Objective To explore the association between dietary patterns and cardiovascular diseases (CVD) among breast cancer survivors in Shanghai, and to provide a scientific basis for improving their overall health.

Methods A cross-sectional investigation was conducted utilizing stratified sampling to recruit breast cancer survivors from district stations affiliated with the Shanghai Cancer Rehabilitation Club. Dietary intake data were systematically collected through validated food frequency questionnaires. Factor analysis was employed to derive distinct dietary patterns from the dietary datasets. The scores for each dietary pattern were divided into four groups by quartiles. The scores of each dietary pattern were categorized into four groups based on percentiles, with Q₁ representing the low-score group, Q₂ and Q₃ the medium-score groups, and Q₄ the high-score group. Multivariate logistic regression models were implemented to adjust for potential confounders and explore associations between identified dietary patterns and CVD risk.

Results Four dietary patterns were identified through factor analysis: staple-food, nut-dairy, vegetable-fruit and high-protein patterns. After adjusting for possible confounding factors, such as age, body mass index, living arrangement and physical activity, breast cancer survivors with a nut-dairy dietary pattern score in Q₂ had a lower CVD risk (OR=0.734, 95%CI: 0.537‒0.993) compared to those in Q₁. Similarly, survivors in Q₄ of the nut-dairy pattern exhibited a reduced CVD risk (OR=0.670, 95%CI: 0.488‒0.920) compared to those in Q₁.

Conclusion Higher adherence to the nut-dairy dietary pattern is associated with lower CVD risk among breast cancer survivors. Personalized interventions should be implemented to promote healthy dietary habits and prevent CVD in this population.