Comparison of anthropometric, metabolic and dietary fatty acids profiles in lean and obese dyslipidaemic Asian Indian male subjects

OBJECTIVES: To compare obesity measures, metabolic profiles and dietary fatty acids in lean and obese dyslipideamic Asian Indian male subjects. DESIGN: Cross-sectional. SETTINGS: Asian Indians living in the eastern part of India.Subjects:One hundred and thirty (Group I: lean control, n=50; Group II: lean dyslipidaemic, n=40 and Group III: obese dyslipidaemic, n=40) Asian Indian male subjects (> or =30 years) living in the eastern part of India. METHODS: Anthropometric measures namely height, weight, circumferences of waist (WC) and hip, lipids (total cholesterol (TC) and triglycerides (TG)), lipoproteins (high- (HDL) and low-density lipoproteins (LDL)), fasting plasma glucose (FPG) and dietary fatty acids were obtained from each participant. Obesity measures, that is, body mass index (BMI), waist-hip ratio (WHR) and conicity index (CI) were subsequently calculated from anthropometric measures. Obesity was defined as individuals having BMI> or =25 kg/m(2). Subjects with one or more of the following conditions were considered as dyslipidaemic: TG> or =2.3 mmol/l, TC> or =6.2 mmol/l, or TC/HDL> or =4.4 mmol/l. Daily intake of nutrients as well as saturated (SFA), monounsaturated (MUFA) and polyunsaturated fatty acids (PUFA) were estimated by adding together all the foodstuffs consumed on weekly and monthly manner. Conversion of foodstuffs into nutrients was performed according to standard nutritive values of Indian foodstuffs. RESULTS: Analysis of variance with Scheffe's post hoc test revealed that Group I had significantly lower mean compared to both Group II and Group III for age, WC, WHR, CI, TC, TG, LDL, FPG, total carbohydrates intake and intake of trans fatty acids. On the other hand, Group I had significantly lower mean than Group III only for BMI as well as intake of total proteins, total fats, total energy and erucic acids. Although, Group I had significantly greater mean compared to both Group II and Group III for HDL, UFA/SFA, MUFA/SFA and PUFA/SFA. Pearson's partial correlations (controlling for age and total energy) revealed that central obesity measures (WC, WHR and CI) had significant association with dietary fatty acids and their ratios. Furthermore, partial correlations (controlling for age) also showed that the ratios of unsaturated to SFA had significant negative association with lipids, lipoproteins (except HDL) and plasma glucose. Discriminant function analysis revealed that overall 78% of all entries were positively (correctly) classified in three groups using fatty acids and their ratios. CONCLUSION: It seems rational to argue that while dealing with dyslipidaemic Asian Indians, clinicians should consider obesity measures, metabolic profiles and dietary fatty acids simultaneously to better comprehend the condition (s).     

The cholesterolaemic effects of dietary fats in cholesteryl ester transfer protein transgenic mice.

In order to investigate the role of cholesteryl ester transfer protein (CETP) in the cholesterolaemic response to dietary fats, we analysed plasma lipid profiles of CETP-transgenic and control C57BL/6 mice fed standard chow (AIN-93G; AIN), a low-fat diet, and diets high in butter (saturated fatty acids; SFA), high-oleic acid safflower oil (monounsaturated fatty acids; MUFA), and safflower oil (polyunsaturated fatty acids; PUFA) for 5 weeks. Each group contained four or five mice. There were significant diet and dietxgenotype effects on plasma total cholesterol (TC; and respectively), liver TC ( and respectively), and esterified cholesterol (EC; and respectively); diet effects on plasma triacylglycerol liver free cholesterol and body weight a genotype effect on body-weight gain and a dietxgenotype effect on energy intake In transgenic mice the SFA diet caused significantly higher plasma TC than the PUFA diet In control mice MUFA and PUFA diets, but not the SFA diet, caused significantly higher plasma TC than the low-fat and AIN diets Transgenic mice fed PUFA had lower plasma TC while transgenic mice fed MUFA had lower LDL+VLDL-cholesterol than controls in the same dietary groups. Transgenic mice fed MUFA and PUFA diets also had significantly higher liver TC and respectively) and EC and respectively) than controls fed the same diets. In the present study we showed that: (1) CETP transgenic mice had a cholesterolaemic response to dietary fats similar to that in human subjects; (2) CETP transgenic mice fed PUFA showed significantly lower plasma TC, while those fed MUFA had lower LDL+VLDL-cholesterol than controls; (3) hepatic accumulation of cholesterol, possibly resulting from the combination of the enhanced cholesteryl ester transfer to apolipoprotein B-containing lipoproteins and increased hepatic uptake of cholesterol, may contribute to the cholesterol-lowering effect of MUFA and PUFA in CETP-transgenic mice; (4) CETP may play a role in appetite and/or energy regulation.     

