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Flax oil is very high (57%) in alpha-linolenic acid (ALA), the basic building block of omega-3 fatty acid.  However, ALA is also more easily obtained by using canola oil (11%), soybean oil (10%), and walnuts (17%). Some is available in greens.  

ALA and LA fatty Acids Linked to Lower Pneumonia Risk: In a 10-year follow-up of 38,378 male US health professionals ages 44-79 at the outset with updated medical and lifestyle information biennially through questionnaires and diet every 4 years and excluding men who reported pneumonia, myocardial infarction, stroke, other heart disease, arterial surgery, cancer, or asthma before the study, there were 441 new cases of nonfatal community-acquired pneumonia. Pneumonia risk was 30% lower in men in the highest energy-adjusted quintiles of intake than in men in the lowest quintiles of intake of linoleic acid [multivariate (RR): 0.70; P= 0.01] and and 32% lower for alpha-linolenic acid (multivariate RR: 0.68; P = 0.01). Pneumonia risk decreased 4% for every 1-g/d increase in linoleic acid intake (multivariate RR: 0.96). Pneumonia risk was reduced by 31% for every 1-g/d increase in alpha-linolenic acid intake (multivariate RR: 0.69). Intakes of EPA and DHA were not significantly related to pneumonia risk. Higher intakes of alpha-linolenic and linoleic acids and possibly of fish may reduce the risk of pneumonia. Intake of n-6 and n-3 fatty acids and fish and risk of community-acquired pneumonia in US men. Merchant AT, et al. McMaster University and Harvard. Am J Clin Nutr. 2005 Sep;82(3):668-74.

Linolenic Reduces Coronary Plaques: High dietary intake of linolenic acid is associated with a lower risk of cardiovascular disease mortality. In a study of 2004 European-American adults in the National Heart, Lung, and Blood Institute (NHLBI) Family Heart Study, from the lowest to the highest quintile of linolenic acid, adjusted odds ratios for calcified plaques in coronary arteries (CAC) were 1.0 (reference), 0.61, 0.55, 0.57, and 0.35, respectively (P <0.0001), after researchers controlled for age, gender, education, family risk group, smoking, fruit and vegetable intake, history of coronary artery disease, hypertension, diabetes mellitus, and statin use. When linolenic acid was used as a continuous variable, the multivariate adjusted odds ratio was 0.38 per gram of linolenic acid intake. Dietary linolenic acid is inversely associated with calcified atherosclerotic plaque in the coronary arteries: the National Heart, Lung, and Blood Institute Family Heart Study. Djousse L, et al. Boston University. . Circulation 2005 Jun 7;111(22):2921-6.

Flax: 1 pound of seeds = 140 g oil, 84 g protein, 84 g fiber, and is high in Mg, Zn, Fe, and some Calcium. There are 6 g flax oil/Tsp seeds. 2-4 Tsp/d of seeds is considered a reasonable diet by individuals who promote flax oil consumption or 1-2 Tsp/d flax oil which contains 7700 mg/Tsp(14 g). This is about 100-200 mg/kg/day. Family of 4 would need 6-10 Tsp/d or 42/wk or #1 of seeds/wk; For max psychiatric effect, use 7 Tsp/day seeds or 3 Tsp oil or roughly 350-450 mg/kg/d. This is based on dosages reported by Stoll of Harvard, but 1/5 this amount might be just as good; Cost: $ 6.26/bushel at grain elevator in Minneapolis (Mark Ask 202-219-0712) usda.mannlib.cornell.edu. Some people are allergic to flax. Prevention Mag 4/97 says it's OK to store oil in frig up to 6 months and recommends 6-25 g/d (1-2 ½ Tsp). FDA at Exper. Biol conference reportedly said 1.25-2.5% flax diet stimulates immune system, incr. Buying flax liquid oil is 2.6 cent/g vs. 7 cent/g in capsules which are 160% more expensive. Barleans cheapest of three I looked at on the internet at 250 capsules for $17.50 and 454g liquid for $11.90. Mailorderfoods.com may be 5.9 cents/capsule. Your local health food store may be cheaper. Walmarts or Oscos are sure to be less if they carry it (I know they carry fish oil capsules). Two types of flax: seed flax grown in Dakotas and Canada and fiber flax in Europe. Grown for linseed oil and meal goes to livestock with little human consumption. NDSU Extensiod Emken, Agri Research Serv.n Service Jim Helm 701-231-7881. Whole seeds keep for several years at room temperature without changing but flour only for several days or weeks. Flour lasts for several months in frig and several months more in freezer. Reimers Seed, Carrington ND 701-652-3322. Hemp seed is said to have 30% of its oil ALA (Energy Times 2/99 p39). It is much more expensive than flax and in some ways helps support the move to legalize marijuana as a drug of abuse.

