dietary fat

Olive Oil Is Junk Food!

Lately, many people have been touting olive oil as some sort of “health food.” Sadly, olive oil is junk food, one of the worst junk foods there is. It’s empty calories that provide practically no essential nutrients.

At roughly 9 calories per gram, olive oil is packed with calories, all of them from fat. Most of the fatty acids in olive oil are a monounsaturated fatty acid called oleic acid. You don’t need to get any monounsaturated fat whatsoever from your diet, and monounsaturated fats have no known role in preventing chronic disease. About 14% of the fatty acids in olive oil are saturated. You don’t need to get any saturated fat whatsoever from your diet, and a high intake of saturated fat has long been known to contribute to coronary artery disease.

There are only two kinds of fatty acid that are essential in human nutrition, which means that you have to get them from the diet. One is an omega-6 fatty acid called linoleic acid, which accounts for somewhere between 3.5% and 21% of the fatty acids in olive oil. Since linoleic acid is commonly found in nuts, seeds, and grains, most people get far more of it than they need. Olive oil contains vanishingly small amounts of alpha-linoleic acid, the essential omega-3 fatty acid that is in relatively short supply in most people’s diets.

Too much fat of any kind will make you fat. Excess fats of all kinds also tend to build up in your arteries, thus leading to heart attack and stroke. Fats of all kinds also tend to promote insulin resistance, thus leading to type 2 diabetes in some people. 

Olive oil has been getting good press because it is considered to be part of the “Mediterranean diet.” Population studies had shown that rates of heart disease were much lower in some of the countries that bordered the Mediterranean Sea than they were in Scandinavia and the United States. However, most people ignore the fact that the people in the Mediterranean countries were eating a more heavily plant-based diet than the people in the United States and Scandinavia. Plants have no cholesterol, and the fiber they contain helps to carry cholesterol out of your system. Instead, people have been focusing on the fact that people in the Mediterranean countries eat some olive oil.

Fat people in Mediterranean countries tend to eat a low-carb, high-fat diet, with olive oil being the predominant fat.  One study found that fat people in Spain had been getting 35% of their calories from carbohydrate and 43% from fats, 55% of which were from monounsaturated fatty acids. So much for the theory that eating fats instead of carbs makes people lose weight, or that olive oil has some sort of belly flattening magic!

dietary fat

Don’t Buy the Snake Oil, Or the Butterfat!

I wrote this as a letter to the editor of Mother Earth News, which is a generally good publication that sometimes publishes bad dietary advice:

In The Fats You Need for a Healthy Diet (August/September 2011 of Mother Earth News), Oscar H. Will, III, provides dangerously misleading dietary advice. Saturated fat does not “do a body good.” You don’t need to get any saturated, monounsaturated, or trans fatty acids whatsoever from the diet. Only two fatty acids are essential, which means that they must come from the food. One is an omega-6 fatty acid called linoleic acid. The other is an omega-3 fatty acid called alpha-linolenic acid. However, the dietary requirement for these fatty acids is so small that you can find true cases of deficiency only in extreme situations, such as people who were being fed nothing but sugar intravenously. For those patients, the requirement for essential fatty acids could be met by rubbing a small amount of vegetable oil on the skin. Fat deficiency is practically nonexistent because even a diet based on low-fat grains and vegetables provides enough of the essential fatty acids

The usual problem is that the person is eating too much fat. Excess fat of any kind promotes obesity, atherosclerosis, diabetes, and other chronic diseases. The omega-3 fatty acids tend to have a blood-thinning effect, which offsets some of the effect of their contribution to atherosclerosis. An excess of the polyunsaturated fatty acids (omega-3 and omega-6) has been linked to an increased risk of cancer, possibly because of their effect on the immune system.

Even vegetarians and vegans often eat too much fat, and they tend to eat a disproportionately large amount of omega-6 relative to omega-3 fatty acids because of a large intake of nuts and oils. The obvious solution to this problem is to restrict the overall fat intake and add a small amount of ground flaxseed to the diet. Flaxseed is an excellent source of the relatively scarce omega-3 fatty acids.

Conjugated linolenic acid is found almost exclusively in foods of animal origin. Yet nutritional epidemiology studies show that those foods promote the sorts of diseases that the dairy industry is claiming that conjugated linolenic acid is supposed to help prevent.

Sources:

http://gorillaprotein.com/efa/
http://fnic.nal.usda.gov/sites/fnic.nal.usda.gov/files/uploads/422-541.pdf
http://www.drmcdougall.com/misc/2007nl/aug/oils.htm
http://www.ncbi.nlm.nih.gov/pubmed/9860369?dopt=Citation