Cervical cancer remains a major health problem for women around the world, but a new study suggests that everyday eating habits may be linked to the risk of developing the disease.
Researchers found that U.S. women whose diets contained higher amounts of several antioxidants were less likely to have cervical cancer than women with lower antioxidant intake.
Most cervical cancers are caused by long-lasting infection with certain high-risk types of human papillomavirus, better known as HPV.
HPV is very common, and in most people the immune system clears the infection, but in some women the virus remains for years and can slowly cause abnormal changes in cells of the cervix.
Vaccination against HPV and regular cervical screening are the most important proven ways to prevent cervical cancer. Even so, researchers are interested in whether other parts of a person’s lifestyle, including diet, could influence how the body responds to infection and cell damage.
The new research focused on antioxidants, natural substances found in many foods. Antioxidants help the body deal with unstable molecules that can damage cells when they build up in excessive amounts.
Foods such as fruits, vegetables, nuts, seeds and whole grains provide a variety of vitamins, minerals and plant compounds with antioxidant activity. Instead of examining only one nutrient, the researchers used a score designed to give a broader picture of antioxidant intake from the diet.
This measure is called the Composite Dietary Antioxidant Index, or CDAI. It combines information about several antioxidant nutrients reported by participants during interviews about what they had eaten.
The investigators examined data collected between 2003 and 2018 through the U.S. National Health and Nutrition Examination Survey, commonly known as NHANES. This large national program collects information about Americans’ diets, health, medical history and other factors.
The analysis included 1,044 women. Of these, 174 had cervical cancer and 870 did not have the disease.
Researchers calculated each woman’s dietary antioxidant score and then looked for a relationship between that score and cervical cancer. They also adjusted their calculations for other factors that could influence cancer risk, an important step because diet is only one part of a person’s overall health and lifestyle.
The results showed a clear association. For every one-point increase in the antioxidant diet score, the prevalence of cervical cancer was about 11.4% lower after the researchers accounted for other factors.
The difference was even larger when women with the highest scores were compared with those with the lowest scores. Women in the highest third of antioxidant intake had about a 55.8% lower prevalence of cervical cancer than women in the lowest third.
Further analysis suggested that the relationship followed a fairly steady pattern. As the dietary antioxidant score increased, the prevalence of cervical cancer tended to decrease rather than showing a benefit only after people reached a particular level.
There are several possible reasons why antioxidant-rich foods might be connected with cervical health. Antioxidants may help protect cells from damage, while a nutritious diet can also support normal immune function, which is important because the immune system plays a major role in clearing HPV infections.
However, the study does not show that antioxidants prevent cervical cancer. It was a cross-sectional study, meaning researchers examined diet and health information rather than assigning women to different diets and following them over many years to see who later developed cancer.
This limitation is important because women who eat more antioxidant-rich foods may differ from other women in many ways. They may exercise more, smoke less, have different incomes, use health services more often or follow other healthy habits that are difficult to fully separate from diet.
Diet information also came from people’s reports of what they ate. Such interviews are useful in large studies, but people may forget foods, misjudge portions or eat differently from one day to another.
The findings should therefore be viewed as an interesting clue rather than proof that increasing antioxidant intake will prevent cervical cancer. They also do not support replacing HPV vaccination, cervical screening or medical treatment with foods or antioxidant supplements.
Still, the size of the association makes the finding worth investigating in stronger studies. Future research that follows women over time could help determine whether diets naturally rich in antioxidant nutrients have a real protective effect and which foods or nutrients may matter most.
The research was published in the International Journal of Gynecology & Obstetrics under the title “Association between composite dietary antioxidant index and cervical cancer: a population-based cross-sectional study.” The authors said prospective studies are needed to confirm the relationship and explain the biological reasons behind it.
Overall, the study fits with the broader idea that a balanced diet rich in plant foods may support health, but it cannot establish cause and effect. The strongest message for cervical cancer prevention remains clear: HPV vaccination and recommended screening have direct evidence behind them, while diet should be considered a possible additional factor that scientists are still working to understand.
Source: Wiley.
