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Medical Forum / General / Cardiology / March 2008Beneficial Actions of Polyunsaturated Fatty Acids in Cardiovascular Diseases: But, How and Why?
More fodder for the endless debate. mikeV http://www.ingentaconnect.com/content/ben/cnf/2008/00000004/00000001/art00002 Beneficial Actions of Polyunsaturated Fatty Acids in Cardiovascular Diseases: But, How and Why? Author: Das, Undurti N. Source: Current Nutrition & Food Science, Volume 4, Number 1, February 2008 , pp. 2-31(30) Publisher: Bentham Science Publishers Abstract: Omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), and to a limited extent n- 6 fatty acids: arachidonic acid (AA), gamma-linolenic acid (GLA) and dihomo-GLA (DGLA), prevent cardiovascular disease, thrombosis and atherosclerosis, reduce cardiac arrhythmias, lower plasma cholesterol and triglycerides, lower high blood pressure and improve endothelial function. These beneficial actions of the fatty acids could be attributed to their ability to augment endothelial nitric oxide generation, inhibit HMG-CoA reductase and angiotensin converting enzyme (ACE) activities, block the production of pro-inflammatory cytokines, and modulate telomerase activity. AA, EPA, and DHA form precursors to anti-inflammatory molecules: lipoxins and resolvins that help in wound healing, inhibit the actions of pro-inflammatory eicosanoids, and suppress the production of free radicals and enhance nitric oxide (NO) generation. In addition, these fatty acids react with NO and NO-derived reactive nitrogen species to form nitroalkene derivative of fatty acids called as nitrolipids. Nitrolipids serve as potent ligands for peroxisome proliferator activated receptors (PPARs), inhibit platelet activation through elevation of cyclic AMP levels; suppress superoxide generation, degranulation, and integrin expression by human neutrophils, and induce vasorelaxation in a concentration dependent manner by releasing NO. Nitrolipids are formed at the sites of inflammation in significant amounts and increased by oxidative inflammatory reactions. Furthermore, ?-3 and ? -6 fatty acids interact with each other to enhance the formation of prostaglandin E1 (PGE1), prostacyclin (PGI2), and PGI3, which are potent platelet anti-aggregators and vasodilators. Thus, GLA, DGLA, AA, EPA, and DHA when present in optimum amounts in the tissues, especially in endothelial cells, myocardium, platelets, and neutrophils, may aid in the prevention of cardiovascular diseases. Mike: You've been reading newsgroup posts here for a while now, correct? There is nothing mysterious about this study. I'll explain in detail. If you have AA in your cells (I don't now, but most Americans do), some PUFAs inhibit/counteract the AA metabolites, which do the damage in most of today's "chronic diseases." Other things will do this too, but usually in a less dangerous way (some antioxidants, for example). And of course, you can simply eat a diet that will allow your body to make the natural Mead acid (rather than converting linoleic acid to AA and storing it in your cells). Just because one monster kills or maims another monster does not mean that the new monster won't do a lot of damage too. In fact, if you were to eat similar to what the native Greenlanders used to, there's a good chance you wouldn't have a heart attack in your 50s or 60s, because the omega 3s would kill you (often by internal bleeding or a "bleeding stroke") before the omega 6s gave you cancer, an ischemic stroke, or a heart attack. In article <742e9573-2cc3-4c3e-bf90-054246670104@q33g2000hsh.googlegroups.com>, > Mike: > [quoted text clipped - 14 lines] > before the omega 6s gave you cancer, an ischemic stroke, or a heart > attack. Is there any evidence that omega 3 oil caused Greenlanders to die in their 50s or 60s from internal bleeding or a "bleeding stroke"? > In article > <742e9573-2cc3-4c3e-bf90-054246670...@q33g2000hsh.googlegroups.com>, [quoted text clipped - 21 lines] > Is there any evidence that omega 3 oil caused Greenlanders to die in > their 50s or 60s from internal bleeding or a "bleeding stroke"? I don't know about that but the Japanese used to die often from bleeding strokes in their brains rather than cancer or CHD. Now that's changing together with the increasing consumption of Omega-6 and trans fat rich vegetable oils. Also they are getting taller. Taka Some traditional diets were very high in salt. Could that have been part of the problem? Or could some of the old local diets been low at least seasonally in vitamin K? Granted the fish oil might reducing clotting and increase bleeding strokes. another factor may be at work. m J Hypertens. 