Oils, Cholesterol, and all that: What's the Story?

. For years I have resented the deprivation I have suffered from avoiding cholesterol. Cholesterol burst on the public scene in the sixties, after having lived exclusively within medical circles for years, scattering fear and excitement among nutritionists and laymen alike. By the end of the seventies, Cholesterol was Public Enemy Number 1, closely followed by Saturated Fats. Coconut Oil, long a major component of the diet of tropical island peoples all over the world, was condemned alongside all the other saturated fats, thus casting a pall over many foods that were delicious, especially in confections, and Thai food. But last year, on a visit to my sister, I was told that there was new research that coconut was not only not harmful, but good for you. Living in the US, we're all a little suspicious of research. In this country, particularly, a great deal of research is unduly influenced by commercial interests. Recent news stories have made the Food and Drug administration look very much like a den of goofballs from whom one is unable to get the merest vestige of unbiased information. So what's the story? A few remarks may be helpful for readers who hate this subject, but feel obliged to read through anyway. The early parts of most of the articles below do give an accurate description of the basic facts: (1) Fat is a component of almost all the food we eat and drink, but there are different types, hence the plural: fats. Both food from animals (meat, fish, eggs, milk) and food from plants (veggies, fruits, juices, grains, oils) contain fats, but oil and lard, of course, contain the most fats of all, ounce for ounce. (2) Fat contains many times the calories of sugars and starches, so we tend to store excess calories as fat in our bodies as a guard against the "lean times." People who eat more calories than they burn up will put on weight, are more likely to get diabetic, high blood pressure, strokes and heart attacks generally speaking. This includes me, so don't get mad. (Though fat is unsightly, we would look incredibly worse if we simply stored the carbohydrates. Fat is actually the low-volume alternative, sort of zipfiles for calories.) (3) Many vitamins are carried only in fat: A, D, E and K, though I don't know what vitamin K is, really. This means that in order to get these vitamins naturally through your diet, you have to eat foods rich in these vitamins, which will carry them dissolved in fat. (It does not mean that all fat contains vitamins.) So you should not totally avoid fat. Kids, especially, should not be put on strict low-fat diets. However: obesity in children is just as bad as --or worse than-- obesity in adults; if your youngster is less active in good ways (games and sports) and overactive in bad ways (inattention in class, inability to concentrate) move him or her towards less sugar and less fat. I remember seeing a study in which obese childhood was linked with obese and unhealthy adults. (You don't need to cut down the amount of food, nor do you need to eliminate fats entirely. You just need to alter the balance.) (4) Unsaturated fats are fats with many carbon-carbon double bonds, for you chemistry freaks. You can force hydrogen into these bonds using a catalyst, which is called saturating the fats. This artificial "saturation" results in the hated Trans Fats, and no study I know has anything good to say about those. Why does anyone want to saturate a fat? Because then they become more thick, and can be made into sticks, just like butter. (5) There are polyunsaturated fats, and monounsaturated fats. Until recently, the polyunsaturated fats (canola oil, for instance has a lot of these) were considered very healthy. New research is showing that there are problems here: frying with polyunsaturated fats can cause something --free radicals-- which is associated with cancer formation. Don't panic right away; a lot of things can cause cancer. But maybe we should avoid frying with polyunsaturated fats. Monounsaturated fats have fewer carbon-carbon double-bonds, and so are less likely to be a problem. At the same time, monounsaturated fats have been associated with improved levels of Good Cholesterol. (6) Cholesterol is a substance found in artery blocks after heart attacks, etc, and was naturally implicated as the culprit. But apparently cholesterol is an essential part of the body's chemistry, especially in growing children. There are different types, though, and as far as I can understand, there is a Good Cholesterol, ("high density" lipoproteins) which helps prevent heart attacks and clogging of blood vessels, and Bad Cholesterol, ("low density" lipoproteins) which does the clogging, and some fats result in increase of one, and some fats result in increase of the other. It was thought that any animal cholesterol you eat is immediately converted into people-cholesterol inside us. This is not apparently the case necessarily, though it's hard to get a definitive word on the matter. (7) Omega-3 Fatty Acids. These are just another kind of oil commonly found in fish, and flax seed oil. This oil is considered very beneficial --it is also an unsaturated oil-- so much so that it is encouraged in the diet, especially for the elderly and children. (8) Trans fats are unsaturated fats that have artificially been partially saturated. All I know about them is that they are harmful, and there is universal agreement that the tiniest bit of trans fat can cause large increases in Bad Cholesterol. They are the villains of the fat world (for the moment). The State of California has passed laws that will eliminate trans fats from all restaurants by next year. (If someone discovers that Trans fats are good for you, I swear I will go totally postal.) The following is simply a brief survey of what's available on the Web. The heading links to the original article. Do please follow up on your own, and act on what you discover. [My own remarks are in green.] Harvard Schools of Public Health : My summary:

• Choose healthy fats, limit saturated fat, and avoid trans fat.
• Monounsaturated fats are healthy,
• polyunsaturated fats are healthy (possibly even healthier?)
• saturated fats are unhealthy,
• trans fats are very unhealthy.
• Omega-3 fatty acids are especially beneficial.

[Note: there is no indication in the Harvard article that some saturated fats might actually be beneficial. - Arch]

Mayo Clinic My summary:

• You don't need to completely eliminate all fats from your meals. Instead, choose the healthier types of fats and enjoy them in moderation.
• Mono- and poly- unsaturated fats are healthy, and reduce both total cholesterol and low-density cholesterol in your blood.
• Saturated and trans fats are "less healthy", and increase your total and low-density cholesterol.

