膳食中的脂肪影响胰岛素敏感性和你的血脂

Dietary fat, insulin sensitivity and the metabolic syndrome

 

Riccardi G1, Giacco R, Rivellese AA。

作者信息：临床和实验医学系，“联邦政府”大学，医学院，通过S Pansini 5, 80131，那不勒斯，意大利。gabriele.riccardi@unina.it

　

文摘

　

胰岛素抵抗（Insulin Resistance) 是代谢综合征中各种代谢异常的发病机制。它可以由不同的环境因素引起，包括饮食习惯。高能量/高脂饮食的摄取与超重有强烈的正相关关系，反过来又会 降低胰岛素敏感性，尤其是当体内脂肪过多位于腹部区域时。然而，脂肪摄入与超重之间的联系并不局限于高脂肪食物的高能量含量; 一些人在遗传上倾向于肥胖，从而使 氧化膳食脂肪的能力受损。胰岛素敏感性也受饮食脂肪的质量影响，与体重无关。

　

　

 

流行病学证据和干预研究清楚地表明，在人类中饱和脂肪显著加重胰岛素抵抗，而单不饱和脂肪酸和多不饱和脂肪酸通过对细胞膜结构的修饰来改善它，这至少部分反映了膳食脂肪的成分。最近的一项多中心研究(KANWU)已经表明，从富含饱和脂肪酸的饮食转变为富含单一不饱和脂肪的食物可以改善健康人群的胰岛素敏感性，而适量的ALPHA-亚麻酸的补充并不会影响胰岛素敏感性。代谢综合征的其他特征也受到不同类型脂肪的影响，尤其是血压和血浆脂质水平。

　

　

　

 

大多数研究表明，阿尔法-亚麻酸可以降低高血压者的血压，而对血压正常者没有影响。从饱和脂肪转移到单不饱和脂肪的摄入会降低舒张压。与脂质异常有关的研究，alpha-亚麻酸降低血浆甘油三酯水平，但同时增加低密度脂蛋白胆固醇(LDL)。

 

不饱和脂肪替代饱和脂肪不仅可以降低低密度脂蛋白胆固醇（LDL），还有助于降低胰岛素抵抗个体的血浆甘油三酯(TG)。

 

综上所述，有证据表明膳食脂肪的质量影响胰岛素敏感性和相关的代谢异常。因此，预防代谢综合征必须通过以下二个方面实现:

(1)通过降低习惯性饮食的能量密度来纠正超重（即，脂肪摄取）；

(2)通过减少膳食饱和脂肪来改善胰岛素敏感性和相关代谢异常，在适当的情况下，由单不饱和脂肪和多不饱和脂肪替代。

　

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Dietary fat, insulin sensitivity and the metabolic syndrome.

Riccardi G1, Giacco R, Rivellese AA.

Author information

1

Department of Clinical and Experimental Medicine, "FedericoII" University, Medical School, Via S Pansini 5, 80131, Napoli, Italy. gabriele.riccardi@unina.it

Abstract

　

Insulin resistance is the pathogenetic link underlying the different metabolic abnormalities clustering in the metabolic syndrome. It can be induced by different environmental factors, including dietary habits.

　

Consumption of energy-dense/high fat diets is strongly and positively associated with overweight that, in turn, deteriorates insulin sensitivity, particularly when the excess of body fat is located in abdominal region.

　

Nevertheless the link between fat intake and overweight is not limited to the high-energy content of fatty foods; the ability to oxidize dietary fat is impaired in some individuals genetically predisposed to obesity. Insulin sensitivity is also affected by the quality of dietary fat, independently of its effects on body weight. Epidemiological evidence and intervention studies clearly show that in humans saturated fat significantly worsen insulin-resistance, while monounsaturated and polyunsaturated fatty acids improve it through modifications in the composition of cell membranes which reflect at least in part dietary fat composition.

　

 A recent multicenter study (KANWU) has shown that shifting from a diet rich in saturated fatty acids to one rich in monounsaturated fat improves insulin sensitivity in healthy people while a moderate alpha-3 fatty acids supplementation does not affect insulin sensitivity. There are also other features of the metabolic syndrome that are influenced by different types of fat, particularly blood pressure and plasma lipid levels. Most studies show that alpha-3 fatty acids reduce blood pressure in hypertensive but not in normotensive subjects while shifting from saturated to monounsaturated fat intake reduces diastolic blood pressure.

　

In relation to lipid abnormalities alpha-3 fatty acids reduce plasma triglyceride levels but in parallel, increase LDL cholesterol. Substitution of unsaturated fat for saturated fat not only reduces LDL cholesterol but contributes also to reduce plasma triglycerides in insulin resistant individuals.

　

In conclusion, there is evidence available in humans indicating that dietary fat quality influences insulin sensitivity and associated metabolic abnormalities. Therefore, prevention of the metabolic syndrome has to be targeted: (1) to correct overweight by reducing the energy density of the habitual diet (i.e., fat intake) and (2) to improve insulin sensitivity and associated metabolic abnormalities through a reduction of dietary saturated fat, partially replaced, when appropriate, by monounsaturated and polyunsaturated fats.

 

https://www.ncbi.nlm.nih.gov/pubmed/15297079