Fat and Oil: The Truth About Their Link to Cholesterol and Heart Disease
Saturated FatsAre all saturated fats unhealthy?
There is clear evidence that not all saturated fatty acids are created equal. "Stearic acid, for instance, appears innocuous; it does not raise serum cholesterol or increase the risk of heart disease. This is one of the reasons why dark chocolate is as heart-healthy as it is," says David L. Katz, MD, a professor at the Yale School of Public Health. So why has saturated fat been vilified? "Most of the demonization of saturated fat is based on the belief that it always raises cholesterol, an argument that has two huge holes in it," says Jonny Bowden, PhD, author of The Healthiest Meals on Earth (Fair Winds Press, July 2008).
Saturated fat doesn't always raise cholesterol, though it sometimes does. "There are many more types of cholesterol than just the commonly understood 'LDL-bad' and 'HDL-good'. LDL alone has at least five different subtypes, and some of them (LDL-A) are absolutely harmless while others (like LDL-B) are not. Saturated fat tends to raise LDL, but it sometimes raises the harmless subtype, not the 'bad' subtype. It also raises HDL, frequently more than it does LDL, leaving an overall better blood lipid profile than before, even though the total cholesterol number may have gone up," says Bowden.
Additionally, "Cholesterol is turning out to be a very poor predictor of cardiovascular disease and death, as we saw in those trials of the cholesterol drug that lowered cholesterol more than any before but did nothing for heart disease, plaque, or mortality. If you take the fear of cholesterol-raising out of the equation, what's the problem with saturated fat? Not too much," adds Bowden.
However, that doesn't mean you should start doubling up on the prime ribs. "Some saturated fatty acids are still very much implicated. So red meat is still a concern; choosing meats that are lean, with relatively low saturated fat content is the way to go," says Katz.
Pritikin Nutrition Research Director James J. Kenney, PhD, is strongly opposed to any saturated fat. "There are no naturally occurring fats that are high in saturated fats that do not raise LDL-C (low-density lipoprotein cholesterol), because they contain palmitic, myristic, and lauric acids -- the three saturated fatty acids proven to raise LDL-C and promote atherosclerosis." He goes on to argue that the only difference among the LDLs is that in some people some LDL patterns may be less harmful than in others -- however, they are still dangerous.
Bottom line: While no one is suggesting a diet high in saturated fat, limited amounts of whole-food sources such as "eggs, butter, grass-fed meat, and the like may not be as bad as we once thought, especially when intake is balanced with plenty of anti-inflammatory omega-3s and phytonutrients from vegetables and fruits," says Bowden.Which is better: polyunsaturated or monounsaturated fat?
Both do good things for the body, but monounsaturated fatty acids might win by a nose in the race for heart health. According to Lona Sandon, MEd, RD, a professor of nutrition at the University of Texas Southwestern Medical Center at Dallas, "Monounsaturated fats (e.g., olive oil and tree nuts) help lower total and LDL cholesterol levels while increasing the artery-protective HDL cholesterol. Monounsaturated fats may also help lower levels of inflammation in the body."
Polyunsaturated fats include the much-talked-about essential fats known as omega-3s and omega-6s. In general, polyunsaturated fats lower total and LDL "bad" cholesterol, but they can also lower heart-healthy HDL cholesterol -- which is not good.
Bottom line: Both are good in moderation.
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