In article <519ikaF1ilbngU1[at]mid.individual.net> ,
"Juhana Harju" <spamshantigiriorama.removespam[at]gmail.com> wrote:

- quote -


The article mentions that previous studies used EPA and DHA from fish
oil. I found two studies. Are there any more?



Effect of fish oil on bone mineral density in aging C57BL/6 female mice.

Bhattacharya A, Rahman M, Sun D, Fernandes G.
J Nutr Biochem. 2006 Sep 7
Division of Clinical Immunology and Rheumatology, Department of
Medicine, University of Texas..

Life expectancy has increased considerably over the last century in the
United States. It is expected that this longevity will be accompanied by
an increase in the prevalence of osteoporosis and accompanying
complications in the elderly population. Age-related loss of bone mass
and bone fragility are major risk factors for osteoporosis, leading to
an increased risk of fractures. Therefore, nutritional strategies and
lifestyle changes that prevent age-related osteoporosis and improve the
quality of life for the elderly population are urgently needed. Hence,
the present study compared the effects of corn oil (CO; n-6 fatty acids;
commonly present in Western diets) and fish oil (FO; n-3 fatty acids) on
bone mineral density (BMD) in aging C57BL/6 female mice. After 6 months
of dietary treatment, we found that 18-month-old FO-fed mice maintained
higher BMD in different bone regions compared to CO-fed mice. These
findings were accompanied by a decreased activity of pro-inflammatory
cytokines, tumor necrosis factor-alpha and interleukin-6 in stimulated
splenocytes; a nonsignificant but greater increase in bone formation
markers alkaline phosphatase and osteocalcin in the serum; and lower
osteoclast generation in bone marrow cell cultures in FO-fed mice. In
conclusion, these findings suggest that providing n-3 fatty acids may
have a beneficial effect on bone mass during aging by modulating bone
formation and bone resorption factors.
http://pmid.us/16963250



Dietary n-3 fatty acids decrease osteoclastogenesis and loss of bone
mass in ovariectomized mice.

Sun D, Krishnan A, Zaman K, Lawrence R, Bhattacharya A, Fernandes G.
J Bone Miner Res. 2003 Jul;18(7):1206-16.
Department of Medicine, Division of Clinical Immunology, University of
Texas.

The mechanisms of action of dietary fish oil (FO) on osteoporosis are
not fully understood. This study showed FO decreased bone loss in
ovariectomized mice because of inhibition of osteoclastogenesis. This
finding supports a beneficial effect of FO on the attenuation of
osteoporosis. INTRODUCTION: Consumption of fish or n-3 fatty acids
protects against cardiovascular and autoimmune disorders. Beneficial
effects on bone mineral density have also been reported in rats and
humans, but the precise mechanisms involved have not been described.
METHODS: Sham and ovariectomized (OVX) mice were fed diets containing
either 5% corn oil (CO) or 5% fish oil (FO). Bone mineral density was
analyzed by DXA. The serum lipid profile was analyzed by gas
chromatography. Receptor activator of NF-kappaB ligand (RANKL)
expression and cytokine production in activated T-cells were analyzed by
flow cytometry and ELISA, respectively. Osteoclasts were generated by
culturing bone marrow (BM) cells with 1,25(OH)2D3. NF-kappaB activation
in BM macrophages was measured by an electrophoretic mobility shift
assay. RESULTS AND CONCLUSION: Plasma lipid C16:1n6, C20:5n3, and
C22:6n3 were significantly increased and C20:4n6 and C18:2n6 decreased
in FO-fed mice. Significantly increased bone mineral density loss (20%
in distal left femur and 22.6% in lumbar vertebrae) was observed in OVX
mice fed CO, whereas FO-fed mice showed only 10% and no change,
respectively. Bone mineral density loss was correlated with increased
RANKL expression in activated CD4+ T-cells from CO-fed OVX mice, but
there was no change in FO-fed mice. Selected n-3 fatty acids
(docosahexaenoic acid [DHA] and eicosapentaenoic acid [EPA]) added in
vitro caused a significant decrease in TRACP activity and TRACP+
multinuclear cell formation from BM cells compared with selected n-6
fatty acids (linoleic acid [LA] and arachidonic acid [AA]). DHA and EPA
also inhibited BM macrophage NF-kappaB activation induced by RANKL in
vitro. TNF-alpha, interleukin (IL)-2, and interferon (IFN)-gamma
concentrations from both sham and OVX FO-fed mice were decreased in the
culture medium of splenocytes, and interleukin-6 was decreased in
sham-operated FO-fed mice. In conclusion, inhibition of osteoclast
generation and activation may be one of the mechanisms by which dietary
n-3 fatty acids reduce bone loss in OVX mice.
http://pmid.us/12854830

Juhana Harju wrote:
- quote -

The study is interesting, but needs to have more subjects and extend
over a longer time and actually measure changes in bone strength.

There is a reduction in saturated fat for omega 6 and omega 3 cases, so
the paper claims some benefit from that.

The omega 3 test has a very low omega 6/omega 3 ratio so it may be
difficult to achieve under normal diets and may be counter productive
in terms of cardiovascular disease.

