I’ve heard from so many magazines, adverts, tv programmes, etc, that polyunsaturated fat is good for you and saturated fat is bad for you, but every scientific paper I read says pretty much the opposite. The only consensus of opinion is that monounsaturated fat, such as olive oil, is the best of the bunch.
So which is worse for you?
saturated: worst, but ok in small am’ts. Is it BAD? Well…it ain’t poison, but you only need a little before it might as well be.
polyunsaturated: gets a bad rap.
transfat: you could argue this is worse than saturated.
The short of the story: anything can be bad in excess. Too much water can kill you.
The issue is: How much do I need and how easy is it to excede that level by a dangerous am’t.? Well, it’ easy to consume too much saturated fat, and it comes with a lot of calories. Now, in modest am’ts, it is ok, and is actually a required part of your daily intake. You NEED it, somnhow bad can it be. But you don’t need 5,000 cals worht per day either.
Transfat is just bad period.
Think of the fats in fihs like Salmon. These unsaturated fats are rich in omega-3’s and are a great part of a sound diet.
I was looking up formation on this subject for personal reasons and found this very useful information concerning FATS:
a glossary of terms
One of the first terms to know is essential fatty acids, or EFAs for short. This term describes the two kinds of fatty acids that your body cannot manufacture on its own and must get from the diet. “Essential” obviously refers to the fact that your body requires these substances. “Fatty acid” refers to composition of the fatty acid molecule: a fatty chain, which is a water-insoluble (think of how oil does not mix with water) chain of carbon and hydrogen atoms, attached to an acid group, which is also composed of carbon and hydrogen atoms (but looks more like a fork than a chain). Unlike the fatty acid part, the acid group does dissolve in water. This mix of different dissolving aspects is one of the things which gives the fatty acid molecule its unique properties. Since fatty acids are such common molecules, they have to be assigned names to differentiate between the many kinds. The two EFAs with which we are concerned are called omega-3 and omega-6, which refers to the unique configuration of the atoms in each molecule (you don’t really need to know about the ins and outs of molecular structure… all you need to know is the names of the two EFAs).
The next set of terms you need to know involve unsaturated and saturated fats. By and large (though there are exceptions, such as tropical oils), fats derived from plants (such as olive or sunflower oil) are unsaturated, and fats derived from animals (such as butter) are saturated. Unsaturated fats differ from saturated fats in terms of molecular shape/structure, physical aspects such as the degree of solidity at room temperature, and chemical properties such as reactivity to light, water, and oxygen. Unsaturated fats are quite chemically dynamic compared to saturated fats, which in chemical terms, are not terribly exciting. For example, flax seed oil, an unsaturated fat and a source of EFAs, reacts to light, heat, and oxygen, and goes bad very quickly upon exposure to these things (it’s normally kept in the fridge or freezer in an opaque bottle for this reason). In contrast, you can leave butter, a saturated fat, on the table at room temperature for a day and not have to worry about it going funky. Unsaturated fats (such as olive or flax seed oil) tend to exist in liquid form as oils, while saturated fats (such as butter or lard) tend to exist in solid form. There are several kinds of unsaturated fats, and the degree to which they are described as unsaturated refers to the number of hydrogens in the fatty acid chain part of the molecule. The more hydrogens there are, the more saturated the fat. You may notice the word “hydrogenated” on the side of your margarine container, which means that hydrogen has been artificially added to the product to make it more like a saturated fat, i.e. nonreactive and solid at room temperature. Monounsaturated fats are the closest to saturated fats (“mono”, meaning one, means that there is only one absent hydrogen). Polyunsaturated fats (which have more missing hydrogens than monounsaturated, since “poly” means many) are the next in line, and this term is generally used to refer to omega-6 fatty acids of the kind found in most vegetable oils. The term superunsaturated fats (which are also polyunsaturated, but to a much greater degree; they have very few hydrogens in the chain) is used to designate omega-3 fatty acids, and to differentiate them from omega-6s.
A term which you may have heard a lot about lately is trans-fatty acids, or TFAs. Polyunsaturated fatty acids are arranged in a shape rather like a caterpillar with a kink in it, as the molecule sort of bends around the missing hydrogens. The more hydrogens that are missing, the greater the degree of bend. This is a naturally occurring shape, and desirable for its interaction with our cells. TFAs are not shaped like this. The naturally occurring kink has been straightened out, usually through artificial hydrogenation (like in the case of the margarine) and/or cooking. Because of the altered shape of the molecule, TFAs can cause problems at the cellular level. The cells cannot interact properly with the TFA molecule, and this has a variety of negative effects, particularly in terms of cardiovascular disease. Recently, nutritional scientists have suggested strongly that there are no safe levels of TFA ingestion. This is a very dramatic statement.
Philster, do you have any cites or data to back up or clarify your statements?
EhhMon, I know what the different chemicals are and what they look like, what I’m trying to discern is how exactly our body digests them and what damage each of them does. I.e. quantifying their risks.
cite:
Check out this month’s Discover Magazine, and the related studies on over 100,000 people by Harvard docs.