What if Genetic Testing Shows Almost Everyone is "At Risk"? A Study of About 900,000 People Re-examines Health Perspectives

You might be living your life as usual, without any health issues, yet a detailed genetic test could reveal that you are at high risk for several diseases.

The German newspaper Tagesspiegel introduced a study that suggests such a possibility. The research team from the University of Exeter in the UK and others questioned not only "what genetic characteristics do sick people have?" but also "how much genetic variation do people typically have?"—a foundation for interpreting test results.

The results indicate that there is a significant gap to be carefully evaluated between finding concerning information in genetic tests and actually developing a disease.

The Meaning of "High Risk for an Average of 3 Diseases"

Published on October 22, 2026, in the academic journal "Genome Medicine," the study utilizes large-scale data platforms such as the UK's UK Biobank and the US's All of Us.

The focus was on the results of examining "polygenic scores," which compile multiple genetic factors for 28 common diseases. The average person ranked in the top 10% for about three diseases.

The top 10% here represents a position within the group. It does not mean "a 90% chance of developing a disease" or "will develop three diseases in the future."

It's important to understand the numerical mechanism. By classifying 10% of people as "high" for each item and counting this across 28 items, the average for the entire group mathematically becomes 2.8 items. This holds even if the items are not independent of each other.

Thus, you cannot conclude that an unexpectedly large number of people will become ill based solely on the number "average of three." The more items you examine, the more likely it is to be classified as high in some area.

Not All DNA Differences Should Be Considered "Abnormal"

According to the university's announcement, there are approximately 5 million variants, or sequence differences, in the human genome. The existence of differences itself is normal for humans.

Words like "mutation," "risk," and "association with disease" in test results resonate strongly in everyday contexts. However, the comparison standards used in research do not directly translate into a "blueprint of a completely healthy person."

Moreover, there are differences whose relationship with disease is not well understood. The fact that something is "found" and the state of "understanding what it means for health" are separate.

This study did not examine the participants' actual health conditions. Therefore, it cannot be read as a follow-up study confirming "how many high-score individuals later developed diseases."

The research team emphasizes the need to interpret genetic information in combination with symptoms, family history, and other clinical and environmental factors.

On Social Media: "Expectations for Prevention" and "Caution Against Overinterpretation"

This study has been discussed in public social media posts by experts. However, the following is a summary of posts found on LinkedIn and does not represent the overall opinion distribution on social media.

Muin J. Khoury highlighted the study's main results and noted that the subjects were limited to the UK and the US. He also discussed the balance between the benefits of returning health management information to individuals and the drawbacks of misdiagnosis and overdiagnosis.

This perspective leads to the question, "Does more information necessarily lead to better health?" Informing individuals of results and improving their lives or medical care as a result are not the same.

On the other hand, Ingo Froböse's post distinguished between genetic risk and actual onset, emphasizing the importance of lifestyle. Responses in the comments section also showed interest in interactions with the environment and epigenetics.

However, caution is needed in the expression of posts. Rephrasing the result "high score for an average of three diseases" as "three gene mutations related to disease" mixes different information. Also, this study alone does not prove that lifestyle is the decisive factor for the onset of all diseases.

It is necessary to maintain a perspective that does not solely attribute the future to genes or hold individuals entirely responsible for their lifestyle choices in relation to disease.

Considering the Difference Between Commercial Tests and Medical Diagnoses in Japan

For Japanese readers, genetic tests available for purchase online might be more familiar.

The National Cancer Center distinguishes between consumer-directed DTC genetic tests and genetic tests conducted in medical institutions. The former predicts diseases and traits involving multiple genes and environmental factors, while the latter investigates genes known to have a strong relationship with diseases, aiming for diagnosis.

At the very least, you cannot interpret the results of both in the same way based solely on the explanation of "examining genes."

Additionally, it is essential to verify whether risk scores developed overseas can be appropriately used for Japanese people. The current paper also cautions against applying scores based on one group to another without sufficient evaluation.

When looking at test result numbers, it is necessary to ask not only "how high is it?" but also "whose data is it compared to?"

Think About "What Comes Next" Before Taking a Test

The value of knowing genetic information cannot be measured solely by the number of disease names displayed. What matters is what you can decide after receiving the results.

