| 1. |
- Bjermo, Helena, 1981-
(författare)
-
Dietary Fatty Acids and Inflammation : Observational and Interventional Studies
- 2011
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Dietary fat quality influences the risk of type 2 diabetes and cardiovascular disease. A low-grade inflammation is suggested to contribute to the disease development, often accompanied by obesity. Whereas n-3 polyunsaturated fatty acids (PUFA) have been considered anti-inflammatory, n-6 PUFA have been proposed to act pro-inflammatory. Saturated fatty acids (SFA) act pro-inflammatory in vitro. This thesis aimed to investigate effects of different fatty acids on low-grade inflammation in observational and interventional studies. In Paper I and II, fatty acid composition in serum cholesterol esters was used as objective marker of dietary fat quality and related to serum C-reactive protein (CRP) and other circulating inflammatory markers in two population-based cohorts, conducted in middle-aged men and elderly men and women, respectively. In Paper III and IV, the impact of diets differing in fat quality on inflammation and oxidative stress was investigated in randomised controlled studies, in subjects with metabolic syndrome and abdominal obesity. In Paper I and II, a low proportion of linoleic acid (18:2 n-6) in serum was associated with higher CRP concentrations, indicating that a low intake of vegetable fats may be related to low-grade inflammation. High CRP concentrations were also associated with high proportions of palmitoleic (16:1) and oleic (18:1) acids and high stearoyl coenzymeA desaturase index, possibly reflecting altered fat metabolism and/or high SFA intake in this population. When comparing two high-fat diets rich in either saturated or monounsaturated fat, and two low-fat diets with or without long-chain n-3 PUFA supplementation during 12 weeks (Paper III), no differences in inflammation or oxidative stress markers were observed. Moreover, a 10-week intervention (Paper IV) with high linoleic acid intake showed no adverse effects on inflammation or oxidative stress. Instead, interleukin-1 receptor antagonist and tumor necrosis factor receptor-2 decreased after linoleic acid intake compared with a diet high in SFA. The results in this thesis indicate that dietary n-6 PUFA found in vegetable fats is associated with lower inflammation marker levels, and to some extent reduces systemic inflammation when compared with SFA. Supplementation of n-3 PUFA did not exert any systemic anti-inflammatory effects, maybe due to a relatively low dose.
|
|
| 2. |
- Miles, Elizabeth A, et al.
(författare)
-
The Salmon in Pregnancy Study : study design, subject characteristics, maternal fish and marine n-3 fatty acid intake, and marine n-3 fatty acid status in maternal and umbilical cord blood
- 2011
-
Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 94:6, s. 1986S-1992S
-
Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Oily fish provides marine n-3 (omega-3) fatty acids that are considered to be important in the growth, development, and health of the fetus and newborn infant. OBJECTIVES: The objectives were to increase salmon consumption among pregnant women and to determine the effect on maternal and umbilical cord plasma marine n-3 fatty acid content. DESIGN: Women (n = 123) with low habitual consumption of oily fish were randomly assigned to continue their habitual diet or were provided with 2 portions of farmed salmon/wk to include in their diet from week 20 of pregnancy until delivery. RESULTS: Median weekly consumption frequency of study salmon in the salmon group was 1.94 portions, and total fish consumption frequency was 2.11 portions/wk in the salmon group and 0.47 portions/wk in the control group (P < 0.001). Intakes of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) from the diet, from seafood, and from oily fish were higher in the salmon group (all P < 0.001). Percentages of EPA and DHA in plasma phosphatidylcholine decreased during pregnancy in the control group (P for trend = 0.029 and 0.008, respectively), whereas they increased in the salmon group (P for trend for both < 0.001). EPA and DHA percentages were higher in maternal plasma phosphatidylcholine at weeks 34 and 38 of pregnancy and in umbilical cord plasma phosphatidylcholine in the salmon group (P < 0.001 for all). CONCLUSION: If pregnant women, who do not regularly eat oily fish, eat 2 portions of salmon/wk, they will increase their intake of EPA and DHA, achieving the recommended minimum intake; and they will increase their and their fetus' status of EPA and DHA. This trial was registered at clinicaltrials.gov as NCT00801502.
|
|