Vegetarians Tend to be Low in Omega-3 Fatty Acids: Fish, seafood, and fish oil are easy sources of large amounts of omega-3 (n-3) fatty acids EPA and DHA used by the body and the brain for cell membrane flexibility.  There is even a little EPA and DHA in range-fed cattle. Clinical studies suggest that tissue levels of long-chain n-3 fatty acids are depressed in vegetarians, particularly in vegans. n-3 Fatty acids have numerous physiologic benefits, including potent cardioprotective effects. These effects have been demonstrated for ALA as well as EPA and DHA, although the response is generally less for ALA than for EPA and DHA. Conversion of ALA by the body to the more active longer-chain metabolites is inefficient: < 5-10% for EPA and 2-5% for DHA. Achieving optimal essential fatty acid status in vegetarians: current knowledge and practical implications. Davis BC, Kris-Etherton PM. Am J Clin Nutr. 2003 Sep;78(3 Suppl):640S-646S. Ed: Vegetarians need to get sizeable amounts of ALA in their diets.  Flax seed (inexpensive) and flax oil are very high while nuts, canola oil, and other sources have some. One alternative is DHA capsules made from plankton, the same source that fish get it from.  While these capsules are much more expensive than fish oil, they are still inexpensive compared to medicines for depression.

Lignans: Flax highest in precursors to mammalian lignans and epidemiol studies suggest mammalian lignans have cancer protective effects. Nutr Cancer 1997;29(3):222-7

In Heart patients: Russian study of flax oil for omega-e diet of patients with IHD, HBP, and hyperlipidemia found positive dynamic of clinical manifastation, blood lipids, and coagulograms. RBCs showed incr linolenic, EPA, DHA and decr linoleic acid. Rozanova, Vopr Pitan 1997;(5):15-7.

Phytoestrogens: Plant compounds with both estrogenic and antiestrogenic. Two categories=isoflavones (soy) and lignans (e.g. flax). Says lab, animal, and some human studies show health benefits for CVD, CA, osteoporosis, menopausal. Tham DM, Stanford Research in Disease Prevention, J Clin Endocrinol Metab 1998 Jul;83(7):2223-35.

Improving Arterial Function: Compliance or elasticity of arteries imp index of circ func and decr with incr CV risk. Fish and fish oil improve. 15 obese given four week diet of sat/high fat or alpha-linolenic acid/low fat with 20 g ALA fr flax oil margarine or diet of oleic/low fat. Compliance markedly better with ALA diet tho incr LDL oxidizability and decr HDL and insulin sensitivity. Arterioscler Thromb Vasc Biol 1997 Jun; 17(6):1163-70. Nestel PJ, Baker Med, Australia.

Flax Oil Helps Arterial Elasticity: 15 obese fed 4 week crossover 20g flax oil in margarine or high sat fat or high oleic control. Big improvement in arterial compliance despite incr in LDL oxidizability and lower HDL. No change total chol, BP, bld glucose. Nestel, Arterioscl Thrombo Vasc Biol 6/97;17:1163

Flax vs. Fish Oil: Fish oil incr DHA and EPA in rat livers but flaxseed incr only EPA. Christiansen, U Oslo, Biochim Biophys Acta 2/91

Flax vs. Fish Oil: 3 mo random assign flax oil, fish oil or olive oil in 26 adults with cross-over design found that the EPA and DHA content of LDL cholesterol esters was highly related to the intake. Clandinin, U Alberta, Biochem Biophys Acta 7/97;1346:247.

