Calling fat one of life's essentials may seem like a bold statement. Health
professionals have recommended cutting back on fat for years, cautioning the
public about the health risks associated with high-fat eating patterns.
However,
some types of fats have health benefits, while other fats when eaten in excess
have adverse effects. Fat facts: Eating excess amounts of certain fats, notably
saturated fat, can increase risk of chronic disease. Unsaturated fats have
important functions in the body that promote health and well-being. On average,
most Americans consume too much fat, especially saturated fat.
Before cutting
back on the fat in our diets, remember that fat serves many important roles,
including maintaining skin and hair ,storing and transporting fat soluble
vitamins A, D, E, and K, protecting cell walls ,keeping our bodies warm
,protecting organs, Gaining a bead on fat. That's a lot of work for a single
nutrient. In fact, "fat" is actually an umbrella term for several
substances, each with its own part to play. We get many fats from the foods we
eat.
Our bodies also manufacture some fats. As with all nutrients, when we
consume fat, our bodies break it down to individual components and then use
those components to build something else. It's like having three kinds of beads
strung together, pulling them apart, and then stringing them in a whole new
pattern. These strands are known as fatty acids and they vary in the combination
and number of "beads.
" We name fatty acids by their chemical structure
and call them saturated, monounsaturated, or polyunsaturated. Saturated fats are
among the most common fats in our diet. They are found in animal foods like
meat, poultry, and full-fat dairy products, and in tropical oils like palm and
coconut. Diets high in saturated fats are associated with higher risks of heart
disease, certain cancers, and stroke. Unsaturated fats are found in foods from
both plant and animal sources.
Unsaturated fatty acids are further divided into
monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). MUFA
are found mostly in vegetable oils such as olive, canola, and peanut. PUFA are
found in nuts and vegetable oils such as safflower, sunflower, and soybean, and
in fatty fish. The importance of PUFA: Our bodies cannot manufacture all the
fatty acids we need. The chart on page 1 will help you follow how the body makes
fatty acids. Alpha-linolenic acid (ALA) and linoleic acid (LA) are essential
fatty acids (EFAs) because we must obtain them from food.
Both ALA and LA are
polyunsaturated but come from two different families of PUFA, omega-3 and
omega-6. ALA is part of the omega-3 family and LA is part of the omega-6 family.
These two EFAs serve as the basic components, or precursors, to other crucial
PUFAs. LA, for example, is used to make another omega-6 fatty acid, arachidonic
acid (AA), which is important for infant growth. ALA, which is the predominant
omega-3 PUFAs in the American diet, is the precursor to other omega-3 PUFA,
including docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). DHA is
important for proper development of the brain and eyes.
Although the body can
manufacture DHA and EPA from ALA, some researchers consider them
"conditionally essential" since they cannot be made if ALA is in short
supply. The body's ability to convert ALA to EPA and DHA may also be limited.
DHA and EPA are found in both fatty fish, such as salmon, mackerel, and herring,
and the marine plants they feed on. Some research suggests that omega-3 PUFA may
help prevent heart disease through their ability to lower triglycerides and
reduce blood clotting, as well as possibly preventing irregular heart beat and
lowering blood pressure. Not too high--not too low: Remember to eat foods rich
in the essential fatty acids linoleic and alpha-linoleic acids, such as the
seeds and oils of plants and fatty fish like salmon, mackerel, and herring.
Choose reduced-fat or fat-free dairy products, and lean meat and poultry.
Even
though it's important to decrease saturated fat intake, it's also important to
keep fat intake in perspective--don't consume a very-high-fat or very-low-fat
diet. A registered dietitian can help you apply these recommendations.
