Influence of herring (Clupea harengus) and herring fractions on metabolic status in rats fed a high energy diet.
OBJECTIVE
Few dietary studies have looked beyond fish oil to explain the beneficial metabolic effects of a fish-containing diet. Our aim was to study whether addition of herring, or sub-fractions of herring, could counteract negative metabolic effects known to be induced by a high-fat, high-sugar diet.


METHODS
Rats were given six different diets: standard pellets; high energy diet with chicken mince (HiE control); high energy diet with herring mince (HiE herring); and high energy diet with chicken mince and either herring oil (HiE herring oil), herring press juice, PJ (HiE PJ) or herring low molecular weight PJ (HiE LMW-PJ). Factors associated with the metabolic syndrome were measured.


RESULTS
There were no differences in energy intake or body weight between the groups, but animals fed high energy diets had a higher body fat content compared with the pellet group, although not statistically significant in all groups. Mesenteric adipocyte size was smaller in the HiE herring oil group compared with the HiE control. Glucose clamp studies showed that, compared with the pellet group, the HiE control and HiE herring diets, but not the HiE herring oil diet, induced insulin resistance. Addition of herring or herring oil to the high energy diet decreased total cholesterol levels, triacylglycerols and the atherogenic index compared with the HiE control group.


CONCLUSIONS
The results suggest that addition of herring or herring oil counteracts negative effects on blood lipids induced by a high energy diet. The lipid component of herring thus seems to be responsible for these beneficial effects.
Lindqvist
H
H
Department of Chemistry and Bioscience, Chalmers University of Technology, Sahlgrenska Academy, Göteborg University, Göteborg, Sweden. helen.lindqvist@chalmers.se
Sandberg
A-S
AS
Undeland
I
I
Stener-Victorin
E
E
Larsson
B M
BM
Sannaveerappa
T
T
Lönn
M
M
Holmäng
A
A
D017667:Adipocytes / Q000166:cytology; D052242:Adiponectin / Q000097:blood; D000273:Adipose Tissue / Q000033:anatomy & histology / Q000166:cytology / Q000378:metabolism; D000818:Animals; D001794:Blood Pressure / Q000502:physiology; D001823:Body Composition / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D048429:Cell Size; D002645:Chickens; D004032:Diet; D004040:Dietary Carbohydrates / Q000032:analysis; D004041:Dietary Fats / Q000032:analysis / Q000378:metabolism; D004044:Dietary Proteins / Q000032:analysis; D002149:Energy Intake / Q000502:physiology; D005231:Fatty Acids, Unsaturated / Q000032:analysis / Q000097:blood / Q000378:metabolism; D005395:Fish Oils / Q000737:chemistry; D005396:Fish Products / Q000032:analysis; D005399:Fishes; D015309:Glucose Clamp Technique; D007333:Insulin Resistance / Q000502:physiology; D050152:Intra-Abdominal Fat / Q000033:anatomy & histology / Q000737:chemistry / Q000378:metabolism; D020738:Leptin / Q000097:blood; D050356:Lipid Metabolism / Q000502:physiology; D008055:Lipids / Q000097:blood; D008297:Male; D008660:Metabolism / Q000502:physiology*; D011202:Poultry Products / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar
D052242:Adiponectin; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D004044:Dietary Proteins; D005231:Fatty Acids, Unsaturated; D005395:Fish Oils; D020738:Leptin; D008055:Lipids