2005 May;18(5 Pt 1):612-8. Relationship between mercury in blood and 24-h ambulatory blood pressure in Greenlanders and Danes. Pedersen EB, Jørgensen ME, Pedersen MB, Siggaard C, Sørensen TB, Mulvad G, Hansen JC, Asmund G, Skjoldborg H. Department of Medical Research, Holstebro Hospital, Holstebro, Denmark. ebp@dadlnet.dk BACKGROUND: Intake of mercury with food items from sea mammals and fish has been suggested to be involved in cardiovascular disease, but the relationship between mercury in blood and 24-h ambulatory blood pressure (BP) has never been studied. METHODS: We measured mercury in blood and 24-h BP in four groups of healthy subjects: group 1, Danes living in Denmark consuming European food; group 2, Greenlanders living in Denmark consuming European food; group 3, Greenlanders living in Greenland consuming European food; and group 4, Greenlanders living in Greenland consuming mainly traditional Greenlandic food. RESULTS: Mercury in blood was highest in Greenlanders and increased when they lived in Greenland and consumed traditional Greenlandic food (group 1: 2.2 microg/L (median), group 2: 4.8 microg/L, group 3: 10.8 microg/L, and group 4: 24.9 microg/L). The 24-h BP was the same in all three groups of Greenlanders. However, 24-h diastolic BP was lower among Greenlanders than Danes (71 v 76 mm Hg, P < .000) and 24-h pulse pressure was higher (54 v 50 mm Hg, P < .000). Mercury in blood was significantly and positively correlated to pulse pressure (rho = 0.272, P < .01). CONCLUSIONS: Pulse pressure was higher and diastolic BP was lower in Greenlanders than Danes. Pulse pressure increased with higher mercury content in the blood. Although genetic factors must be responsible to some extent for the difference in pulse pressure between Greenlanders and Danes, the present results seem to support the hypothesis that mercury intake from maritime food is involved in cardiovascular disease. PMID: 15882543 Other factors. There at lot smoking going on. Wow. Int J Epidemiol. 1997 Dec;26(6):1182-90. Cardiovascular risk factors in Inuit of Greenland. Bjerregaard P, Mulvad G, Pedersen HS. Danish Institute for Clinical Epidemiology, Section for Research in Greenland, Copenhagen, Denmark. BACKGROUND: Mortality from ischaemic heart disease (IHD) and prevalence of coronary arteriosclerosis are low in Inuit of Greenland (Greenlanders). Aetiological considerations have so far focused mostly on diet and blood lipids. The present study is a comprehensive analysis of behavioural, clinical and serological cardiovascular risk factors for IHD in Greenlanders. METHODS: An interview survey from West Greenland (n = 1436) was supplemented with clinical measurements and blood sampling in selected towns and villages (n = 264). RESULTS: The average consumption of marine mammals and fish was 28 meals per month. In Greenland 14% of males and 30% of females were physically inactive compared with 14% and 17% in the general population of Denmark; 79% were current smokers and 22% smoked 15+ cigarettes per day compared with 42% and 21% in Denmark. High density lipoprotein (HDL) concentration was 1.6 mmol/l in Greenland (1.1 in Denmark) and triglyceride concentration 1.0 mmol/l (1.5). Obesity, blood pressure and total cholesterol were similar in Greenland and Denmark. There were significant differences between Greenlanders with a predominantly traditional childhood and those with a more westernized childhood with regard to diet, physical activity (in women) and blood lipids. CONCLUSIONS: In spite of an increased westernization of the Greenlanders' lifestyle and a high prevalence of several cardiovascular risk factors, mortality from IHD is still low. The change in risk factor patterns is, however, recent and an increased IHD mortality is still to be expected. Preventive measures should be initiated to reduce risk factors but they must take into consideration possible negative consequences of e.g. traditional outdoor activities and the consumption of marine mammals. PMID: 9447397 >> In article >> <742e9573-2cc3-4c3e-bf90-054246670...@q33g2000hsh.googlegroups.com>, [quoted text clipped - 26 lines] > > Taka I don't know about getting taller. I read that the average height of Japanese college graduates increased by a foot after WW II over the course of a decade, but haven't heard that it's still increasing. What have you heard?  SignatureMarshall Price of Miami Known to Yahoo as d021317c > >> In article > >> <742e9573-2cc3-4c3e-bf90-054246670...