By John Cannell, MD, The Vitamin D Council

Last month, Dr. Armin Zittermann, of Ruhr University in Germany, published the best vitamin D paper of the month. He reviewed the mounting evidence that vitamin D deficiency is a major cause of heart disease.

Br J Nutr. 2005 Oct;94(4):483-92.

Before we start, let's talk about paradigms and paradoxes. A paradigm is a set of assumptions, concepts, and practices that constitutes a way of viewing reality. The current paradigm is that heart disease is caused by a combination of genetics, hypertension, diabetes, cholesterol, smoking, obesity, inactivity and diet.

A paradox is a fact that contradicts the paradigm.
 
The Framingham Risk Equation is an attempt to use the most reliable risk factors in the paradigm to predict who will get heart disease. When they applied it to British men for 10 years, they found 84 percent of the heart disease occurred in the men classified as low risk!  Furthermore, 75 percent of the men classified as high risk were still free of heart disease 10 years later. It seems the equation is missing a few variables.

BMJ. 2003 Nov 29;327(7426):1267

There are several interesting heart disease paradoxes. How well do you know them? Good time for another quiz.
 
1. The French Paradox is the observation that cardiovascular disease is relatively low in France, despite high intakes of saturated fats.
 
A. True
B. False
 
True. Perhaps the best known of the cardiovascular disease paradoxes, the most common explanation is that the French love red wine and the antioxidants it contains. It was first described in 1987, before the dermatologists scared the French out of their bikinis. The rates of cardiovascular mortality in France are much lower in the South and West than in the North.

One of the world's best vitamin D researchers, Dr. Marie Chapuy, found that vitamin D levels of healthy adults in France follow that same pattern, with a mean level of 38 ngs/ml in the sunnier and drier South and West, but less than half that (17ngs/ml) in the colder, rainier and more polluted, North.

Arch Mal Coeur Vaiss. 1987 Apr;80 Spec No:17-21.
Hypertension. 2005 Oct;46(4):645-6. Epub 2005 Sep 12.
Hypertension. 2005 Oct;46(4):645-6. Epub 2005 Sep 12.
Osteoporos Int. 1997;7(5):439-43.

2. The Israeli Paradox is the observation that cardiovascular disease is high in Israel despite a high consumption of polyunsaturated omega-6 fats.
 
A. True
B. False
 
True. According to the current paradigm, polyunsaturated fats contained in vegetable seed oils are supposed to lower the risk of heart disease. However, high consumption of these oils doesn't appear to prevent the Israelis from dying from heart attacks. Israel does, despite its sunny weather, have a high incidence of vitamin D deficiency.

Average vitamin D levels among healthy adults in Lebanon, right next door, are only 9.7 ngs/ml -- dangerously low. Healthy Jewish mothers, especially orthodox ones, have low vitamin D levels.

(If you are wondering how the pro-inflammatory omega-6 oils could ever help heart disease, one possibility is these oils dissociate vitamin D from its binding protein, making more free vitamin D available. Apparently, the Israelis don't have enough vitamin D in their blood to dissociate).

Isr J Med Sci. 1996 Nov;32(11):1134-43.
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3. The Italian Paradox is the observation that a population of heavy smokers has a low incidence of cardiovascular disease.

A. True
B. False

True. The overall death rate from cardiovascular disease in Italy, a country of heavy smokers, is relatively low. Before you say it is the olive oil and wine, ask yourself where olive trees and grapevines grow -- in the sun. However, at least two good studies show vitamin D levels in Europe are a paradox, the closer a European lives to the equator, the lower their vitamin D level.

Nevertheless, an Italian study showed healthy Roman blood donors had robust vitamin D levels of 48 ngs/ml in the summer. Even average postmenopausal Italian women reached 36 ng/ml in the summer. Anyone who has traveled in Italy, know that most Italians love the sun. As the old Italian proverb points out: "Where the sun does not go, the doctor does."

QJM. 2000 Jun;93(6):375-83.
Br J Nutr. 1999 Feb;81(2):133-7.

4. The Northern Ireland Paradox is the observation that a population with a very high incidence of coronary heart disease does not have high rates of the expected risk factors.

A. True
B. False

True. In fact, the age-adjusted mortality for coronary artery disease was more than four times higher in Belfast than in Toulouse, France, despite almost identical coronary risk factors. There were 761 deaths per 100,000 in Belfast compared to 175 in Toulouse. This is hard to explain, given the current paradigm of heart disease. Of interest, Belfast is at 54 degrees latitude, at sea level, and has 257 rainy days per year.

Toulouse is 11 degrees closer to the equator, its altitude is 500 feet closer to the sun, and Toulouse only has 74 rainy days per year. Lots more vitamin D in Toulouse!

QJM. 1995 Jul;88(7):469-77.
QJM. 1998 Oct;91(10):667-76.
Weatherbase, Belfast
Weatherbase, Toulouse

5. The Indian Paradox is the observation that a high prevalence of coronary artery disease in urban Indians is associated with low saturated fat intake.
 
A. True
B. False

True. Researchers found that a low saturated fat diet did not prevent heart disease in the citizens of the brass-works-polluted city of Moradabad in northern India. The authors did not mention that air pollution dramatically lowers vitamin D levels.

J Am Coll Nutr. 1998 Aug;17(4):342-50.
Arch Dis Child. 2002 Aug;87(2):111-3.

6. The Swedish Paradox is the observation that the strong association between cold weather and heart disease in Sweden is not explained by the usual risk factors.

A. True
B. False

True. Researchers tried to explain why higher annual cardiac mortality is associated with residence in colder regions of Sweden. Try as they might, the authors could not support the current paradigm for heart disease. They failed to mention that cold weather is a marker for low vitamin D levels, as outdoor activity in cold weather is both curtailed and requires extensive clothing.

Scott Med J. 1991 Dec;36(6):165-8.

The point of these six paradoxes is simple. Our current paradigm for understanding heart disease is incomplete. One or more major causes of heart disease remain unknown. One theory -- the theory that vitamin D deficiency is a major cause of heart disease -- may explain these paradoxes.

7. Robert Scragg, Associate Professor in Epidemiology at the University of Auckland, first proposed that vitamin D deficiency plays a role in cardiovascular disease.

A. True
B. False

True. For the last 25 years, Dr. Scragg has been trying to convince anyone who would listen that vitamin D explains many of observations about heart disease. These include the facts that heart disease is higher at higher latitudes, lower altitudes, in the winter, in African Americans, in older, inactive, and in more obese patients.

Remember, vitamin D blood levels are lower at higher latitudes, lower altitudes, in the winter, in African Americans, in older, inactive, and in more obese patients. Altitude is the least known of these associations. The age-adjusted mortality for heart disease in the United States showed a striking inverse correlation with altitude in 1979, before the sun scare.

American populations at the highest altitude had about half the heart disease of sea level populations. Thirty-five years ago, Leaf observed that most of the long-lived populations in the world reside at high altitude.

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