Polyunsaturated fatty acids and type 2 diabetes: Impact on the glycemic control mechanism

There is a growing mortality related to co-morbidities associated with diabetes mellitus. Intake of polyunsaturated fatty acids (PUFA) has been associated with low cardiometabolic risk and reduction of inflammatory process. The objective of this paper is to review the impact of PUFA intake on glycemic control in diabetic patients as well as to elucidate the possible mechanisms involved. Medline/PubMed electronic database was searched to identify studies published within last five years regarding the effect of PUFA intake on glucose metabolism in type 2 diabetics. The search terms used were “polyunsaturated fatty acid(s),” “PUFA,” and “diabetes.” We included only interventional studies that assessed the effects of PUFA intake on glucose metabolism – fasting glucose, serum insulin, HbA1c, and HOMA-IR assessment– in type 2 diabetics. Initially, 48 articles were identified, of which one was not available and 41 did not match the inclusion criteria. Within the selected studies, three articles showed an improvement in fasting blood glucose, two showed an increase in fasting glycemia, and there was no effect of intervention in one article only. Based on the analyzed clinical interventional studies, supplementation of 0.42–5.2-g PUFA/day for at least eight weeks may become an alternative treatment for type 2 diabetes mellitus, particularly in Asian subjects.     

Feeding rumen-inert fats differing in their degree of saturation decreases intake and increases plasma concentrations of gut peptides in lactating dairy cows

Our objective was to determine the effect of feeding rumen-inert fats differing in their degree of saturation on dry matter intake (DMI), milk production, and plasma concentrations of insulin, glucagon-like peptide 1 (7-36) amide (GLP-1), glucose-dependent insulinotropic polypeptide (GIP), and cholecystokinin (CCK) in lactating dairy cows. Four midlactation, primiparous Holstein cows were used in a 4 × 4 Latin square experiment with 2-wk periods. Cows were fed a control mixed ration ad libitum, and treatments were the dietary addition (3.5% of ration dry matter) of 3 rumen-inert fats as sources of mostly saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), or polyunsaturated fatty acids (PUFA). Daily DMI, milk yield, and composition were measured on the last 4 d of each period. Jugular vein blood was collected every 30 min over a 7-h period on d 12 and 14 of each period for analysis of plasma concentrations of hormones, glucose, and nonesterified fatty acids. Feeding fat decreased DMI, and the decrease tended to be greater for MUFA and PUFA compared with SFA. Plasma concentration of GLP-1 increased when fat was fed and was greater for MUFA and PUFA. Feeding fat increased plasma glucose-dependent insulinotropic polypeptide and CCK concentrations and decreased plasma insulin concentration. Plasma CCK concentration was greater for MUFA and PUFA than for SFA and was greater for MUFA than PUFA. Decreases in DMI in cows fed fat were associated with increased plasma concentrations of GLP-1 and CCK and a decreased insulin concentration. The role of these peptides in regulating DMI in cattle fed fat requires further investigation.     

膳食中n-3多不饱和脂肪酸对2型糖尿病患者血糖和胰岛素敏感性的影响

2型糖尿病是世界上最常见的慢性疾病之一。膳食中的n-3多不饱和脂肪酸可能会减少亚洲人的2型糖尿病风险, 中国2型糖尿病患者血浆磷脂n-3不饱和脂肪酸与胰岛素敏感性呈正相关。而欧美的前瞻性研究均发现, 鱼类的摄入和n-3多不饱和脂肪酸的摄入会增加2型糖尿病的发病风险, 在西方白种人群中进行的n-3多不饱和脂肪酸干预的随机对照试验也并未发现n-3多不饱和脂肪酸能够改善患者胰岛素抵抗水平或血糖水平, n-3多不饱和脂肪酸甚至可轻微地降低患者胰岛素的敏感性。本文综述了目前n-3多不饱和脂肪酸摄入量与2型糖尿病风险之间的关系。     

蓝莓花青素对2型糖尿病小鼠糖脂代谢的调节作用

目的:探讨蓝莓花青素(Blueberry anthocyanins,BA)对2型糖尿病小鼠糖代谢、脂代谢的调节作用.方法:采用高脂高糖饮食联合腹腔注射链佐霉素(Streptozocin,STZ)建立2型糖尿病小鼠模型,设置正常组、模型组、阳性药物组(250 mg/kg)、蓝莓花青素组(300、200、100 mg/kg...     