When reading test explanations, clarifying the following points can help make the purpose clear.

• Is the information being examined related to disease diagnosis or statistical likelihood?
• If deemed "high risk," can you consult about additional confirmation or health management?
• Is there a possibility that even if the results are known, the response method is unclear?
• How do you consider knowing information that affects not only yourself but also your family?

The National Cancer Center explains that while tests can provide useful information for health management, knowing the results can also increase anxiety. Genetic counseling is available not only for post-test explanations but also for those undecided about taking the test.

There is no need to rush into a binary choice of "should I know or not?" Organizing why you want to know is also part of effectively using the tests.

Genetic Information is Not Just Personal

Another aspect that cannot be overlooked is the handling of data.

Genetic information relates not only to the individual's constitution and disease possibilities but also connects to information about relatives. The Personal Information Protection Commission's guidance for the medical and caregiving fields indicates the need for careful handling based on this characteristic and psychological and social support for the individual and family.

When choosing a testing service, in addition to the clarity of results, it is also important to check the explanations regarding the storage of samples and data, research use, and provision to third parties.

The same applies when posting results on social media. Even if you intend to share your experience, the information you disclose may include aspects that should be considered in relation to your family.

Don't Make "At Risk" a Certainty for the Future

It is premature to conclude from this study that genetic testing is useless. Tests conducted with a defined purpose within healthcare have roles that lead to diagnosis and health management.

On the other hand, the ability to read genetic information in detail is different from accurately predicting a person's future.

It is easier to utilize the value of test results when they are treated as information to be considered alongside symptoms and family history, rather than viewing them as a future diagnosis.

The key is to move beyond the surprise of "I had risks too." How certain is that information, what does it mean, and how can it aid in the next decision? As genetic testing becomes more accessible, the challenge is not only the ability to investigate but also the ability to interpret the results.

Sources and References

1. Tagesspiegel:
   https://www.tagesspiegel.de/wissen/abweichungen-im-erbgut-sind-die-regel-gentests-konnten-bei-fast-jedem-ein-krankheitsrisiko-finden-16199426.html

2. Genome Medicine: Original Research Paper
   "The average individual genome: a survey of nearly 1 million whole-genome sequences." Check the score for 28 diseases, the meaning of the top 10%, and caution in applying to different groups. The "28×10%=2.8" in the text is an arithmetic supplement explaining this setting.
   https://link.springer.com/article/10.1186/s13073-026-01792-xSpringer Nature Link

3. University of Exeter: Research Announcement
   Overview of the research, typically observed genetic diversity, the point that participants' health status was not verified, and the need for interpretation including symptoms and family history.
   https://news.exeter.ac.uk/faculty-of-health-and-life-sciences/average-human-genome-described-for-first-time-with-implications-for-disease-risk/University of Exeter News

4. LinkedIn: Public Post by Muin J. Khoury
   Introduction of the study and social media reactions about the balance of clinical benefits, misdiagnosis, and overdiagnosis.
   https://www.linkedin.com/posts/muin-j-khoury-3340102a_the-average-individual-genome-a-survey-of-activity-7519068269689876480-bDYBLinkedIn

5. LinkedIn: Public Post and Comments by Ingo Froböse
   Differences between genetic risk and onset, and responses showing interest in lifestyle and environment. Distinguish between the poster's interpretation and the content verified in the study.
   https://de.linkedin.com/posts/ingo-frob%C3%B6se-4834b429_the-average-individual-genome-a-survey-of-activity-7520155998263848961-ndaAIngo Froböse

6. National Cancer Center: "Cancer" and "Genetics" Q&A
   Differences between DTC tests and genetic tests in medical institutions, psychological impact of tests, and the role of genetic counseling.
   https://www.ncc.go.jp/html/scrum-japan/gan_to_iden/index.htmlncc.go.jp

7. Personal Information Protection Commission: Guidance on Handling Personal Information in Medical and Caregiving Fields
   "Handling genetic information in medical practice." Explanation of the characteristics of information related to relatives and the need for psychological and social support.
   https://www.ppc.go.jp/personalinfo/legal/iryoukaigo_guidance/