@q33g2000hsh.googlegroups.com>, [quoted text clipped - 31 lines] > course of a decade, but haven't heard that it's still increasing. What > have you heard? I don't hear it but see it around me while living in Tokyo. The consumption of vegetable oils especially soybean is high (everything is fried). But Japanese consume less amount of everything compared to Americans. Also they consume more fatty fish, seafood, soy products and unsweetened beverages (different kinds of teas - vending machines are everywhere) what may be still impairing their growth to some extent. Their diet is also high in complex carbohydrates such as rice - this is interesting in the context of Gary Taubes talk about the bad effects of carbs on the native Americans (Pigmies). Japanese seem to have the same genetic background as the native Americans and Inuits (at least according to the mitochondrial DNA sequencing) so they should be suffering obesity and malnutrition from the high rice consumption but they are not obese in general. Perhaps rice is much better compared to wheat and HFCS and the negative effects of vegetable oils may be offset by the antioxidants in green tea and EPA +DHA from fish. Taka > -- > Marshall Price of Miami > Known to Yahoo as d021317c It seems to me I heard somewhere that Taka wrote in article <7b9d1fe3-fdf0-4ac3-9b3c-355af16b55e4@e31g2000hse.googlegroups.com>: >> >> In article >> >> <742e9573-2cc3-4c3e-bf90-054246670...@q33g2000hsh.googlegroups.com>, >> >> monty1...@lycos.com wrote: >> >>> Mike: [quoted text clipped - 16 lines] >> >> Is there any evidence that omega 3 oil caused Greenlanders to die in >> >> their 50s or 60s from internal bleeding or a "bleeding stroke"? >> > I don't know about that but the Japanese used to die often from >> > bleeding strokes in their brains rather than cancer or CHD. Now >> > that's changing together with the increasing consumption of Omega-6 >> > and trans fat rich vegetable oils. Also they are getting taller. >> I don't know about getting taller. I read that the average height of >> Japanese college graduates increased by a foot after WW II over the >> course of a decade, but haven't heard that it's still increasing. What >> have you heard? IIUC most of the height increase in Japan (and, probably Korea, China, and other recently developed Asian countries) has been the result of lengthening of the limbs, which would seem to be a self-limiting phenomenon. The stereotypical thinking was that typical Asians from poor areas (therefore poorly nurtured) had proportionately shorter legs and longer bodies. That was beginning to change before I left Japan several decades ago, partly as a result of changes in school nutrition programs. >I don't hear it but see it around me while living in Tokyo. The >consumption of vegetable oils especially soybean is high (everything [quoted text clipped - 5 lines] >- this is interesting in the context of Gary Taubes talk about the bad >effects of carbs on the native Americans (Pigmies). Have Pygmies joined the immigration to the US or North America? > Japanese seem to >have the same genetic background as the native Americans and Inuits >(at least according to the mitochondrial DNA sequencing) so they >should be suffering obesity and malnutrition from the high rice >consumption but they are not obese in general. I suppose the genetic lineage can be traced, but I suspect it's so diluted after several millennia that there's little in common genetic traits between the several populations that evolved out of the source population. > Perhaps rice is much >better compared to wheat and HFCS and the negative effects of >vegetable oils may be offset by the antioxidants in green tea and EPA >+DHA from fish. Don't go overboard in praising the Japanese rice diet/approach <g>. The Japanese long ago began polishing the bran off their rice; the main difference from US rice is that the Japanese have developed shorter grained varieties that when cooked clump together more than long grain rice (much better for chopsticks). Since soon after WW II Japanese government regulations have required that rice be fortified like American bread and for the same reasons, to replace the nutrition removed by polishing and mostly discarding the bran. A comparison may be misleading, because rice, sweet potatoes, and a native tuber (satoimo) have supplied starch in the Japanese diet just as bread, potatoes, rice, and pasta have supplied it for the Western diet, and no Japanese meal is complete without vegetable or animal protein. I thought recent nutritional thinking was that vegetable oils tended to be high in polyunsaturated fats and a good source of the omega- oils. Not? The Japanese have been using vegetable oils for a very long time; one of the original oils, rape seed, is an ancestor/relative of Canola, Canada's patented version. SignatureDon Kirkman >>>> In article >>>> <742e9573-2cc3-4c3e-bf90-054246670...