Which fish fat for bones?

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Hi All,

The data excerpted for the available below paper answer affirmatively the

question

address by the title of the paper: " Is docosahexaenoic acid more effective than

eicosapentaenoic acid for increasing calcium bioavailability? "

Kruger MC, Schollum LM.

Is docosahexaenoic acid more effective than eicosapentaenoic acid for increasing

calcium bioavailability?

Prostaglandins Leukot Essent Fatty Acids. 2005 Nov;73(5):327-34.

PMID: 16154334

Experimental animal and human studies have indicated that long chain

polyunsaturated

fatty acids (LCPUFA) may enhance calcium absorption, reduce urinary calcium

excretion, and increase bone calcium content. In the present study, the effect

of

LCPUFA, as provided in evening primrose oil, fish and tuna oils, on calcium

bioavailability was investigated. Growing male rats were fed a semi-synthetic

diet

for 6 weeks, after which calcium absorption, bone mineral density (ex vivo),

bone

calcium content, and bone biomechanics were measured. Calcium absorption, ex

vivo

bone mineral density, and bone calcium content were significantly higher in the

animals fed tuna oil compared with those of a control group fed corn oil.

Significant correlations were found between the docosahexaenoic acid (DHA)

(22:6n-3)

content of the red cell membranes and bone density and bone calcium content. DHA

increased accretion of calcium in bone significantly more so than

eicosapentaenoic

acid (EPA) (20:5n-3).

.... Table 1. Fatty acid composition of the various oils used in the diets for 6

weeks

=============

Oils 18:2n-6 18:3n-3 20:4n-6 20:5n-3 22:6n-3

=============

Corn oil 53.91 1.19 0 0 0

EPO 72.81 0.20 0.16 0 0

Fish oil 1.01 0.79 0.95 17.86 11.67

Tuna oil 1.41 0.73 2.07 6.79 26.32

=============

Expressed as % area under the curve.

.... Table 2. Body weight, percentage calcium absorbed, femur bone weight and

length

of rats after being fed various oils for 6 weeks

==============

Diets Body weight (g) Ca absorb (%) Bone weight (g) Bone length (mm) Total

Ca/bone

(mg)

==============

Corn oil 465.0 (21.4) 18.4 (1.8) 0.67 (0.02) 38.1 (0.29) 152.4 (4.4)

EPO 458.4 (14.7) 18.1 (2.1) 0.66 (0.02) 37.7 (0.21) 147.8 (5.2)

Fish oil 474.8 (10.8) 21.1 (2.1) 0.69 (0.02) 38.5 (0.21) 157.7 (3.9)

Tuna oil 496.8 (8.5) 25.4 (2.5)* 0.72 (0.01) 38.4 (0.28) 172.6 (5.2)*

==============

Values are given as mean (SEM).

*P<0.05 versus corn oil.

.... Table 3. Rat lumbar spine and femur bone mineral density and urinary

excretion

of C-telopeptide of type I collagen at week 6 of feeding various oils

===============

Diets LSBMD (g/cm2) RFBMD (g/cm2) U-CTx change from baseline (%)

===============

Corn oil 0.219 (0.004) 0.238 (0.002) -80.48 (2.39)

EPO 0.222 (0.004) 0.232 (0.002) -79.68 (2.47)

Fish oil 0.224 (0.004) 0.237 (0.002) -71.16 (1.84)

Tuna oil 0.238 (0.004)* 0.247 (0.002)* -70.39 (3.09)

===============

Values are given as mean (SEM).

*P<0.05 versus corn oil.

LS=lumbar spine, RF=right femur.

.... Table 4. Maximum bone breaking strength and energy to break for the various

diets

=================

Diets Maximum load (N) Energy (mJ)

=================

Corn oil 156.88 (7.08) 0.159 (0.008)

EPO 157.59 (5.45) 0.168 (0.007)

Fish oil 157.49 (7.38) 0.165 (0.010)

Tuna oil 164.29 (6.43) 0.174 (0.011)

=================

Values are given as mean (SEM).

.... Table 5. Fatty acid composition of the various diets expressed as % of the

total

fatty acids

=================

Diet 18:2n-6 18:3n-3 20:4n-6 20:5n-3 22:6n-3

=================

Control 51.97 1.22 ND ND ND

EPO 69.3 0.41 ND ND ND

Fish oil 12.44 0.82 0.75 13.35 7.97

Tuna oil 15.9 0.71 1.74 5.21 18.83

=================

ND=not detected.

.... Table 6. Red blood cell membrane fatty acid composition (wt%) for the

various

dietary groups after 6 weeks of feeding

=================

Diets 18:2n-6 18:3n-3 20:4n-6 20:5n-3 22:6n-3

=================

Corn oil 8.99 (0.33) ND 23.74 (0.28)a ND 1.76 (0.11)a

EPO 8.22 (0.21) ND 24.77 (0.31)a ND 1.30 (0.05)a

Fish oil 5.62 (0.18) ND 12.58 (0.40)b 8.06 (0.22)a 5.62 (0.17)b

Tuna oil 7.96 (2.17) 0.009 16.37 (0.31)c 3.45 (0.32)b 7.53 (0.71)c

=================

Values are given as mean (SEM).

Values with different superscripts are significantly different (P<0.05) as

compared

between the diet groups, for each fatty acid. ND=not detected.

.... Table 7. Correlations between EPA, DHA and bone mineral content, bone

mineral

density and calcium/bone

==================

Variables Right femur BMD Right femur BMC Spine BMD Spine BMC Calcium/bone

==================

RBC 20:5n-3 0.166 0.252 0.143 0.249 0.217

(0.307) (0.116) (0.380) (0.121) (0.180)

RBC 22:6n-3 0.457 0.444 0.458 0.461 0.496

(0.003) (0.004) (0.003) (0.003) (0.002)

=================

P values are given in parentheses. All animals were included for the

correlations.

Al Pater, PhD; email: old542000@...

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