Multiple sclerosis appears to result from a combination of genetic susceptibility and environmental exposures, according to a 2026 review in Autoimmunity Reviews. Gram Research analysis highlights Epstein-Barr virus infection, low vitamin D, obesity, smoking, heavy metal exposure, and gut microbiome changes as key environmental factors under study.
According to research reviewed by Gram, multiple sclerosis (MS) appears to develop when inherited genetic traits meet everyday environmental triggers. MS is a long-term condition in which the immune system attacks the protective coating around nerves in the brain and spinal cord. This 2026 review in the journal Autoimmunity Reviews pulled together a wide range of genetic and environmental studies. The authors point to viral infection, especially Epstein-Barr virus, along with low vitamin D, obesity, smoking, heavy metal exposure, and gut bacteria as factors that may contribute to risk. Children who develop MS have been studied far less than adults, even though their disease shows important differences. The review also calls for more diverse study groups and lab testing of genetic risk signals. Because this is a review of existing studies rather than a new experiment, it explains likely causes but cannot show exactly how much each factor contributes.
Key Statistics
A 2026 review published in Autoimmunity Reviews found that multiple sclerosis results from both genetic susceptibility and environmental exposures, with Epstein-Barr virus, low vitamin D, obesity, smoking, heavy metal exposure, and the gut microbiome among the factors examined.
The same 2026 review noted that children with pediatric-onset multiple sclerosis are underrepresented in cause-finding studies, even though they show distinct clinical and immunological features compared with adults.
The Quick Take
- What they studied: What causes multiple sclerosis, and how do inherited genes and everyday environmental exposures work together to raise the risk of developing it?
- Who participated: This was a review of previously published research rather than a study with new participants, so no single group of people was enrolled. The reviewed work covered adults and children, though children with MS have been studied much less.
- Key finding: The review found that MS likely results from a mix of genetic susceptibility and environmental exposures. Epstein-Barr virus, low vitamin D, obesity, smoking, heavy metal exposure, and gut microbiome changes were all examined as possible contributors. The review did not calculate a single overall percentage for any factor.
- What it means for you: No single habit has been proven to prevent MS. Still, avoiding smoking, maintaining a healthy weight, and keeping vitamin D levels adequate are general health steps that may support overall immune and nerve health. If you have symptoms or concerns, talk with a doctor.
The Research Details
This article is a review, which means its authors gathered and summarized findings from many earlier studies instead of running a new experiment. They combined older foundational research with newer findings to build a single framework for understanding why MS develops.
The review focused on two main areas. The first was genetics. The authors compiled a large list of gene variants linked to MS risk, identified through genome-wide association studies. These large studies scan the entire genetic code of many people to find small differences that appear more often in people with a disease. The review also discussed functional genomics, which examines how these gene differences affect the way genes switch on and off in the body.
The second area was the environment. The authors reviewed evidence on infections, vitamin D levels, body weight, smoking, metal exposure, and gut bacteria. Much of this evidence comes from epidemiologic studies, which track patterns in populations over time. Such studies can reveal links between a factor and a disease, but they cannot by themselves prove that the factor causes the disease.
A review like this is useful because it brings scattered findings together. A single study may look at only one gene or one exposure, but a review can show how several pieces fit together. This helps researchers and clinicians see the bigger picture and spot gaps that need more work.
The review also highlights where knowledge is thin. By naming areas with limited understanding, such as how gene and environment interact and how children’s MS differs from adults’, it points future research toward the questions that matter most.
The paper was published in Autoimmunity Reviews, a peer-reviewed journal that focuses on immune system diseases, which means independent experts reviewed the work before publication. The authors describe their approach as synthesizing classic and emerging literature, which signals a broad overview rather than a formal statistical pooling of results.
Readers should understand that reviews depend on the quality of the studies they summarize. The abstract does not report a sample size or a combined statistic, so the strength of each conclusion depends on the underlying research. The authors themselves note that some environmental links are based on associations whose mechanisms are not fully understood.
What the Results Show
The review’s central message is that MS does not come from a single cause. Instead, the authors describe it as shaped by both genetic susceptibility and environmental exposures. Genetic susceptibility means that some people carry gene variants that make their immune systems more likely to react against the nervous system. Those variants alone do not appear to be enough to cause the disease in most people.
On the environmental side, the review examined several factors. Epstein-Barr virus, a common virus that most people catch at some point, stood out as one of the infections most consistently linked to MS. Low vitamin D, obesity, smoking, and exposure to heavy metals were also associated with higher risk in the studies reviewed. The authors noted that some of these links are strong in patterns across populations, while the biological reasons behind them are still being worked out.
The gut microbiome, the community of bacteria living in the digestive system, was also discussed as a possible contributor. The authors described this area as promising but still limited in mechanistic understanding. In other words, scientists have seen connections, but they do not yet fully know how these factors act on the immune system.
