Total fat and saturated fat
Clinical studies clearly show that diets lower in total and saturated fat reduce blood cholesterol. Saturated fat is changed directly in our liver to cholesterol. A diet higher in saturated fat increases the risk of heart disease, even if blood cholesterol does not elevate. Excessive intake also typically leads to weight gain and is a cause of obesity.
Foods high in saturated fat are concentrated primarily in animal foods. In a typical American diet, dairy products supply one-third of the saturated fat, red meat one-third, and poultry and fish conribute the next highest amounts. For example, 65 percent of the fat in dairy products come in the form of saturated fat, beef and pork 50 percent, chicken 35 percent, and fish 20-30 percent. The only concentrated sources of saturated fat found from plant foods are the tropical vegetable oils. Ninety percent of coconut oil is saturated fat, and palm oil 50 percent.
Many people we see in the office believe that by "making the switch" from red meat to poultry that they have greatly improved their diet. Many feel that this single food substitution alone represents "a low fat diet". The reality is that there is not that big of a difference in saturated fat content between meat and poultry. For non-vegetarians fish is the best choice because it is lowest in saturated fat and some fish give us good omega-3 fatty acids (see "Good Fats"). It becomes apparent, however, that you need to have a plant-centered diet to meaningfully reduce these harmful fats.
Cholesterol is present in animal foods only. It is never found in plant food (grains, legumes, vegetables, fruits). There is no need whatsoever for cholesterol in the diet. Our body produces all that we need in the liver. Ideally, one should strive for zero cholesterol intake per day. The American Heart Association takes a compromise position partly out of the belief that people are unwilling to make more drastic diet changes, and undoubtedly influenced by our countryís powerful agricultural/meat/dairy industry. The AHA recommends eating food with less than 300 mg of cholesterol per day and less than 200 mg daily if you have coronary heart disease. This is not nearly aggressive enough according to many independent nutrition experts. We all know that following the AHA diet does little to lower blood cholesterol (we hope for a 10 percent blood cholesterol reduction with this diet) or help with weight loss. Even the pharmaceutical companies recommend that people try diet before starting lipid-lowering drugs, because they too know that the standard AHA diet just doesnít work. To significantly reduce your cholesterol level you need to make significant dietary changes. No surprise! We know the sources of cholesterol and saturated fat in our diet - animal-based food. If one avoids animal foods entirely then it is easy to keep track of your cholesterol intake - always zero! Donít forget to purchase only no-fat dairy foods ("low fat" foods can still be loaded). Keep in mind that just one mere egg yolk contains 200 mg to 300 mg of cholesterol.
Have you heard that stick margarine is more harmful to your health than butter? Trans-fatty acids are to blame. Of note, newer soft margarine in tubs is often trans-fat free. Stick margarine is formed when liquid vegetable oil is heated under pressure and processed into solid fat and the byproduct of this hydrogenation is the creation of a hard, rigid, less perishable trans-fatty acid, or "trans-fat". Hydrogenation rearranges the actual molecular bonds on fatty acids, reshaping them into the straight "trans" configuration. When consumed, these trans-fats are then incorporated directly into our own cell membranes. They act much like saturated fat but are more harmful in that these unnatural fats alter and disrupt our own cell membranes. They take the place of essential fatty acids.
Trans-fatty acids are very bad fats and we need to avoid them. They raise blood total and LDL cholesterol (the "bad" cholesterol) and lower HDL cholesterol ("good" cholesterol). The effect of these artificial fats in our bodies is not yet even totally appreciated. It is frightening to think that some nutrition experts estimate that trans-fatty acids alone are responsible for more than 30,000 deaths in the United States annually. Of historical interest, trans-fat reliance may explain the "French paradox"- despite a higher consumption of "natural" fats the French enjoy a much lower risk of heart disease than Americans who shifted to trans-fats. The development and wide spread use of trans-fatty acids in our generationís food supply seems hauntingly familiar to the man-made health hazard cigarette smoking proved to be for our parents and grandparents.
Trans-fatty acids are now widely available in our food supply. The chemical process of hydrogenation that creates the trans-fatty acid produces a stable product with a long shelf life, therefore making it very convenient. Simply put, commercial food producers and sellers like to use these "trans-fats" because the product can sit in the store longer and there is less risk that the food will become rancid before it is sold. Consumers also enjoy the crisp, light foods that are produced. We find "trans-fats" in cookies, crackers, margarine, shortening, and used extensively in the fast food industry. MacDonaldís uses "cholesterol-free 100% vegetable oil" but it is actually partially hydrogenated vegetable shortening ("trans-fat"). Frozen foods are frequently no better. Ore-Ida Tater Tots contain partially hydrogenated oils. If we eat a frozen chicken potpie then we consume crust filled with saturated and "trans-fat". When Parkay and Promise boast that their margarine sticks have "70 percent less saturated fat than butter"í they fail to mention their high trans-fatty acid content. Bugles chips illustrates the snack food problem well. The bag of Bugles declares that it contains 9 grams of total fat (2 grams saturated fat, 0 cholesterol) per serving on it's Nutrition Facts section. That is a ton of fat, but what accounts for the other 7 fat grams? If you look at the bag's finer print- the product ingredient list- you see that Bugles is made from mostly trans-fat!
