Prospective pan-cancer analysis of postdiagnosis milk and yogurt intake types with mortality and life expectancy

Dairy products may influence health outcomes, but the impact of post-diagnosis consumption on cancer prognosis is unclear. This study investigated the associations between post-diagnosis intake of various milk types and yogurt with all-cause and cancer mortality and life expectancy in cancer patients.

Using data from the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, 9597 participants aged ≥ 55 years with dietary data (1999-2000) were followed until 2018. Cox proportional hazards models estimated hazard ratios (HRs) and 95% confidence intervals (CIs), and life tables calculated life expectancy by dairy intake levels.

Over a median follow-up of 13.3 years, 3685 all-cause and 1715 cancer deaths occurred. Each 200 g increase in whole milk intake was associated with higher all-cause mortality (HR 1.10, 95% CI 1.03-1.16, p = 0.001); 2% fat milk was linked to increased all-cause (HR 1.06, 95% CI 1.03-1.10, p < 0.001) and cancer mortality (HR 1.07, 95% CI 1.01-1.12, p = 0.012). Skim milk was associated with reduced all-cause (HR 0.95, 95% CI 0.92-0.99, p = 0.007) and cancer mortality (HR 0.94, 95% CI 0.89-1.00, p = 0.040). Substituting whole or 2% fat milk with skim or 1% fat milk decreased mortality risk. Higher whole and 2% fat milk intake at age 55 was linked to 2.15 and 2.01 fewer life-years, respectively, while moderate skim milk intake gained 2.09 years.

Post-diagnosis skim milk intake may reduce mortality and extend life expectancy in cancer patients, whereas whole and 2% fat milk intake may have adverse effects.