Anti-Inflammatory Omega -9 Mead Acid (Eicosatrienoic acid)

Also see:
“Curing” a High Metabolic Rate with Unsaturated Fats
Fat Deficient Animals – Activity of Cytochrome Oxidase
Errors in Nutrition: Essential Fatty Acids
Protective “Essential Fatty Acid Deficiency”
Toxicity of Stored PUFA
PUFA Promote Stress Response; Saturated Fats Suppress Stress Response
Protect the Mitochondria

Quotes by Ray Peat, PhD:
“Linoleic acid, linolenic acid, arachidonic acid: Their toxicity is potentially prevented by the Mead acids, and their eicosanoid derivatives, which behave very differently from the familiar prostaglandins, as far as they have been compared; can be drastically reduced by dietary changes. Prostaglandins, prostacyclin, thromboxane: Formation is blocked by aspirin and other antiinflammatory drugs.”

“The absence of cancer on a diet lacking unsaturated fats, the increased rate of metabolism, decreased free radical production, resistance to stress and poisoning by iron, alcohol, endotoxin, alloxan and streptozotocin, etc., improvement of brain structure and function, decreased susceptibility to blood clots, and lack of obesity and age pigment on a diet using coconut oil rather than unsaturated fats, indicates that something very simple can be done to reduce the suffering from the major degenerative diseases, and that it is very likely acting by reducing the aging process itself at its physiological core.”

“Now, instead of demonstrating harm from a dietary lack of the “essential” fats, the presence of the Mead acid or omega-9 fatty acids is taken as evidence of a deficiency. Our cells (and animal cells) produce these unsaturated fats when their special desaturase enzymes are not suppressed by the presence of exogenous linoleic or linolenic acids. Normally, the inactivation of an enzyme system and the suppression of a natural biological process might be taken as evidence of toxicity of the vegetable oils, but here, the occurrence of the natural process is taken as evidence of a deficiency. To me, this seems very much like the “disease” of having tonsils, an appendix, or a foreskin–if it is there, you have a problem, according to the aggressive surgical mentality. But what is the “problem” in the case of the natural Mead or omega-9 acids? (I think the “problem” is simply that they allow us to live at a higher energy level, with greater resistance to stress, better immunity, and quicker healing.)”

“A “deficiency” of polyunsaturated fatty acids leads to altered rates of cellular regeneration and differentiation, a larger brain at birth, improved function of the immune system, decreased inflammation, decreased mortality from endotoxin poisoining, lower susceptibility to lipid peroxidation, increased basal metabolic rate and respiration, increased thyroid function, later puberty and decreases other signs of estrogen dominance. When dietary PUFA are not available, the body produces a small amount of unsaturated fatty acid (Mead acids), but these do not activate cell systems in the same way that plant-derived PUFAs do, and they are the precursors for an entirely different group of prostaglandins.”

“Many types of evidence indicate that environmental PUFA and prostaglandins produced from the “essential” fatty acids are required for inflammation to progress to degeneration. The n-9 polyunsaturated fatty acids (the kind that we can make from saturated fat or sugar) seem to be positively protective against inflammation.”

“The enzyme that produces the Mead fatty acid is strongly inhibited by PUFA seed oils (less strongly by fish oils), and so the presence of the Mead acid in the tissues is taken as evidence that the animal is suffering damage resulting from the absence of PUFA. The Mead acid happens to have some valuable anti-inflammatory effects, and is associated with many biological advantages, but research in that direction is prevented by the lack of funding.”

“When mitochondria are functioning fully, either glucose or saturated fats can safely
provide energy. Some glucose or saturated fat can be converted to polyunsaturated fats, that can be used as regulators or signals, for example to activate the formation of stem cells. But those PUFA don’t create disruptive cascades of increasing excitation or inflammation or excessive growth, and, from the evidence of animals that are fed fat free diets, or diets lacking omega -3 and omega -6 fatty acids, they aren’t toxic to mitochondria.”