脂肪酸构成对兔主动脉粥样硬化形成的作用

目的 :　探讨防治动脉粥样斑形成的膳食脂肪酸构成 (饱和∶单不饱和∶多不饱和脂肪酸 )并从血脂代谢上阐释其机制。方法 :　 3 1只雄性兔分为脂肪酸构成 1∶ 1∶ 1 (I)、1∶ 1 .7∶1 .2 (II)、1∶ 1 .7∶ 2 .3 (III)的高脂组和对照组。喂养前、喂养第 44d和 77d测空腹血浆总甘油三酯(TG)、总胆固醇 (TC)、低密度脂蛋白胆固醇 (LDL-C)和高密度脂蛋白胆固醇 (HDL-C) ,第 77d处死动物 ,测定升主动脉粥样硬化斑块面积。结果 :　 (1 ) I、II、III组斑块面积 (mm2 )分别为 4.45±2 .3 8、6.0 9± 2 .73和 3 .90± 1 .68,III组显著低于 II组 (P<0 .0 5 ) ;(2 )喂养第 77d III组兔空腹血浆 TG为 0 .63± 0 .2 5 mmol/L显著低于 I组 1 .0 1± 0 .3 8和 II组 1 .2 4± 1 .1 7(P<0 .0 5 ) ,III组HDL-C/TG为 3 .68± 1 .69mmol/L,显著高于 I、II组的 2 .72± 1 .3 8和 2 .76± 1 .5 3 (P<0 .0 5 ) ,III组血浆 TG77d的累积浓度明显小于 I、II组 (P<0 .0 5 )。结论 :　 1∶ 1 .7∶ 2 .3膳食脂肪酸构成能降低血浆 TG和升高 HDL-C/TG,具有抗主动脉粥样硬化的作用     

Effect of dietary fatty acid composition on substrate utilization and body weight maintenance in humans

Background/purpose

Dietary fat content is a primary factor associated with the increase in global obesity rates. There is a delay in achieving fat balance following exposure to a high-fat (HF) diet (≥ 40 % of total energy from fat) and fat balance is closely linked to energy balance. Exercise has been shown to improve this rate of adaptation to a HF diet. Recently, however, the role of dietary fatty acid composition on energy and macronutrient balance has come into question.

Methods

We chose studies that compared monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), and saturated fatty acids (SFA). We have reviewed studies that measured diet-induced thermogenesis (DIT), energy expenditure (EE), or fat oxidation (FOx) in response to a HF meal challenge, or long-term dietary intervention comparing these fatty acids.

Results

While single-meal studies show that SFA induce lower DIT and FOx compared to unsaturated fats, the effect of the degree of unsaturation (MUFA vs. PUFA) appears to yet be determined. Long-term dietary interventions also support the notion that unsaturated fats induce greater EE, DIT, and/or FOx versus SFA and that a high MUFA diet induces more weight loss compared to a high SFA diet. Sex and BMI status also affect the metabolic responses to different fatty acids; however, more research in these areas is warranted.

Conclusion

SFA are likely more obesigenic than MUFA, and PUFA. The unsaturated fats appear to be more metabolically beneficial, specifically MUFA ≥ PUFA > SFA, as evidenced by the higher DIT and FOx following HF meals or diets.     