Historically, trans-fat has been called a phantom fat because food labels of the past never needed to disclose how much trans-fatty acid a product contains. The "Nutritional Facts" label on food packages have listed gram amounts of total fat, saturated fat, and cholesterol of the product only. The U.S. Congress recently passed a law forcing all food manufacturers to clearly list a product's trans-fatty acid contents, but not until 2006! So if you are purchasing a new food product, especially if it is a convenience food, you need to read all labels carefully - check for trans-fat content!
The following are shopping tips to minimize trans-fats in your diet.
- Avoid foods that contain the terms "vegetable shortening", "partially hydrogenated", or "hydrogenated vegetable oil".
- Steer clear of deep-fried foods (this also means Big Macs and fries).
- The less total fat the "Nutritional Facts" label reads, the less trans-fatty acid the food likely contains.
- Eliminate processed, "convenience" foods as much as possible, or at least eat those with lower fat totals.
- Cook with olive or canola oil instead of margarine and shortening.
- Use olive oil (or better yet, flaxseed oil) on baked potatoes, bread, over vegetables, etc. See "Foods to Embrace" section regarding flaxseed oil.
- "Cholesterol-free" foods can be high in trans-fatty acids. Look for the foods to be also low in saturated fat and total fat.
- If you have no choice but to use either a saturated or a "trans-fat", then do pick the natural-occurring saturated fat (like butter) over a processed hydrogenated trans-fat. There is a new generation of soft spread margarines, which are in fact trans-fat free, but you do need to read the labels carefully.
Animal protein alone increases cholesterol buy approximately 5 percent. Studies show that most Americans consume an excessive amount of protein (about one third more than recommended). The World Health Organization recommends that only 10 percent of our calories come from protein. Contrary to popular opinion, a purely vegetarian diet is more than adequate, as the essential amino acids (building blocks for protein) needed by humans come ultimately from the plant kingdom. Think about where cattle get their protein- from open grazing on grasses. To repeat, all animals and therefore humans get their protein ultimately from plant foods. Excellent plant-based sources of protein include whole grains, vegetables, nuts and seeds, and legumes. Soy protein matches up to animal sources equally, and is so much more healthful.
Animal protein is absolutely not of higher quality than protein from plants. In fact, it is felt by many that excessive animal protein consumption explains the great frequency of osteoporosis seen in the Western world. For every gram of protein eaten, our body loses 1 mg of calcium in the urine. Therefore, our calcium balance is not just dependent on how much calcium we take in orally, but also and to a greater degree on how much we lose in output. Excellent replacement sources of foods high in calcium and lower in protein and fat would include green leafy vegetables, tofu, (precipitated with calcium), fortified orange juice, and fortified soymilk. Animal sources of protein contain no calcium, fiber, or phytochemicals. Meat is a poor "protein package" also because it is a major source of saturated fat and cholesterol to boot.
Red meat intake itself appears to increase cancer risk. Lawrence Kushi, Sc.D. at the School of Public Health at the University of Minnesota says, "The evidence is quite consistent that red meat is associated with a higher risk of colon- and possibly prostate- cancer." Why meat increases cancer rates is uncertain. Walter Willett at Harvard says, "For prostate, it is probably related to animal fat. It could be the carcinogens created when meat is cooked, or meatís highly available iron, or something else in meat. The optimal amount of red meat you should eat is zero." The World Cancer Research Fund concluded in their report (Food, Nutrition, and the Prevention of Cancer) that "diets containing substantial amounts of red meat probably increase the risk of colorectal cancerÖ also, such diets possibly increase the risk of pancreatic, breast, prostate, and renal cancers."
Lastly, animal foods present a unique hazard if not handled and cooked properly. If you under-cook your meat you risk infection with the E. coli bacteria, which has in fact been in the news as a potential major health problem at fast food restaurants. If however, you over-cook the meat you create heterocyclic amines and polyaromatic hydrocarbons, both potent cancer causing substances. Barbecuing, smoking, charcoal broiling, and frying tend to increase the risk of forming these carcinogens. Picture the idyllic summer hamburger barbecue- that fat dripping down on hot coals is creating benzopyrenes! It is best to avoid direct food contact with flames or smoke when cooking (baking, roasting, poaching, stewing, and oven broiling are preferred).