Researchers looked at hundreds of studies about how lifestyle choices like diet, exercise, and sun exposure affect cancer risk. They wanted to see if the advice should be different for men versus women. While they found 361 studies that compared men and women, most didn’t find major differences between them. However, the researchers discovered that most of these studies had quality problems, and none of them included transgender or non-binary people. This means we need better research to truly understand if cancer prevention tips should vary by sex or gender.

The Quick Take

  • What they studied: Whether lifestyle factors like diet, exercise, weight, alcohol use, smoking, and sun exposure affect cancer risk differently in men versus women
  • Who participated: This was a review of 705 previous scientific studies that had looked at these questions. The original studies involved hundreds of thousands of people, but this review focused on the 361 studies that actually compared results between men and women
  • Key finding: Most studies (about 98%) that compared men and women found no major differences in how lifestyle factors affected cancer risk between the sexes. However, the researchers found that these studies had serious quality problems that make the results unreliable
  • What it means for you: Current cancer prevention advice (eat healthy, exercise, don’t smoke, limit alcohol, protect skin from sun) appears to apply similarly to both men and women. However, we need better research to be confident about this. The findings don’t apply to transgender or non-binary individuals, as no studies examined these groups

The Research Details

This was an “umbrella review,” which means researchers looked at many previous systematic reviews (which themselves looked at many studies) to find patterns. They searched three major medical databases for reviews published up to May 2023 that examined how 10 different lifestyle factors—including weight, exercise, diet quality, processed foods, alcohol, tobacco, and sun exposure—related to cancer risk. They specifically looked for reviews that compared results between men and women.

The researchers then counted how many of these 705 reviews actually provided separate results for men versus women. They also checked the quality of these reviews using a standard checklist called AMSTAR-2, which looks at things like whether the studies were properly selected, whether conflicts of interest were disclosed, and whether the conclusions matched the evidence presented.

This approach is important because it gives us a bird’s-eye view of what we know (and don’t know) about sex and gender differences in cancer risk. Rather than looking at individual studies, which can be small or have problems, this method helps identify patterns across many studies. It also reveals gaps in the research—like the fact that almost no studies included transgender or non-binary people.

The researchers found that 98.6% of the reviews they examined were rated as “critically low” quality by the AMSTAR-2 tool. This is a major red flag. It means these reviews had significant problems in how they were conducted—such as not clearly describing their methods, not checking for bias, or not being transparent about conflicts of interest. Additionally, 36% of the reviews used the terms “sex” and “gender” interchangeably, which is scientifically imprecise since these terms have different meanings. These quality issues mean we should be cautious about trusting the conclusions.

What the Results Show

Out of 705 systematic reviews that met the study criteria, only 361 (about half) actually provided separate results comparing men and women. This alone is concerning because it means researchers often don’t bother to check if findings differ by sex.

Among the 361 reviews that did compare men and women, the vast majority found no statistically significant differences. In other words, lifestyle factors like diet, exercise, and smoking appeared to affect cancer risk similarly in both groups. However, the researchers emphasize that this finding must be interpreted carefully because of the poor quality of the underlying studies.

The reviews examined 10 different lifestyle factors: body weight, physical activity, whole grains, vegetables, fruits, beans, fast foods, red and processed meat, sugar-sweetened drinks, dietary supplements, alcohol, tobacco, and sun exposure. None of these showed consistent sex-specific patterns across the reviews.

A critical finding was that the terminology used in these reviews was often sloppy. About 36% of the reviews used “sex” and “gender” as if they meant the same thing, when they actually refer to different concepts (sex is biological, gender is social/cultural). More importantly, not a single one of the 361 reviews that compared groups provided separate data for transgender, gender-diverse, or non-binary individuals. This is a major gap because these populations may have different cancer risks or prevention needs.

This review is one of the first to systematically examine whether sex and gender differences are being studied in cancer prevention research. Previous individual studies have sometimes suggested differences between men and women for specific cancers, but this comprehensive look suggests those differences may not be as clear or consistent as once thought. The finding that most reviews show no significant differences aligns with some recent research suggesting that many lifestyle recommendations can apply broadly, though more rigorous studies are needed.

The biggest limitation is that the reviews themselves were of poor quality, which means the “no difference” finding may not be reliable. It’s possible that real differences exist but weren’t detected because the original studies weren’t well-designed. Additionally, the review only looked at non-sex-specific cancers (cancers that affect both men and women), so it doesn’t address cancers like prostate or breast cancer that are specific to one sex. Finally, the complete absence of research on transgender and non-binary individuals means we have no evidence base for these groups at all.

The Bottom Line

Based on current evidence (with low confidence due to study quality issues): General cancer prevention advice appears to apply similarly to men and women. This includes maintaining a healthy weight, exercising regularly, eating plenty of vegetables and whole grains, limiting processed meat and alcohol, not smoking, and protecting skin from sun damage. However, these recommendations should not be assumed to apply to transgender or non-binary individuals without specific research.

Everyone interested in cancer prevention should care about this research, particularly because it highlights a gap in our knowledge. Healthcare providers should be aware that current evidence doesn’t specifically address transgender and non-binary populations. Researchers should prioritize conducting higher-quality studies that examine sex and gender differences more carefully and include diverse gender identities.

Lifestyle changes typically take months to years to show health benefits. You might notice improvements in energy and fitness within weeks, but measurable changes in cancer risk would take years to develop. This is a long-term commitment rather than a quick fix.

Want to Apply This Research?

  • Track weekly physical activity minutes (goal: 150 minutes), daily servings of vegetables and fruits (goal: 5+), and weekly alcohol servings. Monitor these consistently to see if you’re meeting general cancer prevention guidelines, regardless of sex.
  • Use the app to set reminders for daily movement (30 minutes), log meals to ensure adequate plant-based foods, and track alcohol consumption. Create a personalized cancer prevention plan based on these 10 lifestyle factors without assuming different goals are needed based on sex alone.
  • Review monthly trends in physical activity, diet quality, and other tracked factors. Compare your progress against general health guidelines rather than sex-specific targets (since current evidence doesn’t support different targets). Share data with healthcare providers to discuss individual risk factors.

This review examines existing research quality and does not provide personalized medical advice. Cancer risk is complex and involves genetics, environment, and lifestyle factors. These findings apply to general cancer prevention and should not replace individualized medical guidance from your healthcare provider. If you have a personal or family history of cancer, discuss screening and prevention strategies specific to your situation with a doctor. This research does not address sex-specific cancers (breast, prostate, ovarian, etc.) and provides no evidence for transgender or non-binary individuals, who should discuss cancer prevention with their healthcare team.