The effect of replacing dietary saturated fat with polyunsaturated or monounsaturated fat on plasma lipids in free-living young adults

OBJECTIVE: To examine, in free-living adults eating self-selected diets, the effects on plasma cholesterol of substituting saturated fat rich foods with either n-6 polyunsaturated or monounsaturated fat rich foods while at the same time adhering to a total fat intake of 30-33% of dietary energy. DESIGN: Two randomised crossover trials. SETTING: General community. SUBJECTS: Volunteer sample of healthy free-living nutrition students at the University of Otago. Trial I, n=29; and trial II, n=42. INTERVENTIONS: In trials I and II participants were asked to follow for 2(1/2) weeks a diet high in saturated fat yet with a total fat content that conformed to nutrition recommendations (30-33% energy). During the 2(1/2) week comparison diet, saturated fat rich foods were replaced with foods rich in n-6 polyunsaturated fats (trial I) whereas in trial II the replacement foods were rich in monounsaturated fats. Participants were asked to maintain a total fat intake of 30-33% of energy on all diets. MAIN OUTCOME MEASURES: Energy and nutrient intakes, plasma triglyceride fatty acids, and plasma cholesterol. RESULTS: When replacing saturated fat with either n-6 polyunsaturated fat or monounsaturated fat, total fat intakes decreased by 2.9% energy and 5.1% energy, respectively. Replacing saturated fat with n-6 polyunsaturated fat (trial I) lowered plasma total cholesterol by 19% [from 4.87 (0.88) to 3.94 (0.92) mmol/l, mean (s.d.)], low density lipoprotein cholesterol by 22% [from 2.87 (0.75) to 2.24 (0.67) mmol/l], and high density lipoprotein cholesterol by 14% [from 1.39 (0.36) to 1.19 (0.34) mmol/l], whereas replacing saturated fat with monounsaturated fat (trial II) decreased total cholesterol by 12%, low density lipoprotein cholesterol by 15%, and high density lipoprotein cholesterol by 4%, respectively. The change in the ratio of total to high density lipoprotein cholesterol was similar during trial I and trial II. CONCLUSIONS: Young adults are very responsive to dietary-induced changes in plasma cholesterol even when an isocaloric replacement of saturated fat with n-6 polyunsaturated or monounsaturated fat is not achieved. Replacing saturated fat with either n-6 polyunsaturated or monounsaturated fat is equally efficacious at reducing the total to high density lipoprotein cholesterol ratio. SPONSORSHIP: University of Otago, Meadow Lea Ltd.     

The role of fat in the diet – quantity,quality and sustainability

Dietary fat should supply at least 15% of food energy including 2.5% energy and 0.5% energy as linoleic acid and alpha‐linolenic acid respectively: docosahexaenoic acid may also need to be supplied in infants. The proportion of energy from fat is not linked to risk of obesity, cardiovascular disease and cancer. The total cholesterol/HDL cholesterol, which is the most robust lipid indicator of risk of coronary heart disease (CHD), is lowered by unsaturated fatty acids, increased by trans fatty acids and not affected by saturated fatty acids compared with carbohydrates. Using clinical outcomes as endpoints, trans fatty acids increase, polyunsaturated fatty acids decrease and monounsaturated and saturated fatty acids have no effect on CHD risk. Recent recommendations for the prevention of CHD suggest partial replacement of saturated with polyunsaturated fatty acids to give energy intakes in the range of 6–11% energy and a daily intake of 0.25 g long‐chain n‐3 polyunsaturated fatty acids. The recommendation to increase the intake of long‐chain n‐3 fatty acids needs to be considered against the backdrop of falling fish stocks; it is likely that a novel source will be needed in the future. The projected growth in world population will require more fat, mainly for food energy. The oil palm requires only one tenth of the land required by oil seeds to produce the same amount of oil. The impact of increased use of vegetable oils as biodiesel needs to be urgently reconsidered owing to the adverse environmental and economic consequences to people living in South East Asia.     

