Also see:
Fish Oil Toxicity
Arachidonic Acid’s Role in Stress and Shock
Estrogen’s Role in Asthma
Phospholipases, PUFA, and Inflammation
Protective “Essential Fatty Acid Deficiency”
“Unsaturated fats are slightly more water-soluble than fully saturated fats, and so they do have a greater tendency to concentrate at interfaces between water and fats or proteins, but there are relatively few places where these interfaces can be usefully and harmlessly occupied by unsaturated fats, and at a certain point, an excess becomes harmful. We don’t want “membranes” forming where there shouldn’t be membranes. The fluidity or viscosity of cell surfaces is an extremely complex subject, and the degree of viscosity has to be appropriate for the function of the cell. Interestingly, in some cells, such as the cells that line the air sacs of the lungs, cholesterol and one of the saturated fatty acids found in coconut oil can increase the fluidity of the cell surface.” -Ray Peat, PhD
“The relatively few studies of fish oil and linoleic acid that compare them with palmitic acid or coconut oil have produced some very important results. For example, pigs exposed to endotoxin developed severe lung problems (resembling “shock lung”) when they had been on a diet with either fish oil or Intralipid (which is mostly linoleic acid, used for intravenous feeding in hospitals), but not after palmitic acid (Wolfe, et al., 2002).” -Ray Peat, PhD
**Note: Palmitic acid is a saturated fat. Fish oil and linoleic acid are both polyunsaturated fats (PUFA).
Nutrition. 2002 Jul-Aug;18(7-8):647-53.
Dietary fat composition alters pulmonary function in pigs.
Wolfe RR, Martini WZ, Irtun O, Hawkins HK, Barrow RE.
OBJECTIVES: We investigated the effect of various dietary fats on pulmonary surfactant composition and lung function changes that occur before and after endotoxin infusion in pigs.
METHODS: Eighteen pigs were assigned to three groups (n = 6 per group) to receive a diet of protein (20% of calories), carbohydrate (20% of calories), and fat (40% of calories). In one group the fat content consisted entirely of palmitic acid. In the second group, fat came from Intralipid, which provided predominantly linoleic acid. The third group was fed fish oil. Pigs were maintained on these diets for 21 d before the experiment. Cardiovascular and pulmonary functions were determined on day 22. Pigs then were infused with endotoxin (80 mg. kg(-1). min(-1)) until the pulmonary arterial pressure reached a pressure similar to that found in trauma victims (45 to 50 mmHg). Cardiovascular and pulmonary function tests were then repeated, the animals killed, and the lungs removed for study.
RESULTS: Compliance was reduced in the linoleate and fish-oil groups compared with the palmitate group before and after endotoxin. Compliance changes in pigs fed the linoleate and fish-oil diets were consistent with significant increases in lung wet:dry weight ratios, increased CO(2) retention, histologic evidence of vascular congestion, intra-alveolar edema, and alveolar septa thickening. Changes in surfactant phosphatidylcholine composition between groups were consistent with the notion that increased unsaturated fatty acids could affect surfactant function.
CONCLUSIONS: We concluded that the common practice of providing calories in the form of polyunsaturated fatty acids to critically ill patients carries the risk of being detrimental to lung function.
