Pirjo Pietinen

Major types of dietary fat and risk of coronary heart disease: a pooled analysis of 11 cohort studies

BACKGROUND Saturated fatty acid (SFA) intake increases plasma LDL-cholesterol concentrations; therefore, intake should be reduced to prevent coronary heart disease (CHD). Lower habitual intakes of SFAs, however, require substitution of other macronutrients to maintain energy balance. OBJECTIVE We investigated associations between energy intake from monounsaturated fatty acids (MUFAs), polyunsaturated fatty acids (PUFAs), and carbohydrates and risk of CHD while assessing the potential effect-modifying role of sex and age. Using substitution models, our aim was to clarify whether energy from unsaturated fatty acids or carbohydrates should replace energy from SFAs to prevent CHD. DESIGN This was a follow-up study in which data from 11 American and European cohort studies were pooled. The outcome measure was incident CHD. RESULTS During 4-10 y of follow-up, 5249 coronary events and 2155 coronary deaths occurred among 344,696 persons. For a 5% lower energy intake from SFAs and a concomitant higher energy intake from PUFAs, there was a significant inverse association between PUFAs and risk of coronary events (hazard ratio: 0.87; 95% CI: 0.77, 0.97); the hazard ratio for coronary deaths was 0.74 (95% CI: 0.61, 0.89). For a 5% lower energy intake from SFAs and a concomitant higher energy intake from carbohydrates, there was a modest significant direct association between carbohydrates and coronary events (hazard ratio: 1.07; 95% CI: 1.01, 1.14); the hazard ratio for coronary deaths was 0.96 (95% CI: 0.82, 1.13). MUFA intake was not associated with CHD. No effect modification by sex or age was found. CONCLUSION The associations suggest that replacing SFAs with PUFAs rather than MUFAs or carbohydrates prevents CHD over a wide range of intakes.

Urinary sodium excretion and cardiovascular mortality in Finland: a prospective study

BACKGROUND The evidence that high salt intake increases the risk of cardiovascular disease has been challenged. We aimed to find out whether salt intake, measured by 24 h urinary sodium excretion, is an independent risk factor for cardiovascular disease frequency and mortality, and all-cause mortality. METHODS We prospectively followed 1173 Finnish men and 1263 women aged 25-64 years with complete data on 24 h urinary sodium excretion and cardiovascular risk factors. The endpoints were an incident coronary and stroke event, and death from coronary heart disease, cardiovascular disease, and any cause. Each endpoint was analysed separately with the Cox proportional hazards model. FINDINGS The hazards ratios for coronary heart disease, cardiovascular disease, and all-cause mortality, associated with a 100 mmol increase in 24 h urinary sodium excretion, were 1.51 (95% CI 1.14-2.00), 1.45 (1.14-1.84), and 1.26 (1.06-1.50), respectively, in both men and women. The frequency of acute coronary events, but not acute stroke events, rose significantly with increasing sodium excretion. When analyses were done separately for each sex, the risk ratios were significant in men only. There was a significant interaction between sodium excretion and body mass index for cardiovascular and total mortality; sodium predicted mortality in men who were overweight. Correction for the regression dilution bias increased the hazards ratios markedly. INTERPRETATION High sodium intake predicted mortality and risk of coronary heart disease, independent of other cardiovascular risk factors, including blood pressure. These results provide direct evidence of the harmful effects of high salt intake in the adult population.

Intake of Dietary Fiber and Risk of Coronary Heart Disease in a Cohort of Finnish Men The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study

BACKGROUND Even though dietary fiber has been hypothesized to reduce the risk of coronary heart disease, few large epidemiological studies have examined this relation with good methodology. METHODS AND RESULTS The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study was a randomized, double-blind, placebo-controlled trial with daily supplementation of alpha-tocopherol and/or beta-carotene. Of the participants, 21930 smoking men aged 50 to 69 years who were free of diagnosed cardiovascular disease and had completed a validated dietary questionnaire at baseline were followed for 6.1 years. We monitored the incidence of major coronary events (a combination of first nonfatal myocardial infarction and coronary heart disease death; n = 1399) and mortality from coronary heart disease (n = 635). Both entities had a significant inverse association with dietary fiber, but the association was stronger for coronary death. For men in the highest quintile of total dietary fiber intake (median, 34.8 g/d), the relative risk for coronary death was 0.69 (95% confidence interval, 0.54 to 0.88; P < .001 for trend) compared with men in the lowest quintile of intake (median, 16.1 g/d). With an adjustment for known cardiovascular risk factors, intake of saturated fatty acids, beta-carotene, vitamin C, and vitamin E did not materially change the result. Water-soluble fiber was slightly more strongly associated with reduced coronary death than water-insoluble fiber, and cereal fiber also had a stronger association than vegetable or fruit fiber. CONCLUSIONS These findings suggest that independent of other risk factors, greater intake of foods rich in fiber can substantially reduce the risk of coronary heart disease, and particularly coronary death, in middle-aged, smoking men.

