Fish Oil & Fish Rich Diets

[Guest guest]

Hmmm.. I'm doing a little 'fishy research' this saturday night and I

am coming up with a mixed bag of nuts...

Here is a sample of what I am finding:

Lipid peroxidation in different tissues: effect of high cholesterol

and fish oil in the diet.

Upadhya S, Kavitha, Prashanthi, Rajyalakshmi, Rohini P, Seetha,

Sucharitha M, Upadhya S.

Department of Biochemistry, Kasturba Medical College, Manipal-576 119.

Malonyldialdehyde was measured in erythrocytes, aorta and spleen on

feeding mice with high cholesterol diet in presence and absence of

fish oil. Mice were grouped as: Group I: Control laboratory diet

Group II: 0.16% cholesterol (sunflower oil) Group III: 1.16%

cholesterol (sunflower oil) Group IV: 1.16% cholesterol (fish oil)

After 7 weeks on their respective diets, erythrocytic, and splenic

MDA levels were significantly higher in group III compared to

controls. Also, MDA levels in aorta and spleen showed a significant

increase in group IV males compared to group III males. However in

group IV the erythrocyte MDA levels were almost equal to that in

controls. This suggests that high cholesterol diet increases lipid

peroxidation in erythrocytes, spleen and aorta. Addition of fish oil

in the diet further increases lipid peroxidation in aorta and spleen,

but not in the erythrocytes.

PMID: 12683224 [PubMed - indexed for MEDLINE]

----------------------------------

IRP1 activity and expression are increased in the liver and the

spleen of rats fed fish oil-rich diets and are related to oxidative

stress.

Miret S, McKie AT, Saiz MP, Bomford A, Mitjavila MT.

Departament de Fisiologia, Facultat de Biologia, Universitat de

Barcelona, Spain.

Many clinical studies have indicated that diets rich in fish oil (FO)

reduce the risk of cardiovascular disease and have anti-inflammatory

and antithrombotic properties. Although the therapeutic effects of FO

have been well described, their impact on iron metabolism remains

unclear. The aim of this work was to study the activity and

expression of IRP1 in the liver and the spleen of rats fed FO-rich

diets with 0 (FO-0) or 100 (FO-1) mg/kg of all-rac-alpha-tocopherol

acetate. We also measured nonheme iron, alpha-tocopherol and retinol

concentrations, and superoxide (SOD) and catalase activity in these

organs. Rats fed FO were compared to rats fed a corn oil (CO)-rich

diet with 100 mg/kg all-rac-alpha-tocopherol acetate. The activity

and expression of IRP1 in both the liver and the spleen of rats fed

FO diets were greater than in those fed the CO diet. FO-fed rats also

had lower nonheme iron concentrations in these organs. Hepatic alpha-

tocopherol and retinol concentrations and SOD activity were lower in

FO-0-fed rats compared to those fed the CO diet. In the spleen, alpha-

tocopherol and retinal concentrations were not altered but SOD

activity was lower in FO-0- fed rats, whereas catalase activity was

greater than in rats fed CO. The results indicate that there is an

increase in oxidative stress in the liver and in the spleen of rats

fed FO diets. These changes, together with the reduction of nonheme

iron concentrations in both FO-0- and FO-1-fed rats, may explain the

increase in activity and expression of IRP1. Therefore, the ingestion

of FO-rich diets should be monitored under close supervision.

-------------------------------------

Effects of fish oil- and olive oil-rich diets on iron metabolism and

oxidative stress in the rat.

Miret S, Saiz MP, Mitjavila MT.

Departament de Fisiologia, Facultat de Biologia, Universitat de

Barcelona, Avda. Diagonal, 645, Spain.

The objective of the present study was to examine the effects of fish

oil (FO)- and olive oil (OO)-rich diets on Fe metabolism and

oxidative stress. Rats were fed for 16 weeks with diets containing 50

g lipids/kg; either OO, maize oil (MO) or FO. OO or MO diets

contained a standard amount (100 mg/kg) of all-rac-alpha-tocopheryl

acetate. FO diets were supplemented with 0, 100 or 200 mg all-rac-

alpha-tocopheryl acetate/kg (FO-0, FO-1 or FO-2 diets, respectively).

