Current dietary recommendations have placed increasing emphasis on dietary fat
as an important element to decrease risk of cardiovascular disease (CVD). Although total
fat and the fatty acid composition of diets influence the risk of CVD, the optimal amounts
of different fatty acids are not well defined, especially if n-6 and n-3 fatty acids are
considered. Despite the fact that postmenopausal women are at increased risk of CVD,
few studies have investigated the influence of dietary fatty acids on this risk. Therefore,
this study was designed to determine the effect of supplementation with different fatty
acids on risk factors of CVD in postmenopausal women. Sixteen healthy,
postmenopausal women were randomly assigned in a three-period crossover trial to
treatments of 15 g/d supplements of oleic acid-rich sunflower oil (TS), linoleic acid-rich safflower oil (SO), and eicosapentaenoic acid- and docosahexaenoic acid-rich fish oil
(FO). Each treatment period lasted 5 weeks followed by a 7-week washout interval.
When the women were supplemented with FO compared to supplementation with either
TS or SO, the concentration of high density lipoprotein cholesterol tended to increase
(p=0.07 and 0.05, respectively) as did the size of the low density lipoprotein (LDL)
particle (P=0.03 in both instances) while the concentration of triacylglycerol (p=0.0001
and 0.02, respectively) and apolipoprotein B (apo B) (P=0.005 and P=0.01, respectively)
decreased. The concentration , i.e., total cholesterol, cholesterol ester, free cholesterol,
phospholipids, α- and γ-tocopherol, of the two LDL subfractions was not influenced by
any of the oil supplements but was greater in the large (L) subfraction than the small (S).
When the oxidation of the two subfractions was measured by monitoring the formation of
conjugated dienes, the lag time was shorter in both fractions after supplementation with
FO compared to supplementation with SO (P=0.0001) or TS (P=0.0001) but the effect
was greater in the L subfraction. The rate of formation of conjugated dienes, which was
slower after FO supplementation than supplementation with either TS (P=0.02) or SO
(P=0.001), was faster in the L compared to the S subfraction. When oxidation was
measured by monitoring the increase in negative charge on apo B over 23 hr, only the 1
hr time point differed. The increase was greater in the FO-supplemented
group than either the TS- or SO-supplemented groups (P=0.001 in both instances). The
change was greater in S LDL (P=0.007). These findings demonstrate a greater potential
antiatherogenic property of dietary n-3-rich oil than n-6- or n-9-rich ones as indicated by
changes to plasma lipids, lipoproteins, apo B, and particle size but the influence of the
oxidative susceptibility of L and S subfractions is less conclusive. / Graduation date: 2000
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26550 |
| Date | 21 September 1999 |
| Creators | Lee, Ye-Sun |
| Contributors | Wander, Rosemary C. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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