Longitudinal changes in diet from childhood into adulthood with respect to risk of cardiovascular diseases: The Cardiovascular Risk in Young Finns Study

Objective: To assess nutrient intakes relevant in the prevention of cardiovascular diseases (CVD) among young adults in Finland and to find past and present determinants of quality of diet.Design: Prospective study, 21 years of follow-up.Setting: The Cardiovascular Risk in Young Finns Study, Finland.Subjects: At baseline in 1980: 3569 children aged 3–18 y participated (83% of those invited), and every second of them (1780) were selected to the dietary study. At follow-ups in 1986 and 2001: 1200 and 1037 of the original sample, respectively, participated.Methods: Food consumption was assessed using 48-h dietary recall. Intakes in 2001 were compared with those obtained in 1980 and 1986. Nutrients selected for further examination were those implicated in the risk of CVD: saturated, monounsaturated, polyunsaturated and n-3 fatty acids, fibre and salt. An index describing the quality of adulthood diet was constructed. Multivariate logistic regression was used to identify independent childhood and adulthood determinants of the quality index.Results: The average intakes showed substantial changes since 1980. Intakes of fat and saturated fat had decreased, while the consumption of vegetables and fruit had increased. However, a great disparity was present between the recommended levels and actual intakes for many of the nutrients, particularly salt, saturated fat and fibre. Intake of fat and consumption of vegetables in childhood and physical activity in adulthood were important health behavioural determinants of the cardiovascular quality of the adult diet. Socio-demographic factors, including education of the subject and their parents, had no significant associations with diet.Conclusions: While intakes of energy and nutrients have changed favourably in Finnish young adults between 1980 and 2001 with regard to the risk of CVD, they are still far from recommended levels. Childhood diet is a significant determinant of adult diet even after 21 y.Sponsorship: This study was supported by the Academy of Finland (grant 77841) and Juho Vainio Foundation.

Diet and risk of colorectal cancer in a cohort of Finnish men

Objectives: Based on previous epidemiological studies, high fat and meat consumption may increase and fiber, calcium, and vegetable consumption may decrease the risk of colorectal cancer. We sought to address these hypotheses in a male Finnish cohort.Methods: We analyzed data from the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study (ATBC Study) where 27, 111 male smokers completed a validated dietary questionnaire at baseline. After an average of 8 years of follow-up, we documented 185 cases of colorectal cancer. The analyses were carried out using the Cox proportional hazards model.Results: The relative risk (RR) for men in the highest quartile of calcium intake compared with men in the lowest quartile was 0.6 (95% CI 0.4–0.9, p for trend 0.04). Likewise, the intake of milk protein and the consumption of milk products was inversely associated with risk of colorectal cancer. However, intake of dietary fiber was not associated with risk, nor was fat intake. Consumption of meat or different types of meat, and fried meat, fruits or vegetables were not associated with risk.Conclusions: In this cohort of men consuming a diet high in fat, meat, and fiber and low in vegetables, high calcium intake was associated with lowered risk of colorectal cancer.

Gender, socioeconomic status and family status as determinants of food behaviour

This study examines social structural and family status factors as determinants of food behaviour. The data were derived from the FINMONICA Risk Factor Survey, collected in Finland in spring 1992. A multidimensional framework of the determinants of food behaviour was used, including social structural position, family status and gender. The associations between the determinants of food behaviour were estimated by multivariate logistic regression models, adjusted for age and regional differences. Food behaviour was measured by an index including six food items which were chosen based on Finnish dietary guidelines. In general, womens food behaviour was more in accordance with the dietary guidelines than that of men. The pattern of association between educational level and food behaviour was similar for both genders, but slightly stronger for men than women. Employment status was associated only with womens food behaviour, but the tendency was the same for men. Marital status was associated with mens as well as womens food behaviour. The food behaviour of married men and women was more in line with the dietary guidelines than the food behaviour of those who had been previously married. Parental status, however, was only associated with womens food behaviour, that is, the food behaviour of women with young children was more closely in line with the dietary guidelines than that of the rest of the women.

Serum levels of vitamin D metabolites and the subsequent risk of colon and rectal cancer in Finnish men

Experimental and human epidemiologic data suggest a protective rolefor vitamin D in large bowel cancer. To investigate this association, weconducted a nested case-control study within a Finnish clinical trial cohort.Cases (n = 146) were participants diagnosed with primary adenocarcinoma ofthe large bowel. Controls were matched (2:1) to cases on age, date ofbaseline blood draw, and study clinic. Prediagnostic serum levels of thevitamin D metabolites, 25-hydroxyvitamin D (25-OH D), and1,25-dihydroxyvitamin D (1,25-DIOHD) were used as primary exposure measures.The baseline geometric-mean serum level of 25-OH D was 11.6 percent lower incases than in controls (12.2 cf 13.8 ug/l, P = 0.01) while serum levels of1,25-DIOH D did not differ by case-control status. No association was seenbetween serum levels of 1,25-DIOH D and large bowel cancer risk. However, theestimated relative risk (RR) of large bowel cancer decreased with increasinglevel of serum 25-OH D and the associa tion was more pronounced for rectalcancer (55 cases; RR by quartile = 1.00, 0.93, 0.77, 0.37; trend P = 0.06).Neither exclusion of early cases nor multivariate adjustment for potentialconfounders materially altered these estimates. There was no evidence ofeffect modification by level of 1,25-dihydroxyvitamin D or with other knownrisk-factors for large bowel cancer.

