Paula Hakala

Acquired preference especially for dietary fat and obesity: a study of weight-discordant monozygotic twin pairs

Objective: To determine the independent associations of dietary preference for fat with obesity without the confounding by genetic effects.Design: Descriptive comparison of the responses of monozygotic twins discordant for obesity to questions concerning current and past preference for dietary fat, current overconsumption of fatty items and recalled food consumption compared to the co-twin.Setting: The Research and Development Centre of the Social Insurance Institution, Finland.Subjects: Twenty-three healthy monozygotic twin pairs who were discordant for obesity (BMI difference at least 3 kg/m2).Main Outcome Measures: Obesity status of the twin, as a function of the current and recalled dietary preferences and selected psychosocial variables.Results: The obese twins reported current preference for fatty foods three times more frequently than the lean co-twin. Moreover, when comparing recalled taste for fat at the time the twins left their parental homes, both the obese and lean co-twins consistently recalled that the obese twin had greater preference for fatty foods in young adulthood, and that the lean twin had less. Psychological characteristics of lean and obese co-twins did not differ.Conclusion: Acquired preference for fatty foods is associated with obesity, independent of genetic background. Modification of fat preferences may be an important step in the prevention of obesity in the general population.

Calculated vs analysed nutrient composition of weight reduction diets

Abstract The aim of the study was to compare calculated values with analysed values of some nutrients in weight reduction diets. Ten obese adults were instructed to follow a balanced low-energy diet (5.0 MJ/1200 kcal per day) for 6 months. They were asked to collect samples of all food and beverages they consumed on 3 consecutive days in two phases. During these days, the subjects filled in food records. In addition, samples of a low-energy model diet were collected. The following nutrients were analysed: protein, fat, fatty acids, dietary fibre, calcium, magnesium, iron, zinc, copper, selenium, manganese, molybdenum, sodium, potassium, cadmium and lead. The composition of the diets was calculated from food records by using the Nutrica computer program. Fifteen food samples were included in the final analysis. For most nutrients, calculated values were higher than the analysed ones. Results of our study suggest that the calculation method using food records and the current Finnish database can provide: (1) a reasonably good estimation for the intake of protein, fat, fatty acids, dietary fibre, calcium, magnesium, potassium and manganese; (2) a moderate or uncertain estimation for the intake of iron, sodium, zinc and selenium; and (3) a poor estimation for the intake of copper, molybdenum, cadmium and lead.

Cohort Profile: The STRIP Study (Special Turku Coronary Risk Factor Intervention Project), an Infancy-onset Dietary and Life-style Intervention Trial

It is now clear that atherosclerosis develops as a result of a life-long process often leading to coronary heart disease. Nutritional recommendations have been delivered to the general community to manage this epidemic. Since fat is an important source of energy and cholesterol is required for sex hormone synthesis, fears have emerged that low intake of saturated fat and cholesterol might influence children’s growth and development. Infants and young children have therefore been excluded from these nutritional recommendations. However, a number of arguments support the concept that prevention of children’s exposure to atherosclerosis risk factors should be started at an early age. Dietary fat intake and quality of fat regulate serum lipoprotein values in childhood in the same way as they do in adults. It has also been shown that children with high serum cholesterol and LDL cholesterol values are predisposed to early atherosclerotic changes in aorta and large arteries and high LDL cholesterol values in childhood associate with increased atherosclerotic changes in carotid arteries measured decades later. All these changes can be influenced by living habits. A lifestyle with emphasis on avoiding atherosclerosis risk factors might be most easily adopted if introduced in early childhood. A large cross-sectional coronary risk factor follow-up study, the Cardiovascular Risk in Young Finns (CRYF) has continued in Finland since 1980. In that study, an extensive number of atherosclerosis risk factors have been studied repeatedly in an initial cohort of 3596 individuals from age 3 years onwards. CRYF is a follow-up study without intervention, and a need for an interventional approach to control the coronary risk factors in childhood was evident. Finland is an ideal location to perform an atherosclerosis risk factor intervention study, since serum cholesterol values of Finnish boys have been high in international comparisons and, at the same time, coronary artery disease incidence in Finnish adults has also been very high. Moreover, the participation rate has by tradition been high in Finnish epidemiological trials. Due to these reasons, grant-funded Special Turku Coronary Risk Factor Intervention Project (STRIP) study was launched in 1989 to study whether it is possible to reduce exposure to coronary risk factors effectively and safely from early age on.