Dietary intake of fats and fatty acids in the Korean population: Korea National Health and Nutrition Examination Survey, 2013

BACKGROUND/OBJECTIVESThe aim of this study was to estimate average total fat and fatty acid intakes as well as identify major food sources using data from the Korea National Health and Nutrition Examination Survey (KNHANES) VI-1 (2013).SUBJECTS/METHODSTotal fat and fatty acid intakes were estimated using 24-hour dietary recall data on 7,048 participants aged ≥ 3 years from the KNHANES VI-1 (2013). Data included total fat, saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), n-3 fatty acid (n-3 FA), and n-6 fatty acid (n-6 FA) levels. Population means and standard errors of the mean were weighted in order to produce national estimates and separated based on sex, age, income, as well as residential region. Major food sources of fat, SFA, MUFA, PUFA, n-3 FA, and n-6 FA were identified based on mean consumption amounts of fat and fatty acids in each food.RESULTSThe mean intake of total fat was 48.0 g while mean intakes of SFA, MUFA, PUFA, n-3 FA, and n-6 FA were 14.4 g, 15.3 g, 11.6 g, 1.6 g, and 10.1 g, respectively. Intakes of MUFA and SFA were each higher than that of PUFA in all age groups. Pork was the major source of total fat, SFA, and MUFA, and soybean oil was the major source of PUFA. Milk and pork were major sources of SFA in subjects aged 3-11 years and ≥ 12 years, respectively. Perilla seed oil and soybean oil were main sources of n-3 FA in subjects aged ≥ 50 years and aged < 50 years, respectively.CONCLUSIONSEstimation of mean fatty acid intakes of this study using nationally represented samples of the Korean population could be useful for developing and evaluating national nutritional policies.     

不同水产品消费地区孕妇脂肪酸摄入量调查

目的分析我国不同水产品消费地区孕妇脂肪酸摄入状况。方法应用食物频率法分别在淡水产品消费量较高的江苏省句容市、海产品消费量较高的山东省即墨市以及水产品消费量很低的河南省辉县市,对180名22~35岁孕妇进行妊娠中、晚期膳食调查,分析脂肪酸摄入状况。结果句容、即墨、辉县孕妇膳食中饱和脂肪酸(SFA),单不饱和脂肪酸(MUFA),多不饱和脂肪酸(PUFA)的比例分别为1:2.50:1.05、1:1.44:1.31、1:1.48:1.24。n-6PUFA/n-3PUFA分别为5.51、17.62、13.85。辉县孕妇膳食中SFA和n-6PUFA摄入量最高;句容孕妇膳食中MUFA和n-3PUFA摄入量最高;即墨孕妇膳食中二十碳五烯酸(EPA,20:5n-3)和二十二碳六烯酸(DHA,22:6n-3)摄入量最高。句容和辉县孕妇膳食中的花生四烯酸(AA,20:4n-6)摄入量均高于即墨。三地孕妇膳食中EPA和DHA均主要来自水产品;AA主要来自畜禽肉类和蛋类;亚麻酸(ALA,18:3n-3)和亚油酸(LA,18:2n-6)主要来自食用油、畜禽肉类、坚果和主食及糕点类。结论三地区SFA、MUFA、PUFA的摄入比例合理。即墨、辉县孕妇膳食中n-6/n-3PUFA比例偏高;即墨市孕妇膳食中DHA和EPA摄入量高于其它两地,但仍明显低于推荐量。建议增加孕妇膳食n-3PUFA,特别是DHA和EPA的摄入量。     

Total fat and fatty acid intakes and food sources in Mediterranean older adults requires education to improve health