@q33g2000hsh.googlegroups.com>, [quoted text clipped - 44 lines] > vegetable oils may be offset by the antioxidants in green tea and EPA > +DHA from fish. I don't think there are any pygmies in the New World. They're in Africa, and now known by another name. I remember when Ondeko-Za came to Miami. They were playing drums and running the circumference (!) of the continental United States. They were incredibly healthy-looking, and their diet was mainly white rice. As you know, the names of meals in Japanese all end in -gohan ("honorable rice"), since traditionally, they didn't eat different foods for breakfast, lunch, and dinner, as Westerners do, and they get most of their calories from rice. But until World War II, they didn't get much calcium. I once knew a man who worked for Pet Foods, the makers of evaporated and condensed milk, whose brother went to Japan soon after World War II, met a samurai, and was given thousands of acres in the mountains on which to establish a dairy industry. As I understand it, it was the increase in calcium in the Japanese diet, mainly from milk, to which was attributed their rapid increase in height. SignatureMarshall Price of Miami Known to Yahoo as d021317c Corn,is the down fall of the American Indian and now it maybe the down fall of all Native Americans. CHUCK >>>>> In article >>>>> <742e9573-2cc3-4c3e-bf90-054246670...@q33g2000hsh.googlegroups.com>, [quoted text clipped - 66 lines] > calcium in the Japanese diet, mainly from milk, to which was attributed > their rapid increase in height. > Corn,is the down fall of the American Indian and now it maybe the down fall > of all Native Americans. So what is different between corn and rice? I only know that rice oil is higher in antioxidants like VitE but otherwise starch is a starch? Both made from glucose units ... Ah perhaps rice is not GMO! Taka sugar!&who said rice is good food,besides being available. chuck >> Corn,is the down fall of the American Indian and now it maybe the down >> fall [quoted text clipped - 5 lines] > > Taka Bob: The evidence is strong, and at every level (epidemiological, molecular, biochemical, etc.). If you go to my free site, there is a page I put together that cites many passages from the professional literature concerning the dangers of fish oil or omega 3s. First, go to: http://groups.msn.com/TheScientificDebateForum-/ Then scroll down and find the essay on the left, entitled something like "Fish oil quotes you might want to know about." > Bob: > [quoted text clipped - 9 lines] > Then scroll down and find the essay on the left, entitled something > like "Fish oil quotes you might want to know about." The web page mentions "ex vivo bibe PGE2." Is that a typo? SignatureMarshall Price of Miami Known to Yahoo as d021317c 1: Scand J Clin Lab Invest Suppl. 1982;161:7-13. A hypothesis on the development of acute myocardial infarction in Greenlanders. Dyerberg J, Bang HO. Non-emigrated Greenlanders have a low incidence of acute myocardial infarction (AMI), when compared with age- and sex adjusted death rates for ischemic heart disease in western countries. We find that Greenlanders have plasma lipid levels corresponding to favourable risk factor levels for AMI. This can be attributed to their diet, rich in n-3 polyunsaturated fat. This diet further supplies eicosapentaenoic acid which influence platelet vessel wall function in an antithrombotic direction. A high level of plasma-antithrombin-III, raising the anticoagulant activity of the blood, in combination with a genetically high activation threshold for the complement system may further contribute to the resistancy against thrombo-embolic disorders. Bleeding tendency, and susceptibility to infection disorders may be the possible draw-backs. Our data are framed into a hypothesis combining the indications of genetic predispositions and the evidence of exogenous protective factors, inflicting a coherent enhancement of nonsusceptibility to vascular ischemic catastrophies. PMID: 6293041 next posting: Int J Circumpolar Health. 