Trans fats offer a double whammy

Jul 31 2007

Along with the knowledge that 'trans fats' are particularly bad because they clog up arteries and increase the risk of heart attacks comes new information which makes them even more undesirable.

A new study by Canadian researchers says trans fats also interfere with the heart's rhythm thereby increasing the severity of a heart attack and the likelihood of death.

Trans fats (trans fatty acids) are partially hydrogenated oils which are used to extend the shelf life of food and supposedly improve flavour and texture and they also reduce cost.

The hydrogenated oils are highly processed oils and harsh chemical solvents such as hexane (a component of gasoline) are used along with high heat and pressure.

They also have a metal catalyst added to them and are then deodorized and bleached; a small amount of the solvent remains in the finished oil.

Trans fats are in French fries, stick margarine or shortening, microwave oven popcorn, certain chocolate bars, donuts, cookies, cakes and pastries, many processed foods and fast food as well as prepared meals at restaurant chains.

Trans fats raise blood levels of the so-called bad cholesterol (LDL-cholesterol) and lower blood levels of so-called good cholesterol (HDL-cholesterol).

Trans fats cause inflammation inside the body, which signals the deposition of cholesterol as a healing agent on artery walls leading to the clogging of arteries.

There is also concern that trans fats may add to insulin resistance and should be avoided by diabetics.

Dr. Peter Light, the lead author from the Mazankowski Alberta Heart Institute in Edmonton and says trans fats deliver a "double whammy" as they not only clog the arteries, but are stored in the heart cells and can affect how the heart beats.

Dr. Light says this can considerably worsen the condition of a patient suffering a heart attack.

According to the Heart and Stroke Foundation of Canada, trans fats are the culprit in as many as 5,000 deaths annually from cardiovascular disease.

Dr. Light who is an electrophysiologist says the heart is basically an electric organ which uses fat as an energy source; a wave of electricity passes through the heart once per second, and each time calcium is pumped in and then out again.

He found that when trans fats, and to a lesser degree saturated fats, build up in the heart cells, they can affect the crucial flow of calcium.

Bad fats interfere with a protein called the sodium-calcium exchanger which pumps calcium out, but Dr. Light says during a heart attack, it pumps calcium in and the greater the build up of calcium during a heart attack, the more severe the outcome.

An accumulation of calcium can cause irregular heartbeat leading to cardiac arrest.

Dr. Light says the so-called good fats such as olive oil and canola oil remain liquid at room temperature and did not have this effect.

The bad fats such as lard, butter, coconut oil, margarine and partially hydrogenated oils are solid or semi-solid and they are the villains.

Dr. Light says the the research has some potential practical implications for patients scheduled for heart surgery who could be advised to cut out all trans fats for a few weeks before the operation as a way of reducing the risk of a poor outcome.

The study is published in the European Molecular Biology Journal.