The proportion of fat has increased at the expense of carbohydrates in the past years, and we aimed to assess total fat and fatty acids intake and their food sources among Mediterranean older adults and compare them to national and international recommendations. This study was conducted in 211 participants to determine lipid and fatty acid intake using a Spanish food database. The mean daily intake of lipids was 68.6 g/d (standard deviation [SD]: 24.6; 34.4%, SD: 7.0 of total energy consumed). Men, younger participants, and those with higher education ingested more lipids than their peers. Fatty acids were ingested as follows (expressed as percentage of total energy intake): monounsaturated fatty acids (MUFA) (16.7%, SD: 4.1), saturated fatty acids (SFA) (9.6%, SD: 2.6), and polyunsaturated fatty acids (PUFA) (5.0%, SD: 1.7). Oils and seeds were the highest contributors in the intake of lipids (38.8%, SD: 16.0), MUFA (53.9%, SD: 18.7), and PUFA (33.0%, SD: 16.4). The total fat intake (34.4%, SD: 7.0) was within the range of International and Spanish recommendations among Mediterranean older adults; however, the intake of fatty acids did not abide by the international (PUFA) and Spanish recommendations (SFA, MUFA). α-Linoleic acid, eicosapentaenoic acid, and docosahexaenoic acid intake were lower than recommendations, but cholesterol intake (243.9 mg, SD: 140.4) was within the range of recommendations. Therefore, public health campaigns are needed to encourage older adults to decrease SFA intake and increase adherence to the Mediterranean diet pattern for a better health.     

Increasing trends in dietary total fat and fatty acid intake among Korean children: using the 2007–2017 national data

BACKGROUND/OBJECTIVESThe prevalence of obesity has been increasing in Korean children. As an unhealthy diet is known as one of the major determinants of childhood obesity, assessing and monitoring dietary fat intake of children is needed.SUBJECTS/METHODSThis analysis included 9,998 children aged 3–11 yrs from the 2007–2017 Korea National Health and Nutrition Examination Surveys. Dietary data were obtained from a single 24-h dietary recall. Intakes of total fat and fatty acids, including saturated fatty acid (SFA), monounsaturated fatty acid (MUFA), polyunsaturated fatty acid (PUFA), n-3 fatty acid (n-3 FA), and n-6 fatty acid (n-6 FA) were evaluated as the absolute amount (g) and proportion of energy from each fatty acid (% of energy). The total fat and SFA intake were also assessed according to compliance with dietary guidelines. Linear trends in the dietary fats intake across the survey period were tested using multiple regression models.RESULTSTotal fat intake significantly increased from 38.5 g (20.3% of energy) to 43.4 g (23.3% of energy) from 2007 to 2017. This increase was mainly accounted for the increases in intakes of SFA (7.2% to 8.4% of energy) and MUFA (6.2% to 7.5% of energy). PUFA intake increased from 4.4 to 4.7% of energy during the 11-yrs period: from 0.57 to 0.63% of energy for n-3 FA and from 3.8 to 4.1% of energy for n-6 FA. The proportions of children who consumed amounts exceeding the dietary guidelines for total fat and SFA significantly increased from 2007 to 2017, with increases from 9.8% to 17.4% for total fat and from 36.9% to 50.9% for SFA.CONCLUSIONSProminent increasing trends in the consumption of total fat and SFA but tiny change in n-3 FA intake were observed in Korean children. The healthy intake of dietary fats should be emphasized in this population.     

Effects of dietary fatty acids on the composition and oxidizability of low-density lipoprotein

OBJECTIVE: The objective of this study was to compare the effects of dietary monounsaturated fatty acids (MUFA), n-6 and n-3 polyunsaturated fatty acids (PUFA) on LDL composition and oxidizability. DESIGN, SETTING AND SUBJECTS: Sixty-nine healthy young volunteers, students at a nearby college, were included. Six subjects withdrew because of intercurrent illness and five withdrew because they were unable to comply with the dietary regimen. INTERVENTIONS: The participants received a 2-week wash-in diet rich in saturated fatty acids (SFA) followed by diets rich in refined olive oil, rapeseed oil or sunflower oil for 4 weeks. Intakes of vitamin E and other antioxidants did not differ significantly between the diets. RESULTS: At the end of the study, LDL oxidizability was lowest in the olive oil group (lag time: 72.6 min), intermediate in the rapeseed oil group (68.2 min) and highest in the sunflower oil group (60.4 min, P<0.05 for comparison of all three groups). Despite wide variations in SFA intake, the SFA content of LDL was not statistically different between the four diets (25.8-28.5% of LDL fatty acids). By contrast, the PUFA (43.5%-60.5% of LDL fatty acids) and MUFA content of LDL (13.7-29.1% of LDL fatty acids) showed a wider variability dependent on diet. CONCLUSIONS: Enrichment of LDL with MUFA reduces LDL susceptibility to oxidation. As seen on the rapeseed oil diet this effect is independent of a displacement of higher unsaturated fatty acids from LDL. Evidence from this diet also suggests that highly unsaturated n-3 fatty acids in moderate amounts do not increase LDL oxidizability when provided in the context of a diet rich in MUFA.     

