Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

PURPOSE: The insulin-like growth factor (IGF) system is modifiable by diet and lifestyle, and has been linked to prostate cancer development and progression. METHODS: We conducted a prospective cohort study of 621 men diagnosed with localized prostate cancer to investigate the associations of dietary and lifestyle changes with post-diagnosis circulating levels of IGF-I and IGFBP-3. We used analysis of covariance to estimate the associations, controlling for baseline IGF-I or IGFBP-3, respectively. RESULTS: Mean IGF-I levels were 6.5% (95% CI -12.8, -0.3%, p = 0.04) lower in men who decreased their protein intake after diagnosis compared to men who did not change. Men who changed their fruit and vegetable intake had lower IGF-I levels compared to non-changers [Decreased intake: -10.1%, 95% CI -18.4, -1.8%, p = 0.02; Increased intake: -12.0%, 95% CI -18.4, -1.8%, p = 0.002]. IGFBP-3 was 14.6% (95% CI -24.5, -4.8%, p = 0.004) lower in men who achieved a healthy body mass index after diagnosis. Men who became inactive had 9.5% higher average IGF-I levels (95% CI 0.1, 18.9%, p = 0.05). CONCLUSIONS: Decreased protein intake and body mass index, and increased physical activity and fruit and vegetable intake, following a prostate cancer diagnosis were associated with reduced post-diagnosis serum IGF-I and IGFBP-3. Counterintuitively, reduced fruit and vegetable intake was also associated with reduced IGF-I, but with weak statistical support, possibly implicating chance. If confirmed in other studies, our findings may inform potential lifestyle interventions in prostate cancer. ProtecT was registered at International Standard Randomised Controlled Trial Registry, as ISRCTN20141297.

Original publication




Journal article


Cancer Causes Control

Publication Date





877 - 888


Diet, Insulin-like growth factors, Lifestyle, Post-diagnosis, Prostatic neoplasms, Aged, Body Mass Index, Diet, Dietary Proteins, Exercise, Feeding Behavior, Fruit, Humans, Insulin-Like Growth Factor Binding Protein 3, Insulin-Like Growth Factor I, Life Style, Male, Middle Aged, Prospective Studies, Prostatic Neoplasms, Vegetables