8.2: Fat is Not Evil

There has been a lot said about the dangers of eating too much fat. There are good reasons for focusing attention on dietary fat. But for the unwary, these dire warnings can be misleading. For the evils associated with dietary fats are related to excessive use, not to harm in fat itself. In fact, fat is an essential nutrient.

The Essential Fatty Acids

We really don’t know whether the Arctic Indians suffered from fat starvation because their game grew scarce and lean. We do know, however, that certain fats are required for health. These fats are called essential fatty acids, and there are two—linoleic acid and linolenic acid. Like essential amino acids, these fatty acids are required in the diet— they are needed in the body, and the body can’t make them.

Figure 8-1: Fat-soluble nutrients accompany fats in food.

Although our need for essential fatty acids is very basic (for such tasks as forming cell membranes and for the synthesis of some fundamental chemicals), our total need for them is small. Deficiencies of these essential fatty acids are rare, generally occurring only in cases of medical problems severely affecting fat intake or fat absorption.

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The two diet-essential fats:

• linoleic acid
• linolenic acid

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Special medically administered diets, using liquid formula diets or intravenous feedings with little or no fat, have resulted in deficiencies. Linoleic acid deficiency can impair infant growth and cause scaly skin lesions. Symptoms of linolenic acid deficiency include blurred vision and numbness and pain in the legs.

The essential fatty acids come mainly from plant and fish oils. They are scarce in most meats. Game tends to have far less fat than domesticated animal meat. And hungry game has even less fat. So perhaps the Arctic Indians—when they had only some very lean meat and little access to plant foods—did suffer from some sort of shortage of dietary fat. In contrast, the Eskimos consumed whale, seal, and fish oils, which are rich in essential fatty acids.

Fats Carry Vitamins, Too

Another speculation about the Arctic Indian illness stems from the fact that when the game were short of feed, plant foods would have been scarce for the Indians as well. Thus there could have been shortages of a number of other nutrients commonly found in plants, such as vitamin C, folate, magnesium, and potassium. On the other hand, even assuming there were adequate plant food sources of such nutrients, the leanness of their diet alone may have deprived the Indians of some vitamins. Four vitamins (A, D, E, K) are fat-soluble vitamins. That is, they accompany fats in foods (see Fig. 8-1).

Fat and Pleasure

Fat not only carries the fat-soluble vitamins, but gives certain desirable properties to food. Fat satisfies hunger longer, gives a smooth texture to foods, and carries fat-soluble flavors. When cookies are described as so delicious that they “melt in your mouth,” it’s the fat in those cookies (as well as the fat in any chocolate chips) that melts.

Fat makes foods tender, moist, and flavorful— as in the porterhouse steak marbled with fat, and in the croissant baked with layers of butter. When food is put into hot fat, it cooks quickly (fast food) as the fat browns, flavors, and crisps the outside—thus the ever-popular fried chicken and French fries.

So when the Indians were deprived of fat, we can expect that they were deprived of much of the pleasure of eating as well. This may have led to a loss of appetite that could have aggravated any malnutrition.

While we have no sure answers about the Arctic Indian malady, we have seen how the nutritional role of fats could easily have been a critical factor. And we begin to see how fats in appropriate amounts are anything but dietary villains.