Fatty acid composition of nuts--implications for cardiovascular health

It is well established that, due to their high content of saturated fatty acids (SFA), the intake of meat and meat products is strongly associated with elevated blood cholesterol concentrations and an increased risk of hypertension, diabetes and cardiovascular diseases. Conversely, the intake of foods rich in unsaturated fatty acids, such as those contained in most vegetable fats and oils and oily fish, is associated with improved lipid profiles, a lower potency of intermediate biomarkers of atherosclerosis and lesser incidence of cardiovascular diseases. There are persuasive evidences that dietary substitution of monounsaturated fatty acids (MUFA) or n-6 polyunsaturated fatty acids (PUFA) for SFA lowers blood cholesterol and may have beneficial effects on inflammation, thrombosis, and vascular reactivity. MUFA may have an advantage over PUFA because enrichment of lipoprotein lipids with MUFA increases their resistance to oxidation. Marine n-3 PUFA have a number of anti-atherosclerotic effects, including anti-arrhythmic properties and, at relatively high doses, reduce serum triglycerides. These effects appear to be shared in part by vegetable n-3 PUFA. Nuts are natural foods rich in unsaturated fatty acids; most nuts contain substantial amounts of MUFA, while walnuts are especially rich in both n-6 and n-3 PUFA. Healthy fats in nuts contribute to the beneficial effects of frequent nut intake observed in epidemiological studies (prevention of coronary heart disease, diabetes, and sudden death) and in short-term feeding trials (cholesterol lowering, LDL resistance to oxidation, and improved endothelial function).     

Dietary Fat and Polyunsaturated Fatty Acid Intakes during Childhood Are Prospectively Associated with Puberty Timing Independent of Dietary Protein

Dietary fat and fat quality have been inconsistently associated with puberty timing. The aim of this study was to investigate the prospective associations of dietary fat, saturated fatty acid (SFA), polyunsaturated fatty acid (PUFA), and monounsaturated fatty acid (MUFA) with puberty timing. Using longitudinal data from China Health and Nutrition Survey (CHNS) and Southwest China Childhood Nutrition and Growth (SCCNG) Study, we analyzed dietary data, anthropometric measurements, and potential confounders. Dietary intakes were assessed by 3-day 24-h recalls. Age at Tanner stage 2 for breast/genital development (B2/G2) and age at menarche/voice break (M/VB) were used as puberty development markers. Cox proportional hazard regression models were used to estimate the relevance of dietary intake of total fat, SFA, PUFA, and MUFA on puberty timing. Among 3425 girls and 2495 boys, children with higher intakes of total fat and PUFA were more likely to reach their B2/G2 or M/VB at an earlier age. Associations were not attenuated on additional adjustment for childhood dietary protein intake. However, higher intakes of SFA or MUFA were not independently associated with puberty development. A higher intake of dietary fat and PUFA in prepuberty was associated with earlier puberty timing, which was independent of dietary protein intake.     