At the end of the feeding period, we measured non-haem Fe stores in

liver and spleen, and erythrocyte and reticulocyte count. We also

determined antioxidants and products derived from lipid peroxidation

in plasma and erythrocytes. Our results showed reduced non-haem Fe

stores in rats fed any of the FO diets. Reticulocyte percentage was

higher in the rats fed FO-0 and FO-1. Plasma alpha-tocopherol was

very low in rats fed the FO-0 diet. Rats fed the FO-1 and FO-2 diets

showed higher alpha-tocopherol in plasma than the FO-0 group but

lower than the MO or OO groups. We did not observe such differences

in the alpha-tocopherol content in erythrocyte membranes. Superoxide

dismutase and glutathione peroxidase activities were lower in the

erythrocytes of rats fed the FO-0 diet. The products derived from

lipid peroxidation were also higher in the FO groups. The

administration of FO-rich diets increased lipid peroxidation and

affected Fe metabolism. On the other hand, the OO-rich diet did not

increase oxidative stress and did not alter Fe metabolism. Based on

these results, we conclude that FO supplementation should be advised

carefully.

PMID: 12568660 [PubMed - indexed for MEDLINE]

-----------------------------------------

Eicosapentaenoic acid improves endothelial function in

hypertriglyceridemic subjects despite increased lipid oxidizability.

Okumura T, Fujioka Y, Morimoto S, Tsuboi S, Masai M, Tsujino T,

Ohyanagi M, Iwasaki T.

Department of Internal Medicine, Hyogo College of Medicine,

Nishinomiya, Japan.

BACKGROUND: Epidemiologic investigations suggest that fish oil, which

contains eicosapentaenoic acid (EPA), has favorable cardiovascular

effects. Fish oil improves endothelial function in subjects with

hypercholesterolemia or diabetes. However, controversy persists

regarding relationships between primary hypertriglyceridemia and

endothelial dysfunction. Moreover, lipoproteins are more susceptible

to oxidation in vitro after incorporation of fish oil. METHODS: We

determined the effects of EPA on serum lipids, susceptibility of low-

density lipoproteins (LDL) and very-low-density lipoproteins (VLDL)

to oxidation, and endothelial function in hypertriglyceridemic (HTG)

subjects. In 8 men with untreated primary hypertriglyceridemia

(plasma triglyceride between 150 and 500 mg/dL) and 7 control

subjects (triglyceride below 150 mg/dL), forearm blood flow (FBF)

responses were tested. In HTG subjects, this was repeated 3 months

after initiation of EPA (1800 mg/day). Cu2+-induced oxidation of VLDL

and LDL was determined by serial measurement of conjugated dienes. We

used lag time, which corresponded to the period when the lipoproteins

were resistant to oxidation, as a parameter of oxidizability. FBF

responses to acetylcholine and sodium nitroprusside were determined

by strain-gauge plethysmography. RESULTS: Plasma triglyceride in HTG

subjects fell 31% with EPA supplementation. Before EPA, VLDL and LDL

lag times in HTG subjects were shorter than in control subjects. EPA

further reduced lag time for VLDL but not LDL. The FBF response to

acetylcholine (but not to nitroprusside) was significantly less in

HTG subjects before EPA than in control subjects. EPA normalized the

FBF response to acetylcholine. CONCLUSIONS: EPA improves endothelial

function in HTG subjects despite increasing in VLDL oxidizability

[Guest guest]

From what I have read of Dean Ornish he doesn't seem to like lots of

fats from any source. Here an excerpt from WebMD as he delineates his

Reversal Diet:

http://my.webmd.com/content/article/74/89186

" The " reversal " diet is a whole foods vegetarian diet high in complex

carbohydrates, low in simple carbohydrates (e.g. sugar, concentrated

sweeteners, alcohol, white flour), and very low in fat (approximately

10% of calories). Those few plant-based foods that are high in fat

are excluded, including all oils (other than 3 grams per day of

flaxseed oil or fish oil to provide additional omega-3 fatty acids),

nuts, and avocados. The diet consists primarily of fruits,

vegetables, grains, and beans (including soy-based foods)

supplemented by moderate amounts of nonfat dairy and egg whites.