膳食调整单不饱和脂肪酸对妊娠糖尿病患者脂糖代谢及母婴结局的影响

目的 探讨膳食调整单不饱和脂肪酸(monounsaturated fatty acids, MUFA)对妊娠糖尿病(gestational diabetes mellitus, GDM)患者脂糖代谢及母婴结局的影响。方法 选取2017年1月至2018年1月本院收治的GDM患者200例, 依据随机数字表法分为MUFA组和常规组, 每组100例, 常规组给予常规膳食干预, MUFA组在此基础上给予膳食调整MUFA干预, 比较2组膳食营养、血糖、血脂、母婴结局。结果 MUFA组和常规组干预后脂肪及其供能比、MUFA及其供能比明显低于干预前, MUFA组脂肪及其供能比、MUFA及其供能比明显高于常规组, 差异有统计学意义(P<0.05); MUFA组和常规组干预后空腹血糖(fasting blood glucose, FBG)、餐后2 h血糖(2 h postprandial blood glucose, 2 hPBG)、糖基化血红蛋白(glycosylation hemoglobin, HbA1c)、三酰甘油(three acylglycerol, TG)、胆固醇(cholesterol, TC)、低密度脂蛋白(low density lipoprotein, LDL-C)、高密度脂蛋白(high density lipoprotein, HDL-C)明显低于干预前, MUFA组干预后FBG、2hPBG、HbA1c、TG、TC、LDL-C明显低于常规组, MUFA组干预后HDL-C明显高于常规组, 差异有统计学意义(P<0.05); MUFA组不良母婴结局发生率明显低于常规组, 差异有统计学意义(P<0.05)。结论 膳食调整MUFA可有效改善GDM患者膳食营养、脂糖代谢紊乱状态, 有利于改善患者的母婴结局, 值得临床作进一步推广。     

厦门白姑鱼腌制加工过程中的脂肪酸变化分析

探讨厦门白姑鱼（Argyrosomus amoyensis）腌制加工过程中的脂肪酸的变化,并结合脂肪氧化相关指标：过氧化值（peroxide value,POV）及硫代巴比妥酸反应物（thiobarbituric acid reactive substance,TBARS）值,确定脂肪氧化对脂肪酸组成的影响。从腌制加工的7 个关键工序中取样,采用气相色谱-质谱联用法分析脂肪酸,同时考察POV及TBARS值。结果表明：厦门白姑鱼原料含26.41%的饱和脂肪酸（saturated fatty acids,SFA）、20.26%的单不饱和脂肪酸（monounsaturated fatty acids,MUFA）和53.33%的多不饱和脂肪酸（polyunsaturated fatty acids,PUFA）,共24 种,必需脂肪酸占12.49%,二十碳五烯酸（eicosapentaenoic acid,EPA）和二十二碳六烯酸（docosahexaenoicacid,DHA）占40.70%。在腌制加工中,SFA含量显著增加,MUFA含量和PUFA含量显著降低（P＜0.05）。POV和TBARS值都呈现了先增后减的趋势,分别在烘干1 d和3 d出现峰值。相关性分析表明,SFA与MUFA呈显著负相关（P＜0.05）,与PUFA呈极显著负相关（P＜0.01）,MUFA和PUFA没有相关性;SFA与POV和TBARS值呈现显著正相关（P＜0.05）,而PUFA与POV和TBARS值分别呈显著（P＜0.05）和极显著负相关（P＜0.01）。因此,厦门白姑鱼脂肪酸种类多,含有丰富的不饱和脂肪酸,腌制加工过程对主要8 种脂肪酸有显著影响,脂肪的氧化使SFA含量增加,同时使PUFA含量降低,PUFA更容易发生氧化。     

