Unsaturated fat



Types of fats in food
See also

An unsaturated fat is a fat or Antioxidants can protect unsaturated fat from lipid peroxidation. Unsaturated fats also have a more enlarged shape than saturated fats.

Contents

Chemistry and Nutrition

 

Double bonds may be in either a cis or trans temperature than unsaturated fats. Unsaturated chains have a lower melting point, hence increasing fluidity of the cell membranes.

Both mono- and polyunsaturated fats can replace saturated fat in the diet; trans unsaturated fats should be avoided. Substituting (replacing) saturated fats with unsaturated fats helps to lower levels of total stereochemistry allows the fat molecules to assume a linear conformation which leads to efficient packing (i.e., plaque formation). The geometry of the cis double bond introduces a bend in the molecule precluding stable formations (see specific fatty acid links above for drawings that illustrate this). Natural sources of fatty acids (see above) are rich in the cis isomer.

Although polyunsaturated fats are protective against cardiac arrhythmias a study of post-menopauseal women with a relatively low fat intake showed that polyunsaturated fat was positively associated with progression of coronary atherosclerosis, whereas monounsaturated fat was not [1]. This probably is an indication of the greater vulnerability of polyunsaturated fats to lipid peroxidation, against which Vitamin E has been shown to be protective [2].

Examples of unsaturated fats are soybean, canola, and olive oils. Meat products contain both saturated and unsaturated fats.

Although unsaturated fats are healthier than saturated fats,[3] the old Food and Drug Administration (FDA) recommendation stated that the amount of unsaturated fat consumed should not exceed 30% of one's daily caloric intake (or 67 grams given a 2000 calorie diet). The new dietary guidelines have eliminated this recommendation. Most food contain both unsaturated and saturated fats. Marketers only advertise one or the other, depending on which makes up the majority. Thus, various unsaturated fat vegetable oils, such as olive oils, also contain saturated fat.

phospholipids of human skeletal muscle [4].

Membrane composition as a metabolic pacemaker

Cell membranes of mammals have a higher composition of polyunsaturated fat (temperatures[5]

References

  1. ^ Dariush Mozaffarian (2004). "Dietary fats, carbohydrate, and progression of coronary atherosclerosis in postmenopausal women". American Journal of Clinical Nutrition 80 (5): 1175–1184. PMID 15531663.
  2. ^ B Leibovitz (1990). "Dietary supplements of vitamin E, beta-carotene, coenzyme Q10 and selenium protect tissues against lipid peroxidation in rat tissue slices". The Journal of Nutrition 120 (1): 97–104. PMID 2303916.
  3. ^ BBC Health, retrieved June 6, 2007.]
  4. ^ LH Storlien (1996). "Dietary fats and insulin action". Diabetologica 39 (6): 621–631. PMID 8781757.
  5. ^ AJ Hulbert (2003). "Life, death and membrane bilayers". The Journal of Experimental Biology 206: 2303–2311. PMID 12796449.

See also
 
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Unsaturated_fat". A list of authors is available in Wikipedia.