LIPIDS, FATS AND OILS OH MY!
Dietary fats have received much bad press because of their contribution to such disease conditions as heart disease, cancer, gall bladder disease, diabetes, osteoarthritis, and poor physical fitness. However, what is not widely recognized is that there is a difference between various types of fats. Some fats are not only beneficial but vitally important to our health.
Every cell in our body is surrounded by a membrane, a major component of which is fatty acids. These membranes need to be strong enough to protect the cell from infectious agents and other forms of destruction, yet fluid enough to permit smooth passage of nutrients into the cell and cellular products out of the cell. Not only are fats needed to make these membranes, but the type of fats eaten determines the quality of the membrane.
In addition to cell membranes, fatty acids are also used to make cholesterol. Excess cholesterol has detrimental effects on health, but cholesterol in the proper balance is essential for health. Our nerves are surrounded by a substance called myelin, which is made from cholesterol, as are all our steroid hormones. Vitamin D is a substance that is derived from cholesterol and is necessary for the body's utilization of calcium. Vitamin D is available in multivitamins and our bodies can also make Vitamin D from cholesterol when our skin is exposed to sunlight.
Fatty acids are also used to make hormone-like substances called prostaglandins. Prostaglandins have many functions, most notably in terms of regulating inflammation, immunity, production of endocrine hormones and cholesterol, and healthy function of our cardiovascular, respiratory, nervous, and digestive systems. Again, what type of fats we eat determines whether we produce prostaglandins that enhance our health or ones which impair our health.
Finally, fatty acids are a good source of fuel for our bodies. They are the major source of fuel for the heart and in emergency situations can also nourish the brain. These are our two very most vital organs. Fats are also required for us to absorb fat soluble vitamins, such as A, D, E, and K from our foods.
Basically speaking, saturated fats are ones which are more likely to be harmful and unsaturated fats are ones that are more likely to be helpful. Saturated fats are predominantly found in animal products and are solid at room temperature. Unsaturated fats are predominantly from vegetable sources and are liquid at room temperature, otherwise known as oils.
The above is a generalization and of course all aspects of good health involve maintaining a proper balance. There are some saturated fats which are beneficial, such as butyric acid which promotes health of cells in the colon. Similarly, not all fats derived from animal sources are saturated. For example, eicosapentaenoic acid (EPA) is the fat in fish that is beneficial for the health of the heart and blood vessels as well as preventing inflammation.
There are also some unsaturated fats which are harmful, such as oils that have been heated to the point where they change their structures to become what are called trans fatty acids, a contributor to heart disease and cancer. Unsaturated fats which are extracted using chemicals mean those chemicals get absorbed into our systems. Unsaturated fats exposed to hydrogen become saturated fats. Unsaturated fats exposed to oxygen and light can generate free radicals, unstable molecules which can cause cancer, cardiovascular disease, cell degeneration, and aging. Most commercially produced vegetable oils available in grocery stores have at least one of the above problems if not all of them, as opposed to cold pressed vegetable oils from health food stores and food co-ops. Ironically, the beneficial saturated fat butyric acid is found in butter and hydrogenated trans fatty acids are found in margarine. Thus, the widely held belief that it's healthier to use margarine than moderate amounts of butter is another myth about fats.