J Immunol. 1990 Sep 1;145(5):1523-9.
Manipulation of the acute inflammatory response by dietary polyunsaturated fatty acid modulation.
Lefkowith JB, Morrison A, Lee V, Rogers M.
Dietary polyunsaturated fatty acid modulation has been used as an anti-inflammatory strategy in experimental models of disease as well as in clinical trials. To elucidate the mechanisms underlying the anti-inflammatory effects of manipulating dietary polyunsaturated fatty acids, the in vivo effects of essential fatty acid (EFA) deficiency and (n-3) fatty acid supplementation were contrasted using a model of acute inflammation induced by the i.p. injection of zymosan into mice. Both diets led to a substantial decrease in tissue (n-6) fatty acid content. EFA deficiency was also characterized by the accumulation of (n-9) fatty acids, particularly 20:3 (n-9), the fatty acid that uniquely characterizes the deficiency state. Dietary (n-3) fatty acid supplementation led instead to marked increases in (n-3) fatty acids, especially 20:5 (n-3). With respect to the antiinflammatory effects of the two diets, EFA deficiency, but not (n-3) fatty acid supplementation, depleted levels of resident peritoneal macrophages. EFA deficiency was also more effective than (n-3) fatty acid supplementation in inhibiting the influx of polymorphonuclear neutrophils in response to zymosan. The effect of the two diets on the in vivo generation of leukotriene(LT)B also differed markedly. EFA deficiency completely inhibited the synthesis of LTB. Dietary (n-3) fatty acid supplementation, in contrast, reduced the production of LTB4 by only 50%. With (n-3) fatty acid supplementation LTB5 was produced. The more modest effect of (n-3) fatty acid supplementation in decreasing LTB4 generation was not due to blockade of the cyclooxygenase pathway. EFA deficiency, but not (n-3) fatty acid supplementation, was associated with the decreased synthesis of thromboxane. Although dietary fatty acid modulation has been shown to diminish platelet activating factor (PAF) synthesis, studies using the PAF receptor blocker, L659989, established that PAF was not a significant factor in the elicitation of leukocytes in this model of inflammation. In summary, the anti-inflammatory effect of EFA deficiency was more marked that that of dietary (n-3) fatty acid supplementation in acute inflammation. This difference in anti-inflammatory potential appeared to be due to either the greater effect of EFA deficiency in decreasing levels of resident peritoneal macrophages or in suppressing the in vivo generation of LTB4.

LIPIDS Volume 31, Number 8, 829-837, DOI: 10.1007/BF02522978
Effect of dietary n-9 eicosatrienoic acid on the fatty acid composition of plasma lipid fractions and tissue phospholipids
L. G. Cleland, M. A. Neumann, R. A. Gibson, T. Hamazaki, K. Akimoto and M. J. James
n-9 Eicosatrienoic acid (ETrA), also known as Mead acid, is a minor fatty acid in essential fatty acid (EFA)-sufficient healthy subjects but is found at increased levels in EFA deficiency. This study examined the influence of dietary ETrA from a biological source on plasma and tissue ETrA. A synthetic fat-free diet was prepared to which was added Mut 48 oil which contains 19% ETrA (wt%) as well as other n-9 fatty acids. Blends of vegetable oils were used to achieve overall diets with 5% fat (wt%) and varying amounts of ETrA at two different dietary levels of linoleic acid (LA), approximately 4.4 and 19% of total fatty acids. These diets were fed to 5-week-old Dark Agouti rats for four weeks. Plasma lipid fractions and liver, spleen, and peritoneal exudate (PE) cells were analyzed for fatty acid composition. ETrA was present at up to 20% total fatty acids in plasma triglyceride, cholesterol ester, and phospholipid fractions. ETrA also accumulated to substantial levels in phospholipids of liver and spleen (up to 15% of total fatty acids) and PE cells (up to 11%). ETrA was found in plasma and tissue phospholipids in proportion to the amount of ETrA present in the diet. The incorporation was reduced in diets with higher LA content compared to diets containing similar amounts of ETrA but lower LA. All rats remained apparently healthy, and histological survey of major organs revealed no abnormality. While the long-term implications for health of ingestion of diets rich in ETrA remain to be established, rats appear to tolerate high levels of dietary ETrA without adverse effects. Dietary enrichment with ETrA warrants further investigation for possible beneficial effects in models of inflammation and autoimmunity, as well as in other conditions in which mediators derived from n-6 fatty acids can affect homeostasis adversely.

