Does dietary calcium interact with dietary fiber against colorectal cancer? : a case-control study in Central Europe

BACKGROUND: An unfavorable trend of increasing rates of colorectal cancer has been observed across modern societies. In general, dietary factors are understood to be responsible for up to 70% of the disease’s incidence, though there are still many inconsistencies regarding the impact of specific dietary items. Among the dietary minerals, calcium intake may play a crucial role in the prevention. The purpose of this study was to assess the effect of intake of higher levels of dietary calcium on the risk of developing of colorectal cancer, and to evaluate dose dependent effect and to investigate possible effect modification. METHODS: A hospital based case–control study of 1556 patients (703 histologically confirmed colon and rectal incident cases and 853 hospital-based controls) was performed between 2000–2012 in Krakow, Poland. The 148-item semi-quantitative Food Frequency Questionnaire to assess dietary habits and level of nutrients intake was used. Data regarding possible covariates was also collected. RESULTS: After adjustment for age, gender, education, consumption of fruits, raw and cooked vegetables, fish, and alcohol, as well as for intake of fiber, vitamin C, dietary iron, lifetime recreational physical activity, BMI, smoking status, and taking mineral supplements, an increase in the consumption of calcium was associated with the decrease of colon cancer risk (OR = 0.93, 95% CI: 0.89-0.98 for every 100 mg Ca/day increase). Subjects consumed >1000 mg/day showed 46% decrease of colon cancer risk (OR = 0.54, 95% CI: 0.35-0.83). The effect of dietary calcium was modified by dietary fiber (p for interaction =0.015). Finally, consistent decrease of colon cancer risk was observed across increasing levels of dietary calcium and fiber intake. These relationships were not proved for rectal cancer. CONCLUSIONS: The study confirmed the effect of high doses of dietary calcium against the risk of colon cancer development. This relationship was observed across different levels of dietary fiber, and the beneficial effect of dietary calcium depended on the level of dietary fiber suggesting modification effect of calcium and fiber. Further efforts are needed to confirm this association, and also across higher levels of dietary fiber intake

Selected factors affecting relative validity of Food Frequency Questionnaire SFFQ among preschool children - Krakow study

Wprowadzenie. Prowadzenie badań epidemiologicznych nad zależnością pomiędzy stanem zdrowia a sposobem żywienia wymaga, w pierwszej kolejności, trafnej oceny spożycia pokarmów oraz podaży składników pokarmowych. Cel. Celem badań była ocena wpływu wybranych czynników na trafność kwestionariusza częstości spożycia SFFQ w grupie dzieci przedszkolnych w wieku 3 lat ze środowiska krakowskiego. Materiał i metody. Do badań włączonych zostało 172 dzieci trzyletnich. W badaniach porównano podaż energii i wybranych składników pokarmowych, oszacowanych na podstawie półilościowego kwestionariusza częstości spożycia (SFFQ), z podażą tych składników, oszacowaną na podstawie trzech wywiadów 24-godz. Stopień zgodności pomiędzy badanymi metodami pomiaru określono na podstawie analizy skorygowanych współczynników korelacji Spearmana. Wyniki. Najwyższe współczynniki korelacji pomiędzy podażą oszacowaną na podstawie kwestionariusza SFFQ oraz trzech wywiadów 24-godz. zaobserwowano dla podaży witaminy B2 (RS=0,635) oraz wapnia (RS=0,605), natomiast najniższe dla podaży witamin PP oraz A (odpowiednio RS =0,344 i RS=0,355). Czynnikiem w największym stopniu wpływającym na trafność danych żywieniowych było uczęszczanie przez dziecko do przedszkola. Zaobserwowano również różnice w wielkości współczynników korelacji w zależności od poziomu wykształcenia i wieku matki oraz od masy ciała dziecka. Wnioski. Podaży energii oraz wszystkich badanych składników pokarmowych, oszacowana na podstawie kwestionariusza SFFQ, była znacząco wyższa w porównaniu do podaży wyliczonej na podstawie powtarzanych wywiadów 24-godz. Jednak trafność pomiaru podaży energii oraz podstawowych składników pokarmowych, mierzona współczynnikiem korelacji, była akceptowalna w odniesieniu do innych narzędzi wykorzystywanych do oceny żywienia dzieci.Background. Epidemiological studies of the relationship between health status and the mode of nutrition should be based primarily on valid assessment of the intake of food products and the intake of nutrients. Objective. The objective of the study was to assess the effect of selected demographic factors on the validity of semiquantitative Food Frequency Questionnaire (SFFQ) among three-year-old children from Krakow. Material and methods. The study group consisted of 172 three-year-old children. The intake of energy and selected nutrients assessed, based on the SFFQ, were compared with the intake from repeated 24-h recalls. The attenuated Spearman rank correlation was used to assess the level of compatibility between the two methods adjusted for the variability in the referent method. Results. The highest correlation between SFFQ and three 24-h recalls was found for vitamin B2 (RS =0.635) and calcium (RS =0.605) intake, while the lowest – vitamins PP and A (RS =0.344 and RS =0.355, respectively). It was found that the strongest factor influencing the level of compatibility of the two methods was attending a nursery school by child. Differences were also discovered in the values of correlation coefficients according to the level of education and age of the mother, and body weight of the child. Conclusions. The intake of energy and all the nutrients examined based on the SFFQ was significantly higher, compared to the intake assessed by repeated 24-h recalls. Nevertheless, the validity of measurement of intake of energy and basic nutrients measured by the correlation method were found to be at the acceptable level, compared to other instruments used for assessing food- nutrition among preschool children