Researchers used a special genetic analysis method to study whether diet, sleep, weight, and exercise actually cause multiple sclerosis (MS) or just happen alongside it. They looked at genetic data from thousands of people and found that four factors appear to truly influence MS risk: being overweight, eating more pork, having type 2 diabetes, and not exercising enough all seem to increase MS risk, while moderate-to-vigorous exercise appears to lower it. This genetic approach is stronger than regular studies because it helps prove cause-and-effect rather than just showing that things happen together.

The Quick Take

  • What they studied: Whether lifestyle factors like diet, exercise, sleep, and body weight actually cause multiple sclerosis or just appear connected to it
  • Who participated: The study analyzed genetic information from large groups of people (exact numbers not specified in the paper), using existing genetic databases rather than recruiting individual participants
  • Key finding: Four factors showed a real cause-and-effect link with MS risk: being overweight and having type 2 diabetes increased risk, while exercising regularly and taking fish/liver oil supplements decreased risk. Eating more pork appeared to increase risk.
  • What it means for you: If you’re concerned about MS risk, maintaining a healthy weight, staying physically active, managing blood sugar, and possibly taking fish oil supplements may help. However, this research shows associations in genetic data—it doesn’t mean these factors guarantee you will or won’t develop MS. Talk to your doctor about your personal risk factors.

The Research Details

This study used a method called Mendelian randomization, which is like using your genes as a natural experiment. Instead of following people over time and watching what happens, researchers looked at genetic variations that naturally occur in humans and used them to figure out cause-and-effect relationships. They examined 29 different traits related to sleep, diet, metabolism, and exercise by analyzing genetic data from large databases. The researchers first looked at each factor individually, then studied them all together to see which effects held up when other factors were considered.

The main analytical approach was called the inverse-variance weighted method, which is a statistical technique that combines information from many genetic markers to estimate whether a factor truly causes a disease. This is stronger than regular observational studies because genes are randomly inherited and don’t change based on lifestyle choices, making it harder for other factors to confuse the results.

Regular studies that just observe people can’t easily prove cause-and-effect because many things happen together in life. For example, people who exercise might also eat better, sleep more, and have lower stress—so it’s hard to know which factor actually matters. Mendelian randomization uses genetics to create a more natural experiment, helping researchers separate true causes from coincidences. This approach is particularly valuable for MS research because the disease is complex and develops over many years, making traditional long-term studies difficult and expensive.

This study’s strength comes from using genetic data, which provides objective information that can’t be influenced by memory or reporting bias. However, the paper doesn’t specify the exact sample sizes used, which makes it harder to evaluate the statistical power. The fact that findings held up in multivariable analysis (when multiple factors were considered together) suggests the results are more robust. The study was published in a peer-reviewed journal, indicating it passed expert review. One limitation is that genetic studies work best for populations of European ancestry, so results may not apply equally to all ethnic groups.

What the Results Show

When researchers looked at each factor individually, they found eight factors associated with MS risk. However, when they adjusted for other factors that might be confusing the picture, only four associations remained strong and reliable: moderate-to-vigorous physical activity showed the strongest protective effect (reducing MS risk by about 72%), while higher BMI, type 2 diabetes, and greater pork intake all increased MS risk.

The physical activity finding was particularly striking—people with genetic predisposition toward more moderate-to-vigorous exercise had significantly lower MS risk. This suggests that exercise itself, not just being generally healthy, may protect against MS. The BMI finding showed that each unit increase in body mass index was associated with a 35% increase in MS risk, suggesting that weight management may be important for MS prevention.

Pork intake showed an unexpected strong association, with higher consumption linked to increased MS risk. This finding was surprising and may relate to specific components in pork or dietary patterns associated with pork consumption. Type 2 diabetes also showed a clear link, with people genetically predisposed to diabetes having about 12% higher MS risk.