They also provide useful information about sources of fats:

Monounsaturated fat: Olive oil, peanut oil, canola oil, avocados, nuts and seeds Polyunsaturated fat: Vegetable oils (such as safflower, corn, sunflower, soy and cottonseed oils), nuts and seeds Omega-3 fatty acids: Fatty, cold-water fish (such as salmon, mackerel and herring), flaxseeds, flax oil and walnuts Saturated fat: Animal products (such as meat, poultry, seafood, eggs, dairy products, lard and butter), and coconut, palm and other tropical oils Trans fat: Partially hydrogenated vegetable oils, commercial baked goods (such as crackers, cookies and cakes), fried foods (such as doughnuts and french fries), shortening and margarine Dietary cholesterol: Animal products (such as meat, poultry, seafood, eggs, dairy products, lard and butter)

Suggestions:

• Saute with olive oil instead of butter.
• Use olive oil in salad dressings and marinades. Use canola oil when baking.
• Sprinkle slivered nuts or sunflower seeds on salads instead of bacon bits.
• Snack on a small handful of nuts rather than potato chips or processed crackers. Or try peanut butter or other nut-butter spreads — nonhydrogenated — on celery, bananas, or rice or popcorn cakes. [Note: I believe that some peanut butter products are, regrettably, hydrogenated, and thus sources of trans fat.]
• Add slices of avocado, rather than cheese, to your sandwich. [I endorse this idea!]
• Prepare fish such as salmon and mackerel, which contain monounsaturated and omega-3 fats, instead of meat one or two times a week.
• Do not consume large amounts of any fats; fats add excess calories.
• Butter or margarine? Answer: Margarine, provided you choose one without any trans fat.

Stephan's Whole Health Source My Summary: some major studies that relate reduced saturated fats to reduced cholesterol and heart problems are flawed, or actually indicate the opposite.

[Note: Stephan's blog is directed towards medical students, but the conclusions are easy enough to understand. - Arch]

American Heart Association My Summary: no summary information, but a plethora of minutiae (which would be obviously interesting to specialists). Perhaps their Fats and Heart Disease Bulletin for the public is hidden somewhere I (and The Public) cannot easily find it. If nobody else, these folks, at least, should give us an unambiguous statement about the facts. Penn State at Hershey My Summary: eat a low-fat, high fiber diet. Trans fat is identified as definitely unhealthy. Recommendations

• Choose lean, protein-rich foods such as soy, fish, skinless chicken, very lean meat, and fat free or 1% dairy products.
• Eat foods that are naturally low in fat such as whole grains, fruits, and vegetables.
• Get plenty of soluble fiber such as oats, bran, dry peas, beans, cereal, and rice.
• Limit fried foods, processed foods, and commercially prepared baked goods (donuts, cookies, crackers).
• Limit animal products such as egg yolks, cheeses, whole milk, cream, ice cream, and fatty meats (and large portions of meats).
• Look at food labels, especially the level of saturated fat. Avoid or limit foods high in saturated fat.
• Look on food labels for words like "hydrogenated" or "partially hydrogenated" -- these foods are loaded with bad fats and should be avoided.
• Liquid vegetable oil, soft margarine, and trans fatty acid-free margarine are preferable to butter, stick margarine, or shortening.
• Children under age 2 should NOT be on a fat-restricted diet because cholesterol and fat are thought to be important nutrients for brain development.

[Generally a disappointing report from Hershey Medical Center, which enjoys great admiration as a center of health education. Still, the suggestions, in line with 20th-century research, are not terrible. Some sources say that eggs, milk, cream, etc are not bad, and possibly good for you: see below. Finally, this report is almost identical with the NY Times article below.]

University of Iowa Hospitals and Clinics My Summary: Excessive fat intake is linked to obesity and certain cancers. Saturated and trans fats are are bad. Polyunsaturated and monounsaturated fats are good.

[Again, not very informative, and restricted to conventional wisdom.]

New York Times

[Article essentially the same as that of Penn State at Hershey. Someone has been copying their homework assignment, but who?]

National Institutes of Health Women's Health Initiative My Summary: Reducing Total Fat Intake May Have Small Effect on Risk of Breast Cancer, No Effect on Risk of Colorectal Cancer, Heart Disease, or Stroke.

[Study was terminated prematurely, because some of the treaments (not related to diet, but to estrogen, etc) had to be discontinued.]

BBC Health My Summary: Keep total fats low. Avoid saturated fats. Sweets and juices are bad for your teeth.

[At least the bit about sweets and juices was refreshingly different.]

Coconut Research Center My Summary: coconut oil, unlike the majority of saturated fats, has a different fatty acid structure, which makes it actually more beneficial to use than most other oils. Recommendations:

• Once mistakenly believed to be unhealthy because of its high saturated fat content, it is now known that the fat in coconut oil is a unique and different from most all other fats and possesses many health giving properties. It is now gaining long overdue recognition as a nutritious health food.
• Furthermore, saturated fats might not be the villains they were thought to be. (Certainly, cooking with saturated fats minimizes the free radical problem.) And eggs and dairy products could be a part of a healthy diet.

[I'm just as cautious about adopting their recommendations as I am suspicious of the opposite recommendations of more conventional sources. On one hand, coconut research is (naturally) funded by the coconut industry. On the other hand, if any of these claims are false or misleading, refutations will surely be forthcoming soon. I'm planning to enjoy a bit of cholesterol and coconut oil --which is great to cook with-- until and unless the AHA or the ADA or AXA comes out against these recommendations. Note: Eggs and dairy products should be used in moderation, but that's true about anything.]

Archimedes