Researchers studied over 4,000 American women to see if eating foods rich in antioxidants—like fruits, vegetables, nuts, and certain minerals—could help prevent pelvic inflammatory disease (PID), a serious infection that can cause infertility and chronic pain. Women who ate more antioxidant-rich foods had about 5% lower chances of developing PID. However, when scientists used genetic analysis to test whether antioxidants directly cause this protection, the results were unclear. The study suggests a connection exists, but more research is needed to prove antioxidants truly prevent the condition.

The Quick Take

  • What they studied: Whether eating foods and nutrients with antioxidants (like vitamins A, C, E, zinc, and selenium) could reduce the chances of getting pelvic inflammatory disease, a serious infection in women’s reproductive organs.
  • Who participated: 4,003 American women aged 20 and older who participated in a national health survey between 2013 and 2018. The group included women of different ages, races, and backgrounds.
  • Key finding: Women who ate more antioxidant-rich foods had about 5% lower odds of having pelvic inflammatory disease. Specifically, eating more zinc was linked to lower disease risk. This pattern was consistent across different groups of women.
  • What it means for you: Eating more antioxidant-rich foods like colorful fruits, vegetables, nuts, and whole grains may help protect against pelvic infections. However, this doesn’t prove antioxidants directly prevent the disease—it just shows a connection. Talk to your doctor before making major dietary changes, especially if you have concerns about pelvic health.

The Research Details

This study looked at information from women who participated in the National Health and Nutrition Examination Survey, a large government health study. Researchers asked women about their diets and whether they had ever been diagnosed with pelvic inflammatory disease. They then calculated an antioxidant score based on how much of six different antioxidant nutrients each woman ate (vitamins A, C, and E, plus zinc, selenium, and another compound). The researchers used statistical methods to see if women with higher antioxidant scores were less likely to have PID, while accounting for other factors like age, smoking, and other health conditions that might affect the results. To go deeper, they also used a genetic method called Mendelian randomisation, which uses inherited genes to test whether antioxidants might directly cause lower disease risk, similar to how a natural experiment would work.

This research approach is important because it combines two different types of evidence. The first part (observational data) shows whether a real-world connection exists between antioxidants and pelvic disease in actual women. The second part (genetic analysis) helps determine whether that connection is truly causal—meaning antioxidants actually prevent the disease—or whether it’s just a coincidence. This two-step approach gives scientists more confidence in their conclusions.

The study used a large, nationally representative sample of American women, which makes the findings more likely to apply to the general population. The researchers carefully controlled for many other factors that could influence results. However, the study relied on women’s memories of whether they had PID, which may not be completely accurate. The genetic analysis didn’t find clear proof of causation, which suggests the connection may be more complicated than it first appears. More research is needed to confirm these findings.

What the Results Show

Among the 4,003 women studied, 224 (about 5.6%) reported having been diagnosed with pelvic inflammatory disease at some point. Women who ate more antioxidant-rich foods had lower odds of having PID—specifically, for each increase in the antioxidant score, the chances of having PID dropped by about 5%. This protective association held true whether researchers looked at all women together or examined specific groups separately (different ages, races, and other characteristics). The pattern was consistent and statistically significant, meaning it’s unlikely to be due to chance alone. Among the individual antioxidants studied, zinc showed the strongest protective effect, with higher zinc intake linked to about 4% lower odds of PID.

The protective association between antioxidants and lower PID risk remained consistent across all subgroups examined, including women of different ages, races, and socioeconomic backgrounds. This consistency suggests the finding is robust and not limited to just one type of woman. However, when researchers used genetic analysis to test whether antioxidants directly cause lower PID risk, they did not find a clear causal relationship. This suggests that while women who eat more antioxidants tend to have lower PID rates, antioxidants may not be the direct cause of this protection.

This study adds to growing evidence that diet plays a role in women’s reproductive health. Previous research has shown that antioxidants help reduce inflammation and support immune function, both of which could theoretically protect against infections like PID. However, few studies have directly examined the connection between antioxidant intake and pelvic inflammatory disease specifically. This research fills that gap by providing the first large-scale evidence of an association in American women. The finding that the genetic analysis didn’t confirm causation suggests the relationship is more complex than a simple cause-and-effect, possibly involving multiple factors working together.

The study has several important limitations. First, women reported whether they had PID from memory, which may be inaccurate—some may have forgotten, while others might misremember. Second, the study only captured a snapshot in time (cross-sectional), so researchers couldn’t determine whether women ate more antioxidants before or after developing PID. Third, the genetic analysis didn’t find proof of direct causation, suggesting the observed connection might be due to other factors. Women who eat more antioxidants may also have healthier lifestyles in other ways that protect against PID. Finally, the study only included American women, so results may not apply to women in other countries with different diets and healthcare systems.

The Bottom Line

Based on this research, eating more antioxidant-rich foods appears to be associated with lower pelvic infection risk and is generally healthy for many reasons. Include colorful fruits and vegetables, nuts, seeds, and whole grains in your diet. However, this study doesn’t prove antioxidants directly prevent PID, so don’t rely on diet alone to prevent infections. If you’re concerned about pelvic health or have symptoms like pelvic pain, fever, or unusual discharge, see a healthcare provider. Confidence level: Moderate—the association is clear, but causation isn’t proven.

This research is relevant for all women, especially those concerned about pelvic health or at risk for infections. Women with a history of sexually transmitted infections, multiple sexual partners, or those not using barrier protection should be particularly interested in preventive strategies. However, this study doesn’t replace medical treatment—if you have symptoms of pelvic inflammatory disease, you need antibiotics prescribed by a doctor. This research is not specifically relevant to men or children.

If you increase your antioxidant intake, you wouldn’t expect immediate protection against PID. Building a healthier diet is a long-term strategy. Any protective benefits would likely develop over months to years of consistent healthy eating. If you develop symptoms of pelvic infection (pelvic pain, fever, unusual discharge), seek medical care immediately rather than waiting for dietary changes to work.

Want to Apply This Research?

  • Track daily antioxidant-rich food intake by logging servings of colorful fruits, vegetables, nuts, seeds, and whole grains. Set a goal of 5+ servings of fruits and vegetables daily and monitor zinc intake through foods like oysters, beef, pumpkin seeds, and chickpeas.
  • Use the app to create a simple meal plan that includes antioxidant-rich foods at each meal. Set reminders to add one new colorful vegetable or antioxidant-rich food to your weekly grocery list. Track which antioxidant foods you enjoy most to build sustainable eating habits.
  • Monitor your antioxidant intake weekly and track any changes in pelvic health symptoms over months. Use the app to identify patterns between dietary choices and how you feel. Share this data with your healthcare provider during annual checkups to discuss overall wellness strategies.

This research shows an association between antioxidant intake and lower pelvic inflammatory disease risk, but does not prove antioxidants prevent PID. This information is for educational purposes only and should not replace professional medical advice. If you have symptoms of pelvic inflammatory disease—including pelvic pain, fever, unusual vaginal discharge, or pain during intercourse—contact a healthcare provider immediately. PID requires medical treatment with antibiotics. Do not attempt to treat PID with diet alone. Always consult with your doctor before making significant dietary changes, especially if you have existing health conditions or take medications. This study was conducted in the United States and may not apply to all populations.