J Nutr. 1996 Jun;126(6):1534-40.
Dietary (n-9) eicosatrienoic acid from a cultured fungus inhibits leukotriene B4 synthesis in rats and the effect is modified by dietary linoleic acid.
Cleland LG, Gibson RA, Neumann MA, Hamazaki T, Akimoto K, James MJ.
Eicosatrienoic acid (ETrA) is the (n-9) homologue of (n-6) arachidonic acid (AA) and (n-3) eicosapentaenoic acid (EPA). ETrA can be synthesized endogeneously, but tissue levels are normally undetectable except in essential fatty acid (EFA) deficiency. An ETrA-rich oil extracted from a cultured fungus was used to prepare diets which had varying levels of ETrA (0-8 g/kg diet) in combination with one of two levels of linoleic acid (LA, 2.2 or 9.5 g/kg diet). All diets were sufficient in essential fatty acids. Groups of rats were fed these diets for 4 wk after which leucocyte fatty acid content and leukotriene B4 (LTB4) synthesis were measured. The influence of dietary LA on ETrA accumulation in cells was studied and correlations with LTB4 synthesis determined. ETrA was efficiently incorporated into peritoneal exudate cell (PEC) phospholipids with no evident saturation being observed with levels up to 10 mol/100 mol total fatty acids in peritoneal exudate cells. Cellular ETrA levels were lower (P < 0.001) in rats fed the higher level of LA. ETrA accumulation in peritoneal exudate cells correlated (r(2) = 0.63, P < 0.05) with reduced LTB4 synthesis which was attributable to LTA hydrolase inhibition. Thus, dietary ETrA from a biological source can accumulate in leucocytes and suppress inflammatory eicosanoid synthesis. The findings justify further studies into the biochemical and anti-inflammatory effects of dietary ETrA, which could be incorporated into palatable food additives.

J Exp Med. 1993 Dec 1;178(6):2261-5.
Effect of dietary supplementation with n-9 eicosatrienoic acid on leukotriene B4 synthesis in rats: a novel approach to inhibition of eicosanoid synthesis.
James MJ, Gibson RA, Neumann MA, Cleland LG.
Studies were undertaken to assess the biochemical effects of dietary supplementation with n-9 eicosatrienoic acid (ETrA), an arachidonic acid analogue that is normally present in cell membranes at very low levels but is raised in the presence of essential fatty acid deficiency (EFAD). The incorporation of dietary ETrA into rat neutrophils and its effect on A23187-stimulated 5-lipoxygenase metabolism in these cells was examined; in addition, the effect of ETrA was compared with that of another arachidonic acid analogue, eicosapentaenoic acid (EPA), which is known to accumulate in cell membranes and inhibit synthesis of leukotriene B4 (LTB4) a product of the 5-lipoxygenase metabolic pathway. Rats were fed a defined diet that was sufficient in essential fatty acids and that contained EPA or ETrA (0.014% of energy) or no added fatty acid, for 3 wk. In the cells from ETrA-fed rats, LTB4 synthesis was inhibited relative to control values, but synthesis of the other products of 5-lipoxygenase metabolism, 5-hydroxyeicosatetraenoic acid (5-HETE) and the all-trans isomers of LTB4, were not inhibited. This pattern indicates inhibition of LTA hydrolase in ETrA-fed rats. In EPA-fed rats, there was inhibition of LTB4 and the all-trans isomers of LTB4, but there was no inhibition of 5-HETE. This pattern indicates inhibition of LTA synthase in EPA-fed rats. The results establish that dietary ETrA effectively inhibits synthesis of the inflammatory mediator, LTB4, and suggest that ETrA may confer antiinflammatory benefits similar to those observed with EFAD or dietary fish oil (which contains EPA). Because ETrA is substantially less unsaturated than EPA, it can be expected to have greater chemical stability, which could be an important practical advantage when used as a dietary constituent or supplement.

