Heart Disease

Heart Disease and Arginine

Why do we have the phrase "heart disease"? We don't talk about "lung disease" or "brain disease". (And, as irony would have it, the problems of high blood pressure and clogged arteries are not located in the heart.)

There is an amino acid called arginine. Depriving animals of arginine can lead to high blood pressure, or clogged arteries (and perhaps to another problem called heart failure).

There are a number of factors that influence heart disease, and they (almost all) have the same effect on arginine. For example, exercise reduces heart disease. Exercise also reduces circulating levels of an amino acid called glutamine, and glutamine inhibits arginine. Women have less heart disease than men, and estrogen has a positive effect on arginine. Nitroglycerin, which is used to treat heart problems, increases NO, and arginine is intimately involved in the production of NO.

Does a Lack of Arginine Cause Heart Disease?

To my memory, scientists have actually tried arginine on humans to see if markers of heart disease could be reduced, without success.

So the answer here is a big maybe. There is a whole lot of evidence to connect arginine with heart disease, and no other explanation of why we would even have the concept of heart disease. But the most critical piece of evidence -- a successful intervention study in humans -- is missing. As a very recent scientific article phrases it: "There is growing interest in asymmetric dimethyl arginine [and homocysteine] as biomarkers of cardiovascular [and renal] risk, but the usefulness of these biomarkers in clinical practice remains to be proven."

Should you supplement your diet with arginine? I know of one person who took arginine, had heart problems, and credits arginine with saving his life. And arginine should be harmless to take. But there is little scientific evidence to support the effectiveness of arginine supplements. (Note that taking supplements does not necessarily increase circulating levels of arginine or arginine effectiveness.)

Restaurant Fried Foods

To summarize two studies, if you give the animals the same fat/oil that restaurants buy to use for frying food, it has no effect on arginine levels or effectiveness. However, if you feed animals the fat/oil that restaurants have actually been using for a week to fry food, arginine levels/effectiveness drop dramatically.

In other words, the fat/oil itself is harmless. But something is added to the fat/oil, or more likely, chemical changes occur as the fat/oil is heated and used. These create a fat/oil that does impair arginine.

So, to follow the tenuous line of evidence, restaurant fried foods might contribute to heart disease. There isn't much evidence on this because scientists would not think to differentiate used versus unused fats and oils.

Should You Believe This?

I investigated arginine over 5 years ago. My hard drive crashed and I lost my report and all my notes. So this is from memory. But it is a solid memory. There may be more research since then.

The connection between arginine and heart disease is tenuous. The studies relating arginine to used restaurant fats/oils are small. So, I think a healthy scepticism is warranted. I myself am not convinced that used restaurant fat/oil contributes to heart disease.

Summary

The good news is, there are no experts telling you that you shouldn't eat restaurant fried foods. The bad news is, doing so might contribute to heart disease.

Robert Frick