A gene called APOE ε4 that raises cholesterol and heart disease risk in modern cities may have actually helped your ancestors survive, according to Gram Research analysis of a 2026 study in PLoS Genetics. Researchers found the gene’s harmful effects on cholesterol are consistent everywhere, but its impact on the immune system changes depending on whether you live a traditional or modern lifestyle, suggesting your environment matters as much as your genes.
Scientists discovered something surprising about a gene called APOE ε4 that affects cholesterol and heart health. This gene is bad for you in modern cities with lots of food and cars, but it may have actually helped your ancestors survive. Researchers studied Indigenous groups in Kenya and Malaysia who live different lifestyles—some traditional, some modern—to understand how the same gene can be helpful or harmful depending on where you live. The findings show that our genes aren’t simply good or bad; they work differently depending on our environment.
Key Statistics
A 2026 study published in PLoS Genetics comparing Indigenous populations in Kenya and Malaysia found that people with more APOE ε4 gene copies consistently showed higher LDL cholesterol and lower HDL cholesterol across both traditional and modern lifestyles.
According to research reviewed by Gram, the APOE ε4 gene’s effects on immune system markers varied by lifestyle in the Malaysian population but not the Kenyan population, demonstrating that local environmental factors determine how genes affect health.
A 2026 analysis of two Indigenous groups found that APOE ε4 carriers showed a slightly extended reproductive lifespan, but this effect was weak and did not result in higher overall reproductive output.
The Quick Take
- What they studied: How a gene called APOE ε4 affects cholesterol, immune system, and reproduction in people living traditional versus modern lifestyles
- Who participated: Indigenous people from Kenya (Turkana) and Malaysia (Orang Asli) who live on a spectrum from traditional village life to modern urban life
- Key finding: The APOE ε4 gene raises cholesterol and LDL (bad cholesterol) in all environments, but its effects on the immune system depend on whether you live a traditional or modern lifestyle
- What it means for you: If you carry this gene, your health risks may depend more on your lifestyle than the gene itself. Living traditionally or adopting traditional habits (more activity, less processed food) might reduce the gene’s negative effects
The Research Details
Researchers studied two Indigenous groups in Africa and Southeast Asia where some people still live traditionally while others have moved to cities. They compared people with different versions of the APOE gene and measured their cholesterol, immune markers, and reproductive health. By looking at the same gene in both traditional and modern environments, they could see how lifestyle changes the gene’s effects.
This approach is powerful because it lets scientists see how genes and environment interact in real people, not just in laboratories. The researchers measured cholesterol levels, immune system markers, and tracked reproductive history across all participants. They then compared results between people living traditionally versus those in urban areas.
Most genetic studies happen in wealthy, modern countries where everyone eats processed food and drives cars. This study is important because it shows what happens when the same gene exists in completely different environments. Understanding this helps explain why a gene that seems harmful today might have survived in human populations for thousands of years—it was actually useful in ancestral environments.
This study has real-world strength because researchers studied actual people living in their natural environments rather than laboratory conditions. The study included two different populations, which helps confirm findings aren’t just specific to one group. However, the exact sample size wasn’t specified in the abstract, and the researchers note that effects weren’t always consistent between the two populations, suggesting environmental factors beyond just ’traditional versus modern’ matter.
What the Results Show
The research confirmed what scientists already knew: people with more copies of the APOE ε4 gene have higher total cholesterol and LDL (bad) cholesterol, and lower HDL (good) cholesterol. This was true whether people lived traditionally or in cities.
However, the study found something new about the immune system. In the Malaysian group (Orang Asli), the gene’s effects on immune markers changed depending on lifestyle—traditional living seemed to reduce the gene’s negative immune effects. Interestingly, this lifestyle-dependent effect didn’t show up in the Kenyan group (Turkana), suggesting that different environments have different effects.
The researchers also looked at reproduction and found that people with more APOE ε4 copies had slightly longer reproductive lifespans (could have children over a longer age range). However, this effect was weak and didn’t lead to more children overall, so it’s not clear how important this is.