Patients with high triglycerides and/or diabetes are especially

encouraged to limit their intake of simple sugars and alcohol. As a

rule of thumb, try to include foods in your diet that have less than

three grams of fat per serving while avoiding saturated fat and

sugar. "

I get the impression Dean is not a big fish oil fan. Or oil of any

kind. He (begrudgingly?) allows for up to 3 grams of fish oil, but

disallows NUTS and other high-fat plant foods.

Definitely food for thought for those considering a high fish (or

fish pill) diet.

>

> Hmmm.. I'm doing a little 'fishy research' this saturday night and

I

> am coming up with a mixed bag of nuts...

>

> Here is a sample of what I am finding:

>

> Lipid peroxidation in different tissues: effect of high

cholesterol

> and fish oil in the diet.

>

> Upadhya S, Kavitha, Prashanthi, Rajyalakshmi, Rohini P, Seetha,

> Sucharitha M, Upadhya S.

> Department of Biochemistry, Kasturba Medical College, Manipal-576

119.

> Malonyldialdehyde was measured in erythrocytes, aorta and spleen on

> feeding mice with high cholesterol diet in presence and absence of

> fish oil. Mice were grouped as: Group I: Control laboratory diet

> Group II: 0.16% cholesterol (sunflower oil) Group III: 1.16%

> cholesterol (sunflower oil) Group IV: 1.16% cholesterol (fish oil)

> After 7 weeks on their respective diets, erythrocytic, and splenic

> MDA levels were significantly higher in group III compared to

> controls. Also, MDA levels in aorta and spleen showed a significant

> increase in group IV males compared to group III males. However in

> group IV the erythrocyte MDA levels were almost equal to that in

> controls. This suggests that high cholesterol diet increases lipid

> peroxidation in erythrocytes, spleen and aorta. Addition of fish

oil

> in the diet further increases lipid peroxidation in aorta and

spleen,

> but not in the erythrocytes.

> PMID: 12683224 [PubMed - indexed for MEDLINE]

>

> ----------------------------------

>

> IRP1 activity and expression are increased in the liver and the

> spleen of rats fed fish oil-rich diets and are related to oxidative

> stress.

>

> Miret S, McKie AT, Saiz MP, Bomford A, Mitjavila MT.

> Departament de Fisiologia, Facultat de Biologia, Universitat de

> Barcelona, Spain.

> Many clinical studies have indicated that diets rich in fish oil

(FO)

> reduce the risk of cardiovascular disease and have anti-

inflammatory

> and antithrombotic properties. Although the therapeutic effects of

FO

> have been well described, their impact on iron metabolism remains

> unclear. The aim of this work was to study the activity and

> expression of IRP1 in the liver and the spleen of rats fed FO-rich

> diets with 0 (FO-0) or 100 (FO-1) mg/kg of all-rac-alpha-tocopherol

> acetate. We also measured nonheme iron, alpha-tocopherol and

retinol

> concentrations, and superoxide (SOD) and catalase activity in these

> organs. Rats fed FO were compared to rats fed a corn oil (CO)-rich

> diet with 100 mg/kg all-rac-alpha-tocopherol acetate. The activity

> and expression of IRP1 in both the liver and the spleen of rats fed

> FO diets were greater than in those fed the CO diet. FO-fed rats

also

> had lower nonheme iron concentrations in these organs. Hepatic

alpha-

> tocopherol and retinol concentrations and SOD activity were lower

in

> FO-0-fed rats compared to those fed the CO diet. In the spleen,

alpha-

> tocopherol and retinal concentrations were not altered but SOD

> activity was lower in FO-0- fed rats, whereas catalase activity was

> greater than in rats fed CO. The results indicate that there is an

> increase in oxidative stress in the liver and in the spleen of rats

> fed FO diets. These changes, together with the reduction of nonheme

> iron concentrations in both FO-0- and FO-1-fed rats, may explain

the

> increase in activity and expression of IRP1. Therefore, the

ingestion

> of FO-rich diets should be monitored under close supervision.

>

> -------------------------------------

>

> Effects of fish oil- and olive oil-rich diets on iron metabolism

and

> oxidative stress in the rat.

>

> Miret S, Saiz MP, Mitjavila MT.