Intake of Flavonoids, Carotenoids, Vitamins C and E, and Risk of Stroke in Male Smokers

Background and Purpose Antioxidants may protect against atherosclerosis and thus prevent cerebrovascular disease. We studied the association between dietary antioxidants and subtypes of stroke. Methods The study cohort consisted of 26 593 male smokers, aged 50 to 69 years, without a history of stroke. They were participants of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study in Finland. The men completed a validated dietary questionnaire at baseline. Incident cases were identified through national registers. Results During a 6.1-year follow-up, 736 cerebral infarctions, 83 subarachnoid hemorrhages, and 95 intracerebral hemorrhages occurred. Neither dietary flavonols and flavones nor vitamin E were associated with risk for stroke. The dietary intake of &bgr;-carotene was inversely associated with the risk for cerebral infarction (relative risk [RR] of highest versus lowest quartile 0.74, 95% CI 0.60 to 0.91), lutein plus zeaxanthin with risk for subarachnoid hemorrhage (RR 0.47, 95% CI 0.24 to 0.93), and lycopene with risks of cerebral infarction (RR 0.74, 95% CI 0.59 to 0.92) and intracerebral hemorrhage (RR 0.45, 95% CI 0.24 to 0.86). Vitamin C intake was inversely associated with the risk for intracerebral hemorrhage (RR 0.39, 95% CI 0.21 to 0.74). After simultaneous modeling of the antioxidants, a significant association remained only between &bgr;-carotene intake and risk for cerebral infarction (RR 0.77, 95% CI 0.61 to 0.99). Conclusions Dietary intake of &bgr;-carotene was inversely associated with the risk for cerebral infarction. No association was detected between other dietary antioxidants and risk for stroke.

Increasing prevalence of underreporting does not necessarily distort dietary surveys

Objectives: To study the magnitude of and trends in energy underreporting and to compare food consumption, nutrient intake and socioeconomic characteristics of underreporters to those of other Finnish adults. Design: Cardioavscular risk factor surveys in 1982 and 1992 using a 3 d food record. Underreporting was defined as energy intake lower than 1.27*BMR, since energy intake <1.27*BMR is improbable. Setting: Four areas in Finland, both rural and urban. Subjects: 1746 men and 1921 women, aged 25–64 y. Results: Proportion of underreporters has increased from 33% in 1982 to 46% in 1992 among women and from 27% in 1982 to 42% in 1992 among men. In a logistic regression model, BMI over 25 kg/m2, female gender, age over 45 y and high educational level predicted underreporting. Shares of energy intake from fat, carbhoydrates, protein and alcohol remained the same whether or not underreporters were excluded. However, underreporters consumed significantly higher proportion of vegetables, fish, meat, potatoes, fruit and berries and less fat than others. In the 1992 data the absolute intake of most micronutrients increased and micronutrient densities decreased when underreporters were excluded. Conclusions: The proportion of underreporters has grown from 1982 to 1992. Results expressed as a percentage of energy intake are not affected by the exclusion of underreporters. In contrast, micronutrient intakes, both absolute and energy density values, were distorted by underreporting. Underreporting should be taken into account in future studies. Sponsorship: National Public Health Institute.

Sodium in the Finnish diet: 20-year trends in urinary sodium excretion among the adult population

Objective:High sodium intake increases the risk of cardiovascular diseases and may also be associated with higher rates of stomach cancer, asthma disorders and infections. In Finland, cross-sectional population surveys to monitor cardiovascular risk factors have been carried out since the 1970s. The main aim of this paper is to present trends in urinary sodium and potassium excretion from 1979 to 2002.Design:Cross-sectional population surveys on cardiovascular risk factors.Setting:Surveys were carried out in Finland in 1979, 1982, 1987 and 2002 in four geographical areas: North Karelia, the Kuopio area, Southwestern Finland and the Helsinki area.Subjects:For each survey a random sample stratified by age and sex was drawn from the population register. In this analysis, participants of urine collection subsamples aged 25–64 years (n=4648) were included.Interventions:A 24-h urinary collection was carried out in subsamples (n=2218–2487) in connection with population risk factor surveys. Urinary sodium and potassium concentrations were analyzed in the same laboratory throughout, using a flame photometer in 1979, 1982 and 1987 and an ion-selective electrode in 2002.Results:Between 1979 and 2002 urinary sodium excretion in Finland decreased from over 220 to less than 170 mmol/day among men and from nearly 180 to less than 130 mmol/day among women. Although potassium excretion decreased somewhat as well, the decrease in sodium–potassium molar ratio was also significant.Conclusions:The 24-h urinary sodium excretion in Finland has decreased significantly during the last 20 years. However, excretion levels are still considerably higher than recommendations. A further decrease in sodium intake remains a goal for the Finnish food industry and consumers.Sponsorship:All surveys were funded by the National Public Health Institute in Finland.