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LETTERS: Niall A Herity, Rajendra H Mehta, Kim A Eagle, Roger Harrison, Michael Burr, Angus Nightingale, Andrew Marshall, Jørgen Fischer Hansen, and R D Rice Secondary prevention in acute myocardial infarction BMJ 1998; 317: 1152a [Full text]

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Fish oil and cardioprotection

Tom Oommen   (28 October 1998)

Fish Oil and Cardio Protection: Herrings & Red Herrings

Tom Oommen   (5 November 1998)

Fish oil and cardioprotection 28 October 1998
Tom Oommen, Assistant professor in pharmacology Kasturba Medical College, Manipal Send response to journal: Re: Fish oil and cardioprotection	The paper on the effect of fish oil on cardio-protection (1) is interesting but incomplete in a few aspects. Non-pharmacological management of hypertension has the potential to reverse mild hypertension, to enhance the effects of anti-hypertensive drugs and to diminish fatal and non- fatal heart attack and stroke rates. Advice on non-pharmacological management needs to be targeted appropriately for individuals and populations with widely varying behaviors which put them at risk of hypertension and its complications (2). There is clinical and epidemiological evidence that long chain poly- unsaturated fatty acids of the omega series (eicosapentaenoic acid and docosahexaenoic acid) decrease the incidence of heart attack, coronory re- stenosis and platelet aggregation, leukotrine synthesis and arterial pressure. They also significantly decrease the severity of atherosclerosis in hyperlipidemic models. Incorporation of squid oil (Illex argentinus), one of the natural oils with the highest concentration of eicosapentaenoic acid (31-34%), into plasma lipoproteins reduced atherosclerosis in rats (3). Those who prefer vegetarian diet may want to know that three and a half ounces of oat germ had more omega-3 than the same amount of salmon or mullet. Common dry beans have more omega-3 than many kinds of fish. Spinach and soya bean are also very rich in omega-3 oils (4). The higher the serum cholesterol the better the fish oil works (4). However in normotensive persons fish oil does not prevent development of hypertension at a later age. In a hypertensive patient without cardiac illness the systolic pressure can be reduced by 4 mm Hg and their diastolic by 3 mm Hg by taking about 7.7 grams of omega-3 fatty acids, which is about 15 fish oil capsules every day (4). Fish oil from cold water fish, such as cod, tuna, salmon, halibut, shark and mackerel produce less of the gastrointestinal side effects of diarrhea, dyspepsia or gas distension. Eating canned fish is not recommended since the process of canning destroys the omega-3 fatty acids. Among the freshwater fish the highest omegas-3 levels are found in lake trout and whitefish. The Pacific herring has less omega-3 than the Atlantic herring. But too much emphasis on fish oils could become a red herring! References: 1. Harrison R and Burr M. Diet containing oil-rich fish confers more benefit than some pharmacological regimens. Brit Med J. 1998; 317: 1153 2. Beilin LJ. Non-pharmacologicalmanagement of hypertension: optimal strategies for reducing cardiovascular risk. J Hypertens Suppl. 1994 ; 12 (10): 71-81 3. Introzzi A, Paglione AM, Slobodianik N,et al. Incorporation of squid oil fatty acids to plasma lipoproteins in rats. Medicina B Aires. 1991; 51(2): 143-147 4. Scuillo LM and Wade SD : The final word on fish oil. In, High Blood Pressure Lowered Naturally. FC&A Publishing, GA, USA; July 1995, pp. 161-164
Fish Oil and Cardio Protection: Herrings & Red Herrings 5 November 1998
Tom Oommen, Asst. Prof. in Pharmacology Kasturba Medical College, Manipal Send response to journal: Re: Fish Oil and Cardio Protection: Herrings & Red Herrings	Dr. Tom Oommen Department of Pharmacology Kasturba Medical College, Manipal 576 119 November 04, 1998 To: The Web Editor, British Medical Journal Sir, The paper on the effect of fish oil on cardio-protection (1) is interesting but incomplete in a few aspects. Non-pharmacological management of hypertension has the potential to reverse mild hypertension, to enhance the effects of anti-hypertensive drugs and to diminish fatal and non-fatal heart attack and stroke rates. Advice on non-pharmacological management needs to be targeted appropriately for individuals and populations with widely varying behaviors which put them at risk of hypertension and its complications (2). There is clinical and epidemiological evidence that long chain poly- unsaturated fatty acids of the omega series (eicosapentaenoic acid and docosahexaenoic acid) decrease the incidence of heart attack, coronory re- stenosis and platelet aggregation, leukotrine synthesis and arterial pressure. They also significantly decrease the severity of atherosclerosis in hyperlipidemic models. Incorporation of squid oil (Illex argentinus), one of the natural oils with the highest concentration of eicosapentaenoic acid (31-34%), into plasma lipoproteins reduced atherosclerosis in rats (3). Those who prefer vegetarian diet may want to know that three and a half ounces of oat germ had more omega-3 than the same amount of salmon or mullet. Common dry beans have more omega-3 than many kinds of fish. Spinach and soya bean are also very rich in omega-3 oils (4). The higher the serum cholesterol the better the fish oil works (4). However in normotensive persons fish oil does not prevent development of hypertension at a later age. In a hypertensive patient without cardiac illness the systolic pressure can be reduced by 4 mm Hg and their diastolic by 3 mm Hg by taking about 7.7 grams of omega-3 fatty acids, which is about 15 fish oil capsules every day (4). Fish oil from cold water fish, such as cod, tuna, salmon, halibut, shark and mackerel produce less of the gastrointestinal side effects of diarrhea, dyspepsia or gas distension. Eating canned fish is not recommended since the process of canning destroys the omega-3 fatty acids. Among the freshwater fish the highest omegas-3 levels are found in lake trout and whitefish. The Pacific herring has less omega-3 than the Atlantic herring. But too much emphasis on fish oils could become a red herring! References: 1. Herity NA, Mehta RH, Eagle KA et al. Secondary prevention in acute myocardial infarction. Brit Med J. 1998; 317: 1152 2. Beilin LJ. Non-pharmacologicalmanagement of hypertension: optimal strategies for reducing cardiovascular risk. J Hypertens Suppl. 1994 ; 12 (10): 71-81 3. Introzzi A, Paglione AM, Slobodianik N,et al. Incorporation of squid oil fatty acids to plasma lipoproteins in rats. Medicina B Aires. 1991; 51(2): 143-147 4. Scuillo LM and Wade SD : The final word on fish oil. In, High Blood Pressure Lowered Naturally. FC&A Publishing, GA, USA; July 1995, pp. 161-164