The Omega-6/Omega-3 Fatty Acid Ratio

The Omega-6/Omega-3 Fatty Acid Ratio

by Dr. Daniel J. Murphy D.C., D.A.B.C.O.



1. “Human beings evolved on a diet with a ratio of omega-6 to omega-3 essential fatty acids of approximately 1/1, whereas in Western diets the ratio is 15/1–20/1.”

2 “Western diets are deficient in omega-3 fatty acids, and have excessive amounts of omega-6 fatty acids compared with the diet on which human beings evolved and their genetic patterns were established.”

3. “Excessive amounts of omega-6 polyunsaturated fatty acids (PUFA) and a very high omega-6/omega-3 ratio, as is found in today’s Western diets, promote the pathogenesis of many diseases, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases, whereas increased levels of omega-3 PUFA (a lower omega-6/omega-3 ratio) exert suppressive effects.”



4. The ratio of omega-6/omega-3 should be below 4/1. A ratio of 2.5/1 reduced rectal cell proliferation in colorectal cancer patients, whereas a ratio of 4/1 with the same amount of omega-3 PUFA had no effect. [Important]

5. A lower ratio of omega-6/omega-3 fatty acids is more desirable in reducing the risk of many of the chronic diseases of high prevalence in Western societies.

6. “Genetic factors determine susceptibility to disease and environmental factors determine which genetically susceptible individuals will be affected.” “Nutrition is an environmental factor of major importance.”

7. The spontaneous mutation rate for nuclear DNA is estimated at 0.5% per million years, which means our genes today are very similar to the genes of our ancestors during the Paleolithic period 40,000 years ago.



8. Humans today live in a nutritional environment that differs from that for which our genetic constitution was selected, particularly in the type and amount of essential fatty acids and in the antioxidant content of foods. Today’s industrialized societies diets are characterized by

• An increase in calories

• An increase in cereal grains

• An increase in saturated fat

• An increase in trans fatty acids

• A decrease in omega-3 fatty acid intake

• A decrease in complex carbohydrates and fiber

• A decrease in energy expenditure

• A decrease in fruits and vegetables

• A decrease in protein

• A decrease in antioxidants

• A decrease in calcium

9. “The increase in trans fatty acids is detrimental to health.”

10. The beneficial health effects of omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are low rates of coronary heart disease, asthma, type 1 diabetes, multiple sclerosis, cancer, inflammatory bowel disease, rheumatoid arthritis, and psoriasis.

11. “The rapid changes in our diet, particularly in the last 150 years, are potent promoters of chronic diseases such as atherosclerosis, essential hypertension, obesity, diabetes, arthritis and other autoimmune diseases, and many cancers, especially cancer of the breast, colon, and prostate.”

12. The present Western diet is deficient in omega-3 fatty acids with a ratio of omega-6 to omega-3 of 15-20/1, instead of 1/1 as is the case with wild animals and Paleolithic humans.

13. “An absolute and relative change of omega-6/omega-3 in the food supply of Western societies has occurred over the last 150 years. A balance existed between omega-6 and omega-3 for millions of years during the long evolutionary history of the genus Homo, and genetic changes occurred partly in response to these dietary influences. During evolution, omega-3 fatty acids were found in all foods consumed: meat, wild plants, eggs, fish, nuts and berries.”

14. “Omega-6 and omega-3 fatty acids are essential because humans, like all mammals, cannot make them and must obtain them in their diet.”

15. Omega-6 fatty acids are represented by linoleic acid (LA) and are plentiful in seeds and grains.

16. Omega-3 fatty acids are represented by alpha-linolenic acid (ALA), and are found in the chloroplasts of green leafy vegetables, and in the seeds of flax, rape, chia, perilla and in walnuts.

17. EPA and DHA are found in the oils of fatty fish.

18. (AA) is found predominantly in the phospholipids of grain-fed animals and eggs.

19. DHA is one of the most abundant components of the brain’s structural lipids.

20. When humans ingest fish or fish oil, the EPA and DHA from the diet replace the omega-6 fatty acids, especially AA, in the membranes of all cells.

21. “Because of the increased amounts of omega-6 fatty acids in the Western diet, the eicosanoid metabolic products from AA, specifically prostaglandins, thromboxanes, leukotrienes, hydroxy fatty acids, and lipoxins, are formed in larger quantities.” These eicosanoids from AA contribute to the formation of thrombus and atheromas, to allergic and inflammatory disorders, shifting the physiological state to prothrombotic and increase in blood viscosity, vasospasm, and vasocontriction.

22. An omega-6/omega-3 Ratio of 1/1 decreases C-reactive protein.

23. “The higher the ratio of omega-6/omega-3 fatty acids in platelet phospholipids, the higher the death rate from cardiovascular disease.”

