New study links higher antioxidant intake to reduced erectile dysfunction risk, highlighting the potential role of diet in ED prevention.

Study: Association between composite dietary antioxidant index and erectile dysfunction among American adults: a cross sectional study. Image Credit: R Photography Background / Shutterstock.com

A recent Scientific Reports study assesses the association between erectile dysfunction (ED) and the Compound Dietary Antioxidant Index (CDAI) through the use of data obtained from the National Health and Nutrition Examination Survey (NHANES).

What causes ED?

ED, which refers to difficulty in obtaining or maintaining an erection to gratify sexual activity, can develop due to irregularities in the inflow and outflow of blood in the penile tissue. The prevalence of ED rises with age and poor lifestyle habits, such as smoking, drinking, and lack of exercise. Diabetes, atherosclerosis, high blood pressure, hypercholesterolemia, and coronary artery disease may also contribute to ED.

Molecular inflammation and oxidative stress play a key role in ED pathophysiological mechanisms. The accumulation of reactive oxygen species (ROS) leads to oxidative stress, which can precipitate vascular endothelial dysfunction and atherosclerosis.

The CDAI provides a scoring framework by integrating a wide range of dietary antioxidants, such as selenium, zinc, vitamins A, C, and E, as well as several carotenoids, to assess the overall antioxidant capacity of an individual’s dietary intake. To date, there remains a lack of data on how CDAI may influence ED risk.

About the study

Data for the current study were obtained between 2001 and 2004, as the NHANES data on the erectile function questionnaire only existed during these years. A total of 3,665 men 20 years and older were included in the study cohort.

Individuals with a prostate cancer diagnosis and those lacking data on dietary antioxidants, body mass index (BMI), smoking or alcohol use, marital status, level of education, cardiovascular disease, recreational activity, and hypertension were excluded from the study.

The primary exposure variable was CDAI. Only food sources of daily intake were considered to estimate dietary antioxidants, whereas medications and dietary supplements were not included. A direct question from the Massachusetts Male Aging Study (MMAS) was used to determine ED, which is the key outcome variable.

Study findings

The prevalence of ED in the study cohort was about 27%. As compared to individuals without ED, the CDAI was significantly reduced in ED patients. ED patients also reported a lower total daily energy intake as compared to those without ED.

Men with ED were typically in a marriage or cohabitating, older, had greater BMI values, possessed a higher level of education, engaged in less physical activity, and consumed alcohol. ED patients were also more likely to be diagnosed with hypertension, diabetes, cardiovascular disease (CVD), and hypercholesterolemia.

Weighted multivariate logistic regression analysis was conducted to assess the relationship between CDAI and ED. To this end, a reduced risk of ED was associated with higher CDAI scores. This statistically significant result was robust across multiple estimated models, even after adjusting for all covariates.

Across all models, individuals in the highest tertile of CDAI were associated with a significantly lower risk of ED as compared to those in the lowest tertile.

The dose-dependent relationship between CDAI and ED was examined using restricted cubic splines (RCS). Herein, a non-linear and negative association was observed, in which the risk of ED declined sharply with initial increases in CDAI scores until ultimately reaching a plateau.

Subgroup analyses were conducted to assess heterogeneity across individuals. The association between CDAI score and ED risk was not significantly different across subgroups after controlling for BMI, smoking status, age, race, hypercholesterolemia, hypertension, diabetes, CVD, drinking status, and recreational activity.

A sensitivity analysis was conducted by excluding 320 participants who were prescribed sex hormones, antipsychotics, antidepressants, phosphodiesterase-5 (PDE5) inhibitors, and steroids in the past 30 days. A negative association between ED and CDAI was observed after controlling for these covariates, with the risk of ED remaining significantly reduced in the highest tertile of CDAI as compared to the lowest tertile.

Conclusions

The study findings suggest that high levels of CDAI have the potential to reduce ED risk; however, extensive and prospective cohort studies should be conducted to further validate these observations.

A key limitation of the current study is its cross-sectional design, which precludes causal analysis. The precision of the diagnosis could also be compromised due to the reliance of self-reported data from a single questionnaire.

Additionally, the researchers also did not measure oxidative stress in the study participants. It is also difficult to ensure that these associations remain relevant for modern ED patients, as data from the current study were obtained between 2001 and 2004.