Flax Increases 20:5n-3 in Cattle: Linseed increased 20:5n-3 by 50% but fish oil doubled 20:5n-3 and 22:6n-3 in muscle phospholipids. Neither changed the P:S ratio. Br J Nutr 2001 Jan;85(1):115-24

Greek Eggs Highest in DHA: Study comparing Greek eggs to eggs of chickens raised on fish meal or flax. Breast milk at 1 mo. Gives 250 mg LCPUFAs=.94 greek yolks, 1.6 flax yolks, 1.4 fish yolks, and 8.3 regular yolks. Simopolous, DC,  Am J Clin Nutr 2/92:55:411; Also see Cherian, Lipids ’92;27:706 & 27:274; The LCPUFAs are incorporated preferentially in phosphatidylethanolamine over phosphatidylcholine by 7:1. ’91;Poult Sci 70:2467; @ Lipids 93;28:811; Kaminskas, Vopr Pitan 92’L 5-6):13. fed 20 DM pt 30g flax oil/d and only 6 obtained minor incorp of LCPUFAs into lipoprotein maybe due to low delta6-desatur activity. Recommends fish.

Flax Flour or Fish Oil Decr Rat Breast CA: Rats fed diet with flax four had less CA due to 7,12-dimethlbenzanthracene administration with 67% decr in size of tumors. Serraino, Nutr Cancer 17,153-9, ’92; Several studies with fish oil have found the same effect and also inhibition of human breast cancer cell growth in mice. David Rose, Nutr & Cancer ’94 21:103-11

Garlic & Linseed Help Mice: long-term dietary application of garlic (dried powder, 0.5% in weight of standard chow; G group) or linseed oil (2.5%; L group) as well as a combination of both interventions (L G group) on the life span of hypertensive rats (SHR SP) was investigated. A further group fed with standard chow served as control (C). The dietary interventions were started at the age of three weeks. Besides regular measurements of the systolic arterial blood pressure (oscillometrically at the tail artery) as well as of heart rate and body weight, autopsy and histological investigations were performed. Both diets, and particularly their combination, prolonged life span significantly (mean values (days) C: 434.5 23.5; G: 453.2 16.2; L: 470.0 26.2; L G: 494.8 39.2). There was no significant interaction of the factors garlic and linseed oil. Systolic blood pressure as measured during the compensatory stage (data used until the 39th week of life) was significantly lowered by both garlic (mean -5.8 mm Hg), linseed oil (mean -6.3 mm Hg), and their combination (mean -11.3 mm Hg). Tubingen, Germany. Basic Res Cardiol 1997 Aug;92(4):223-32

Flax seeds Not Help RA: 3 mo random study vs sunflower seeds no decr pain and AA, EPA, nor DHA changed. Rheum Int ’95 14:231-4. Nordstrom DC.

Flax Decr anovulatory Cycles: U Minn study with flaxseeds found longer luteal phase with incr progesterone:estradiol ratio in luteal with fewer anovulatory cycles and less ovarian dysfunction which may be linked to CA. Was State U study with whole wheat bread with seeds eaten for 6 weeks with incr in enteros in urine with hormones change. Bowen found secoisolariciresinal in urine of men fed flax. Therefore absorbed intact this chemical and also converted some to lignans. Jan Ziegler, www.cancernet.nci.nhi.gov. without omega-3. Breast milk much higher than formula but still only 1/5 to 1/10 that of Nigerian women who eat lots of nuts. Says a 3/91 Mayo Clinic study found all 19 nursing women were deficient.; 18 healthy women 3 mo control diet and 3 months flax. 3 anovulatory periods on control and none on flax. Phipps, J Clin Endocrin Metab 11/93;77:1215 @

Fish Oil, Not Flax, Lower TG in NIDDM: DB PC fish vs flax vs olive for 3 months found decrease in hypertriglyceridemia with fish only only. Flax incr ALA and slight incr EPA but no incr DHA. Goh, U Alberta, Diabetology 1/97;40:45. Fish and flax oil were given at doses to equalized n-3 fatty acids at 35mg/kg/d of EPA+DHA or ALA respectively

Fish Oil, Not Flax, Lowers TG in Equal Doses: DB PC cross-over study of 26 adults using 35mg/kg/d EPA+DHA in fish oil vs. 35mg/kg/d ALA in flax oil vs. olive oil found fish oil decr TG and incr plasma EPA and DHA while flax oil had no signif effect of TG and only a slightly increasing effect on plasma EPA and DHA level. Layne, U Alberta, J Nutr 9/96;126:2130

