Nutritional therapist Henrietta Norton explores the importance of fats and oils.
Fats and oils may well be the most important part of your daily diet. Over the past 20 to 30 years, there has been an explosion of research on the significance of fats in health and disease and there is considerable evidence which links certain ones with many most common forms of degenerative illnesses affecting society today, including cancer and heart disease. But it is fundamental to understand that not all fats are created equal. Simply put, there are actually good and bad fats. Becoming familiar with the different types of fats and oils will help you make informed decisions.
The physical characteristics and nutritional activity of a lipid depends on the kinds of fatty acids it contains. These are the basic units of all fats, and they are classified as saturated, monounsaturated or polyunsaturated according to the type of fatty acids they contain in the greatest quantity. Dietary fats serve many functions in the body. Perhaps the most important is structural – they are the major constituent of every cell membrane in the body. The membrane, or outer lining of a cell, determines what goes into and out of that cell, like a gatekeeper of sorts. As such, they are critical in the proper functioning of the cell.
Fats derived from unprocessed food sources are generally good ones. Polyunsaturated and monounsaturated oils are more fluid and allow easier and healthier function. There are also some natural unprocessed saturated fats that participate in many functions such as repair of gut cells and the formation of healthy brain and nerve cells such as coconut oil. There are two families of fats that are not good but are termed essential – meaning that the body cannot make them and they must be obtained from the diet. They are omega 3 and omega 6 essential fatty acids (EFAs). These perform a crucial function in the body by producing messengers called prostaglandins. Prostaglandins are hormone-like substances that can be thought of as ‘master switches’ that regulate and control almost all cellular activity.
EFAs are very important, but unfortunately they are fragile and easily ‘deactivated’. The main processes that deactivate EFAs are heat, oxygenation, and hydrogenation. These can have an impact on the fats we eat in a variety of ways. Oils can be exposed to high heat during processing and cooking, for example, while oxygenation occurs when the oil is exposed to air and light, such as when they sit on shelves. Hydrogenation occurs when hydrogen is bubbled through oils, as is done in the making of margarine. This process, which results in fats that are labeled as ‘hydrogenated’ or ‘partially hydrogenated’, extends the shelf life of the oil, and , as in the case of margarine, turns a liquid vegetable oil into one that is solid at room temperature.
The beneficial oils actually change their molecular configuration or shape when they are ‘deactivated’ and they are then termed trans fatty acids (TFAs). These are biochemically different and are not able to fulfill the same function as the original oil. Unfortunately, they can still take the place of the biochemically active essential fats in the cell membranes, acting to slow production of the beneficial prostaglandins. There is also evidence to suggest that they may act like free radicals and promote tissue destruction.
A variety of dietary and lifestyle factors are known to interfere with proper EFA function including trans fatty acids (found in starchy foods such as crisps, chips and bread), alcohol, environmental pollutants such as lead and cadmium, aspirin and anti-inflammatory drugs.
Consuming the wrong types of fats, consuming altered good fats, or just not enough of the good types can result in myriad of health problems. The consumption of good quality essential fatty acids and natural fats is crucial for optimal cellular function and health. To rephrase an old adage, your cells are what you eat.