All of life involves risk. Whether it’s crossing the street, taking a new job, or falling in love.
When it comes to living a long, healthy life, there’s always going to be some amount of risk. Avoiding it entirely isn’t realistic.
The good news is… You can be proactive about your and your future children's health today to reduce risks in the future.
In our disease reports, we use the word “risk” a lot. Risk is a way of measuring the chances of getting a disease. There are two main kinds of risk — absolute and relative risk — and each has different implications for your and your future children's health (1).
01
Absolute risk
Let’s start with absolute risk, which measures how many people who share lifestyle and genetic factors will develop a particular disease. For example, a researcher could measure how many smokers with a specific genetic disposition develop lung cancer. This is the smoker’s absolute risk for lung cancer.
We always aim to calculate absolute risk in our reports. For you, we combine your DNA with other relevant information, like your BMI, sex at birth, age, and others. For your future children, we choose the most likely set of non-genetic factors and use those to calculate absolute risk.
The more we understand the genetics of a specific disease — like migraines, asthma, and type 2 diabetes — the more the absolute risk estimate will be shaped by DNA. The less scientists currently know about the genetics underlying a specific disease — like ovarian cancer or chronic pain — the more the risk estimate is shaped by lifestyle and the environment.
Absolute risk can change over time. For example, BMI greatly impacts your risk for type 2 diabetes. If your BMI goes up or down, your absolute risk for type 2 diabetes could also change.
Age is another key variable. For example, it’s the main non-genetic factor we use when calculating someone’s risk for age-related macular degeneration, a common eye condition. Young people tend to have extremely low absolute risk for the condition.
Hence, in cases like this, absolute risk isn’t very informative. We’ll instead provide only a relative genetic risk.
02
Relative risk
Relative risk generally compares people who share certain risk factors to those without. For example, a researcher could see how many smokers get lung cancer compared to non-smokers in order to determine a smoker’s increased risk for the disease.
In your reports, we compare your and your future children's relative risk to other people who share the same genetic ancestry.
It’s important to note that having a higher relative genetic risk doesn’t always mean that you also have a high absolute risk for a disease.
Understanding the different kinds of risk is important to your and your future children's health, and understanding absolute risk — which captures DNA and lifestyle — is especially important. Our Beyond your DNA survey, where you can tell us a little more about yourself, helps us make your personal results as accurate as possible. The more details you can provide, the more accurate your risk assessment will be.
References
1
🔗 “Absolute versus relative risk” Cancer Research UK.
2
Fritsche L, Chen W, Schu M, et al. 🔗 “Cancer risk: What the numbers mean” Mayo Clinic.
3
Noordzij M, Dekker F, Zoccali C, et al. 🔗 “Measures of disease frequency: prevalence and incidence.” . Nephron Clin Pract 2010;115(1):c17-20. doi: 10.1159/000286345. Epub 2010 Feb 19. PMID: 20173345
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