Types of Fatty Acids - The Basic Facts About Fat

Do you find the facts about fat confusing? Don't worry, even nutritionists have to stop and think. Here is a list of Frequently Asked Questions about fat that explains the types of fatty acids and how they affect your health.

Q. What is a fatty acid?

A. A fatty acid is the basic building block of body fat. It is also the basic building block of the linings of cells and of all the body's hormones. The "acid" part of the fatty acid refers to the fact that it can react with an alkali to form a new substance. Most fatty acids are only very, very mildly acidic, and they do not "acidify" the body in any way.

Q. What is a saturated fatty acid?

A. Saturation refers to how much a fatty acid can interact with other substances. All fatty acids are molecules composed of long chains of carbon atoms. If each carbon atom is joined to four other atoms, the molecule is said to be saturated. If some carbon atoms are joined to just two or three other atoms (and can react with more), then the fatty acid is unsaturated.

Q. What is the difference between short-, medium-, and long-chain fatty acids.

A. Short-chain fatty acids have just six carbon atoms. They float through the bloodstream easily and they are quickly burned as fuel. Medium-chain fatty acids have more than six but no more than 12 carbon atoms. They readily form the triglycerides stored inside fat cells. Long-chain fatty acids have more than 12 carbon atoms. They are the saturated fats that aren't easy for the body to burn and aren't easy to store, either.

Q. Why are saturated fatty acids bad for health?

A. All of the saturated fatty acids aren't bad for your health. Lauric acid in coconut oil, for instance, is a long-chain fatty acid. But because saturated fatty acids are hard to burn and hard to store, the body usually uses them to make cholesterol.

Q. Why is a mono-unsaturated fatty acid supposed to be beneficial?

A. A mono-unsaturated fatty acid, such as the oleic acid in olive oil, tends to be a long-chain fatty acid that is long enough to be transformed into HDL ("good") cholesterol but not long enough to be transformed into LDL ("bad") cholesterol. Not all mono-unsaturated fatty acids are beneficial for health, but those in olive oil and nut oils are.

Q. What is a trans- fat?

A. A trans- fat is an unsaturated fat with a "twist" around the double bond between two carbon atoms. The "twist" of the molecule tends to make it stick in the lining of cells, where it can be attacked by free radicals that damage the rest of the lining of the cell.

Q. What is an "essential" fatty acid?

A. "Essential" refers to the fact that body can't make the fatty acid from other nutrients. Omega-3 fatty acids (very short fatty acids with a double bond at one end) and omega-6 fatty acids (slight longer fatty acids with a double bond at one end) are essential, but the body can make omega-9 fatty acids (used to fight inflammation) from almost any kind of fat. Omega-3's and omega-6's have to come from diet.

Q. Isn't omega-6 fat the "bad" fat?

A. No. It's essential to human health. Without omega-6 fats, our bodies could not make the hormones that activate the immune system and that help the body respond to stress. The problem is that we get too much omega-6 fat and we usually have to supplement omega-3 essential fatty acids to bring the two kinds of essential fatty acids into balance.

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