“Eat a low-fat, low-cholesterol diet” has been the mantra for healthful eating for decades. Touted as a way to lose weight and prevent or control heart disease and other chronic conditions, millions of people have followed or, more likely, have tried to follow, this advice.
Seeing a tremendous marketing opportunity, food companies re-engineered thousands of foods to be lower in fat or fat free. The low-fat approach to eating may have made a difference for the occasional individual, but as a nation it hasn’t helped us control weight or become healthier.
Detailed research, much of it done at Harvard, shows that the total amount of fat in the diet isn’t really linked with weight or disease. What really matters is the type of fat in the diet. Bad fats increase the risk for certain diseases. Good fats do just the opposite.
Fat is a nutrient, and one that we absolutely need. We have about 100 trillion cells in our bodies and every single one of them has a cell membrane that is made of fat. Depending on the type of fat you eat is how healthy your cell membranes will be. Fat is crucial for normal body function and without it we could not live. It plays a vital role in maintaining healthy skin and hair, insulating body organs against shock, maintaining body temperature and the absorption of fat-soluble vitamins, a, d, e and k.
Fat also serves as a buffer between the body and a host of diseases. Whenever chemical or biotic substances reach unsafe levels in the bloodstream, the body stores it in our fat tissue until the offending substances can be metabolized or removed from the body. This helps protect our vital organs from being damaged.
Fats are also called oils, and when they are in the body we refer to them as lipids, cholesterol or triglycerides, as in a lipid or cholesterol panel that your doctor will do to measure the levels of your good cholesterol (HDL), bad cholesterol (LDL) and triglycerides.
We get fat in our diet from animal sources, which are usually solid, such as butter, lard, cream and meat. We also get fat from fish oil that is liquid; and vegetable sources, which are usually liquid, as in olive, peanut, flax and corn oils.
There is a fear of fat in our society. We always hear that fats lead to heart disease. This is too general a statement, not all fats cause heart disease. There are actually fats that are good for us and when these good fats replace the bad fats in our diets they can actually help reduce our risk of heart disease. What makes fats different from each other is the number of hydrogen molecules they have. And within each category there are many different fats, the difference between these fats is the number of carbon atoms they contain.
CATEGORIES OF FAT
Saturated fats are totally saturated with hydrogen atoms. It is a naturally occurring fat found in meat and meat products, the skin of poultry, dairy products, many processed foods such as cakes, biscuits, pastries and crackers, as well as coconut and palm oils. A diet high in saturated fat tends to lead to heart disease as well as decreased fertility
Monounsaturated fats are not saturated with hydrogen atoms; each fat molecule has only the space for one hydrogen atom and has only single bonds. It is a naturally occurring fat found in olives and olive oil, ground nut oils and avocados. Foods containing monounsaturated fats lower LDL cholesterol, while raising HDL cholesterol. It has been shown in studies that replacing saturated fats with monounsaturated fats may help lower total cholesterol, raise HDL and lower triglycerides. Good sources of monounsaturated fats are olive oil, peanut oil, canola oil, avocado, nuts and seeds.
There is another monounsaturated fat worth mentioning called Omega-9. We always hear about Omega 3, but there are two other Omega fats, 6 and 9. Omega 9 is created in the body from unsaturated fat. It is thought to improve immune function, reduce insulin resistance, reduce hardening of the arteries and lower cholesterol levels. It is found in olives, olive oil, avocado, almonds, sesame oil, pecans and macadamia nuts. Omega 3 and Omega 6 will be discussed shortly.
Polyunsaturated fats are not saturated with hydrogen atoms; each molecule has only the space for one hydrogen atom. What makes it different from monounsaturated fat is that it as double bonds. It is a naturally occurring fat found in safflower oil, grapeseed oil, and sunflower oil.
Omega 3 is a marketing buzzword these days. It is a polyunsaturated fat that the human body can’t make from scratch so it must be supplied by the food we consume. It is found in fatty fish such as salmon, sardines, chunk light tuna and mackerel as well as flax seed and flax seed oil, canola oil, walnuts and soybean oil. It protects us from heart disease by lowering blood cholesterol levels, and acts as an anti-inflammatory, has been shown to be beneficial to the brain.
Omega 6 is also a polyunsaturated fat and it is extremely abundant in our food supply. We get it from poultry, avocado, eggs, mayonnaise, salad dressing, shortening, pork, bacon, trail mix, chocolate chips, egg substitute, cereal, whole grain breads, nuts and vegetable oils. Omega 6, unto itself is not an unhealthy fat, but our Standard American Diet (SAD) typically has a ratio of 10:1 Omega 6 to Omega 3 and some as high as 30:1, while the optimal ratio for health is thought to be 4:1. It is this unbalanced ratio that is believed to increase the possibility of a number of diseases as well as depression. Excessive amounts of Omega 6 interfere with the health benefits of Omega 3 because they compete for the same enzymes. A high proportion of Omega 6 to Omega 3 is associated with heart attacks, stroke, arrhythmia, arthritis, osteoporosis, inflammation, mood disorders, cancer and reduced fertility.