Lack of efficacy of a food-frequency questionnaire in assessing dietary macronutrient intakes in subjects consuming diets of known composition

BACKGROUND: We compared the validity of a semiquantitative food-frequency questionnaire in assessing intakes of macronutrients (absolute amounts and percentages of energy) by 19 subjects fed natural-food diets of known composition. In small subsets (n = 5 or 6), we also tested 3-d diet records. OBJECTIVE: The objective of this study was to investigate the efficacy of food-frequency questionnaires and diet records in subjects fed natural-food diets of known composition. DESIGN: Each subject consumed 3 different diets for >/=6 wk and self-reported his or her food intake by using a food-frequency questionnaire and a diet record. The diets varied in their chemically analyzed contents of fat (15-35% energy), saturated fat (5-14%), monounsaturated fat (5-14.5%), polyunsaturated fat (2.5-10.5%), carbohydrate (49-68%), and cholesterol (108-348 mg/d). RESULTS: The food-frequency questionnaire significantly underestimated fat, saturated fat, monounsaturated fat, and protein intakes and significantly overestimated carbohydrate intake with the high-fat diet. The percentage of energy from fat was significantly underestimated for the high-fat diet and significantly overestimated for the very-low-fat diet. Estimates from the food-frequency questionnaire differed significantly from actual intakes for fat (absolute and percentage), saturated fat (absolute and percentage), monounsaturated fat (absolute and percentage), and protein (percentage) in the high-fat diet and for polyunsaturated fat (absolute and percentage), saturated fat (percentage), fiber (absolute), and cholesterol (daily absolute; in mg/d) in the lower-fat diet. Estimates from the diet records better agreed with actual intakes than did estimates from the food-frequency questionnaire except for monounsaturated fat (absolute and percentage) in the high-fat diet and polyunsaturated fat (percentage) in the lower-fat diet and the very-low-fat diet. CONCLUSION: Our data indicated that the food-frequency questionnaire did not provide reliable estimates of absolute amounts of dietary fats or cholesterol.     

Dietary fat intake and risk of type 2 diabetes in women

BACKGROUND: The long-term relations between specific types of dietary fat and risk of type 2 diabetes remain unclear. OBJECTIVE: Our objective was to examine the relations between dietary fat intakes and the risk of type 2 diabetes. DESIGN: We prospectively followed 84204 women aged 34-59 y with no diabetes, cardiovascular disease, or cancer in 1980. Detailed dietary information was assessed at baseline and updated in 1984, 1986, and 1990 by using validated questionnaires. Relative risks of type 2 diabetes were obtained from pooled logistic models adjusted for nondietary and dietary covariates. RESULTS: During 14 y of follow-up, 2507 incident cases of type 2 diabetes were documented. Total fat intake, compared with equivalent energy intake from carbohydrates, was not associated with risk of type 2 diabetes; for a 5% increase in total energy from fat, the relative risk (RR) was 0.98 (95% CI: 0.94, 1.02). Intakes of saturated or monounsaturated fatty acids were also not significantly associated with the risk of diabetes. However, for a 5% increase in energy from polyunsaturated fat, the RR was 0.63 (0.53, 0.76; P < 0.0001) and for a 2% increase in energy from trans fatty acids the RR was 1.39 (1.15, 1.67; P = 0.0006). We estimated that replacing 2% of energy from trans fatty acids isoenergetically with polyunsaturated fat would lead to a 40% lower risk (RR: 0.60; 95% CI: 0.48, 0.75). CONCLUSIONS: These data suggest that total fat and saturated and monounsaturated fatty acid intakes are not associated with risk of type 2 diabetes in women, but that trans fatty acids increase and polyunsaturated fatty acids reduce risk. Substituting nonhydrogenated polyunsaturated fatty acids for trans fatty acids would likely reduce the risk of type 2 diabetes substantially.     

Dietary assessment instruments for preschool children: reliability of parental responses to the 24-hour recall and a food frequency questionnaire

Nutrient intakes of preschool-age children were assessed with a 24-hour dietary recall and a 3-month food frequency questionnaire (FFQ). Parents of 55 preschoolers (mean age = 4.25 +/- 0.59 years) completed the recall and FFQ on two occasions 1 week apart. The recalls and FFQs were analyzed for energy, cholesterol, protein, total carbohydrate, calcium, sodium, potassium, and saturated, polyunsaturated, and monounsaturated fats; each nutrient was expressed as raw value, value per kg body weight, and value per 1,000 kcal. Test-retest reliability estimates for the 24-hour recall indicated significant variability in reported total energy intake, but stable reports of intake were observed for one or all units of expression for polyunsaturated fats, cholesterol, protein, total carbohydrate, calcium, and potassium. The FFQ showed significant positive test-retest reliability estimates for all nutrients for all units of expression. Comparison of the recall and FFQ data showed similar percentages of intakes of energy from fat, carbohydrate, and protein and significant correlations for reported intakes of cholesterol, protein, calcium, and potassium. Comparison of the recall and FFQ data with recall data from a comparable cohort showed lower reported intakes for our sample, with the exception of protein, carbohydrate, calcium, and potassium. If validation studies are successful, the FFQ may be useful in epidemiological studies of preschoolers' intakes over extended periods. The recall may prove to be a useful tool in the assessment of day-to-day variations in macronutrient intakes.     