Bioavailability of Quercetin From Berries and the Diet

Abstract: Berries are a rich source of various polyphenols, including the flavonoid quercetin. In this article, the results of three intervention studies investigating the bioavailability of quercetin from berries are reviewed. In the first study, we investigated the short-term kinetics of quercetin after consumption of black currant juice and showed that quercetin is rapidly absorbed from it. In the second study, we showed that plasma quercetin levels increase up to 50% in subjects consuming 100 g/day of bilberries, black currants, and lingonberries as a part of their normal diets for 2 mo. In the third study, healthy subjects consumed a diet high or low in vegetables, berries, and other fruit for 6 wk. Quercetin concentrations nearly doubled in the high-vegetable, -berry, and -other fruit group and decreased by 30% in subjects consuming less of these foods than normally. The results showed that plasma quercetin is bioavailable from a diet containing berries and indicate that it may be a good biomarker of fruit and vegetable intake in general.

Vascular Endothelial Function and Leisure-Time Physical Activity in Adolescents

Background— Exercise training improves endothelial function in high-risk adolescents, but the influence of habitual leisure-time physical activity on endothelial function in healthy adolescents is unknown. Methods and Results— Brachial artery flow-mediated endothelial function and physical activity habits were assessed in 483 adolescents (13 years of age) participating in an atherosclerosis prevention study (Special Turku Coronary Risk Factor Intervention Project for Children [STRIP]). Endothelial function was examined with ultrasound; physical activity was assessed with self-administered questionnaires. A leisure-time physical activity index was calculated by multiplying mean weekly leisure-time exercise intensity, duration, and frequency [boys, 31.2±23.0 MET h/wk (mean±SD); girls, 24.0±20.9 MET h/wk; P for gender difference=0.0003]. Maximum flow-mediated dilatation (FMD) and total FMD response (the area under the dilatation curve 40 to 180 seconds after hyperemia) were calculated. In boys, maximum FMD and area under the dilatation curve 40 to 180 seconds after hyperemia were directly associated with leisure-time physical activity index in regression analyses adjusted for brachial artery diameter (maximum FMD, P=0.020; area under the dilatation curve 40 to 180 seconds after hyperemia, P=0.0055). These associations remained significant after further adjustments for body mass index, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, high-sensitivity C-reactive protein, and systolic blood pressure. A difference of ≈50 MET h/wk corresponding to ≈10 hours of moderate intensity activity weekly between sedentary and active boys was associated with an ≈1% unit difference in maximum FMD. Conclusions— Leisure-time physical activity is directly associated with brachial artery FMD responses in 13-year-old boys, providing evidence that physical activity beneficially influences endothelial function in healthy male adolescents. Lack of association in girls may reflect their overall lower physical activity level.

Leisure-time physical activity of 13-year-old adolescents

The leisure‐time physical activity of 13‐year‐old Finnish adolescents was assessed in the prospective STRIP study. A self‐administered questionnaire (N=565) was used. The leisure‐time physical activity index (PAI; MET h/week) was calculated on the basis of reported exercise intensity, duration and frequency (N=558; 53% boys). The participants were divided into Sedentary, Moderately Active and Active groups by PAI tertiles. A subpopulation (N=197) also used a heart rate monitor (3 days, ≥8 h/day) to assess the time spent on different activity intensities. The median male PAI was 31.3 (inter‐quartile range (IQR) 44.2) MET h/week and female 19.5 (IQR 26.3) MET h/week (P=0.0002). The cutoff points of the PAI tertiles were similar for the Active girls (31.3 MET h/week) and boys (32.6 MET h/week), but for the Sedentary boys it was 19.5 MET h/week and only 5.0 MET h/week for the Sedentary girls. High self‐reported leisure‐time physical activity associated poorly with time spent on moderate or vigorous exercise measured by heart rate monitoring. Active mothers had more often Active daughters or sons. In conclusion, the amount of leisure‐time physical activity of one‐third of 13‐year‐old girls is extremely low. Sedentary adolescents, especially girls, should therefore be put into focus for active efforts to increase their leisure‐time physical activity. Parental models may be important.

