12 January - 20 June 2016

Increasing intake of polyunsaturated fats may be beneficial for a prediabetes subtype

According to a study published in PLOS ONE, replacing saturated fat in the diet with polyunsaturated fat is linked to slower progress of type 2 diabetes in people with prediabetes whose muscles do not take up glucose properly.

According to a study published in PLOS ONE, replacing saturated fat in the diet with polyunsaturated fat is linked to slower progress of type 2 diabetes in people with prediabetes whose muscles do not take up glucose properly.  Previous findings have reported that prediabetes can be split into two distinct conditions, one in which the liver produces too much glucose and one where glucose is not taken up properly by the muscles. Prediabetes is a condition in which blood glucose levels are higher than normal, but not sufficient to be classified as type 2 diabetes.  The scientists state their study is the first to examine the effect of dietary fat on prediabetes as two separate conditions, although others have shown dietary fat to effect insulin sensitivity. Guess et al., in this current study, investigated the relationship between dietary fatty acid intake on measures of fasting and 2 hour glucose homeostasis. 

The team recruited participants across a wide spectrum of glucose levels including healthy (15) athletic (14), and obese (23) people, and people with prediabetes (10) or type 2 diabetes (11). Apart from the athletes all participants reported doing less than 3 hours of activity per week. Normal glucose levels, prediabetes and type 2 diabetes (T2D) were confirmed by oral glucose tolerance testing.  Glucose lowering medication was suspended for two week prior to screening and throughout testing for the T2D participants.  Diet was assessed at baseline using a food frequency questionnaire (FFQ) which reported food intake over 3 months and was validated for the intake of saturated fat, monounsaturated fat, polyunsaturated fat and total energy intake at baseline.  Further validation was provided by analysing C18:2 (linoleic acid – a polyunsaturated omega 6 fatty acid commonly used to measure PUFA intake) in the participant’s blood. 

The participants fasted overnight at the study centre, and the next morning a sampling catheter and an intravenous catheter were placed in veins.  Thirty minutes later baseline measurements for concentrations of plasma glucose and insulin and glucose enrichment were taken.  The participants then received a constant infusion of 6,62H2-glucose throughout the study period and, after 2 hours, a descending insulin prime, followed by a constant infusion of insulin.  Plasma glucose was measured every 5 minutes for 3 hours and maintained at ~90mg/dl with a variable dextrose infusion. Blood samples were taken over the final 30 minutes and analysed for plasma glucose and insulin and glucose enrichments.   

Guess et al. then examined the relationship between dietary fat intake, as assessed and validated as noted above, and fasting glucose levels and other measured indicators using multiple regression techniques.

They report that in participants with the prediabetes condition in which glucose uptake into muscles is impaired, the replacement of saturated fats in the diet with polyunsaturated fats showed a beneficial effect in slowing the development of diabetes.  They note that this is because polyunsaturated fats promote uptake of glucose by the insulin receptors in muscle.  In participants whose livers were producing too much glucose, reduction of saturated fat in the diet was found to be linked to slower progress of diabetes but replacement with polyunsaturated fat had no effect. The study states “the findings suggest that increasing dietary intake of polyunsaturated fats may have a beneficial effect for patients with a certain type of prediabetes but also illuminates why certain dietary changes may have no effect on progression of type 2 diabetes in the other subtype”. Guess et al conclude that their findings show that it might be possible for prediabetes type-specific dietary advice to “increase the effectiveness of traditional lifestyle modification programs.”

RSSL can determine the fatty acid profile of all dietary fats and oils. For more information please contact Customer Services on +44 (0) 118 918 4076 or email enquiries@rssl.com 

 

share this article
RSSL endeavours to check the veracity of news stories cited in this free e-mail bulletin by referring to the primary source, but cannot be held responsible for inaccuracies in the articles so published. RSSL provides links to other World Wide Web sites as a convenience to users, but cannot be held responsible for the content or availability of these sites. This document may be copied and distributed provided the source is cited as RSSL's Food e-News and the information so distributed is not used for profit.

Previous editions

Load more editions

Make an Enquiry