DIETARY HABITS AND CARDIOVASCULAR DISEASE

BACKGROUND AND AIM: Diet, in particular dietary fats, and cardiovascular disease (CVD) are closely related. Dietary fats might be captured by measuring blood fatty acid profiles. The role of diet as well as the role of blood fatty acid (FA) levels, in CVD aetiology is still uncertain. Aims of this thesis were to investigate in a large cohort of 60-year-old Swedish men and women: 1) The association between self-reported dietary intake, with a specific focus on foods rich in fat, and selected serum cholesterol ester FAs (Project I); 2) The relation between self-reported intake of specific types of dietary fats (primary aim) and fruit and vegetables (secondary aim) and incident of CVD and all-cause mortality (Project II); 3) The relation between serum cholesterol FAs, with a specific focus on polyunsaturated FAs (PUFA)eicosapentaenoic acid (EPA), docosaesaenoic acid (DHA), linoleic (LA) and linolenic (ALA) acid and incident CVD and all-cause mortality (Project III). METHODS: Data collected between 1997 and 1998 from 4,232 individuals (2,039 men and 2,139 women) aged 60, randomly selected from Stockholm County were used. The participants were followed regarding incident CVD up to 31st December 2012 using national registers yielding 359 incident CVD cases and 595 deaths. From nutritional data, collected by questionnaires, we created: 1) five diet scores reflecting intake of saturated fats in general, and fats from dairy, fish, processed meat and vegetable oils and margarines (Project I, II) 2) binary variables classifying study participants into exposed and unexposed and evaluating 16 specific dietary factors (Project II). Gas chromatography was used to assess 13 FAs in serum cholesterol esters (Project I, III). Association between each diet score and specific FAs was assessed by percentile differences (PD) with 95% confidence intervals (CI) at the 10th, 25th, 50th, 75th, and 90th percentile of each FA across levels of diet scores using quantile regression (Project I). Crude and adjusted Cox proportional hazards models were used to estimate hazard ratios (HR) with 95% CI in the association between specific self-reported dietary fats (diet scores and single dietary items), fruit and vegetables intake (Project II) and serum PUFA (Project III) and incidence of CVD and all-causes mortality. RESULTS: In men and women combined, fish intake was associated with high serum proportions of EPA (50thPD=31.41, 95% CI= 27.77; 35.05) and DHA (50thPD=10∙51, 95% CI= 9.40; 11.62). Vegetable fat intake was associated with high serum proportion of total PUFA (50thPD 36.34, 95% CI= 22.77;49.92) and low proportion of total SFA (50thPD=11.33, 95%CI= 14.92;7.73). (Project I) In women, an increased risk of CVD was related to high consumption of spread butter or margarine (≥10g/day vs <10g/day), HR=1.49, CI=1.02 ; 2.20, and oily potatoes (≥2 times/week vs <2time/week), HR=2.00, CI=1.11;3.60. In men, an increased risk of early death was related to the consumption of butter (vs margarine), HR=1.28, CI=1.01; 1.62, high consumption of spread butter or margarine, HR=1.57, CI=1.23; 2.02 and egg consumption ≥4 times/week (vs <4times/week), HR=1.53, CI=1.15;2.02. In men, daily intake of fruits (vs <1time/day) was inversely related to early death, HR=0.75, CI=0.60; 0.94. (Project II) High serum EPA and DHA proportions were inversely associated with CVD in women (for EPA HR= 0.79, 95% CI 0.64; 0.97; for DHA HR= 0.74 0.61; 0.89) but not in men. Inverse associations with early death were also noted in men for high serum EPA proportion, HR=0.82, 95% CI 0.71;0.95; and DHA proportion, HR= 0.82, 95%CI= 0.71;0.94, and in women for high serum EPA proportion, HR=0.79, 95%CI= 0.65;0.96, and DHA proportion, HR= 0.78, 95% CI= 0.66;0.93. High serum ALA proprotion was associated with moderately increased of CVD incidence, HR= 1.16, 95% CI=1.02;1.32 in women whereas high serum LA proportion was associated with reduced all-cause mortality in men, HR= 0.73 95% CI=0.64;0.83. (Project III). CONCLUSION: Based on our results, self-reported intake of fish and vegetable fats was clearly associated with serum PUFA. High intake of specific foods and not fats in general may have negative effects on CVD for women and all-causes mortality for men, whereas fruit may reduce mortality only in men. Similarly serum EPA, DHA and LA were protective for CVD and all-causes mortality with gender difference whereas serum ALA might be associated with increased of CVD in only women.