> Departament de Fisiologia, Facultat de Biologia, Universitat de

> Barcelona, Avda. Diagonal, 645, Spain.

> The objective of the present study was to examine the effects of

fish

> oil (FO)- and olive oil (OO)-rich diets on Fe metabolism and

> oxidative stress. Rats were fed for 16 weeks with diets containing

50

> g lipids/kg; either OO, maize oil (MO) or FO. OO or MO diets

> contained a standard amount (100 mg/kg) of all-rac-alpha-tocopheryl

> acetate. FO diets were supplemented with 0, 100 or 200 mg all-rac-

> alpha-tocopheryl acetate/kg (FO-0, FO-1 or FO-2 diets,

respectively).

> At the end of the feeding period, we measured non-haem Fe stores in

> liver and spleen, and erythrocyte and reticulocyte count. We also

> determined antioxidants and products derived from lipid

peroxidation

> in plasma and erythrocytes. Our results showed reduced non-haem Fe

> stores in rats fed any of the FO diets. Reticulocyte percentage was

> higher in the rats fed FO-0 and FO-1. Plasma alpha-tocopherol was

> very low in rats fed the FO-0 diet. Rats fed the FO-1 and FO-2

diets

> showed higher alpha-tocopherol in plasma than the FO-0 group but

> lower than the MO or OO groups. We did not observe such differences

> in the alpha-tocopherol content in erythrocyte membranes.

Superoxide

> dismutase and glutathione peroxidase activities were lower in the

> erythrocytes of rats fed the FO-0 diet. The products derived from

> lipid peroxidation were also higher in the FO groups. The

> administration of FO-rich diets increased lipid peroxidation and

> affected Fe metabolism. On the other hand, the OO-rich diet did not

> increase oxidative stress and did not alter Fe metabolism. Based on

> these results, we conclude that FO supplementation should be

advised

> carefully.

> PMID: 12568660 [PubMed - indexed for MEDLINE]

>

> -----------------------------------------

>

> Eicosapentaenoic acid improves endothelial function in

> hypertriglyceridemic subjects despite increased lipid oxidizability.

>

> Okumura T, Fujioka Y, Morimoto S, Tsuboi S, Masai M, Tsujino T,

> Ohyanagi M, Iwasaki T.

> Department of Internal Medicine, Hyogo College of Medicine,

> Nishinomiya, Japan.

> BACKGROUND: Epidemiologic investigations suggest that fish oil,

which

> contains eicosapentaenoic acid (EPA), has favorable cardiovascular

> effects. Fish oil improves endothelial function in subjects with

> hypercholesterolemia or diabetes. However, controversy persists

> regarding relationships between primary hypertriglyceridemia and

> endothelial dysfunction. Moreover, lipoproteins are more

susceptible

> to oxidation in vitro after incorporation of fish oil. METHODS: We

> determined the effects of EPA on serum lipids, susceptibility of

low-

> density lipoproteins (LDL) and very-low-density lipoproteins (VLDL)

> to oxidation, and endothelial function in hypertriglyceridemic

(HTG)

> subjects. In 8 men with untreated primary hypertriglyceridemia

> (plasma triglyceride between 150 and 500 mg/dL) and 7 control

> subjects (triglyceride below 150 mg/dL), forearm blood flow (FBF)

> responses were tested. In HTG subjects, this was repeated 3 months

> after initiation of EPA (1800 mg/day). Cu2+-induced oxidation of

VLDL

> and LDL was determined by serial measurement of conjugated dienes.

We

> used lag time, which corresponded to the period when the

lipoproteins

> were resistant to oxidation, as a parameter of oxidizability. FBF

> responses to acetylcholine and sodium nitroprusside were determined

> by strain-gauge plethysmography. RESULTS: Plasma triglyceride in

HTG

> subjects fell 31% with EPA supplementation. Before EPA, VLDL and

LDL

> lag times in HTG subjects were shorter than in control subjects.

EPA

> further reduced lag time for VLDL but not LDL. The FBF response to

> acetylcholine (but not to nitroprusside) was significantly less in

> HTG subjects before EPA than in control subjects. EPA normalized

the

> FBF response to acetylcholine. CONCLUSIONS: EPA improves

endothelial

> function in HTG subjects despite increasing in VLDL oxidizability