Genetics is increasingly part of the conversation around personalised health and longevity. But what can genetic information actually tell us, and where are its limitations?
Genetic testing has become much more visible in conversations about health, prevention and longevity.
Today, people can access information about inherited traits and genetic variants more easily than ever before. But having more information does not automatically mean having a clearer understanding of your health.
Your genetics are one part of a much larger picture.
Family history, age, medical history, environment and lifestyle all influence health over time. Genetic information can sometimes add useful context, but it cannot predict with certainty what will happen to an individual.
Understanding that distinction is important.
What do we mean by genetics?
We inherit our DNA from our biological parents.
Small differences within that DNA help make each of us unique. Some genetic variations are associated with characteristics such as eye colour, while others have been studied in relation to certain health conditions.
In some circumstances, healthcare professionals may use genetic testing to investigate inherited conditions or better understand an individual's medical risk.
This is very different from saying that a genetic result determines someone's future.
For many common health conditions, genetics represents only one part of a much broader combination of influences.
Genetics is not destiny
A genetic predisposition does not necessarily mean a person will develop a particular condition.
Common chronic diseases are often influenced by multiple factors, including age, family history, lifestyle, environment and other aspects of health.
This is why genetic information needs context.
For example, two people could receive similar genetic information but have very different medical histories, lifestyles and overall health profiles.
The information may therefore mean something different for each person.
Where genetic testing is undertaken, clinical interpretation should sit with an appropriately qualified doctor, genetic counsellor or other relevant healthcare professional.
What can genetic testing tell us?
There are many different types of genetic testing.
Some tests look for specific genetic changes associated with inherited medical conditions.
Others look at many small differences across a person's DNA and use those findings to estimate genetic susceptibility to certain conditions.
One example is a polygenic risk score.
A polygenic risk score combines information from many genetic variants to estimate relative genetic susceptibility to a particular condition.
The National Human Genome Research Institute notes an important limitation: these scores are calculated using genetic information. They do not automatically incorporate factors such as lifestyle, environment or medical history.
That means a genetic risk estimate should not be viewed as a complete assessment of someone's health.
Why context matters
This is one of the most important considerations in the wider longevity conversation.
A piece of data rarely tells the whole story.
Genetic information may need to be considered alongside things such as:
family history
medical history
age and life stage
clinically appropriate health assessments
environment
nutrition
physical activity
sleep and recovery
other lifestyle factors
How these pieces relate to one another is individual.
And where those factors involve medical risk, diagnosis, screening or treatment, they should be discussed with the appropriate healthcare professional.
More information does not always mean better information
The growth of longevity and health technology has made a huge amount of personal data available.
Genetic reports are only one example.
The challenge is not simply collecting more information. It is understanding which information is meaningful, how reliable it is and whether it has any practical relevance.
Genetic results can also be easy to misunderstand without appropriate interpretation.
An indication of increased genetic susceptibility does not necessarily mean that someone is likely to develop a condition.
Similarly, a result suggesting lower genetic susceptibility does not guarantee protection.
This is one reason genetic testing should not replace established medical care, appropriate clinical screening or professional advice.
What genetic testing cannot tell you
A genetic test cannot tell you exactly how long you will live.
It cannot reliably predict every condition you may experience.
And it cannot represent the entirety of your health.
It also does not tell us everything about the way someone lives.
Your DNA does not show the complete picture of your sleep, physical activity, nutrition, relationships, stress, environment or other everyday behaviours.
Those factors remain an important part of long-term wellbeing regardless of whether someone chooses to undertake genetic testing.
What about polygenic risk scores?
Polygenic risk scores are an interesting and rapidly developing area of research.
Researchers are investigating their potential use across areas including cardiovascular disease, diabetes and some cancers.
But there are still important limitations.
For example, some genetic datasets have historically included a higher proportion of participants with European ancestry. This can affect how accurately certain risk models perform across different populations.
Research published through the NIH-funded eMERGE Network has explored how polygenic risk scores might be implemented across more diverse populations, while also highlighting continuing questions around accuracy, interpretation and clinical use.
The science is developing.
That is why it is important to distinguish between an interesting emerging technology and something that is appropriate or useful for every individual.
Do you need genetic testing to take a personalised approach to health?
No.
Genetic testing is only one possible source of health information.
A person's medical history, family history, lifestyle and conversations with their healthcare team can already provide valuable context.
For many people, genetic testing may not be necessary or may not materially change the advice they receive.
Whether genetic testing is appropriate is an individual medical decision and should be discussed with a qualified healthcare professional where relevant.
What remains within our everyday influence
One of the reasons genetics is interesting within the longevity conversation is that it highlights an important distinction between the things we inherit and the things we can influence.
We cannot change the DNA we were born with.
But many aspects of everyday life remain modifiable.
Regular movement.
Maintaining strength and physical capacity.
Eating a varied and nutritious diet.
Prioritising sleep.
Managing stress and recovery.
Avoiding smoking.
Maintaining social connection.
Following appropriate medical care and screening.
These may sound less exciting than a sophisticated genetic report, but they remain important foundations of long-term health.
The Global Glow Perspective
At Global Glow, we view genetics as one potential piece within a much broader conversation about health and longevity.
We do not diagnose conditions, assess genetic disease risk or interpret genetic test results.
When genetic testing is clinically relevant, those conversations belong with qualified medical professionals and genetic specialists.
Our focus is on the areas of everyday health that sit alongside medical care: nutrition, movement, sleep, recovery, stress management and sustainable lifestyle behaviours.
Because personalised health does not necessarily mean collecting every possible piece of data.
It means understanding that health is individual and building the foundations that can support wellbeing over time.
Genetics may help explain part of the picture.
But it is only one part.
References
National Human Genome Research Institute. Polygenic Risk Score (PRS).
Centers for Disease Control and Prevention. Precision Health: Predict and Prevent Disease.
Lennon NJ et al. Selection, optimization and validation of ten chronic disease polygenic risk scores for clinical implementation in diverse US populations. Nature Medicine. 2024.
American Heart Association. Polygenic Risk Scores for Cardiovascular Disease: A Scientific Statement.