Dietary polyphenols and type 2 diabetes: Human Study and Clinical Trial

Abstract

Significant evidence from epidemiological investigations showed that dietary polyphenols might manage and prevent type 2 diabetes (T2D). This review summarizes human studies and clinical trials of polyphenols as anti-diabetic agents. Polyphenols from coffee, guava tea, whortleberry, olive oil, propolis, chocolate, red wine, grape seed, and cocoa have been reported to show anti-diabetic effects in T2D patients through increasing glucose metabolism, improving vascular function as well as reducing insulin resistance and HbA1c level. However, individual flavonoid or isoflavonoid compounds appear to have no therapeutic effect on diabetes, based on the limited clinical data. Preliminary clinical trials provided evidence that resveratrol had anti-diabetic activity in humans by improving glycemic control in subjects with insulin resistance. Besides, anthocyanins exhibited anti-diabetic properties by reducing blood glucose and HbA1c levels or the improvement of insulin secretion and resistance. The structure-activity relationship of polyphenols as anti-diabetic agents in humans has been rarely reported.     

GC-MS法分析蚕蛾油与蚕蛹油的脂肪酸组成

采用超临界CO2 萃取雄蚕蛾与蚕蛹中的油脂,经甲酯化处理用气相色谱- 质谱联用仪进行分析,在雄蚕蛾油中分离鉴定出15 种脂肪酸,含量最高的是α- 亚麻酸(36.71%),其中直链饱和脂肪酸(SFA)54.52%;单不饱和脂肪酸(MUFA)6.89%;多不饱和脂肪酸(PUFA)38.63%。在蚕蛹油中共分离鉴定出14 种脂肪酸成分,含量最高的是亚油酸(39.03%),其次是α- 亚麻酸(33.22%),其中直链饱和脂肪酸(SFA)占25.73%;单不饱和脂肪酸(MUFA)占2.12%;多不饱和脂肪酸(PUFA)占72.25%。     

Differences in Oils from Nuts Extracted by Means of Two Pressure Systems

Nuts are nutrient dense foods especially appreciated for the fatty acids composition of the oil fraction and other bioactive compounds, like polyphenols or sterols. Almond, pistachio, and walnut oils were extracted by two pressure systems (hydraulic press and screw press) in order to obtain virgin oils. A comparison of the fatty acids was performed for oils from different sources. Although the main components of oils (fatty acids and sterols) did not vary according to the system used, some differences among the three types of nut oils were found. Almond and pistachio oil samples showed a similar fatty acid profile with a substantial amount of monounsaturated fatty acids, 70 and 61%, respectively. However, the majority proportion in walnut oils was the polyunsaturated fatty acids (60%). The highest total sterol content was presented by pistachio oils (4476 mg/kg). Screw press oils showed higher values of the regulated quality parameters (acidity, peroxide value, K₂₃₂, and K₂₇₀). In the same way, polyphenols and oxidative stability were slightly higher when the nut oils were extracted with a screw press.     

不同养殖模式对牦牛背最长肌挥发性风味物质及脂肪酸组成的影响

为确定不同养殖模式对青海牦牛背最长肌挥发性风味物质和脂肪酸组成的影响,选择传统放牧和育肥6 个月2 种养殖模式下的12 头2～3 岁龄成年公牦牛背最长肌作为实验材料,采用顶空固相微萃取和气相色谱-质谱联用技术分析肌肉中风味物质组成,同时测定2 种养殖模式下牦牛背最长肌的脂肪酸组成。结果表明：2 组样品均检出13 种饱和脂肪酸（saturated fatty acid,SFA）、5 种单不饱和脂肪酸（monounsaturated fatty acid,MUFA）和7 种多不饱和脂肪酸（polyunsaturated fatty acid,PUFA）,放牧组牦牛背最长肌脂肪酸相对含量由大到小依次为SFA（40.77%）＞PUFA（35.15%）＞MUFA（24.07%）,育肥组为SFA（44.72%）＞MUFA（40.10%）＞PUFA（15.18%）;2 组样品共检出32 种挥发性风味物质,包括酮类4 种、醛类10 种、酸类2 种、酯类1 种、醇类5 种、烯类2 种及芳香类8 种,放牧组牦牛背最长肌中检出26 种,育肥组检出30 种。综上,育肥模式对牦牛肉脂肪酸和挥发性风味物质组成具有较大影响。     