Consumption of black currants, lingonberries and bilberries increases serum quercetin concentrations.

Objective: To study serum quercetin concentrations of subjects consuming berries or habitual Finnish diets.Design: Randomized parallel dietary intervention.Subjects: Forty healthy men (age 60 y).Intervention: Twenty subjects consumed 100 g/day of berries (black currants, lingonberries and bilberries) for 8 weeks. Twenty subjects consuming their habitual diets served as controls. Fasting blood samples were obtained 2 weeks prior to the study, at baseline, and at 2, 4 and 8 weeks. Intake of quercetin was assessed from 3 day food records collected at baseline and at 8 weeks.Results: The serum quercetin concentrations were significantly higher in the subjects consuming berries compared to the control group (P=0.039 ANCOVA with repeated measures). During the berry consumption period the mean serum concentrations of quercetin ranged between 21.4 and 25.3 µg/l in the berry group, which was 32–51% higher compared with the control group. According to 3 day food records, there was no difference in quercetin intake at baseline, but at 8 weeks the intake was 12.3±1.4 mg/day (mean±s.e.m.) in the berry group and 5.8±0.6 mg/day in the control group (P=0.001).Conclusion: The results indicate that the berries used in this study are a good source of bioavailable quercetin.Sponsorship: The study was supported by the Academy of Finland, Juho Vainio Foundation and the Finnish Foundation for Cardiovascular Research.

Environmental factors in the development of obesity in identical twins.

OBJECTIVE: To study environmental factors promoting obesity when genetic factors are identical.DESIGN: Monozygotic (MZ) twins discordant for overweight were examined during a 3-day stay in an inpatient setting.SUBJECTS: The subjects were selected from the Finnish Twin Cohort. The study sample consisted of 23 healthy adult MZ twin pairs (14 female, nine male) with a difference of at least 3 kg/m2 in BMI. The mean BMI was 29.5 kg/m2 for the overweight twins and 22.9 kg/m2 for their lean co-twins.MEASUREMENTS: Interviews and standardized questionnaires were used to obtain information about energy and nutrient intake, eating behaviour, physical activity history, smoking and other background factors.RESULTS: The overweight co-twins had higher disinhibition scores (P=0.007) and hunger scores (P=0.005) in the 3-Factor Eating Questionnaire than their lean co-twins. Among women the mean daily energy intake was higher in the overweight twins than in their lean co-twins (8.8 vs 7.4 MJ; P=0.045). In the twins discordant for smoking the mean BMI was higher in non-smokers than in smokers (BMI 29.7±4.4 kg/m2 vs 23.8±3.1 kg/m2; P=0.031).CONCLUSIONS: Difficulty in controlling eating in both sexes and high energy intake in women were related to overweight, independent of genetic background. Smoking explained the BMI difference among smoking discordant pairs. It is probable that individual twin pairs had different reasons behind the variation in weight gain resulting in non-significant intrapair differences in single obesity-promoting factors. Difference in living conditions (e.g. family- and work-related factors) may have promoted different living habits, especially eating behaviour, and may have led to different weight gain in identical twins.

