Do women change their diet after breast cancer diagnosis? An exploratory analysis

Objective: To investigate whether the dietary patterns differ among women newly diagnosed with breast cancer and among long-term survivors.

Methods: Factor analysis was used to identify dietary patterns based on daily consumptions of 19 food groups. Women were categorized into different groups according to the interval between date of breast cancer diagnosis and date of dietary assessment. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI).

Results: Two dietary patterns were identified: the “prudent” dietary pattern characterized by a high intake of fruits and vegetables and the “western” dietary pattern characterized by a high intake of energy-dense foods. The prudent diet was associated with a reduced breast cancer risk among women with diet assessed ≤ 1 year of cancer diagnosis (OR=0.89, 95% CI: 0.62-1.28) but an increased risk among women with diet assessed ≥ 3 years after diagnosis (OR=1.70, 95% CI: 1.04-2.77). The western diet was associated with an increased breast cancer risk among women with diet assessed ≤ 1 year of cancer diagnosis (OR=1.73, 95% CI: 1.12-2.65) but a reduced risk among women with diet assessed at 2 years after diagnosis (OR=0.69, 95% CI: 0.44-1.10). However, the western diet resumed a positive association with breast cancer among women with diet assessed ≥ 3 years after cancer diagnosis (OR=1.84, 95% CI: 1.05 -3.22).

Conclusion: Women with newly diagnosed breast cancer tend to consume a healthy diet one or two years after cancer diagnosis but this trend did not continue among long-term cancer survivors.