Dietary intakes vary with age among Eskimo adults of Northwest Alaska in the GOCADAN study, 2000-2003

Dietary factors influence the development of cardiovascular disease (CVD). The diet of Alaskan Eskimos differs from that of other populations. We surveyed Eskimo adults in Northwest Alaska to document their usual dietary intakes, differences based on gender and age, and sources of selected nutrients, and to generate appropriate dietary advice to reduce CVD. Interviewers surveyed 850 men and women 17-92 y old, using a quantitative food-frequency instrument. We observed many significant (chi(2) analysis P < 0.05) differences in nutrient intakes among 3 age-groups. Energy intake from carbohydrate was negatively related to participant age-group (P < or = 0.01). Energy intake from all fats (P < 0.001) and polyunsaturated fat (P < or = 0.01) was positively related to age-group among both men and women in contrast to other studies in which age differences were either not observed or decreased with age. Native foods were major sources of monounsaturated and polyunsaturated fats, including 56% of (n-3) fatty acids primarily from seal oil and salmon. However, Native foods contributed significantly less to the diets of young adults than to those of elders, especially among women. Store-bought foods were the main sources of energy, carbohydrate, fat, saturated fat, and fiber for all adults. Based on their nutrient density and potential to inhibit CVD, continued consumption of traditional foods is recommended. Variations in intake by age may portend changing eating patterns that will influence CVD as participants age. These data will contribute to understanding dietary risk factors for cardiovascular disease in this population.     

Dietary fatty acid intakes and the risk of ovulatory infertility

BACKGROUND: Pharmacologic activation of the peroxisome proliferator-activated receptor gamma (PPAR-gamma) improves ovulatory function in women with polycystic ovary syndrome, and specific dietary fatty acids can affect PPAR-gamma activity. OBJECTIVE: The objective of the study was to assess whether the intakes of total fat, cholesterol, and major types of fatty acids affect the risk of ovulatory infertility. DESIGN: We conducted a prospective cohort study of 18 555 married, premenopausal women without a history of infertility who attempted a pregnancy or became pregnant between 1991 and 1999. Diet was assessed twice during follow-up by using a food-frequency questionnaire. RESULTS: During follow-up, 438 incidents of ovulatory infertility were reported. In logistic regression analyses, intakes of total fat, cholesterol, and most types of fatty acids were not related to ovulatory infertility. Each 2% increase in the intake of energy from trans unsaturated fats, as opposed to that from carbohydrates, was associated with a 73% greater risk of ovulatory infertility after adjustment for known and suspected risk factors for this condition [relative risk (RR) = 1.73; 95% CI: 1.09, 2.73]. Obtaining 2% of energy intake from trans fats rather than from n-6 polyunsaturated fats was associated with a similar increase in the risk of ovulatory infertility (RR = 1.79; 95% CI: 1.11, 2.89). In addition, obtaining 2% of energy from trans fats rather than from monounsaturated fats was associated with a more than doubled risk of ovulatory infertility (RR = 2.31; 95% CI: 1.09, 4.87). CONCLUSION: trans Unsaturated fats may increase the risk of ovulatory infertility when consumed instead of carbohydrates or unsaturated fats commonly found in nonhydrogenated vegetable oils.     

Alcohol consumption and nutrient intake in middle-aged Scottish men

The relation between alcohol consumption and dietary intake was examined in 164 middle-aged Scottish men taking part in a study of risk factors for coronary heart disease (CHD). A 7-d weighed dietary record was used to assess alcohol and nutrient intake. The mean daily intake of alcohol was 26 g (SD 31 g). Energy derived from alcohol tended to replace energy derived from other nutrients and increasing intake of alcohol was associated with a decrease in the amounts of carbohydrate, total fat, and saturated and monounsaturated fatty acids in the diet. Those with a low alcohol intake (0.1-9 g alcohol/d) had a higher intake of total fiber, cereal fiber, polyunsaturated fatty acids, and linoleic acid and a smaller proportion smoked cigarettes. The differences are small but may contribute to the lower mortality from CHD reported by other studies in those with a low alcohol intake.     

