Re: Re: Fish Oil & Fish Rich Diets

[Guest guest]

Arguments have been made that increased long chain omega-3 fatty acids

(fish oils) may increase peroxidation of mitochondrial inner

membranes, accelerating mitochondrial senescence and hence hastening

aging.

On Sun, 24 Oct 2004 01:33:39 -0000, freebird5005 <freebird5005@...> wrote:

>

>

> 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

>

>