Comparison of nutrient intake data calculated on the basis of two different databases. Results and experiences from a Swedish–Finnish study

Background and objective: In international surveys of food consumption and nutrient intake, it is essential that the dietary data are comparable when different databases and calculation programs are used. The aim of the present analysis was to examine the comparability of nutrient intake data calculated on the basis of the Swedish food composition database PC-kost and the Finnish food composition database Nutrica.Subjects and methods: A total of 20 male adults currently living in Sweden were selected from a group of Finnish twins of the Finnish Twin Cohort Study. Food consumption data were collected by means of diet history interviews. The estimated intakes of 30 nutrients calculated on the basis of PC-kost were compared to the corresponding estimates calculated on the basis of Nutrica. The calculation procedures were standardised.Results: No statistically significant differences were observed in the mean intakes of energy, total fat, saturated fat, carbohydrates, dietary fibre, alcohol, cholesterol, vitamin A, retinol, β-carotene, vitamin D, α-tocopherol, riboflavin, niacin, vitamin B12, vitamin C or phosphorus. PC-kost yielded a 20% higher intake (NS) for vitamin D and 23% higher intake (P<0.001) for thiamine than Nutrica, which is mainly attributed to the differences in the enrichment of foodstuffs between Sweden and Finland. Conversely, PC-kost yielded 53% lower values (P<0.001) for selenium than Nutrica, owing to the increased selenium content in many Finnish foodstuffs as a result of the addition of selenium to fertilisers. Statistically significant differences were found for protein, monounsaturated fatty acids, vitamin B6, iron and sodium (5–9% higher values from PC-kost) and for polyunsaturated fatty acids, folate, zinc, calcium, magnesium and potassium (4–10% lower values from PC-kost). The variation in the intake of these nutrients between the two methods may be explained by the differences in foodstuff-specific nutrient values (eg product formulations), or differences in the sources of data, recipes or calculation procedures.The correlation coefficient was ≥0.81 for most nutrients. At least 85% of the subjects in each PC-kost quintile were classified into the same or adjacent Nutrica quintile for all nutrients.Conclusions: Our results indicate that, for a dominant part of the examined nutrients, the estimated intakes calculated by means of standardised procedures using the PC-kost and Nutrica databases are comparable between Sweden and Finland. Differences observed for some nutrients reflect either actual differences in foods between the two countries or methodological differences in the assessment of nutrient intakes.

Assessment of alcohol consumption by mailed questionnaire in epidemiological studies: Evaluation of misclassification using a dietary history interview and biochemical markers

Background: Self-reported information on alcohol from questionnaires is generally assumed to introduce misclassification of consumption, mainly in the direction of underestimation. The aim of this study was to evaluate self-reported information on alcohol consumption from a mailed questionnaire by comparing to a dietary history interview and biochemical markers of alcohol intake. Subjects and Methods: For 76 male twin pairs of the Finnish Twin Cohort Study aged 40–70 years information on self-reported alcohol consumption was collected through mailed questionnaire and dietary history interview. Carbohydrate-deficient transferrin (CDT), Gamma-glutamyltransferase (Gamma-GT) and mean corpuscular volume (MCV) were determined from blood samples. Results: Mean levels of CDT, gamma-GT and MCV showed a rise with increased self-reported alcohol consumption already at low levels of reported consumption (<20 g alcohol/day). There was a positive correlation between reported amount alcohol intake per day and levels of CDT (r = 0.46), gamma-GT (r = 0.32) and MCV (r = 0.36) but within the high consumption group (≥ 30 g/day) there was no such correlation. The questionnaire had sensitivity of 28–43% and specificity of 89% for identification of high consumers of alcohol using the biochemical markers as reference and sensitivity 41% and specificity 94% using the dietary history interview as reference. Sensitivity was improved when information on binge drinking (82%) or possible drinking problems (73%) was considered. Conclusion: Comparison to dietary history interview as well as to biochemical markers indicate that self-reported information on alcohol consumption from a mailed questionnaire may be used to distinguish between groups with different levels of alcohol consumption. The suggested misclassification of high consumers implies that only strong associations between high alcohol intake and disease are likely to be detected in studies based on questionnaire data.