Secondary prevention in acute myocardial infarction
BMJ 1998; 317 doi: https://doi.org/10.1136/bmj.317.7166.1152a (Published 24 October 1998) Cite this as: BMJ 1998;317:1152
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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
Competing interests: No competing interests
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
Competing interests: No competing interests