Grasas de la dieta y salud cardiovascular

Although dietary fat and its role in cardiovascular prevention has been one of the most extensively studied nutritional topics, it continues to be an ever-expanding research area. Particularly thanks to studies on Mediterranean diet, we now know that fat quality is more relevant than the amount of fat we eat in the diet. Thus, saturated and trans fats have been found to increase the risk of atherogenic disease. This is why it is recommended to substitute complex carbohydrates or unsaturated fat for unsaturated and trans fats with the aim of reducing saturated and trans fat intake to <10% and <1%, respectively, of the total calorie intake. Recent population studies, particularly that conducted in Kuopio, Finland, and those on Mediterranean diet, stress the important role of monounsaturated and polyunsaturated fats as key nutrients in preventing cardiovascular disease in modern societies. Furthermore, a special type of polyunsaturated fatty acids, i.e. those of the omega-3 (n-3) series, is increasingly becoming essential nutrients for a healthy diet, especially in the case of children. Therefore, there is a rationale for four the Scientific Societies that are strongly committed to disseminate the benefits of a healthy diet in preventing cardiovascular disease, and to prepare a joint statement with the purpose of spreading improved knowledge on the importance of changing to a healthy diet with a well-balanced fat intake for industrialized populations. Accordingly, a multidisciplinary panel of experts from the following institutions has developed the present joint statement targeted at both adults and children of different ages: Spanish Society of Arteriosclerosis, Spanish Society of Family and Community Medicine, Spanish Association of Paediatrics, Spanish Society of Gastroenterology, Hepatology and Paediatric Nutrition and Dietetics, and Spanish Society for Food Sciences.     

Diet and nutrient intakes and risk of non-Hodgkin's lymphoma in Connecticut women

A population-based case-control study (601 cases and 717 controls) was conducted in 1995-2001 among Connecticut women to evaluate the relation between diet and nutrient intakes and the risk of non-Hodgkin's lymphoma (NHL). When the highest quartile of intake was compared with the lowest, the authors found an increased risk of NHL associated with animal protein (odds ratio = 1.7, 95% confidence interval: 1.2, 2.4) and saturated fat (odds ratio = 1.9, 95% confidence interval: 1.1, 2.3) but a reduced risk for polyunsaturated fat (odds ratio = 0.6, 95% confidence interval: 0.4, 0.9) and no relation for vegetable protein and monounsaturated fat. An increased risk was also observed for higher intakes of retinol, eggs, and dairy products. On the other hand, a reduced risk was found for higher intakes of dietary fiber and for several fruit and vegetable items. Risk of NHL associated with diet and nutrient intakes appeared to vary based on NHL subtype. An association between dietary intake and NHL risk is biologically plausible because diets high in protein and fat may lead to altered immunocompetence, resulting in an increased risk of NHL. The antioxidant or inhibiting nitrosation reaction properties of vegetables and fruits may result in a reduced risk. Further investigation of the role of dietary intakes on the risk of NHL is warranted.     

Trends in nutrient intake of 10-year-old children over two decades (1973-1994) : the Bogalusa Heart Study

Dietary intakes of 10-year-old children were examined in seven cross-sectional surveys to observe secular trends in nutrient intake and food consumption patterns over 2 decades (1973-1994). Total energy intake remained unchanged from 1973 to 1994. However, when expressed as energy per kilogram body weight, intake decreased from 65.5 kcal in 1973 to 55.4 kcal in 1994 because children's weight increased. A significant trend was noted in ponderal index, which increased from 12.31 (1973-1974) to 13.71 (1992-1994), with an actual weight gain of 1.45 kg from 1973 to 1979 and 2.71 kg from 1981 to 1994. Linear trends also were noted for total fat (negative), saturated fat (negative), dietary cholesterol (negative), polyunsaturated fat (positive), and total carbohydrate (positive). There was a significant increase in percent energy from protein and carbohydrate and a significant decrease in percent energy from fat, primarily saturated and monounsaturated fat. Trends in nutrient intakes of children reflected trends in food consumption. The percentage of total fat from fats/oils, mixed meats, eggs, milk, pork, and desserts decreased, while that from poultry, cheese, and snacks increased. Although more children met dietary recommendations for total fat, saturated fat, and dietary cholesterol, the vast majority continued to exceed prudent diet recommendations.     

