Do cancer survivors change their diet after cancer diagnosis?

Improvements in lifestyle such as diet and exercise can minimise the risk of a new cancer diagnosis or cancer recurrence. We investigated dietary changes and supplement use by survivors attending Sydney Cancer Survivorship Centre (SCSC) clinic to plan future interventions to help survivors improve their diet.

Eligible survivors were SCSC cancer patients who had completed anticancer treatment with curative intent and attended their initial clinic between September 2013 and July 2019. Attendees completed questionnaires investigating dietary change and a 3-day food diary before attending clinic.

Overall, 520 (91%) survivors completed questionnaires and 310 (54%) a 3-day food diary. Mean age was 57 (range 18-90 years), and 68% were female. The main cancer types were breast (41%), colorectal (31%), and haematological (17%). In total, 318/520 (55%) reported making dietary change after their cancer diagnosis. Most common changes were increased fruit and vegetable intake (36%), reduced or avoidance of red meat (25%), sugar or sweets (20%) and fat (12%), while some (7%) specifically avoided dairy products. Overall, 269/439 (61%) reported taking dietary supplements, with a median of 2 supplements (range 0-8). Based on their 3-day food diary assessed by a dietitian, only 53/270 (20%) and 110/276 (40%) met the recommended serves of vegetables and fruit respectively.

The majority of survivors modified their diet after their cancer diagnosis; some modifications appeared to be beneficial, while others were not evidence-based. More than half of survivors reported taking dietary supplements. There is a need for providing appropriate dietary education in a timely manner to improve cancer survivors' diet.