Obsisity
J Am Coll Nutr. 2007
Feb;26(1):66-75. Flaxseed reduces plasma
cholesterol levels in hypercholesterolemic mouse
models. ¡P
Pellizzon
MA, Billheimer
JT, Bloedon
LT, Szapary
PO, Rader DJ. M.D., Center for Experimental Therapeutics,
University of Pennsylvania School of Medicine, 421 Curie Blvd., BRB II/III,
Philadelphia, PA 19104-6160. rader@mail.med.upenn.edu. OBJECTIVE: We examined the effects of whole ground
flaxseed added to a Western diet on plasma and hepatic lipids and hepatic
gene expression in male and female human apolipoprotein
B-100 transgenic (hApoBtg) mice which have a
plasma lipid profile more closely resembling man than wild type mice and in
mice lacking the low density lipoprotein receptor (LDLr)
and apolipoprotein B mRNA editing enzyme complex
1 (LDLr(-/-)/apobec(-/-)). METHODS:
The Westernized control diet containing 0.1% cholesterol and 30% kcal as
fat was fed for 10 days to hApoBtg mice and for
14 days to LDLr(-/-)/apobec(-/-)
mice. Animals from each genetic background were then divided into 2 groups
based on gender and mean plasma total cholesterol (TC). The hApoBtg and LDLr(-/-)/apobec(-/-) mice either continued on the control diet
for a total of 31 and 35 days, respectively or were fed 20% w/w whole
ground flaxseed (flax) with comparable caloric, macronutrient and fiber content
for 21 days. Blood was obtained after a 4 hour fast from all mice prior to
feeding both control and flax diets, after 10 days on the flax diet, and
after 21 days on the flax at which time all mice were exsanguinated.
RESULTS: The control diet increased TC by >100 mg/dl in the hApoBtg with a greater increase observed in males and
by 800 mg/dl in mice lacking the LDLr. After 3
weeks, the flax diet significantly reduced plasma TC by 19% and 22% in hApoBtg and LDLr(-/-)/apobec(-/-),
respectively and non-high density lipoprotein cholesterol (non-HDL-C) by
24% in both models (p for all <0.05). Flax significantly reduced hepatic
cholesterol in hApoBtg by 32% and 47% in males
and females, respectively and LDLr(-/-)/apobec(-/-) mice by 66%.
Flax had no effect on the expression of the following hepatic genes: LDLr, 3-hydroxy-3-methylglutaryl (HMG) CoA reductase, phospholipid transfer protein, cholesterol 7alpha hydroxylase, fatty acid synthase,
and acyl CoA oxidase in either mouse model. CONCLUSIONS: Flaxseed reduces
plasma and hepatic cholesterol in hApoBtg mice,
but had no effect on hepatic lipogenic genes and
was equally effective in mice lacking LDLr. The
combined data suggest that the lipid lowering effect of flax is not hepatic
mediated and may be at the level of cholesterol absorption and/or bile acid
reabsorption. PMID: 17353585 [PubMed - in
process] Arch
Intern Med. 2007 Mar 12;167(5):502-6. Effect of a High-Fiber Diet vs
a Fiber-Supplemented Diet on C-Reactive Protein Level. ¡P
King DE, Egan BM, Woolson
RF, Mainous
AG 3rd, Al-Solaiman Y, Jesri
A. Departments of Family Medicine,
Medicine, and Biometry, Bioinformatics, and Epidemiology, Medical BACKGROUND: Diets high in fiber are associated with
lower levels of inflammatory markers. This study examined the reduction in
inflammation from a diet supplemented with fiber compared with a diet
naturally high in fiber. METHODS: Randomized crossover intervention trial
of 2 diets, a high-fiber (30-g/d) Dietary Approaches to Stop Hypertension
(DASH) diet or fiber-supplemented diet (30 g/d), after a baseline (regular)
diet period of 3 weeks. There were 35 participants (18 lean normotensive and 17 obese hypertensive individuals)
aged 18 to 49 years. RESULTS: The study included 28 women and 7 men; 16
(46%) were black, the remainder white. The mean (SD) fiber intake on
baseline diets was 11.9 (0.3) g/d; on the high-fiber DASH diet, 27.7 (0.6)
g/d; and on the supplemented diet, 26.3 (0.4) g/d. Overall, the mean
C-reactive protein (CRP) level changed from 4.4 to 3.8 mg/L (-13.7%; P =
.046) in the high-fiber DASH diet group and to 3.6 mg/L (-18.1%) in the
fiber-supplemented diet group (P = .03). However, CRP levels decreased in
the 18 lean normotensive participants in either
intervention diet group (2.0 mg/L [baseline] vs
1.4 mg/L [high-fiber DASH] vs 1.2 mg/L
[supplemented]); P<.05) but did not change significantly (7.1 mg/L
[baseline] vs 6.2 mg/L [high-fiber DASH] vs 6.5 mg/L [supplemented]; P>.05) in obese
hypertensive participants. Neither age nor race influenced the response of
CRP levels to the diets. No evidence of a crossover effect was detected.
CONCLUSIONS: The results demonstrate that fiber intake of about 30 g/d)
from a diet naturally rich in fiber or from a supplement can reduce levels
of CRP. Further research is needed to more clearly elucidate the
differential effect seen in lean vs obese
individuals and whether modification of dietary fiber may be helpful in
modulating inflammation and its consequent cardiovascular consequences. PMID: 17353499 [PubMed - in
process] ]