You are unique; and the same as everyone else
We all know, that with the exception of identical twins, we are genetically unique. We also know that public health messages don’t appreciate our uniqueness when they sternly warn us about the risks of smoking and salted meats. Within families those warnings are offset by the great stories of a grandmother or an uncle who drank, smoked and loved salami but lived to a ripe old age. Whilst these things can seem at odds, they are consistent with the way public health research is done and communicated to us.
The basis of many large observational studies is to discover how sick and healthy individuals are different; to search for ‘risk factors’, which identify certain people, or groups called cohorts, as being more susceptible to disease. Often a whole new set of studies are conducted to test whether these risk factors are also the causes of disease, which can explain why some people get sick while others remain healthy. An example is that watching TV is a risk factor for developing chronic disease. The TV doesn’t directly cause the disease, that’s an outcome of a sedentary lifestyle. Public health research informs us about the risk of illness when we are exposed to things like cigarette smoke or a poor diet. These risks are averages for a cohort that is exposed, like smokers, compared to non-smokers.
The public health campaigns that remain constant, like anti-smoking, are based on long-term studies and the risks are very large. Smoking is the number one risk factor for lung cancer and people who smoke cigarettes are 15 to 30 times more likely to get lung cancer or die from lung cancer than people who do not smoke. So, for things like smoking where the risks are clear and large, you’re essentially the same as everyone else.
Getting back to the individual, for most risk factors there is variation within each cohort; people who do better or worse than the average, because of their exposure to other risk factors such as their genetic makeup and overall lifestyle. If we look at the distributions of body mass index (BMI) in Australian adults, there’s a clear difference between the male and female cohorts, with only 28% of males in the normal weight range compared to 42% of females.
The combination of family history (genetic predisposition) and lifestyle choices, such as diet, exercise, alcohol consumption, smoking and stress play a role in where an individual will be in the BMI distributions shown above.
Your genetic makeup, which is referred to as your genotype, can give an indication of what might happen. There are well known examples of this, such as the BRCA1 mutation, where it’s estimated that 55 – 65% of women with that will develop breast cancer before they reach 70.
In the development of so-called ‘lifestyle diseases’ such as Type II Diabetes, your diet, exercise, alcohol consumption, smoking and stress levels play a major role in determining what is likely to happen. Ideal lifestyle choices can decrease the risk of many diseases, such as heart disease, even when there is a family history.
At Drop Bio we are developing a health risk index that combines blood testing and lifestyle to provide a comprehensive profile. Our ongoing research incorporates genetic predisposition, with lifestyle data, such as diet, exercise, alcohol, smoking and stress. These factors combine to determine a person’s health status, which can be assessed over time by measuring specific markers of risk in a blood sample.
The health risk index Drop Bio is developing is focused on using inflammation to predict your chronic disease risk. Long term, or chronic, inflammation may be present for months or years and is a key risk factor in the development of lifestyle-related diseases. We track inflammation with repeated sampling to observe risk-related changes in your level of inflammation.