Olive oil, diet and colorectal cancer: an ecological study and a hypothesis.
ABSTRACT Colorectal cancer (CRC) is a common cancer in many western countries and is probably caused in part by dietary factors. Southern European countries have lower incidence rates of CRC than many other western countries. It was postulated that, because olive oil is thought to influence bile salt secretion patterns in rats, it may influence the occurrence of CRC. The purpose of this study was to compare national levels of dietary factors, with particular reference to olive oil, with national differences in CRC incidence.
Ecological study using existing international databases. Incidence rates for CRC, food supply data, and olive oil consumption data were extracted from published sources, combined, and analysed to calculate the correlations between CRC and 10 dietary factors. Associations were then explored using stepwise multiple regression.
28 countries from four continents.
76% of the intercountry variation in CRC incidence rates was explained by three significant dietary factors-meat, fish and olive oil-in combination. Meat and fish were positively associated, and olive oil was negatively associated, with CRC incidence.
Olive oil may have a protective effect on the development of CRC. The proposed hypothesis is that olive oil may influence secondary bile acid patterns in the colon that, in turn, might influence polyamine metabolism in colonic enterocytes in ways that reduce progression from normal mucosa to adenoma and carcinoma.
Full-textDOI: · Available from: Valerie Seagroatt, May 01, 2014
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ABSTRACT: To validate a detailed semiquantitative food frequency questionnaire designed to measure habitual fish and seafood consumption. Cross-sectional validation study using an independent biomarker of fish consumption. Perth metropolitan area, Western Australia. Ninety-one healthy volunteers of both sexes aged 21-75 years. Participants completed the questionnaire and provided a fasting blood sample for erythrocyte membrane omega-3 fatty acid (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)) analysis. The questionnaire was then validated by linear regression analysis of EPA and DHA levels on categories of fish and seafood and overall consumption, adjusted for age, sex, smoking status, body mass index (BMI) and alcohol intake. Regression coefficients were statistically significant for most fish and seafood items with both EPA and DHA. The strongest association was observed between oily fish and EPA, whereas no significant association was observed between lean fish and omega-3 fatty acids. Variation in omega-3 fatty acids was best accounted for by a model containing variables representing different categories of fish and seafood consumption (R (2) 0.484), rather than a single variable representing overall fish and seafood consumption (R (2) 0.313). This study confirms that the varying content of omega-3 fatty acids in foods are reflected in omega-3 biomarkers, and that the questionnaire is a valid measure of fish consumption that enables differentiation between cooking and processing methods and oily versus lean fish intake.European Journal of Clinical Nutrition 09/2007; 61(8):1023-31. DOI:10.1038/sj.ejcn.1602617 · 2.95 Impact Factor
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ABSTRACT: Recent evidence suggested a protective role of dietary monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) intakes against several chronic diseases and, therefore, an increased human longevity. After a median follow-up of 8.5 years, we investigated the possible role of MUFA, PUFA, and other selected food groups in protecting against all-causes mortality in a population-based, prospective study, conducted in one of the eight centers of the Italian Longitudinal Study on Aging (ILSA), Casamassima, Bari, Italy. Out of 704 elderly subjects (65-84 years), 278 nondemented persons agreed to participate at the first survey (1992-1993). During the follow-up, there were 91 deaths. A semi-quantitative food frequency questionnaire evaluating macronutrient daily intakes were performed at the first survey. Higher MUFA intake was associated with an increase of survival (hazard ratio 0.81, 95% CI 0.66-0.99), a higher unsaturated fatty acids (UFA) to SFA ratio (hazard ratio 1.20, 95% CI 0.99-1.45) increased total mortality only marginally, while no effect about other selected food groups were found. In conclusion, in this prospective study on older nondemented subjects with a typical Mediterranean diet, a higher MUFA intake increased survival, while a higher UFA/SFA ratio increased total mortality, but only marginally.Experimental Gerontology 05/2005; 40(4):335-43. DOI:10.1016/j.exger.2005.01.003 · 3.53 Impact Factor
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ABSTRACT: The olive has a history almost as long as that of Western civilization and has been looked upon as a sign of hope, peace, and sacredness. Olive oil, extracted from the olive, is the principal source of dietary fat in the Mediterranean basin. The composition differs from that of other dietary fats in that olive oil is rich in monounsaturated fatty acids. Even other than as a source of monounsaturated fats, olive oil has own unique effects. Accumulating evidence suggests that olive oil may have beneficial health effects, especially when it comes to reducing risk factors for coronary heart diseases, preventing cancer, and modifying immune and inflammatory responses. However, evidence remains limited, definitive conclusions are difficult to draw, and there remains a significant need for further studies, particularly prospective cohort and well-designed, controlled intervention studies. In this manuscript, the beneficial health effects of olive oil are reviewed, with particular attention paid to cancer prevention and immune functions..Asian Pacific journal of cancer prevention: APJCP 01/2005; 6(1):77-82. · 1.50 Impact Factor