Fish Can Cause You Heart Disease
Dr. John McDougall M.D.
Mercury, fish oils, and risk of acute
coronary events and cardiovascular disease, coronary heart disease, and
all-cause mortality in men in eastern Finland by Jyrki Virtanen in
the January 2005 issue of Atherosclerosis, Thrombosis and Vascular
Biology found, “High content of mercury in hair may be a risk factor for
acute coronary events and CVD (vascular disease), CHD (heart disease),
and all-cause mortality in middle-aged eastern Finnish men.
Mercury may also attenuate the protective
effects of fish on cardiovascular health.” More specifically, the high
mercury content negated the so-called, protective effects of the “good”
fish fats (like DHA, DPA, and EPA) on the blood vessels and heart. The
toxic metal mercury comes to us mainly from eating fish.
Comment: Fish is promoted as health food,
a preventative for heart disease, and the only “safe meat” to eat. Here
is a case of a little bit of truth being blown way out of proportion.
Fish fats (omega-3 fats) will thin the blood and make the formation of a
potentially fatal blood clot in your heart artery less likely.
(Remember, the sudden formation of a blood clot – thrombus – in one of
your heart arteries is the cause of a heart attack – coronary artery
The problem is, mercury causes the blood
to clot. Furthermore, the mercury is a powerful oxidant, producing free
radicals, which damage your arteries. Fish muscle is inherently high in
cholesterol, so eating it causes your blood cholesterol to rise.
In this study by Jyrki Virtanen, those
people with the higher amounts of mercury in their hair (indicating more
consumption of fish) also had higher total cholesterol and LDL “bad”
cholesterol levels, and higher rates of hypertension and diabetes. This
is the second major study to show this important health hazard of
An earlier study, published in the New
England Journal of Medicine in 2002, found that higher levels of mercury
in toenail clippings predicted a greater chance of future heart attacks.
2 (Nails and hair accumulate mercury and provide evidence of long-term
accumulation in the body.)
Environmental mercury is a major
pollutant from industry. The toxic form, methylmercury, is accumulated
and concentrated in the food chain.
Because fish are near the top of the food
chain they have very high concentrations of this poison. At the very top
of the food chain are fish-eating people (and, even higher up, their
breast-feeding infants). Almost all of the mercury consumed is
efficiently absorbed by our intestinal tract. Since our bodies have no
way of excreting this toxin, mercury continues to accumulate throughout
life, exerting its detrimental effects.
The final statements of the authors are
worth noticing, “In conclusion, this prospective population-based study
shows that high mercury content in hair is associated with increased
risk of acute coronary events and CVD, CHD, and all-cause mortality, and
that the beneficial effects of fish oils on the risk are negated by high
mercury content in hair. Does this mean that contrary to the current
recommendations for a healthy diet, we should not eat fish? No, but we
should vary the type of fish we eat (plankton-eating, fatty fish is
usually low in mercury, although it may contain other lipid-soluble
environmental pollutants) and avoid regular intake of large fish from
lakes with known high mercury content.” This is another case of
scientists’ personal eating habits getting in the way of their judgment
and honest recommendations for the public.
The truth is: eating fish will give you a
heart attack, not prevent one – and they should have the integrity to
say so. And to tell the public that the least amount of environmental
mercury is found in foods low on the food chain – a diet of starches,
vegetables and fruits. This same diet is also proven to prevent heart
attacks and reverse the underlying mechanisms causing heart attacks –
atherosclerosis and thrombosis.
You can read more about these subjects in
my newsletter archive articles found at
www.drmcdougall.com. See August 2004: A Cesspool of Pollutants
– Now Is the Time to Clean-up Your Body; and February 2003 – Fish Is Not
1) Virtanen JK, Voutilainen S, Rissanen
TH, Mursu J, Tuomainen TP, Korhonen MJ, Valkonen VP, Seppanen K,
Laukkanen JA, Salonen JT. Mercury, fish oils, and risk of acute coronary
events and cardiovascular disease, coronary heart disease, and all-cause
mortality in men in eastern Finland. Arterioscler Thromb Vasc Biol. 2005
2) Guallar E, Sanz-Gallardo MI, van't
Veer P, Bode P, Aro A, Gomez-Aracena J, Kark JD, Riemersma RA,
Martin-Moreno JM, Kok FJ; Heavy Metals and Myocardial Infarction Study
Group. Mercury, fish oils, and the risk of myocardial infarction. N Engl
J Med. 2002 Nov 28;347(22):1747-54.
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