The chemical structure of the fat that you eat is more important than you think. Everyone needs some fat in their diet, but too much and too much of the wrong types of fat can be bad for your health. A Dutch group of researchers has recently reported that trans fat (more correctly trans fatty acids) are more detrimental to cardiovascular health than saturated fats.
Generally speaking, polyunsaturated fats like those found in most vegetable oils and monounsaturated fats that are found in olive and canola oil are considered good fats to have in the diet. Saturated fats, most abundant in animal products such as meat and milk, are usually considered bad, but recent evidence suggests that trans fatty acids are worse.
Trans fatty acids do occur in milk naturally, but are more commonly produced during food processing. However, because we eat so much processed food now, in countries like the United States and the Netherlands, trans fat can make up to 7% of our total fat intake.
Avoiding trans fats may be difficult for the average consumer because the amount of trans fat in foods is not identified on their labels. It is included however in the total fat reported. The French fries, fried chicken, and doughnuts from fast food outlets all contain high levels of trans fat. Since the manufacturing process of hydrogenation is primarily responsible for the creation of trans fats, avoid anything containing hydrogenated oils.
Other reported effects of trans fatty acids that may be detrimental to health:
- Increases blood insulin levels in humans in response to glucose load
- Affects immune response
- Decreases the response of the red blood cell to insulin
- Inhibits the function of membrane-related enzymes
- Causes alterations in physiological properties of biological membranes
- Causes alterations in adipose cell size, cell number, lipid class, and fatty acid composition
Hydrogenated Fats / Trans Fatty Acids Avoidance can help with the following
Atherosclerosis
Dietary trans-fats cause hardening of the arteries. A mouse study suggests that high levels of trans-fats cause atherosclerosis by reducing the responsiveness of transforming growth factor (TGF)-beta. This protein controls growth and differentiation in cells. The findings of this study reinforce research that has linked the predominantly man-made fat with a range of health problems.
“Trans-fats are attractive for the food industry due to their extended shelf life and flavor stability, and have displaced natural solid fats and liquid oils in many areas of food processing.”
” . . . trans-fatty acids raise serum levels of LDL-cholesterol, reduce levels of HDL-cholesterol, can promote inflammation can cause endothelial dysfunction, and influence other risk factors for cardiovascular diseases (CVD) . . .” [The Journal of Nutritional Biochemistry October 30, 2010]
Elevated LDL/HDL Ratio
Trans fat has also been shown in studies to raise the levels of LDL or “bad cholesterol” and may also increase total serum cholesterol. In one Dutch study, blood levels of HDL or “good cholesterol” were lowered by 20% compared to when the same subjects ate a diet rich in saturated fats. [http://www.medicinalfoodnews.com/vol05/issue6/transfat.htm]
Mayo Clinic reports “Unlike other fats, trans fat – also called trans-fatty acids – both raises your “bad” (LDL) cholesterol and lowers your “good” (HDL) cholesterol.
And, dietary trans-fats cause hardening of the arteries. A mouse study suggests that high levels of trans-fats cause atherosclerosis by reducing the responsiveness of transforming growth factor (TGF)-beta. This protein controls growth and differentiation in cells. The findings of this study reinforce research that has linked the predominantly man-made fat with a range of health problems.
“Trans-fats are attractive for the food industry due to their extended shelf life and flavor stability, and have displaced natural solid fats and liquid oils in many areas of food processing.” ” . . . Trans-fatty acids raise serum levels of LDL-cholesterol, reduce levels of HDL-cholesterol, can promote inflammation can cause endothelial dysfunction, and influence other risk factors for cardiovascular diseases (CVD) . . .” [The Journal of Nutritional Biochemistry October 30, 2010]
Metabolic Syndrome (Syndrome X)
The major findings of this study, conducted in monkeys, showed that, in the absence of caloric excess, Trans-fatty acid (TFA) induces greater weight gain over time, with enhanced intra-abdominal deposition of fat between the two groups as measured at study termination.
There was evidence of impaired insulin sensitivity in the TFA group associated with abdominal obesity and reductions in insulin signal transduction efficiency at the post-receptor binding level compared with monkeys fed the unmodified fat diet at study end. The TFA diet models the trends seen in fats available in grocery stores, which have become more oleate rich and less TFA rich as canola oil has been increasingly substituted for partially hydrogenated soybean oil. Therefore, a comparison of cis- and trans-monounsaturates better represents the shift in the food fat composition that is already occurring in the U.S.
The trans fat used in this study was partially hydrogenated soybean oil, which constitutes the major source (80% to 90% ) of TFAs in the American diet [Obesity (2007) 15, pp. 1675–1684]
Increased Risk of Coronary Disease / Heart Attack
Eating trans fatty acids leads to a greater risk of coronary heart disease. According to the Dutch research, trans fat in the diet can cause even more health problems than saturated fats. Using a “cross over” design in which healthy subjects ate a diet containing trans fat or saturated fat for 4 weeks and then switched to the opposite diet for 4 weeks, several cardiovascular events were affected. When the subjects ate the trans diet their blood vessels dilated 29% less efficiently.
Key
| May do some good |
| Likely to help |
| Highly recommended |
Glossary
Fatty Acids
Chemical chains of carbon, hydrogen, and oxygen atoms that are part of a fat (lipid) and are the major component of triglycerides. Depending on the number and arrangement of these atoms, fatty acids are classified as either saturated, polyunsaturated, or monounsaturated. They are nutritional substances found in nature which include cholesterol, prostaglandins, and stearic, palmitic, linoleic, linolenic, eicosapentanoic (EPA), and decohexanoic acids. Important nutritional lipids include lecithin, choline, gamma-linoleic acid, and inositol.
Cardiovascular
Pertaining to the heart and blood vessels.
Saturated Fat
A type of fat that is readily converted to LDL cholesterol and is thought to encourage production of arterial disease. Saturated fats tend to be hard at room temperature. Among saturated fats are animal fats, dairy products, and such vegetable oils as coconut and palm oils.
Polyunsaturated
Polyunsaturated fats or oils. Originate from vegetables and are liquid at room temperature. These oils are a good source of the unsaturated fatty acids. They include flaxseed with added vitamin B6 (pyridoxine), sunflower oil, safflower oil, and primrose oil.
Hydrogenated Fat
Usually containing trans-fatty acids (or simply "trans" fats), hydrogenated fats show up mostly in margarine, shortening and many prepared and processed foods such as cookies, crackers, cakes, potato chips and other deep-fried foods. The best way to spot hydrogenated fats is to read the ingredient lists on foods and identify those listing hydrogenated or "partially" hydrogenated fats.
Insulin
A hormone secreted by the pancreas in response to elevated blood glucose levels. Insulin stimulates the liver, muscles, and fat cells to remove glucose from the blood for use or storage.
Glucose
A sugar that is the simplest form of carbohydrate. It is commonly referred to as blood sugar. The body breaks down carbohydrates in foods into glucose, which serves as the primary fuel for the muscles and the brain.
Red Blood Cell
Any of the hemoglobin-containing cells that carry oxygen to the tissues and are responsible for the red color of blood.
Enzymes
Specific protein catalysts produced by the cells that are crucial in chemical reactions and in building up or synthesizing most compounds in the body. Each enzyme performs a specific function without itself being consumed. For example, the digestive enzyme amylase acts on carbohydrates in foods to break them down.
Lipid
Fat-soluble substances derived from animal or vegetable cells by nonpolar solvents (e.g. ether); the term can include the following types of materials: fatty acids, glycerides, phospholipids, alcohols and waxes.