Several factors that initially appeared important became less significant when other factors were considered. Fish and liver oil supplements initially showed strong protective effects but lost statistical significance in the full analysis, suggesting their apparent benefit might have been due to confounding with other healthy behaviors. Similarly, sleep duration and chronotype (whether you’re naturally a morning or evening person) showed initial associations but didn’t hold up in the adjusted analysis. This suggests these sleep factors may be markers of other underlying conditions rather than direct causes of MS.

Previous observational studies had suggested that sleep disorders, diet, and physical inactivity were all linked to MS risk, but couldn’t prove these were actual causes. This genetic study provides stronger evidence for some of these connections while questioning others. The finding that exercise protects against MS aligns with general MS research and clinical recommendations. The BMI and type 2 diabetes findings fit with the growing understanding that metabolic health influences autoimmune disease risk. However, the strong pork intake association is novel and somewhat unexpected, suggesting this may be an area needing further investigation.

The study has several important limitations. First, the exact sample sizes aren’t specified, making it difficult to assess statistical power. Second, Mendelian randomization assumes that genetic variants only affect MS through the studied factors, which may not always be true. Third, the study primarily reflects genetic patterns in people of European ancestry, so findings may not apply equally to other populations. Fourth, the genetic associations found in this study are relatively small in magnitude, meaning they explain only a portion of MS risk. Finally, this is observational genetic research—it suggests cause-and-effect but doesn’t prove it definitively. Individual genetic variations are just one piece of MS risk; environmental factors and gene-environment interactions also play important roles.

The Bottom Line

Based on this research, maintaining a healthy weight, engaging in regular moderate-to-vigorous exercise, managing blood sugar levels, and considering fish/liver oil supplements may help reduce MS risk (moderate confidence level). Limiting pork consumption may be worth considering, though the evidence is less clear about why this association exists (lower confidence level). These recommendations should complement, not replace, guidance from your healthcare provider, especially if you have a family history of MS or other risk factors.

This research is most relevant for people with a family history of MS, those concerned about autoimmune disease risk, and individuals interested in preventive health strategies. It’s particularly important for people who are overweight or have type 2 diabetes, as these factors showed the strongest associations. However, these findings don’t mean people without these risk factors are safe from MS, nor do they mean that having these factors guarantees MS will develop. MS is a complex disease with many contributing factors.

Changes in physical activity and weight management typically show health benefits within weeks to months, but MS is a slowly developing disease. It may take years or decades to see whether these lifestyle changes actually prevent MS. Don’t expect immediate results, but think of these changes as long-term investments in your overall health and potentially your MS risk reduction.

Want to Apply This Research?

  • Track weekly moderate-to-vigorous physical activity minutes (aim for 150+ minutes per week) and monitor body mass index monthly through weight tracking. Users could log specific exercise types and intensity levels to correlate with their health markers over time.
  • Set a goal to gradually increase moderate-to-vigorous exercise to 150 minutes per week through activities like brisk walking, cycling, or swimming. Users could use the app to schedule exercise sessions, track completion, and receive reminders. Additionally, implement a simple food diary focusing on pork consumption frequency and fish/omega-3 intake to increase awareness of dietary patterns.
  • Establish a quarterly review of exercise consistency, weight trends, and dietary patterns. Users could set alerts for weight changes exceeding 5 pounds and track exercise streaks to maintain motivation. For those with type 2 diabetes risk, integrate blood sugar monitoring data if available through connected health devices.

This research suggests associations between certain factors and MS risk based on genetic analysis, but does not prove these factors will cause or prevent MS in any individual. Multiple sclerosis is a complex disease influenced by genetics, environment, and other factors not fully understood. This information is for educational purposes only and should not replace professional medical advice. If you have concerns about MS risk, a family history of MS, or are experiencing symptoms, consult with a healthcare provider or neurologist. Genetic predisposition does not determine disease outcome, and many people with risk factors never develop MS. Always discuss lifestyle changes and supplements with your doctor before starting, especially if you have existing health conditions or take medications.