Researchers looked at 21 studies to see if diet affects your chances of getting appendicitis, a painful condition where your appendix becomes infected. They found that people who eat less fiber and more meat and sugar might have a higher risk of appendicitis, while those eating more fiber might have lower risk. However, the evidence isn’t super strong yet because most studies weren’t perfectly designed. Scientists say we need better research to be sure about the connection between what we eat and appendicitis.

The Quick Take

  • What they studied: Whether eating certain foods (especially fiber, meat, and sugar) affects your risk of getting appendicitis, an infection of the appendix that sometimes needs surgery.
  • Who participated: The review combined results from 21 different studies that looked at thousands of people—some comparing people who had appendicitis to those who didn’t, and others looking at whole countries’ eating habits and appendicitis rates.
  • Key finding: People who eat less fiber appear to have a higher risk of appendicitis, and diets high in meat and sugar also seem to increase risk. However, the connection wasn’t statistically certain (p = 0.11), meaning we can’t be completely sure yet.
  • What it means for you: Eating more fiber-rich foods like vegetables, fruits, and whole grains may help protect against appendicitis, but this isn’t proven enough to be a guarantee. It’s still a good idea to eat these foods for many other health reasons anyway.

The Research Details

Researchers searched four major medical databases for all studies about diet and appendicitis published through December 2024. They followed strict guidelines (PRISMA) to make sure they did the search fairly and completely. They looked for two main types of studies: case-control studies (comparing people who had appendicitis to similar people who didn’t) and cohort studies (following groups of people over time to see who gets appendicitis). They also included ecological studies that looked at whole populations’ eating patterns and appendicitis rates by country or region.

The researchers carefully checked each study for quality problems using a special tool called ROBINS-E. They found that most studies had significant weaknesses—things like not measuring diet accurately, not controlling for other factors that affect appendicitis risk, or having small numbers of participants. Because the studies were so different from each other and had quality issues, the researchers couldn’t combine all the data mathematically. Instead, they combined results from four similar case-control studies in a meta-analysis and used a special statistical method called meta-regression for ecological studies.

For studies that didn’t fit into these categories, they summarized the findings by hand, looking for patterns across all the research. This mixed approach (combining some studies statistically and summarizing others by hand) is common when research on a topic is messy or inconsistent.

This research approach matters because appendicitis is a common condition that sometimes requires emergency surgery, so understanding what causes it could help prevent it. However, appendicitis is relatively rare, making it hard to study. By combining results from many smaller studies, researchers can get a better picture than any single study could provide. The systematic review approach also helps identify gaps in our knowledge and shows where we need better research.

The researchers were honest about major limitations: most studies were observational (just watching what people eat and what happens) rather than experiments where people are randomly assigned to eat different diets. Many studies measured diet poorly or didn’t account for other factors that might affect appendicitis risk, like genetics, infections, or physical activity. The studies also disagreed with each other quite a bit (high heterogeneity), suggesting they may have measured things differently or studied different populations. The fact that the main finding wasn’t statistically significant (p = 0.11) means there’s a real possibility the connection between fiber and appendicitis could be due to chance.

What the Results Show

When researchers combined four case-control studies that compared fiber intake in people with and without appendicitis, they found that people with appendicitis ate about 4.5 grams less fiber per day on average. However, this difference wasn’t statistically significant (p = 0.11), meaning it could have happened by chance. The studies disagreed with each other a lot (I² = 98.3%), suggesting they measured fiber intake very differently or studied very different groups of people.

When looking at ecological studies (which compared whole countries’ fiber intake to their appendicitis rates), there was a trend suggesting that countries where people eat more fiber have lower appendicitis rates. However, this type of study is weaker because it can’t prove that fiber itself prevents appendicitis—other differences between countries might explain the pattern.

When researchers looked at all the remaining studies together (not combining them mathematically, but reading through them), they found a consistent pattern: studies linked low-fiber diets, high-meat diets, and high-sugar diets to higher appendicitis risk. This consistency across different studies is encouraging, even though individual studies had quality problems.

