Fruktosintag stimulerar fettsyresyntes hos vuxna. - Kolozzeum Forum

King Grub · 2008-06-06, 11:05

Fruktosintag ökar fettinlagringen, även efter den akuta fasen, upp till dubbelt så mycket jämfört med inget fruktosintag.

Citat:

The goal of this study was to determine the magnitude by which acute consumption of fructose in a morning bolus would stimulate lipogenesis (measured by infusion of 13C1-acetate and analysis by GC-MS) immediately and after a subsequent meal. Six healthy subjects [4 men and 2 women; aged (mean ± SD) 28 ± 8 y; BMI, 24.3 ± 2.8 kg/m2; and serum triacylglycerols (TG), 1.03 ± 0.32 mmol/L] consumed carbohydrate boluses of sugars (85 g each) in a random and blinded order, followed by a standardized lunch 4 h later. Subjects completed a control test of glucose (100:0) and a mixture of 50:50 glucose:fructose and one of 25:75 (wt:wt). Following the morning boluses, serum glucose and insulin after 100:0 were greater than both other treatments (P < 0.05) and this pattern occurred again after lunch. In the morning, fractional lipogenesis was stimulated when subjects ingested fructose and peaked at 15.9 ± 5.4% after the 50:50 treatment and at 16.9 ± 5.2% after the 25:75 treatment, values that were greater than after the 100:0 treatment (7.8 ± 5.7%; P < 0.02). When fructose was consumed, absolute lipogenesis was 2-fold greater than when it was absent (100:0). Postlunch, serum TG were 11–29% greater than 100:0 and TG-rich lipoprotein-TG concentrations were 76–200% greater after 50:50 and 25:75 were consumed (P < 0.05). The data demonstrate that an early stimulation of lipogenesis after fructose, consumed in a mixture of sugars, augments subsequent postprandial lipemia. The postlunch blood TG elevation was only partially due to carry-over from the morning. Acute intake of fructose stimulates lipogenesis and may create a metabolic milieu that enhances subsequent esterification of fatty acids flowing to the liver to elevate TG synthesis postprandially.

J Nutr. 2008 Jun;138(6):1039-46. Dietary sugars stimulate fatty acid synthesis in adults.

http://jn.nutrition.org/cgi/content/full/138/6/1039

Ronja · 2008-06-06, 12:12

Ska vi sluta äta frukt nu också eller vad? :rolleyes

Eddie Vedder · 2008-06-06, 12:17

Citat:

Ursprungligen postat av Ronja

Ska vi sluta äta frukt nu också eller vad? :rolleyes

Hur ofta trycker du i dig så mycket frukt i samband med måltid att fruktosen motsvarar studiens mängder?

Och det är ju en hyfsat stor skillnad på akut postprandiell fettmetabolism och den långsiktiga hälsan. Så givetvis ska inte sudien tolkas på det sättet, frukten är förstås den sista fruktoskällan att tumma på om man skulle oroa sig.

Här är kvantiteterna socker som försökspersonerna fick i samband med måltiden samt energifördelning hos en av måltiderna:
http://jn.nutrition.org/cgi/content-...38/6/1039/TBL1