The study revealed that APOE ε4 isn’t universally beneficial in traditional environments, contradicting the simple idea that ‘ancestral genes must be good in ancestral environments.’ Instead, the specific benefits and costs of this gene depend on local conditions that vary between populations. This suggests that evolution is more complicated than a simple ‘good gene’ versus ‘bad gene’ story.
Previous research suggested that high physical activity, low-fat diets, and high pathogen exposure could reduce APOE ε4’s harmful effects. This study builds on those ideas by directly testing whether lifestyle actually changes how the gene works. The findings partially support previous theories but show the picture is more complex—lifestyle matters for immune effects in one population but not the other.
The study doesn’t specify exact sample sizes, making it hard to judge statistical strength. The effects weren’t consistent across both populations studied, which suggests that ’traditional versus modern’ is too simple a way to categorize environments. The reproductive findings were weak and inconsistent, so conclusions about reproduction should be considered preliminary. The study also can’t prove cause-and-effect; it shows associations between genes and traits, not mechanisms.
The Bottom Line
If you carry the APOE ε4 gene (which you can learn through genetic testing), focus on lifestyle factors that appear to reduce its negative effects: regular physical activity, a diet lower in saturated fat, and maintaining a healthy weight. These recommendations have moderate confidence because they’re supported by this research and previous studies. However, this gene is just one of many factors affecting heart health, so don’t assume you’re doomed if you carry it.
People with family history of heart disease or dementia who want to understand their genetic risk should pay attention to this research. People of African or Southeast Asian ancestry may find this particularly relevant since APOE ε4 is more common in these populations. However, these findings don’t change medical care for most people—standard heart-healthy advice (exercise, good diet) still applies to everyone.
If you change your lifestyle based on these findings, you might see improvements in cholesterol levels within 3-6 months. However, long-term benefits for heart and brain health would take years to measure. Don’t expect dramatic changes; this gene is just one piece of your health puzzle.
Frequently Asked Questions
Does the APOE ε4 gene mean I’ll definitely get heart disease?
No. Having this gene increases risk but doesn’t guarantee disease. Your lifestyle—exercise, diet, and stress—significantly influences whether the gene causes problems. Many people with APOE ε4 stay healthy through good habits.
Can I reduce the harmful effects of APOE ε4 through lifestyle changes?
Research suggests yes. Regular physical activity, a diet lower in saturated fat, and maintaining healthy weight appear to reduce this gene’s negative effects on cholesterol and immune function, though results vary between individuals.
Why did this harmful gene survive in human evolution if it causes heart disease?
In ancestral environments with high physical activity, low processed food, and different disease patterns, APOE ε4 may have provided benefits that outweighed costs. Modern environments changed these conditions, making the gene’s downsides more apparent.
Should I get genetic testing to see if I have APOE ε4?
Genetic testing can be helpful if you have family history of heart disease or dementia, but discuss it with your doctor first. The test results should guide lifestyle improvements, not replace standard heart-healthy recommendations everyone should follow.
Does this research apply to all populations or just Indigenous groups?
The study focused on two Indigenous populations, so results may not apply equally to everyone. However, the basic principle—that genes and environment interact—applies universally. Your specific response may differ based on ancestry and local conditions.
Want to Apply This Research?
- Track weekly physical activity minutes and daily saturated fat intake if you know you carry APOE ε4. Aim for 150+ minutes of activity weekly and monitor cholesterol levels every 6 months through your doctor.
- Set a goal to increase physical activity to 30 minutes most days and reduce processed foods high in saturated fat. Log these activities in the app to see patterns between your lifestyle choices and how you feel.
- Use the app to track cholesterol-related habits (exercise, diet quality) monthly and correlate with periodic blood work results from your doctor. This personal data helps you see whether lifestyle changes are working for your specific genetics.
This research describes associations between a gene and health outcomes in specific populations; it does not establish cause-and-effect relationships or provide medical diagnosis. If you have concerns about heart disease risk, high cholesterol, or genetic predisposition to disease, consult with a healthcare provider or genetic counselor. Genetic testing should only be done under medical supervision. This article is for educational purposes and should not replace professional medical advice, diagnosis, or treatment.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.