Nutrient intakes of different social-class groups: results from the Scottish Heart Health Study (SHHS)

Food frequency questionnaire and socio-demographic data were collected from over 10,000 Scottish men and women aged 40-59 years in a cross-sectional study of coronary heart disease (CHD) risk factors. Dietary intake, including the antioxidant vitamins C and E and beta-carotene, was assessed for different socio-economic groups. Trends in nutrient intakes were found with social-class (occupational) groups I-V. The non-manual-manual distinctions were clear even after standardizing for serum cotinine, and alternative classification by housing tenure and level of education did not confound the social-class effect. Total energy intake was significantly higher in the manual (men 10,363 KJ, women 7507 KJ) than in the non-manual (men 9156 KJ, women 7169 KJ) groups, and all nutrient amounts except for vitamin C, vitamin E, beta-carotene and fibre were significantly higher in the manual than the non-manual groups. Alcohol intake was lower in manual women, but higher in manual men compared with their respective non-manual groups. Sex and social-class differences were maintained after adjusting for total energy. Women in general, and manual women in particular, had the highest percentage energy from total fat (40.2) and saturated fat (18.2), while the percentage energy from polyunsaturated fat was lower in men than women, and lowest in manual men (4.4). The polyunsaturated:saturated fat (P:S) ratios were, for non-manual and manual men 0.32 and 0.31, and for non-manual and manual women 0.31 and 0.28. Fibre and antioxidant vitamin intakes, when expressed as nutrient densities, were lower in men than women, and lowest in manual men. Overall, men and women in manual occupations had a poorer-quality diet than did those in non-manual occupations. The coincident low P:S ratios and low antioxidant vitamin intakes in manual groups may contribute to an increased risk of CHD. Thus, the findings are compatible with the view that poor diet may be a contributory factor to the higher mortality rates for CHD which occur in the lower socio-economic groups.     

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.     

Interrelation of saturated fat, trans fat, alcohol intake, and subclinical atherosclerosis

BACKGROUND: Intake of saturated fat, trans fat, and alcohol alter cardiovascular disease risk, but their effect on subclinical atherosclerosis remains understudied. OBJECTIVE: The objective was to examine and quantify the interrelation of saturated fat, trans fat, alcohol intake, and mean carotid artery intimal medial thickness (IMT). DESIGN: We conducted a population-based, cross-sectional study among 620 persons of Aboriginal, South Asian, Chinese, or European origin aged 35-75 y, who had lived in Canada for >or=5 y. Mean IMT was calculated from 6 well-defined segments of the right and left carotid arteries with standardized B-mode ultrasound, and saturated fat, trans fat, and alcohol intakes were measured with validated food-frequency questionnaires. RESULTS: For every 10-g/d increase in saturated fat intake, IMT was 0.03 mm higher (P=0.01) after multivariate adjustment. A 1-g/d higher intake of trans fat was associated with a 0.03-mm higher IMT (P=0.02) after multivariate adjustment. The ratio of polyunsaturated to saturated fat (P:S) was inversely associated with IMT after multivariate adjustment (change in IMT: -0.06 mm; P<0.01). Saturated and trans fat intakes were independently associated with IMT thickness (change in IMT: 0.03 mm; P<0.01 and 0.02, respectively; P for interaction=0.01). Polyunsaturated, monounsaturated, cholesterol, and total fat intakes were unrelated to IMT. The relation between saturated fat intake and IMT strengthened (beta=0.0066, P<0.001) in persons who never or rarely consumed alcohol as compared with moderate or heavy drinkers (beta=0.0001, P=0.79, P for interaction=0.01). CONCLUSION: Higher habitual intakes of saturated and trans fats are independently associated with increased subclinical atherosclerosis, and alcohol intake may attenuate the relation between saturated fat and subclinical atherosclerosis.     