A review of the evidence for the effects of total dietary fat, saturated, monounsaturated and n-6 polyunsaturated fatty acids on vascular function, endothelial progenitor cells and microparticles

Vascular dysfunction is recognised as an integrative marker of CVD. While dietary strategies aimed at reducing CVD risk include reductions in the intake of SFA, there are currently no clear guidelines on what should replace SFA. The purpose of this review was to assess the evidence for the effects of total dietary fat and individual fatty acids (SFA, MUFA and n-6 PUFA) on vascular function, cellular microparticles and endothelial progenitor cells. Medline was systematically searched from 1966 until November 2010. A total of fifty-nine peer-reviewed publications (covering fifty-six studies), which included five epidemiological, eighteen dietary intervention and thirty-three test meal studies, were identified. The findings from the epidemiological studies were inconclusive. The limited data available from dietary intervention studies suggested a beneficial effect of low-fat diets on vascular reactivity, which was strongest when the comparator diet was high in SFA, with a modest improvement in measures of vascular reactivity when high-fat, MUFA-rich diets were compared with SFA-rich diets. There was consistent evidence from the test meal studies that high-fat meals have a detrimental effect on postprandial vascular function. However, the evidence for the comparative effects of test meals rich in MUFA or n-6 PUFA with SFA on postprandial vascular function was limited and inconclusive. The lack of studies with comparable within-study dietary fatty acid targets, a variety of different study designs and different methods for determining vascular function all confound any clear conclusions on the impact of dietary fat and individual fatty acids on vascular function.     

A macadamia nut-rich diet reduces total and LDL-cholesterol in mildly hypercholesterolemic men and women

Epidemiologic studies and clinical trials have demonstrated that the unique fatty acid profile of nuts beneficially affects serum lipids/lipoproteins, reducing cardiovascular disease (CVD) risk. Nuts are low in SFA and high in PUFA and monounsaturated fatty acids (MUFA). Macadamia nuts are a rich source of MUFA. A randomized, crossover, controlled feeding study (5-wk diet periods) compared a Macadamia nut-rich diet [42.5 g (1.5 ounces)/8.79 MJ (2100 kcal)] [MAC; 33% total fat (7% SFA, 18% MUFA, 5% PUFA)] vs. an average American diet [AAD; 33% total fat (13% SFA, 11% MUFA, 5% PUFA)] on the lipid/lipoprotein profile of mildly hypercholesterolemic (n = 25; 15 female, 10 male) subjects. Serum concentrations of total cholesterol (TC) and LDL cholesterol (LDL-C) following the MAC (4.94 +/- 0.17 mmol/L, 3.14 +/- 0.14 mmol/L) were lower than the AAD (5.45 +/- 0.17 mmol/L, 3.44 +/- 0.14 mmol/L; P < 0.05). The serum non-HDL cholesterol (HDL-C) concentration and the ratios of TC:HDL-C and LDL-C:HDL-C were reduced following consumption of the MAC diet (3.83 +/- 0.17, 4.60 +/- 0.24, and 2.91 +/- 0.17, respectively) compared with the AAD (4.26 +/- 0.17, 4.89 +/- 0.24, and 3.09 +/- 0.18, respectively; P < 0.05). There was no change in serum triglyceride concentration. Thus, macadamia nuts can be included in a heart-healthy dietary pattern that reduces lipid/lipoprotein CVD risk factors. Nuts as an isocaloric substitute for high SFA foods increase the proportion of unsaturated fatty acids and decrease SFA, thereby lowering CVD risk.     

Acute effects of meal fatty acid composition on insulin sensitivity in healthy post-menopausal women

Postprandial plasma insulin concentrations after a single high-fat meal may be modified by the presence of specific fatty acids although the effects of sequential meal ingestion are unknown. The aim of the present study was to examine the effects of altering the fatty acid composition in a single mixed fat-carbohydrate meal on glucose metabolism and insulin sensitivity of a second meal eaten 5 h later. Insulin sensitivity was assessed using a minimal model approach. Ten healthy post-menopausal women underwent four two-meal studies in random order. A high-fat breakfast (40 g fat) where the fatty acid composition was predominantly saturated fatty acids (SFA), n-6 polyunsaturated fatty acids (PUFA), long-chain n-3 PUFA or monounsaturated fatty acids (MUFA) was followed 5 h later by a low-fat, high-carbohydrate lunch (5.7 g fat), which was identical in all four studies. The plasma insulin response was significantly higher following the SFA meal than the other meals after both breakfast and lunch (P<0.006) although there was no effect of breakfast fatty acid composition on plasma glucose concentrations. Postprandial insulin sensitivity (SI(Oral)) was assessed for 180 min after each meal. SI(Oral) was significantly lower after lunch than after breakfast for all four test meals (P=0.019) following the same rank order (SFA < n-6 PUFA < n-3 PUFA < MUFA) for each meal. The present study demonstrates that a single meal rich in SFA reduces postprandial insulin sensitivity with 'carry-over' effects for the next meal.     

