diet and lifestyle factors can also mean that any stressors placed on the body such as infections and psychological stress, can wreak a lot more havoc with a persons health compared to someone who has a lot of metabolic reserve. A person with a high amount of metabolic reserve would be less effected in terms of symptom severity when exposed to stressors on the body like infections and stress. Also, having more metabolic reserve decreases the risk of acquiring infections in the first place due to cells being in a stronger position to fight off infections. Increased age also decreases metabolic reserve due to accumulation of stressors on cells over time, which is why older people are more susceptible to health issues in the backdrop of stressors. This doesn’t mean that having a good diet and lifestyle throughout ones life and in old age can still increase the bodies robustness.
Metabolic reserve also increases effectiveness of treatments for health issues. For example, giving anti-biotics to a person with high metabollic reserve will increase its efficacy, as well as decrease the side effects of the medication on the body.
Lastly, disease is multi – faceted and no one environmental trigger usually causes disease. It is usually an accumulation of various environmental exposures and risk factors. One example could be smoking. It is a large risk factor for many diseases, especially lung cancer (oxidative stress on the lungs), however we also know smokers tend to engage in other unhealthy habits, which increase their disease risk. We also know that not everyone gets lung cancer if they smoke and some people don’t even develop a chronic disease. Again, this comes down to genetic predispositions and it also may come down to a persons metabolic reserve and diet and lifestyle. There may even be a possibility of a “heathy” smoker who has a really good diet (lots of whole foods) and lifestyle (e.g. low stress, sleeps well, has a healthy mindset and does a lot of physical activity), which in turn increases their metabolic reserve in order to deal with the effects of the smoking.
Due to the complexity of multi-factorial diseases, it is always hard to quantify the magnitude of one variable on disease risk, as it is hard to control all the other factors in a real world setting, to get a cause and effect relationship between two variables. Also, for some people disease may occur early in life, while others later in life (certain diseases have higher prevalence in older or younger people, as well as gender and ethnicity) – it all depends on our genes and activation of disease-causing genes depending on accumulation of certain types of environmental exposures. Therefore, due to the multi-factorial nature of disease, we must treat it by addressing all the multi-faceted contributing/exacerbating factors. This is why pharmaceuticals for symptoms are not an effective treatment in our current medical model and will simply suppress symptoms as the underlying causes are still manifesting.
What does this mean for you?
So what does the all mean for you? Well, the way in which our diet, lifestyle and environmental exposures (i.e. exposome) will manifest is dependent on our genetic predispositions.
This means that diet, lifestyle and environmental factors are the biggest determents of your health and longevity. One can say that while our genes may load the gun, our environment ultimately pulls the trigger. As you can see, depending on how strong our genetic predispositions are towards a certain health issue, will determine the amount of environmental exposures needed to activate disease causing genes. Sometimes the amount is a lot smaller for one person compared to another.
In saying that, if an individual has a generally good diet and lifestyle and enough environmental exposures occur to activate a particular disease (e.g. toxins, infections, poor diet and lifestyle habits form time to time), the symptoms of the disease/health issue is likely to be less severe. This also increases the effectiveness of treatment required. The body is better equipped to deal with the stressor.
If you would like to improve your diet and lifestyle in order to increase your metabolic reserve, improve your health and wellbeing, as well decrease disease risk and progression, make sure you start with addressing the 4 pillars of health – diet, sleep, exersize and stress management. Consistency around these 4 areas of your diet and lifestyle is the foundation of good health.