Food processing groups and colorectal cancer risk in Morocco: evidence from a nationally representative case-control study.

OBJECTIVE: The aim of this study was to investigate the association between the consumption of foods and drinks from different food processing categories using the NOVA classification and CRC risk among Moroccan adults. METHODS: 1453 cases and 1453 matched controls aged at least 18 years and recruited from the 5 greater Moroccan regions were interviewed by trained investigators about their habitual diet using a standardized food frequency questionnaire (FFQ). Foods were categorized according to their degree of processing by the NOVA classification. Intakes of each food processing group were categorized into tertiles based on the distribution of controls with the lowest tertile considered as the reference category. Multivariable conditional logistic regression models were used to assess the association between each group and CRC risk (Odds Ratio (OR) and 95% Confidence Intervals (CI)), taking relevant confounders into account. RESULTS: High consumption of unprocessed or minimally processed foods (NOVA group 1) was significantly inversely (OR = 0.82, 95%CI = 0.72-0.93), while high consumption of ultra-processed foods and drink products (NOVA group 4) was significantly positively (OR = 1.40, 95% CI = 1.22-1.61) associated with CRC risk as compared to the lowest intake group. These results were similar for colon and rectum sub-sites. CONCLUSION: This is the first study to evaluate the association between the NOVA classification groups and CRC risk in an African country. Our results suggest that the consumption of ultra-processed foods and drink products may be associated with an increased risk of developing CRC, but longitudinal studies are needed to confirm these results.

Dietary Fat Intake and KRAS Mutations in Colorectal Cancer in a Moroccan Population.

Epidemiologic data support an association between diet and mutations in the Kirsten-ras (KRAS) gene involved in colorectal cancer (CRC) development. This study aimed to explore the associations between fat intake and KRAS mutations in codons 12 and 13 in cases of CRC in the Moroccan population. A multicenter case-series study nested in a large-scale Moroccan CRC case-control study was conducted. Among all CRC cases recruited, 151 specimens were available for the DNA mutation analysis. Logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (Cis) for KRAS mutation status according to the fat intake variables. A KRAS mutation was detected in the CRC tumor of 34.4% of the patients among whom 65.4% had a single mutation at codon 12 and 34.6% had a single mutation at codon 13. Compared to low levels of consumption, a positive association was observed between high polyunsaturated fatty acids (PUFA) consumption (>16.9 g/day) and prevalence of KRAS mutations (OR = 2.15, 95% CI = 1.01-4.59). No statistically significant associations were observed for total fat, monounsaturated fatty acids, saturated fatty acids and KRAS mutations. The results of this study suggest that PUFA may be relevant in the etiology of CRC, possibly through the generation of G > A transitions at the KRAS oncogene. Further studies are needed to verify and explain this finding.

Adaptation and validation of a food frequency questionnaire (FFQ) to assess dietary intake in Moroccan adults.

BACKGROUND: To date, no culture-specific food frequency questionnaires (FFQ) are available in North Africa. The aim of this study was to adapt and examine the reproducibility and validity of an FFQ or use in the Moroccan population. METHODS: The European Global Asthma and Allergy Network (GA2LEN) FFQ was used to assess its applicability in Morocco. The GA2LEN FFQ is comprised of 32 food sections and 200 food items. Using scientific published literature, as well as local resources, we identified and added foods that were representative of the Moroccan diet. Translation of the FFQ into Moroccan Arabic was carried out following the World Health Organization (WHO) standard operational procedure. To test the validity and the reproducibility of the FFQ, 105 healthy adults working at Hassan II University Hospital Center of Fez were invited to answer the adapted FFQ in two occasions, 1 month apart, and to complete three 24-h dietary recall questionnaires during this period. Pearson correlation, and Bland-Altman plots were used to assess validity of nutrient intakes. The reproducibility between nutrient intakes as reported from the first and second FFQ were calculated using intra-class correlation coefficient (ICC). All nutrients were log-transformed to improve normality and were adjusted using the residual method. RESULTS: The adapted FFQ was comprised of 255 items that included traditional Moroccan foods. Eighty-seven adults (mean age 27.3 ± 5.7 years) completed all the questionnaires. For energy and nutrients, the intakes reported in the FFQ1 were higher than the mean intakes reported by the 24-h recall questionnaires. The Pearson correlation coefficients between the first FFQ and the mean of three 24-h recall questionnaires were statistically significant. For validity, de-attenuated correlations were all positive, statistically significant and ranging from 0.24 (fiber) to 0.93 (total MUFA). For reproducibility, the ICCs were statistically significant and ranged between 0.69 for fat and 0.84 for Vitamin A. CONCLUSION: This adapted FFQ is an acceptable tool to assess usual dietary intake in Moroccan adults. Given its representativeness of local food intake, it can be used as an instrument to investigate the role of diet on health and disease outcomes.