The review also emphasized that pediatric-onset MS, which begins in childhood, has distinct features and has been underrepresented in cause-finding research. The authors compared genetic burden, environmental exposures, and immune activity between children and adults, identifying factors that appear shared across ages as well as some that seem specific to one age group.
The authors call for better representation of different ancestries and age groups in future research. Many genetic studies have focused on people of European ancestry, so risk patterns found in these groups may not apply equally to everyone. Improving diversity would help determine which findings hold true across populations.
The review also recommends functional validation of risk loci, meaning lab experiments that test whether specific gene regions actually change how immune cells behave. Finally, it suggests studying treatment-naive patient samples, which are taken from people who have not yet started MS medications. This approach can show what drives the disease before treatment alters the body’s chemistry.
The review builds on decades of MS research that has repeatedly identified Epstein-Barr virus, vitamin D status, smoking, and genetic variants in immune genes as factors linked to the disease. By placing these findings side by side, the authors reinforce the idea that MS arises from interacting influences rather than one trigger.
At the same time, the review points out that pediatric MS has received less attention than adult MS, so some earlier conclusions drawn mostly from adult populations may need testing in younger people. This is an area where the review adds an important call for change rather than a settled answer.
This is a review, not a new experiment, so it cannot prove cause and effect. It reports associations found in earlier studies, and those studies vary in design, size, and quality. The abstract does not provide a sample size or combined numerical results, so readers cannot judge how large each effect is from this summary alone.
The review also acknowledges gaps in its own evidence base. Many genetic findings come from people of European ancestry, and children with MS are underrepresented in the research. Some environmental links, such as those involving the gut microbiome and metal exposure, are still poorly understood at the biological level. Results from these areas should be considered preliminary.
The Bottom Line
Confidence that MS has multiple contributing causes, both genetic and environmental, is high because this view is consistent across many studies. Confidence that specific habits prevent MS is low, since the evidence is mostly observational. General health guidance, such as not smoking, keeping a healthy weight, and discussing vitamin D levels with a doctor, is sensible for overall health with moderate confidence in its relevance to MS risk. Any changes to supplements or treatments should be made with a healthcare professional.
This research is most relevant to people with a family history of MS, to parents and caregivers of children, to clinicians who treat neurological conditions, and to researchers studying autoimmune disease. People without risk factors can read it for general awareness. Those who already have MS should discuss any changes in care with their own medical team rather than applying these findings directly.
Findings like these guide research rather than produce quick personal results. Scientists will likely need years of new studies, including lab testing and studies of more diverse populations, before prevention strategies are clearly established. Anyone making lifestyle changes for general health should expect benefits to build gradually over months and years, and should not expect a direct, short-term effect on MS risk.
Frequently Asked Questions
What causes multiple sclerosis?
Multiple sclerosis is not caused by a single factor. A 2026 review in Autoimmunity Reviews suggests it develops when inherited genetic susceptibility combines with environmental exposures such as Epstein-Barr virus infection, low vitamin D, obesity, smoking, heavy metal exposure, and gut microbiome changes. How these factors interact is still not fully understood.
Does low vitamin D increase the risk of multiple sclerosis?
Low vitamin D is one of several environmental factors linked to multiple sclerosis in population studies. A 2026 review notes these links are observational, meaning they show an association rather than proof that vitamin D prevents the disease. Anyone concerned about their vitamin D level should ask a doctor for a blood test.
Is multiple sclerosis different in children?
Pediatric-onset multiple sclerosis differs from adult-onset disease in clinical features and immune activity, according to a 2026 review. Children with MS have been underrepresented in cause-finding research, so many questions about their specific risk factors remain unanswered.
Can Epstein-Barr virus cause multiple sclerosis?
Epstein-Barr virus is among the infections most consistently linked to multiple sclerosis in studies summarized by a 2026 Autoimmunity Reviews paper. The review notes the biological mechanism is not fully understood, and infection alone does not explain why only some people with the virus develop the disease.
Want to Apply This Research?
- Log daily minutes of outdoor sun exposure, weekly smoking days, and body weight once per week. Track vitamin D supplement doses if a doctor has recommended them. These measurable entries give a clear picture of modifiable habits linked to general immune and nerve health.
- Set one achievable goal, such as a smoke-free week or a daily walk, and check progress in the app each day. Use reminders to take prescribed vitamin D supplements or to schedule a blood test to check vitamin D levels with a doctor.
- Review trends monthly rather than daily. Over six to twelve months, compare weight, sun exposure, supplement adherence, and smoking status. Share the summary with a healthcare provider at routine visits. If any new neurological symptoms appear, such as vision changes, numbness, weakness, or balance problems, seek medical care promptly instead of relying on app tracking.
This article summarizes a review of existing research and is for general education only. It is not medical advice and does not diagnose, treat, or prevent any condition. Multiple sclerosis is a serious neurological disease. Anyone with symptoms such as vision changes, numbness, weakness, or balance problems should see a doctor promptly. Do not start, stop, or change medications, supplements, or treatment based on this article without consulting a qualified healthcare professional.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.