Low fat and high monounsaturated fat diets decrease human low density lipoprotein oxidative susceptibility in vitro

Oxidative modification of low density lipoprotein (LDL) is thought to play an important role in the development of atherosclerosis. Some studies have found that LDL enriched in monounsaturated fatty acids (MUFA) are less susceptible to oxidation than LDL enriched in polyunsaturated fatty acids (PUFA). A high MUFA diet is an alternative to a lower-fat blood cholesterol-lowering diet. Less is known about the effects of high MUFA versus lower-fat blood cholesterol-lowering diets on LDL oxidative susceptibility. The present study was designed to evaluate the effects of men and women consuming diets high in MUFA (peanuts plus peanut butter, peanut oil and olive oil) on LDL oxidative susceptibility, and to compare these effects with those of a Step II blood cholesterol-lowering diet. A randomized, double-blind, five-period crossover design (n = 20) was used to study the effects of the following diets on LDL-oxidation: average American [35% fat, 15% saturated fatty acids (SFA)], Step II (25% fat, 7% SFA), olive oil (35% fat, 7% SFA), peanut oil (35% fat, 7% SFA) and peanuts plus peanut butter (35% fat, 8% SFA). The average American diet resulted in the shortest lag time (57 +/- 6 min) for LDL oxidized ex vivo, whereas the Step II, olive oil and peanuts plus peanut butter diets resulted in a lag time of 66 +/- 6 min (P < or = 0.1). The slower rate of oxidation [nmol dienes/(min x mg LDL protein)] observed when subjects consumed the olive oil diet (24 +/- 2) versus the average American (28 +/- 2), peanut oil (28 +/- 2) and peanuts plus peanut butter diets (29 +/- 2; P < or = 0.05) was associated with a lower LDL PUFA content. The results of this study suggest that lower-fat and higher-fat blood cholesterol-lowering diets high in MUFA have similar effects on LDL oxidative resistance. In addition, our results suggest that different high MUFA sources varying in the ratio of MUFA to PUFA can be incorporated into a high MUFA diet without increasing the susceptibility of LDL to oxidation.     

膳食脂肪摄入对女童初潮影响的前瞻性研究

  目的  探讨初潮前膳食总脂肪及不同类型脂肪酸摄入对女童初潮发生的前瞻性影响,为预防中国儿童青春期发育提前提供理论依据。  方法  利用“中国居民健康与营养调查(CHNS)”数据,选取1997—2015年有初潮信息且具有基线膳食调查数据并至少参与了一次随访调查的1 240名6~13岁女童为研究对象,采用Cox回归模型分析初潮前膳食总脂肪及脂肪酸摄入对女童初潮发生的前瞻性影响。  结果  调查对象的平均基线年龄为(8.3±1.8)岁。调整出生年代、居住地、家庭人均年收入水平、膳食能量摄入量及体质量指数Z评分(BMI SDS)后,膳食总脂肪及多不饱和脂肪酸(PUFA)摄入量最高组女童出现初潮提前的风险分别比最低组高30% 和34%[HR值(HR值95%CI)分别为1.30(1.01~1.68)、1.34(1.05~1.70)];未发现膳食饱和脂肪酸(SFA)、单不饱和脂肪酸(MUFA)摄入量与初潮发生的关联[HR值(HR值95%CI)分别为1.24(0.98~1.58)、1.25(0.97~1.62), P值均>0.05]。  结论  初潮前较高的膳食总脂肪及PUFA摄入可能导致女童初潮发生提前;未发现SFA及MUFA摄入与初潮发生的关联。     

Serum lipid profile and fatty acid composition of erythrocyte phospholipids in children and adolescents with primary hyperlipidemia