Endogenous production of n-3 and n-6 fatty acids in mammalian cells

Polyunsaturated fatty acids (PUFA) are important components of mammalian diets, and the beneficial effects of n-3 PUFA on human development and cardiovascular health have been well documented. Caenorhabditis elegans is one of the few animals known to be able to produce linoleic (LA, 18:2n-6) and alpha-linolenic (ALA, 18:3n-3) essential fatty acids. These essential PUFA are generated by the action of desaturases that successively direct the conversion of monounsaturated fatty acids (MUFA) to PUFA. The cDNA coding sequences of the C. elegans Delta(12) and n-3 fatty acid desaturases were each placed under the control of separate constitutive eukaryotic promoters and simultaneously introduced into HC11 mouse mammary epithelial cells by adenoviral transduction. Phospholipids from transduced cells showed a significant decrease in the ratios of both MUFA:PUFA and n-6:n-3 fatty acids relative to control cultures. The fatty acid profile of transduced cellular phospholipids revealed significant decreases in MUFA and arachidonic acid (20:4n-6), and increases in LA, ALA, and eicosapentaenoic acid (20:5n-3). The fatty acid composition of triacylglycerols derived from transduced cells was similarly, but less dramatically, affected. These results demonstrate the functionality of C. elegans fatty acid desaturase enzymes in mammalian cells. Expression of these desaturases in livestock might act to counterbalance the saturating effect that rumen microbial biohydrogenation has on the fatty acid profile of ruminant products, and allow for the development of novel, land-based dietary sources of n-3 PUFA.     

Quantitative determination of saturated-, monounsaturated- and polyunsaturated fatty acids in pork adipose tissue with non-destructive Raman spectroscopy

The composition of dietary fat has received increased attention during the recent years because it influences human health. Seventy seven samples from pork adipose tissue and melted fat from the same tissue were measured with Raman spectroscopy. Gas chromatography analysis was conducted as reference. Iodine values (IV) ranged from 58.2 to 90.4 g iodine added per 100 g fat. Polyunsaturated fatty acids (PUFA) ranged from 7.8% to 31.7% and monounsaturated fatty acids (MUFA) from 35.2% to 51.5% of total fatty acids. When applied on pre-processed spectra of melted fat, partial least square regression (PLSR) with cross-validation gave a correlation coefficient (R) = 0.98, and root mean square error of cross-validation (RMSECV) = 1.4 for IV, using 3 PLS factors in the model. PUFA gave R = 0.98 and RMSECV = 1.0% of total fatty acids, using 5 PLS factors. MUFA were predicted with R = 0.96 and RMSECV = 1.0% of total fatty acids, using 9 PLS factors. On adipose tissue a model with 3 PLS factors gave R = 0.97 and RMSECV = 1.8 for IV. For PUFA, a model with 3 PLS factors gave R = 0.95 and RMSECV = 1.5% of total fatty acids. For MUFA a model with 6 PLS factors gave R = 0.91 and RMSECV = 1.5% of total fatty acids. The results indicate the feasibility to use Raman spectroscopy as a rapid and non-destructive method to determine IV, PUFA, MUFA and saturated fatty acids (SFA) measured directly on pork adipose tissue and in melted fat from the same tissue.     