Trans fats, also known as partially hydrogenated oils are extremely unhealthy. The only natural source of trans fats are the bacteria living in the stomachs of cows, sheep, deer, and other ruminants. As a result beef, lamb, buffalo, venison, and dairy products have small amounts of naturally occurring trans fat and until recently they were the only source.
Today trans fats are created by the process of adding hydrogen to liquid vegetable oils to make them more solid which gives the oil a longer shelf life. Mono and polyunsaturated fats have a very short shelf life, they don’t last very long when baked into food items that are expected to sit on store shelves, such as, cakes, cookies and muffins, they go rancid. By adding hydrogen to these fats they last much longer, can give food a nice taste and texture and turn it into something so unhealthy that it has been proven to increase LDL cholesterol levels and lower HDL cholesterol levels, which in turn raises the risk of developing coronary heart disease and stroke. It has been found that, gram for gram trans fat has twice the adverse effects on these cholesterol levels then saturated fats. Trans fats have become popular because food companies find them easy to use and cheap to produce.
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Wen reading nutrient labels on pre-package food products always look at the ingredient list because even if it says “0” the nutritional values, there can still be trans fats in the food product. The FDA allows labels to read “0” even if there is ½ gram or less, so you need to read the list of ingredients, if it says “partially hydrogenated” or vegetable shortening, then it has trans fat.
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Trans fats can be heated over and over again so they are used in commercial fryers by restaurants and fast food chains to prepare French fries, fried mozzarella sticks and fried shrimp. Several cities around the world have banned the use of trans fats. But they are still used in mass produced foods such as doughnuts, pies, pastries, biscuits, pizza dough, cookies, crackers, stick margarines, shortenings, and many other baked foods. The FDA has estimated that until recently, 95 percent of prepared cookies, 100 percent of crackers and 80 percent of frozen breakfast products contained partially hydrogenated fats. Most of the time we don’t choose to eat trans fats; they are fed to us unknowingly. Trans fats are so detrimental to our health that many states have banned the use of them
I mentioned cell membranes earlier and I want to expand on that now that I’ve explained the different categories of fats. Monounsaturated, polyunsaturated and omega 3 fatty acids are essential to healthy cell membranes. Why is this important? When we spoke of carbohydrates, we spoke of insulin opening the cell door for glucose to move out of the blood stream into our cells and glucagon to help it move out again and in order for this to happen the glucose has to go through the cell membrane. Consuming mono, poly and omega 3 fats keeps our cell membranes soft so glucose can move in and out easily. If we consume high amounts of saturated and trans fats then our cell membranes aren’t as soft as they could be and we start to have a problem moving glucose in and out of our cells which leads to too much glucose in the blood.
Cholesterol is a type of fat found in nature and in the body. We do need cholesterol although our livers usually make all we need and any additional is building up in our arteries causing plaque. Although it is still important to limit the amount of cholesterol you eat, dietary cholesterol isn’t nearly the villain it’s been portrayed to be. Cholesterol in the bloodstream is what’s most important. Dietary sources of cholesterol include cheese, egg yolks, beef, pork, poultry, and shrimp. It is not present in plant based food sources unless it has been added during preparation.
There are two types of cholesterol:
- HDL is your good cholesterol; it cleans up the arteries of LDL and triglyceride deposits, so it helps prevent heart disease. This is why you want your HDL level to be as high as possible.
- LDL is your bad cholesterol; it sticks to your arteries and causes heart disease. This is why you want this number as low as possible.
Triglycerides are another type of fat found in nature and in the body. This is a very bad type of fat. Many people have high triglyceride levels due to being overweight/obese, physical inactivity, cigarette smoking, excess alcohol consumption and/or a diet very high in carbohydrates. High triglycerides are a lifestyle-related risk factor for heart disease; however, underlying diseases or genetic disorders can be the cause. Usually, when people have high triglycerides they also have high LDL and low HDL as well as diabetes
When your doctor does a lipid panel what is being measured is the amount of cholesterol floating around in your blood. You usually get four numbers total cholesterol, HDL, LDL and triglycerides.
These are the healthy numbers:
- Total Cholesterol – under 200
- HDL –
- Men the ideal range is 40 to 50 mg/dL.
- Women, ideal range from 50 to 60 mg/dL.
- An HDL cholesterol of 60 mg/dL or higher gives some protection against heart disease.
- LDL – Less than 100
- Triglycerides – Less than 150
Donna Mintz is the owner of Basil & Barbells, Inc., a NYC based personal chef and personal training service that specializes in helping busy people fit healthy meals and exercise into their hectic schedules by offering cooking classes, personal training and personal chef services