Validation of a semi-quantitative food frequency questionnaire: comparison with a 1-year diet record

The validity of a self-administered semi-quantitative food frequency questionnaire was evaluated for a group of 27 men and women aged 20 to 54. Intakes of 18 nutrients computed from the questionnaire were compared with those derived from 1-year diet records completed approximately 18 months earlier. The questionnaire estimates of mean nutrient intake were within 10% of the mean diet record measurements for 11 of the 18 nutrients evaluated, and the difference was less than 25% for all but one nutrient (total vitamin A). Correlation coefficients comparing unadjusted nutrient intakes measured by the two methods ranged from 0.38 (vitamin C) to more than 0.65 (total calories, total fat, saturated fat, polyunsaturated fat, oleic acid, and cholesterol). The overall mean of correlation coefficients comparing intakes of the 18 nutrients measured by questionnaire and by diet record was 0.60. Coefficients for macronutrients decreased somewhat after adjustment for age and gender or caloric intake. The data provide further evidence that a simple and relatively inexpensive questionnaire can provide useful information on dietary intake over an extended period.     

Exchanging partially hydrogenated fat for palmitic acid in the diet increases LDL-cholesterol and endogenous cholesterol synthesis in normocholesterolemic women

Partial hydrogenation of oil results in fats containing unusual isomeric fatty acids characterized by cis and trans configurations. Hydrogenated fats containing trans fatty acids increase plasma total cholesterol (TC) and LDL-cholesterol while depressing HDL-cholesterol levels. Identifying the content of trans fatty acids by food labeling is overshadowed by a reluctance of health authorities to label saturates and trans fatty acids separately. Thus, it is pertinent to compare the effects of trans to saturated fatty acids using stable isotope methodology to establish if the mechanism of increase in TC and LDL-cholesterol is due to the increase in the rate of endogenous synthesis of cholesterol. Ten healthy normocholesterolemic female subjects consumed each of two diets containing approximately 30% of energy as fat for a fourweek period. One diet was high in palmitic acid (10.6% of energy) from palm olein and the other diet exchanged 5.6% of energy as partially hydrogenated fat for palmitic acid. This fat blend resulted in monounsaturated fatty acids decreasing by 4.9 % and polyunsaturated fats increasing by 2.7%. The hydrogenated fat diet treatment provided 3.1% of energy as elaidic acid. For each dietary treatment, the fractional synthesis rates for cholesterol were measured using deuterium-labeling procedures and blood samples were obtained for blood lipid and lipoprotein measurements. Subjects exhibited a higher total cholesterol and LDL-cholesterol level when consuming the diet containing trans fatty acids while also depressing the HDL-cholesterol level. Consuming the partially hydrogenated fat diet treatment increased the fractional synthesis rate of free cholesterol. Consumption of hydrogenated fats containing trans fatty acids in comparison to a mixtur e of palmitic and oleic acids increase plasma cholesterol levels apparently by increasing endogenous synthesis of cholesterol.     

Phylloquinone intake as a marker for coronary heart disease risk but not stroke in women

OBJECTIVE: To examine the feasibility of using phylloquinone intake as a marker for coronary heart disease (CHD) and stroke risk in women. DESIGN AND SETTING: Nurses' Health Study, a prospective cohort study during 1984-2000. Dietary data were collected in 1984, 1986, 1990, and 1994 using a validated semiquantitative food frequency questionnaire. SUBJECTS: A total of 72 874 female nurses, aged 38-65 y, without previously diagnosed angina, myocardial infarction (MI), stroke, or cancer at baseline. MAIN OUTCOME MEASURES: Incidence of nonfatal MI, CHD deaths, total CHD events, ischemic, and total strokes. RESULTS: There were 1679 CHD events (1201 nonfatal) and 1009 strokes (567 ischemic). After adjustment for age and lifestyle factors associated with cardiovascular disease risk, the multivariate relative risks (RR) (95% CI) of total CHD from the lowest to the highest quintile category of phylloquinone intake were 1 (reference), 0.80 (0.69-0.94), 0.86 (0.74-1.00), 0.77 (0.66-0.99), and 0.79 (0.68-0.92), P for trend=0.01. Further adjustment for dietary intakes of saturated fat, polyunsaturated fat, trans fatty acids, eicosapentaenoic, and docosahexaenoic acids, cereal fiber, and folate attenuated the association (RR comparing extreme quintiles 0.84 [0.71-1.00], P for trend=0.12). Incidence rates of total or ischemic strokes were not associated with phylloquinone intake. CONCLUSION: The data suggest that high phylloquinone intake may be a marker for low CHD risk. Dietary and lifestyle patterns associated with phylloquinone intakes, rather than intake of the nutrient itself, might account for all or part of the weak association. .     