Several studies found that eating a lot of processed foods and sugar was linked to higher appendicitis risk. Some research suggested that eating more vegetables and whole grains (good sources of fiber) was protective. A few studies looked at specific nutrients like vitamin C and antioxidants, with mixed results. The pattern across studies suggested that the typical Western diet—high in processed foods, meat, and sugar but low in fiber—appears to increase appendicitis risk, while more traditional diets with more plant foods appear protective.

The idea that low-fiber diets increase appendicitis risk isn’t new—doctors have suspected this for decades. This review is important because it’s the first to systematically gather all the evidence and try to measure how strong this connection really is. Previous reviews were less thorough or didn’t use modern systematic review methods. The findings generally support what doctors have long suspected, but the evidence is weaker than many people assumed, showing we need better studies.

The biggest limitation is that almost all studies were observational—they watched what people ate and what happened, but couldn’t prove diet caused appendicitis. People who eat more fiber might also exercise more, have different genetics, or have other healthy habits that actually prevent appendicitis. Many studies measured diet poorly, sometimes asking people to remember what they ate years ago, which is unreliable. Studies also didn’t always measure the same things the same way, making it hard to combine results. The main finding (lower fiber in appendicitis patients) wasn’t statistically significant, meaning it might not be real. Finally, most studies were from developed countries, so results might not apply everywhere in the world.

The Bottom Line

Based on this research, eating more fiber appears to be associated with lower appendicitis risk, but the evidence is moderate at best and not definitive. We can recommend eating more fiber-rich foods (vegetables, fruits, whole grains, beans) because they’re healthy for many other reasons and may help prevent appendicitis. Reducing processed foods, excess meat, and added sugar is also reasonable based on this evidence, though again, it’s not proven. However, don’t expect fiber to guarantee you won’t get appendicitis—many other factors are involved. If you have appendicitis symptoms (severe belly pain, nausea, fever), seek medical care immediately regardless of your diet.

Everyone might benefit from eating more fiber for general health reasons, and this research suggests it might also help prevent appendicitis. People with family histories of appendicitis might be especially interested in this research. However, appendicitis isn’t entirely preventable through diet—some people get it despite eating well, and some people eating poorly never get it. If you’ve already had appendicitis, this research doesn’t apply to you since you can’t get it again after surgery. People with digestive conditions that limit fiber intake should talk to their doctor before making major diet changes.

If you change your diet to eat more fiber, you won’t see immediate effects on appendicitis risk. Appendicitis is relatively rare, so you’d need to follow a high-fiber diet for years to see if it actually prevents appendicitis. However, you’ll likely notice other benefits from eating more fiber within weeks—better digestion, more stable energy, and improved overall health.

Want to Apply This Research?

  • Track daily fiber intake (target 25-30 grams per day) by logging servings of vegetables, fruits, whole grains, and legumes. Note any digestive changes and overall wellness scores weekly.
  • Set a goal to add one high-fiber food to each meal: add berries to breakfast, include a vegetable with lunch, and eat beans or lentils with dinner. Use the app to find easy high-fiber recipes and get reminders to eat these foods.
  • Monitor fiber intake weekly and track it alongside general health metrics. Create a 12-week challenge to gradually increase fiber intake while noting any changes in digestion, energy levels, or overall wellness. Review monthly trends to ensure you’re maintaining a fiber-rich diet.

This research suggests a possible connection between diet and appendicitis risk, but the evidence is not conclusive. Eating more fiber may help reduce appendicitis risk, but it cannot guarantee prevention. Appendicitis is a medical emergency requiring immediate professional care—if you experience severe abdominal pain, fever, nausea, or vomiting, seek emergency medical attention immediately. Do not attempt to treat appendicitis with diet changes. Always consult with your healthcare provider before making significant dietary changes, especially if you have existing digestive conditions or take medications. This information is for educational purposes and should not replace professional medical advice.