澳洲美利奴羊肉脂肪酸组成

选择3 只澳洲美利奴羔羊的背最长肌、臀肌及臂三头肌,利用气相色谱-质谱联用技术对其脂肪酸含量进行测定及分类探讨。结果表明：澳洲美利奴羊肉中共含有脂肪酸35 种,其中C15:1、C16:0、C17:1、C18:0、C18:1 n-9c脂肪酸含量较高,3 个部位肌肉中：不饱和脂肪酸含量＞饱和脂肪酸含量＞单不饱和脂肪酸含量＞多不饱和脂肪酸含量,且每个部位肌肉中单不饱和脂肪酸含量比多不饱和脂肪酸含量均高出2～3 倍;n-3脂肪酸亚麻酸甲酯（C18:3 n-3）在臂三头肌中的含量显著高于背最长肌（P＜0.05）;与另外2 个部位相比,臂三头肌总脂肪酸、饱和脂肪酸、不饱和脂肪酸、中链脂肪酸及长链脂肪酸含量均最高;臂三头肌中多不饱和脂肪酸与饱和脂肪酸含量比值最高,背最长肌中最低。     

传统金华火腿加工过程中皮下脂肪的变化

分别提取0、32d、60d、160d、240d的金华火腿中的皮下脂肪,分析其甘油酯、磷脂、游离脂肪酸的含量和脂肪酸组成。结果表明:甘油酯的含量从95.7%减少到85.4%,游离脂肪酸的含量从2.1%增加到14.3%,磷脂的含量没有发生显著性变化;甘油酯中的SFA有显著性变化,MUFA和PUFA无显著性变化;磷脂中的SFA、MUFA和PUFA都没有显著性变化;游离脂肪酸中,PUFA的含量显著减少,MUFA的含量减少,但其变化不显著,SFA的含量显著增加。     

Determination of the seasonal changes on total fatty acid composition and ω3/ω6 ratios of carp (Cyprinus carpio L.) muscle lipids in Beysehir Lake (Turkey)

The muscle lipid and fatty acid composition of carp, Cyprinus carpio in Beysehir Lake the largest freshwater lake in Turkey, was determined. Polyunsaturated fatty acids (PUFA) of carp, the most abundant fish species in Beysehir Lake, were found to be higher than those of saturated fatty acids (SFA) in spring, summer and autumn and also the monounsaturated fatty acids (MUFA) in spring and summer. Palmitic acid was the major SFA (14.6–16.6%) in all seasons. Oleic acid was identified as the major MUFA (15.1–20.3%). Docosahexaenoic acid (DHA) was the major PUFA in summer and winter, whereas linoleic acid (LA) was the major PUFA in spring and autumn. The percentages of total ω3 fatty acid were higher than those of total ω6 fatty acid in the fatty acid composition of carp in winter. It was shown that the fatty acid composition in the muscle of carp was significantly influenced by feeding period and seasons.     

n-3多不饱和脂肪酸对疾病的预防与治疗作用

n-3多不饱和脂肪酸主要源于亚麻籽、胡桃仁、大豆以及海洋生物。增加n-3多不饱和脂肪酸摄取量可以促进视网膜、大脑和神经系统发育。n-3多不饱和脂肪酸通过各种途径降低人体心血管疾病和炎症的发生,降低糖尿病患者血清低密度脂蛋白胆固醇(LDL-C)和甘油三酯(TG)水平。膳食中增加n-3多不饱和脂肪酸的含量可以对心血管疾病、糖尿病、炎症等患者有辅助治疗效果;n-3多不饱和脂肪酸可以作用于神经细胞,对注意力不集中、抑郁症、精神分裂症有一定的疗效。n-3多不饱和脂肪酸可抑制体外培养的乳腺、前列腺和结肠癌细胞增生,促进细胞凋亡。     