“Many types of evidence indicate that environmental PUFA and prostaglandins produced from the “essential” fatty acids are required for inflammation to progress to degeneration. The n-9 polyunsaturated tatty acids (the kind we can make make from saturated fat or sugar) seems to be positively protective against inflammation. For example, rats fed a diet with 2% hydrogenated coconut oil for two weeks had lower levels of IL-6 and C-reactive protein than when a small amount of arachidonic acid and docosahexaenoic acid (DHA) were added. Mead acid (20:3n9) was lower in the group with the PUFA supplement, and the inflammatory reaction to endotoxin was greater in the supplemented group (Ling, et aI., 2012).” -Ray Peat, PhD

Metabolism. 2012 Mar;61(3):395-406. Epub 2011 Sep 23.
Arachidonic acid and docosahexaenoic acid supplemented to an essential fatty acid-deficient diet alters the response to endotoxin in rats.
Ling PR, Malkan A, Le HD, Puder M, Bistrian BR.
This study examined fatty acid profiles, triene-tetraene ratios (20:3n9/20:4n6), and nutritional and inflammatory markers in rats fed an essential fatty acid-deficient (EFAD) diet provided as 2% hydrogenated coconut oil (HCO) alone for 2 weeks or with 1.3 mg of arachidonic acid (AA) and 3.3 mg of docosahexaenoic acid (DHA) (AA + DHA) added to achieve 2% fat. Healthy controls were fed an AIN 93M diet (AIN) with 2% soybean oil. The HCO and AA + DHA diets led to significant reductions of linoleic acid, α-linolenic acid, and AA (20:4n6) and increases in Mead acid (20:3n9) in plasma and liver compared with the AIN diet; but the triene-tetraene levels remained well within normal. However, levels of 20:3n9 and 20:4n6 were lower in liver phospholipids in the AA + DHA than in HCO group, suggesting reduced elongation and desaturation in ω-9 and -6 pathways. The AA + DHA group also had significantly lower levels of 18:1n9 and 16:1n7 as well as 18:1n9/18:0 and 16:1n7/16:0 than the HCO group, suggesting inhibition of stearyl-Co A desaturase-1 activity. In response to lipopolysaccharide, the levels of tumor necrosis factor and interleukin-6 were significantly lower with HCO, reflecting reduced inflammation. The AA + DHA group had higher levels of IL-6 and C-reactive protein than the HCO group but significantly lower than the AIN group. However, in response to endotoxin, interleukin-6 was higher with AA + DHA than with AIN. Feeding an EFAD diet reduces baseline inflammation and inflammatory response to endotoxin long before the development of EFAD, and added AA + DHA modifies this response.

Surg Today. 2003;33(8):600-5.
Beneficial effects of n-9 eicosatrienoic acid on experimental bowel lesions.
Yoshida H, Soh H, Sando K, Wasa M, Takagi Y, Okada A.
PURPOSE:
Dietary fortification of n-9 polyunsaturated fatty acids (PUFA) or 5,8,11-eicosatrienoic acid (ETrA) as well as n-3 PUFA might contribute to the suppression of leukotriene B4 (LTB4) synthesis and thereby reduce inflammatory bowel lesions. As a result, the effect of an ETrA-enriched diet on experimental bowel lesions was examined in this study.
METHODS:
In Expt. 1, rats were freely fed either an ETrA-enriched or a standard diet. After 7 days of feeding, acute bowel lesions were induced by the subcutaneous injection of 10 mg/kg indomethacin. In Expt. 2, chronic bowel lesions were made by performing subcutaneous injections of 7.5 mg/kg indomethacin twice. After the first injection, the rats were freely fed either an ETrA-enriched or a standard diet for 7 days.
RESULTS:
In both experiments, the rats fed an ETrA-enriched diet showed increased levels of ETrA in the plasma and intestinal mucosa, and a decreased inflammation score. However, there was no significant decrease in plasma and intestinal mucosal LTB4 in the ETrA-enriched diet-fed rats.
CONCLUSION:
These results suggest that the dietary supplementation of ETrA may have both prophylactic and therapeutic effects on experimentally produced bowel lesions. Further investigations are necessary to clarify the effects of ETrA on bowel lesions and its mechanisms.