The mediating effect of Mediterranean diet on the relation between smoking and colorectal cancer: a case-control study.
BACKGROUND
The protective role of Mediterranean diet (MD) and the detrimental effect of smoking on colorectal cancer (CRC) have already been shown. The aim of this work was to evaluate the potential mediating effect of MD on the association between the aforementioned factor (smoking) and CRC.


METHODS
It is a case-control study. Two hundred fifty consecutive patients with CRC (63 ± 12 years, 59% males) and 250 age-sex group-matched controls, both from the area of Attica, were studied. Various socio-demographic, clinical, lifestyle (including detailed smoking habits) and dietary characteristics were measured. Adherence to the MD was evaluated using the MedDietScore (theoretical range 0-55).


RESULTS
Each unit increase in the MedDietScore was associated with 13% lower likelihood of CRC (P < 0.001). Smoking habits were associated with 2.9-fold the likelihood of CRC among participants who were away from the MD (i.e. MedDietScore < 29) and with 2.1-fold the likelihood of CRC among those who were close to the MD (P < 0.05).


CONCLUSIONS
Adherence to the MD was associated with a less detrimental association of smoking habits with CRC, suggesting indirect benefits of adherence to this dietary pattern with regards to CRC morbidity and mortality.
1 Department of Nutrition and Dietetics, Harokopio University, Athens, Greece.
Niki
N
Kontou
Theodora
T
Psaltopoulou
Nick
N
Soupos
Evangelos
E
Polychronopoulos
Dimitrios
D
Xinopoulos
Athena
A
Linos
Demosthenes B
DB
Panagiotakos
D000368:Aged; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000517:prevention & control*; D038441:Diet, Mediterranean; D005260:Female; D006115:Greece / Q000453:epidemiology; D006293:Health Promotion; D006801:Humans; D008019:Life Style; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology