Image by net_efekt via FlickrFat has taken a bad rap over the years but, it is very essential to your health and well being. “Eat a low-fat, low-cholesterol diet” has been the mantra for healthy eating for decades now. Touted as a way to lose weight and prevent heart disease and other chronic conditions, millions of people have followed 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 has not helped us control our weight or become healthier. In the 1960s, fats and oils supplied Americans with about 45 percent of their calories and about 13 percent of the population was obese and less than 1 percent had type 2 diabetes. Today Americans take in less fat, getting about 33 percent of calories from fats and oils, yet 34 percent of the population is obese and 8 percent has diabetes (mostly type 2).Your body packages fat and cholesterol into tiny protein-covered particles called lipoprotein in order to get them into your blood stream. Some of these lipoproteins are big and fluffy, and others are small and dense. However, the most important ones to remember for your health and well-being are low-density lipoproteins, high-density lipoproteins, and triglycerides as explained below.
Low-density lipoproteins (LDL) carry cholesterol form your liver to the rest of your body. Your cells latch onto these particles and extract fat and cholesterol from them. When there is too much LDL cholesterol in your blood, these particles can form deposits in the walls of your coronary arties and other arties throughout your body. These deposits, called plaque can cause your arties to narrow and limit blood flow resulting in a heart attack or stroke. Thus LDL cholesterol is called your bad cholesterol.
High-density lipoprotein (HDL) scavenge cholesterol from your bloodstream, from your LDL, and from your artery walls and ferry it back to your liver for disposal. Thus HDL cholesterol is referred to as your good cholesterol.
Triglycerides make up most of the fat that you eat and that travels through your bloodstream. Triglycerides are your body’s main vehicle for transporting fats to your cells and thus, are very important for your good health. However, an excess of triglycerides can be unhealthy.
The type of fat your diet determines to a large extent the amount of total and LDL cholesterol in your bloodstream. Cholesterol in food matters too, but not nearly as much. You can basically break the fats in your diet into three categories; good, bad, and very bad.
Good Fats
Unsaturated fats are called good fats because they can improve blood cholesterol levels, ease inflammation, stabilize heart rhythms, and play a number of other beneficial roles. Unsaturated fats are predominantly found in foods from plants, such as vegetable oils, nuts, and seeds. They are liquid at room temperature.
Further, there are two types of unsaturated fats. First monounsaturated fats which are found in high concentrations in canola, peanut, and olive oils; avocados; nuts such as almonds, hazelnuts, and pecans; and seeds such as pumpkin and sesame seeds. Secondly, polyunsaturated fats which are found in high concentrations in sunflower, corn, soybean, and flaxseed oils, and also in foods such as walnuts, flax seeds and fish.
Research has shown that replacing carbohydrates in your diet with good fats reduces harmful levels of LDL and increases protective HDL in your bloodstream. A randomized trail known as the Optimal Macronutrient Intake Trial for Heart Health showed that replacing a carbohydrate-rich diet with one rich in unsaturated fat, predominantly monounsaturated fats lowers blood pressure, improves lipid levels, and reduces the estimated cardiovascular risk.
Bad Fats
Saturated fats are called bad fats because they increase your total cholesterol level by elevating your harmful LDL. Your body can make all the saturated fat that it needs, so you don’t need to get any in your diet. In the US and other developed countries saturated fats come mainly from meat, seafood, poultry with skin, and whole-milk dairy products. A few plant sources are also high in saturated fats, such as coconuts and coconut oil, palm oil, and palm kernel oil.
As general rule it’s a good idea to keep your intake of saturated fats as low as possible. Saturated fats are a part of many foods, including vegetable oils that are mainly unsaturated fats, so you can’t totally eliminate them from your diet. Red meat and dairy fats are the main sources of saturated fats in most people’s diets, so minimizing them in your diet is the primary way to reduce your intake of saturated fat.
Very Bad Fats
Trans fatty acids, more commonly known as trans fats are made by heating liquid vegetable oils in the presence of hydrogen gas, a process called hydrogenation. Partially hydrogenating vegetable oils make them more stable and less likely to spoil. It also converts the oil into a solid which makes transportation easier. Partially hydrogenated oils can also withstand repeated heating without breaking down, which makes them ideal for frying fast foods. This is why partially hydrogenated oils have been a mainstay of restaurants and the food industry.
Trans fats are worse for cholesterol levels than saturated fats because they raise bad LDL and lower good HDL. They also increase inflammation, an over-activity of the immune system that has been implicated in heart disease, stroke, diabetes, and other chronic conditions. Even small amounts of trans fats in diet can have harmful health effects. For every extra 2 percent of calories from trans fat daily (the amount in a medium order of fast food French fries) the risk of coronary heart disease increases by 23 percent. It is estimated that eliminating trans fats from the US food supply would prevent between 6 and 19 percent of heart attacks and related deaths (more than 200,000) each year.