Nutritive value of fats in 3 basic meals of university students

The nutritional value of assessed of fat consumed by a selected group of university students. The assessment showed that although the intake of fat with the diet was adequate, its nutritional value might arouse objections. The predominant group constituted monounsaturated fats, saturated fats were present in about one-third lower amount, while polyunsaturated fats accounted for only one fourth of the amount of monounsaturated fats. The percent of energy derived from unsaturated fatty acids in the daily food ration differed from one ration to another, but its mean value was 4.34% while the percent of energy from hypercholesterolaemia-producing fatty acids was higher--10.6%. In the analysed meals the content of erucic acid was relatively low.     

Dietary fat,calories, and the risk of breast cancer in postmenopausal women: a prospective population-based study.

We tested the hypothesis that a high-fat diet increases the risk of breast cancer in a population-based study of 590 women aged 40-79 years who were without known breast cancer when they provided a quantitative 24-hour diet recall. Fifteen postmenopausal women were diagnosed with incident breast cancer during the next 15 years (approximately 7600 person-years of follow-up). These women had significantly higher age-adjusted intake of all fats (monounsaturated, polyunsaturated, and saturated), and oleic, linoleic, and linolenic acids, with a stepwise increase in risk across tertiles of intake. Fat intake was associated with total calories, protein, and carbohydrates, and women with incident breast cancer consumed more calories, protein, and carbohydrates than did other subjects. When each nutrient variable (calories, fats, protein, and carbohydrates) was adjusted for age, body mass index, age at menopause, parity, and alcohol consumption, the strongest risks for incident breast cancer were associated with total calories (relative risk per standard deviation = 2.72, 95% confidence interval = 1.51-4.89, p = 0.002) and total fats (relative risk per standard deviation = 2.01, 95% confidence interval = 1.19-3.41, p = 0.01). Fat composition of the diet, expressed either as percent of energy or as fat intake adjusted for calories by regression analysis, was not significantly associated with risk of breast cancer. These results support the hypothesis that total calorie consumption, as well as dietary fat consumption, is a risk factor for breast cancer in postmenopausal women, and parallel observations in animal models.     

Diet during early pregnancy and development of gestational diabetes

Diet composition may be a modifiable predictor of risk for abnormal glucose tolerance during pregnancy. Prior studies suggest that diets high in total fat, saturated fat, red and processed meats, and with high glycaemic load increase the risk of developing gestational diabetes mellitus (GDM), while polyunsaturated fats, carbohydrates and fibre are protective. The aim of this study was to investigate associations of these and other nutrients and foods, including n-3 fatty acids, trans fats, whole grains and dietary patterns, with risk of GDM. We studied 1733 women with singleton pregnancies enrolled in Project Viva, a prospective pregnancy and birth cohort study in eastern MA. Using multinomial logistic regression, we examined associations of first trimester diet, assessed by validated food frequency questionnaire, with results of glucose tolerance testing at 26-28 weeks of gestation. A total of 91 women developed GDM and 206 women had impaired glucose tolerance (IGT). Pre-pregnancy body mass index (BMI) was a strong predictor for GDM risk (OR 3.44 [95% CI 1.88, 6.31] for pre-pregnancy BMI > or =30 vs. <25 kg/m(2)). After adjustment for confounders, the OR [95% CI] for risk of GDM for total dietary fat was 1.00 [0.96, 1.05], for saturated fat 0.98 [0.88, 1.08], for polyunsaturated fat 1.09 [0.94, 1.26], for trans fat 0.87 [0.51, 1.49], and for carbohydrates 1.00 [0.96, 1.03] per each 1% of total energy. The adjusted OR [95% CI] for risk of GDM for a one standard deviation increase in energy-adjusted glycaemic load (32 units, about two soft drinks) was 0.96 [0.76, 1.22] and for each daily serving of whole grains was 0.90 [0.73, 1.13]. Dietary patterns and intake of red and processed meats were not predictive of glucose tolerance outcome. Estimates for IGT were similar to those for GDM. Intake of n-3 fatty acids was associated with increased GDM risk (OR 1.11 [95% CI 1.02, 1.22] per each 300 mg/day), but not with IGT risk. Except for this finding, perhaps due to chance, these data do not show that nutrient or food intake in early pregnancy is linked to risk of GDM. Nutritional status entering pregnancy, as reflected by pre-pregnancy BMI, is probably more important than pregnancy diet in development of GDM.