This study aimed at characterizing the fatty acid (FA) composition of red blood cell (RBC) phospholipids in children and adolescents with primary hyperlipidemia, and to ascertain potential association with serum lipid profile and dietary factors. At this purpose, 54 probands aged 6–17 years were recruited. Subjects showed a low omega-3 index (eicosapentaenoic acid, EPA?+?docosahexaenoic acid, DHA <4%). Compared to males, females had a trend toward lower levels of total monounsaturated fatty acids (MUFA) and MUFA/saturated fatty acids (SFAs) ratio in RBCs. An inverse relationship between MUFA concentration in RBCs and serum cholesterol or HDL-C/triglycerides ratio was found. Omega-6 polyunsaturated fatty acids (n-6 PUFA) were positively associated to serum HDL-C levels, and inversely to dietary cholesterol. Fiber intake was positively associated with MUFA/SFA ratio. In conclusion, we provide the first experimental data on phospholipid FA composition of RBCs in hyperlipidemic children, showing sex differences and an overall low omega 3-index.     

Cholesterol, phytosterol and polyunsaturated fatty acid levels in 1982 and 1957 Japanese diets

The dietary intake of cholesterol, phytosterol and PUFA in Japanese was investigated to obtain information on dietary parameters related to coronary artery disease. Three daily menus for both 1957 and 1982 were prepared based on the daily per capita consumption of foods and nutrient intakes from national surveys. From 1957 to 1982, the average daily intake of cholesterol rose 2.1-fold from 183 to 376 mg while that of phytosterol remained at about 373 mg. Daily intakes of total fatty acid (19.2 g), PUFA (7.3 g), MUFA (5.8 g) and SFA (6.1 g) in 1957 increased in 1982 to 48.7 g, 11.9 g, 19.5 g and 17.3 g, respectively. The ratio of PUFA/SFA decreased to 56% from 1.23 in 1957 to 0.69 in 1982 and the PUFA/MUFA ratio also decreased to 48%. The PUFA/cholesterol ratio was lower in 1982 (31.8) than in 1957 (42.6), and the decrease in the phytosterol/cholesterol ratio to 46% was greater than that in the PUFA/cholesterol ratio (which only fell to 75% of the 1957 value). Thus, comparison of the 1982 and 1957 intakes indicated the increase in risk factors, cholesterol and SFA intake, and the decrease in the ratio of PUFA/SFA in the Japanese population during the past few decades.     

Substitution of dietary monounsaturated fatty acids for saturated fatty acids in a free-living population: a feasibility study

The fatty acid composition of the diet of seven free-living subjects (five men and two women) aged 41–56 years was altered for 1 month. The aim was to increase the intake of monounsaturated fatty acids (MUFAs) from subjects current habitual levels of 12% dietary energy to a target intake of 18% dietary energy, and to decrease saturated fatty acid (SFA) from habitual levels of 16% dietary energy to target levels of 10% dietary energy. The change in fatty acid intake was achieved by supplying volunteers with foods prepared using MUFA-containing spreads or olive oil (ready meals, sweet biscuits and cakes) and also by supplying spreads, cooking oil and MUFA-enriched milk for domestic use. Body weight and plasma total cholesterol measurements were made at baseline and at 2 and 4 weeks on the diet as an aid to maintaining subject compliance. MUFA consumption was significantly increased from 12% dietary energy to 16% dietary energy ( P <0.01), and SFA intake was reduced from 16% dietary energy to 6% dietary energy ( P <0.01) during the 4-week intervention. The diet failed to achieve the target increase in MUFA but exceeded the target reduction in SFA. This was due to the fact that subjects reduced their total fat intake from a mean habitual level of 38% dietary energy to a mean level of 30% dietary energy. During the dietary period, mean plasma cholesterol levels were lower at 2 weeks ( P <0.01) and at 4 weeks ( P <0.01) than the baseline, with a mean reduction of 20% over the dietary period. This study demonstrates the difficulty of achieving increased MUFA intakes (by SFA substitution) in free-living populations when only a limited range of fatty-acid modified food products are provided to volunteers.