2004;63 Suppl 2:290-1. Incidence of myocardial and cerebral infarction in Nuuk, Greenland. Kjaergaard JJ, Bjerregaard P. Queen Ingrid Hospital, Nuuk, Greenland. jensjk@dadlnet.dk INTRODUCTION: Myocardial and cerebral infarction are held to be rare among the Inuit, whereas cerebral haemorrhage is thought to be frequent. Recent studies have questioned these beliefs. We report data form our institution. METHOD: Retrospective data collection and review of all charts from Greenlandic patients from the Nuuk area admitted to the city hospital, Dronning Ingrids Hospital, from 1999 to 2002. RESULTS: A total of 8 patients with myocardial infarction were found, median age 70 years, 4 with ST elevation MI and 4 with non-ST elevation MI. Two of the former had thrombolysis. Thirty-five patients were admitted with stroke, excluding subarachnoid haemorrhage, median age 65 years. Of these, twenty-nine had a CT. Five scans were reported as being normal, one patient had an intracerebral haemorrhage and twenty-three had cerebral infarctions. Six had no CT. One of these was admitted comatose and died without regaining consciousness, the rest were minor strokes in patients over 70. CONCLUSION: Myocardial infarction is a rare disease in Greenlanders, whereas stroke is four times as frequent. The overwhelming majority of strokes are infarctions, whereas intracerebral haemorrhage seems to account only for a small minority. PMID: 15736670 full paper available without charge here: http://ije.oxfordjournals.org/cgi/reprint/26/6/1182 On Feb 24, 4:15 pm, monty1...@lycos.com wrote: > Mike: > [quoted text clipped - 7 lines] > your body to make the natural Mead acid (rather than converting > linoleic acid to AA and storing it in your cells). Just curious here. What sort of diet would stimulate the body to make a good amount of Mead acid? Deane: If you go to the site I cited above, you will see one essay on my diet and also there are several posts that are relevant in the nutrition forum. Basically, you need to eliminate any major source of polyunsaturated fatty acids. Even oils that are classified as "monunsaturates," like canola oil, should be avoided if they are rich in PUFAs. Olive oil is okay if it is of the highest quality, still fresh, and you don't use it for cooking. Otherwise, use butter (again, don't cook with it) or coconut oil (palm kernel oil is okay, but costs more and has no taste). You can eat small amounts of food made with palm oil, but make sure the saturated fat content is around 50% (preferably higher). Meat should also be eaten in moderation, though I avoid it entirely. Once Mead acid replaces AA, then you can eat more meat, if you feel you must. On my site there have been long threads on eating meat, and if so, how to prepare it. Obviously, a small amount won't do any harm (unless, of course, it was seriously tainted with something), but the combination of a lot of meat and a lot of PUFA-rich items (like the oils used for cooking) are a terrible combination (generating dangerous molecules like HCAs). > Basically, you need to eliminate any major source of > polyunsaturated fatty acids... > Meat should also be eaten in moderation, > though I avoid it entirely... Questions. What are the major factors that trigger AA? Are LPS and physical injury two of them? Does chewing raw meat trigger release of AA? Does cooking meat disable the AA cascade? AA is converted to other metabolites via COX1, COX2, 5,12,15-LOX, etc. What determines which oxygenase is used? A link to a diagram would help me understand. Thx. Jay: One thing I learned in grad. school that has helped me a lot over the years is to distinguish between what is clear and what is still in doubt, as well as to see if there is a "big picture" that does not require all the "ends" to be "tied up." From what I've seen of the evidence, there is still plenty of work that needs to be done on which metabolite gets generated. What surprised me were the studies that pointed out how unstable AA is, even at physiologically "normal" concentrations. I don't think meat is really the issue, but rather if the animal was healthy, how you cook it, what you cook or eat it with, and how much of it you eat. If you cook it, you will destroy (change) at least some of the AA into molecules that can't be changed back (though that does not mean these are now "good" for you, just less dangerous in this context). You can do pubmed.com searches and you will find a huge amount of evidence, for example, just search for arachidonic and see the thousands of results. Mary Enig has tried to generalize about this, though she thinks AA is "essential." See: http://www.westonaprice.org/knowyourfats/tripping.html There's other, similar material on the WP website you might want to take a look at, and of course there are many citations on my site. |
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