Fish Oil, Not Flax Lowers TG in DM: Type II DM 11 pts DB cross-over of 3 months of fish vs flax oil at 35mg/kg/d n-3s each after three months of olive oil. No different in diabetic serum measures but decr in TG in fish oil group. McManus, U Alberta, Diabetes Care, 5/96;19:463

Flax Oil Does Help: Russian study without much info available. Pts with CHD, HBP, and hyperlipidemia Rx and improved clinically as well as better lipid profile. EPA and DHA in RBC did go up. Rozanova, Vopr Pitan ’97;(5):15

Fish Oil & Garlic Lower Chol: Univ Guelph 50 men with high cholesterol (>200 mg/dL or 5.2 mmol/L) rendom to 4 grous for 12 week: two placebos, 900mg garlic (Kwai), 12g fish oil (12 caps with 180 EPA 120 DHA), or both. After 12 wk, combo had 12% decr total chol, 9.5% decr LDL, 34% decr triacylglycerol and better HDL:LDL ratio. Garlic by self did not lower TG but fish oil by self incr LDL. Adam Adler, Am J Clin Nutr 2/97;65:445-50

Flax Seed Eggs No Impact on Lipids: Leghorms raised on flaxseeds incr ALA content by 2000% and DHA content by 70%. Humans eating four eggs/d for 2 week had no change in TG or lipid profile. Ferrier, U Guelph, Am J Clin Nutr 7/96;62:81. Ed: The huge incr in ALA and small incr in DHA suggests that chickens may have some diff, just like humans, in converting ALA into DHA.

High Flax Diet Prevents Prostate CA in Mice: 5% flax diet helped genetic variant mice with high propensity to prostate CA. 11/02 Urology.

Algae DHA Lowers TG, Improves Lipids in Vegetarians: DB PC 24 vegetarians rx 6 wk DHA 1.62g/d found over 200% incr DHA in serum and platelet phospholipids and over 100% incr in EPA in serum and platelet phospholipids. AA and docosapentanoic acid (22:5n-3) decreased moderately. TG, HDL:chol ratio and HDL:LDL ratios improved. Conquer, U Guelph, J Nutr Julie A Conquer & Bruce J Holub, Dept Human Biol and Nutr Sci, Guelph ONT N1G2W1. Note that efficiency of conversion of ALA to DHA in healthy adults via desaturation and elongation is about 5% (Emken, Biochim Biophys Acta 1213:277-88, ’94). Vegans and vegetarians have lower DHA than omnivores (Reddy, ‘94 Eur J Clin Nutr 48:358). This is despite consuming as much or more n-3 from plant sources as ALA relative to omnivores, i.e. 3.6 vs. 2.7 g/d. (Pan, studied buddhist vegetarians, Am J Clin Nutr 58:354). DHASCO capsules from David Kyle of Martek Biosciences, Columbia, MD. Neuromin’s dha, raw material, www.martekbio.com 410-995-0821

Says No Increase in Cancer due to Linoleic; Linolenic May Increase Prostate CA: Meta-analysis of many studies says no increase in cancers of the breast, colorectal or prostate from linoleic, even very high levels. Peter Zock, Am J Clin Nutr ’98;68:142-53. Says higher prostate cancer is higher with linolenic, not linoleic in Health Care Professionals and Physicians studies ((J Natl Cancer Inst ’93;85:1571; J Natl Cancer Inst ’94;86:281-6). In the Health Prof study (’93) total fat RR 1.79 for advanced prostate cancer, primarily due to animal fat (RR 1.63 and not veg fat. Red meat the strongest RR 2.64. Fat from dairy (except butter) and fish unrelated with non-signif lower RR .90 with highest fish. Alpha-linolenic RR 3.43! At low levels alpha-linolenic increased mammary tumors but at high intake it decreases them. Many in study had alpha-linolenic intake under the recommended 800-1100 mg/d. Oxidation of alpha-linolenic acid in cooking of meat could be a culprit or absence of balance of linoleic and linolenic in meat eaters. Level of linolenic in tissue correlates with cancer prostate risk. In ’94 physician study linoleic RR .70 and linolenic RR 3.0. Mice prostate cancer was increased by corn oil and decreased by fish oil. No relationship found at f/u when 120 cancer patients were compared to 120 matched controls for plasma fatty acid contents. Rat studies consistently find lower cancer of the prostate with fish oil but mixed results with flax and soy.