蒙古斑点马不同部位脂肪和肌肉组织中脂肪酸组成的比较研究

通过对蒙古斑点马不同部位脂肪和肌肉组织中脂肪酸组成进行分析比较,旨在明确蒙古斑点马体脂脂肪酸组成特点。选择3 匹成年蒙古斑点马,屠宰后采集肾周、肠周和皮下脂肪以及肩肌、背最长肌和臀肌样品,利用气相色谱法测定脂肪酸组成及含量。结果表明：蒙古斑点马不同脂肪组织中均检出19 种脂肪酸,其中饱和脂肪酸（saturated fatty acid,SFA）含量34.77%～37.38%,不饱和脂肪酸（unsaturated fatty acid,UFA）含量达60%以上,UFA中单不饱和脂肪酸（monounsaturated fatty acid,MUFA）含量33.04%～36.39%,多不饱和脂肪酸（polyunsaturated fatty acid,PUFA）含量26.47%～27.51%,其中皮下脂肪C10:0、C18:0、C20:0含量显著低于肾周和肠周脂肪（P＜0.05）;MUFA在皮下脂肪的沉积程度较其他2 个部位高,但均无统计学差异;PUFA中C18:3 n-3含量最高,其在各脂肪组织间无显著差异。3 个不同部位肌肉中均检出15 种脂肪酸,其中SFA含量占总脂肪酸含量的38.32%～40.04%,MUFA含量占35.70%～40.19%,PUFA含量占15.25%～20.33%;SFA中背最长肌和臀肌C12:0含量显著高于肩肌（P＜0.05）,其余SFA在不同部位肌肉间无显著差异;MUFA中背最长肌C16:1含量显著高于肩肌和臀肌（P＜0.05）;肩肌n-6/n-3 PUFA比值显著高于背最长肌和臀肌（P＜0.05）;皮下脂肪的C18:3 n-3和总PUFA含量显著高于背最长肌（P＜0.05）。综上所述,蒙古斑点马不同部位脂肪和肌肉组织脂肪酸组成各具特点,但UFA含量均较高。     

The potential role of olive oil-derived MUFA in insulin sensitivity

Dietary fatty acids play an important role in the development of insulin resistance, the prelude to type 2 diabetes mellitus. This review addresses the potential role of olive oil-derived MUFA in insulin sensitivity, particularly how dietary fat interacts with insulin resistance looking at whole body metabolic measures, as well as molecular effects. The review focuses on the role of non-esterified fatty acids, fatty acid composition in vivo and dietary fat modification on insulin resistance in the metabolic syndrome. Particular emphasis is placed on the role of olive oil within the context of dietary modification to improve insulin sensitivity and for the prevention of the metabolic syndrome.     

Fatty acid composition of Celta pig breed as influenced by sex and location of fat in the carcass

BACKGROUND: The influence of sex and location of fat in the carcass on the fatty acid profile of Celta pigs was studied. Twenty pigs (10 castrated males and 10 females) from the Carballina line were used. RESULTS: The fatty acids composition was predominated by monounsaturated fatty acids (MUFA; approximately 48% of total methyl esters), followed by saturated fatty acids (SFA; approximately 40% of total methyl esters) and, finally, polyunsaturated fatty acids (PUFA; approximately 12% of total methyl esters). The sex and location of fat in the carcass showed significant differences in PUFA and SFA content while both factors were not significantly different with respect to MUFA content. Linoleic, linolenic, eicosatrienoic and arachidonic fatty acids showed the largest difference among the three locations (intramuscular, subcutaneous ventral and subcutaneous dorsal) of the fat in the carcass. CONCLUSION: The fatty acid profile that we observed in the fat of the Celta pigs does not differ greatly from those described by other authors in other autochthonous pig breeds. Principal component analysis offered a good separation of the mean samples according to the sex and location of fat of the pigs. Copyright © 2011 Society of Chemical Industry     

Feeding interruption and quality of cultured gilthead sea bream

Proximate composition, fatty acid and amino acid profiles and sensory attributes of semi-intensive cultured gilthead sea bream were determined without feeding interruption and with feeding interruption from 1 to 13 days. Average proximate composition was protein: 19.4–19.9%, fat 14.1–15.4%, moisture: 64.1–65.3%, and ash: 1.3%. The monounsaturated fatty acids (MUFA) were dominant: 43%, followed by polyunsaturated fatty acids (PUFA): 32% and saturated fatty acids (SFA) 25%. For each fatty acid class the major compounds were palmitic acid (SFA), vaccenic and oleic acid (MUFA) and docosahexaenoic acid (PUFA). Regarding the feeding interruption, it appears that the perivisceral fat can supply the required energy for up to 13 days of starvation.