Carrot Intake and Risk of Colorectal Cancer: A Prospective Cohort Study of 57,053 Danes

Abstract

Carrots are consumed worldwide. Several meta-analysis studies on carrot consumption have indicated that carrots play a central role as a protecting vegetable against development of different types of cancers. A cancer-preventive role of carrots is plausible because they are the main dietary source of the bioactive polyacetylenic oxylipins falcarinol (FaOH) and falcarindiol (FaDOH), which have shown anti-proliferative and anti-inflammatory activity in numerous in vitro studies. In addition, purified FaOH and FaDOH have, in recent studies in colorectal cancer (CRC)-primed rats, demonstrated an anti-neoplastic effect in a dose-dependent manner. The mechanisms of action for this effect appears to be due to inhibition of pro-inflammatory and transcription factor biomarkers for inflammation and cancer. However, studies of the CRC-preventive effect of carrots in a large cohort are still missing. We therefore examined the risk of being diagnosed with CRC as predicted by intake of carrots in a Danish population of 57,053 individuals with a long follow-up. Self-reported intake of raw carrots at a baseline of 2–4 carrots or more each week (>32 g/day) was associated with a 17% decrease in risk of CRC with a mean follow-up of >18 years, compared to individuals with no intake of raw carrots even after extensive model adjustments (HR 0.83 CI 95% 0.71; 0.98). An intake below 2–4 carrots each week (<32 g/day) was not significantly associated with reduced risk of CRC (HR 0.93 CI 95% 0.82; 1.06). The results of this prospective cohort study clearly support the results from studies in cancer-primed rats for CRC and hence a CRC-preventive effect of carrots.