24. “Excessive amounts of omega-6 PUFA and a very high omega-6/omega-3 ratio, as is found in today’s Western diets, promote the pathogenesis of many diseases, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases, whereas increased levels of omega-3 PUFA (a lower omega-6/omega-3 ratio), exert suppressive effects.”

25. The total omega-3 fatty acids are associated with lower levels of pro-inflammatory markers and higher anti-inflammatory markers.

26. Increased dietary AA significantly enhances atherosclerosis, whereas increased dietary intake of omega-3 fatty acids EPA and DHA blunt this effect.

27. Dietary omega-6 fatty acids promote, whereas omega-3 fatty acids EPA and DHA inhibit, leukotriene-mediated inflammation that leads to atherosclerosis.

28. Olive oil increases the incorporation of omega-3 fatty acids into membranes.

29. Reducing the ratio to 4/1 of LA/ALA for two years decreases total mortality by 70 percent.

30. Supplementing with 850–882 mg of omega-3 fatty acids at a ratio of 2/1 EPA to DHA decreases sudden cardiac death by 45 percent.

31. EPA is a promising treatment for prevention of major coronary events, especially nonfatal coronary events.

32. Studies show that reducing the levels of omega-6 and increasing the levels of omega-3 fatty acids:

• Is antiinflammatory

• Is cardioprotective

• Reduces the risk for heart disease

• Reduces the prevalence of non-insulin diabetes mellitus

• Is beneficial for patients with rheumatoid arthritis

• Is beneficial for patients with asthma

• Reduces colorectal cancer risk

• Reduces breast cancer risk

• Reduces the incidence of osteoporosis by helping adolescents establish a better bone mineral base early in life and in preserving skeletal integrity in old age

• Reduces depressive illness

• Reduces the incidence of dry eye syndrome

• Reduces age-related macular degeneration

33. “Asthma is a mediator driven inflammatory process in the lungs and the most common chronic condition in childhood. The leukotrienes and prostaglandins are implicated in the inflammatory cascade that occurs in asthmatic airways.” The inflammatory mediators eicosanoids are the products of AA metabolism, and are important mediators in the underlying inflammatory mechanisms of asthma.

34. “Leukotrienes and prostaglandins appear to have the greatest relevance to the pathogenesis of asthma. The leukotrienes are potent inducers of bronchospasm, airway edema, mucus secretion, and inflammatory cell migration, all of which are important to the asthmatic symptomatology.”

35. “Fatty acid levels in breast adipose tissue (which reflect dietary intake) suggest a protective effect of omega-3 fatty acids on breast cancer risk and support the hypothesis that the balance between omega-3 and omega-6 fatty acids plays a role in breast cancer.”

36. Omega-3 fatty acids are beneficial to bone health. Omega-3 fatty acids may attenuate postmenopausal bone loss.

37. “Psychologic stress in humans induces the production of proinflammatory cytokines. An imbalance of omega-6 and omega-3 PUFA in the peripheral blood causes an overproduction of proinflammatory cytokines. There is evidence that changes in fatty acid composition are involved in the pathophysiology of major depression.”

38. “Diets with a high omega-6/omega-3 ratio may enhance the risk for both depression and inflammatory diseases.”

39. Inflammation of the lacrimal gland, the meibomian gland, and the ocular surface plays a significant role in dry eye syndrome. A higher ratio of omega-6/omega-3 consumption is associated with a significantly increased risk of dry eye syndrome.

40. “Age-related macular degeneration (AMD) is the leading cause of vision loss among people sixty-five and older,” and ingestion of omega-3 fatty acids reduce the risk of AMD.

41. “Western diets are characterized by high omega-6 and low omega-3 fatty acid intake, whereas, during the Paleolithic period when human’s genetic profile was established, there was a balance between omega-6 and omega-3 fatty acids.”

42. Increased dietary intake of LA [omega-6 fats from grains and seeds] leads to oxidation of LDL and platelet aggregation. [Very Important]

43. “Inflammation is at the base of many chronic diseases, including coronary heart disease, diabetes, arthritis, cancer, osteoporosis, mental health, dry eye disease and age-related macular degeneration. Dietary intake of omega-3 fatty acids may prevent the development of disease, particularly in persons with genetic variation.”

44.”It is essential to increase the omega-3 and decrease the omega-6 fatty acid intake in order to have a balanced omega-6 and omega-3 intake in the background diet.”


Dr. Dan Murphy graduated magna cum laude from Western States Chiropractic College in 1978. He received Diplomat status in Chiropractic Orthopedics in 1986. Since 1982, Dr. Murphy has served part-time as undergraduate faculty at Life Chiropractic College West, currently teaching classes to seniors in the management of spinal disorders. He has taught more than 2000 postgraduate continuing education seminars. Dr. Murphy is a contributing author to both editions of the book Motor Vehicle Collision Injuries and to the book Pediatric Chiropractic. Hundreds of detailed Article Reviews, pertinent to chiropractors and their patients, are available at Dr. Murphy’s web page,

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