--
Ron

Juhana Harju wrote:
: Juhana Harju wrote:
:: Consuming more plant omega-3 alpha-linolenic acid (ALA) like walnuts
:: and flaxseeds oil improves bone health according to a new controlled
:: feeding study in humans.
::
:: http://tinyurl.com/37f7fy
::
:: http://www.nutritionj.com/content/6/1/2
:: (The full study is also freely available. Click 'pdf'.)
:
: IMHO, there is also a possibility that the reduction in bone
: resorption markers can be accounted for myricetin or gamma-tocopherol
: in walnuts. The study group ate 37 grams walnuts, 15 grams walnut oil
: and ~ 20 grams flaxseed oil daily. Walnuts are an exceptionally high
: source of myricetin and a good source of gamma-tocopherol.

Actually there is some evidence for the benefit of myricetin and vitamin E.
Myricetin increases bone formation and vitamin E may suppress bone
resorption.


(1) Biochem Pharmacol. 2007 Feb 15;73(4):504-14. Epub 2006 Oct 26.
Myricetin induces human osteoblast differentiation through bone
morphogenetic protein-2/p38 mitogen-activated protein kinase pathway.
Hsu YL, Chang JK, Tsai CH, Chien TT, Kuo PL.
Department of Pharmacy, Chia-Nan University of Pharmacy and Science, Tainan,
Taiwan.

Myricetin (3,3',4',5,5',7-hexahydroxyflavone), a flavonoid compound, is
present in vegetables and fruits. By means of alkaline phosphatase (ALP)
activity, osteocalcin, and type I collagen enzyme-linked immunosorbent assay
(ELISA), we have shown that myricetin exhibits a significant induction of
differentiation in MG-63 and hFOB human osteoblasts. Alkaline phosphatase
and osteocalcin are phenotypic markers for early-stage differentiated
osteoblasts and terminally differentiated osteoblasts, respectively. Our
results indicate that myricetin stimulates osteoblast differentiation at
various stages, from maturation to terminally differentiated osteoblasts.
Induction of differentiation by myricetin is associated with increased bone
morphogenetic protein-2 (BMP-2) production. The BMP-2 antagonist noggin
blocked myricetin-mediated ALP activity and osteocalcin secretion
enhancement, indicating that BMP-2 production is required in
myricetin-mediated osteoblast maturation and differentiation. Induction of
differentiation by myricetin is associated with increased activation of
SMAD1/5/8 and p38 mitogen-activated protein kinases. Cotreatment of p38
inhibitor SB203580 inhibited myricetin-mediated ALP upregulation and
osteocalcin production. In conclusion, myricetin increased BMP-2 synthesis,
and subsequently activated SMAD1/5/8 and p38 MAPK, and this effect may
contribute to its action on the induction of osteoblast maturation and
differentiation, followed by an increase of bone mass. PMID: 17113042


(2) J Womens Health (Larchmt). 2006 Apr;15(3):295-300.
Antioxidant vitamin supplements and markers of bone turnover in a community
sample of nonsmoking women.
Pasco JA, Henry MJ, Wilkinson LK, Nicholson GC, Schneider HG, Kotowicz MA.
The University of Melbourne, Department of Clinical and Biomedical Sciences,
Barwon Health, Geelong, Victoria, Australia.

BACKGROUND: Whereas several epidemiological studies suggest that low dietary
intake of vitamins C and E is linked to increased hip fracture in smokers
and antioxidants (dietary and endogenous) are reduced in elderly
osteoporotic women, none has demonstrated an effect of supplemental
antioxidants on bone turnover. METHODS: In an observational study of 533
randomly selected women, we investigated the associations among the use of
antioxidant supplements, vitamins C and E, serum levels of biochemical
markers of bone turnover (C-telopeptide [CTx] and bone-specific alkaline
phosphatase [BSAP]), and whole body bone mineral density (BMD). RESULTS:
Twenty-two women were identified as current users of supplemental vitamin C
or E. Duration of antioxidant supplement use was negatively associated with
age-adjusted and weight-adjusted serum CTx, such that mean CTx levels
(natural log transformed) were 0.022 units lower for each year of exposure.
No significant differences were detected for adjusted serum BSAP or whole
body BMD. CONCLUSIONS: Our results suggest that antioxidant vitamin E or C
supplements may suppress bone resorption in nonsmoking postmenopausal women.
Coupling of bone formation and resorption may explain the absence of an
effect on bone formation markers, given evidence of enhanced effects of
antioxidants on osteoblast differentiation; this warrants further
investigation. This work adds to the growing body of evidence that
antioxidants may play a role in preventing osteoporosis. PMID: 16620188

--
Juhana

Juhana Harju wrote:
: Consuming more plant omega-3 alpha-linolenic acid (ALA) like walnuts
: and flaxseeds oil improves bone health according to a new controlled
: feeding study in humans.
:
: http://tinyurl.com/37f7fy
:
: http://www.nutritionj.com/content/6/1/2
: (The full study is also freely available. Click 'pdf'.)

IMHO, there is also a possibility that the reduction in bone resorption
markers can be accounted for myricetin or gamma-tocopherol in walnuts. The
study group ate 37 grams walnuts, 15 grams walnut oil and ~ 20 grams
flaxseed oil daily. Walnuts are an exceptionally high source of myricetin
and a good source of gamma-tocopherol.

--
Juhana

Consuming more plant omega-3 alpha-linolenic acid (ALA) like walnuts and
flaxseeds oil improves bone health according to a new controlled feeding
study in humans.

http://tinyurl.com/37f7fy

http://www.nutritionj.com/content/6/1/2
(The full study is also freely available. Click 'pdf'.)

--
Juhana