Extremely high intake of omega-6s creates need for major increase in omega-3 intake; drastic drop in omega-6 intake would cut omega-3 requirement dramatically
by Craig Weatherby and Randy Hartnell
- Landmark study shows that most Americans need to boost omega-3 intake to 3.5 gm per day to match Japan’s low rates of heart disease and depression.
- This is just over the amount found in a 6 oz serving of King Salmon, Sardines, or Sablefish (see "How much does it take?" sidebar, below).
- Study was first to consider Americans’ excessive intake of metabolically competitive omega-6 fats.
- Cutting average omega-6 intake by 80 percent would drop the need for omega-3s to just 350 mg per day.
The recently published results of a landmark study suggest that Americans need to increase their intake of omega-3 fattyacids dramatically to enjoy the low rates of heart disease, stroke, depression, homicide, and bipolar disorder seen in fish-loving Japan (Hibbeln JR 2006).
Two of the world’s best-respected omega-3 researchers—Vital Choice science advisor William E. Lands, Ph.D., and psychiatrist Joseph Hibbeln, M.D.—were part of a team from the US National Institutes of Health (NIH) that set out to calculate the omega-3 intake needs of people in 13 countries, including America.
A groundbreaking aspect of the study was their decision to take into account the amounts of omega-6 fatty acids Americans and others consume. They took this approach because omega-3s compete with dietary omega-6 fatty acids for passage through a metabolic bottleneck called the delta-6 desaturase pathway.
As our readers know, the average American’s diet is grossly imbalanced in favor of omega-6 fatty acids, which are concentrated in certain areas of the American diet:
Cow’s milk and cheeses are not high in omega-6s, but are high in saturated fat, which presents its own cardiovascular problems.
- The vegetable oils most commonly used in homes and in packaged or restaurant foods (corn, canola, soy, safflower, sunflower)
- Eggs (except high-omega-3 eggs from flaxseed-fed hens)
- Soy milk
- Poultry (especially fatty parts)
- Red meats (pork, lamb, and beef, except grass-fed beef).
Olive oil, macadamia nut oil, and special “hi-oleic” safflower and sunflower oils are the only oils low in omega-6s.
|The “uncontrolled experiment”|
on American public health
Drs. Lands and Hibbeln conducted an earlier study that found close correlations between the huge increases in omega-6 intake since 1960 in five developed countries and a 100-fold rise in homicides there.
As they said, “The increases in world [omega-6] LA consumption over the past century may be considered a very large uncontrolled experiment that may have contributed to increased societal burdens of aggression, depression, and cardiovascular mortality” (Hibbeln JR et al 2004). Most experts estimate that we consume 20 to 40 times as much omega-6 as omega-3 fatty acids, when we should be eating the two types in roughly equal amounts, with no more than three grams of omega-6 fatty acids consumed for every gram of omega-3 fatty acids.
This extreme imbalance in Americans’ diets reduces the amounts of omega-3s that can get into their cells.
Accordingly, the team led by Drs. Lands and Hibbeln considered the US population’s average omega-6 intake in order to calculate how much dietary omega-3s Americans need to ensure that adequate amounts of omega-3s get absorbed into their cells.
The goal: Dietary Reference Intakes for omega-3s
The Recommended Dietary Allowance (RDA) figures once found on food package reflectedthe amount of a nutrient needed to prevent signs of deficiency in 97–98 percent of consumers.
But in recent years, the US Institute of Medicine established new, generally higher intake guidelines called “Dietary Reference Intakes” (DRIs), with the goal of reducing the risk of chronic, degenerative diseases rather than just preventing obvious nutrient deficiencies.
In essence, the NIH team led by Drs. Lands and Hibbeln set out to establish "super" DRIs for omega-3s.
In particular, they sought to determine the omega-3 intake levels needed to increase the proportion of omega-3 fatty acids in Americans’ tissues to 60 percent of total fatty acids: the proportion found in Japan, where people enjoy far lower rates of cardiovascular disease, stroke, and depression.
Their findings indicate that Americans need to consume 3.5 grams (3,500mg) of marine omega-3s per day to achieve this goal: a figure much higher than their actual daily intake of omega-3s, which averages a pathetically inadequate 23mg.
|How much fish and fish oil does it take?|
The recommendation of 3.5 grams of omega-3s (EPA+DHA) per day is for Americans eating standard diets, high in omega-6 fatty acids. You’ll cut back on these fats a lot if you use olive oil, minimize meats, eggs, and butter, and cook mostly at home using whole foods.
If you cut back on omega-6 intake significantly, you could meet the new omega-3 needs with about two grams of omega-3s per day, which you’d get from eating 3-3.5 ounces of salmon per day and taking two salmon oil capsules at each meal.
These are the omega-3 (EPA+DHA) contents of some of our fish* (cooked with dry heat):
Omega-3s per 6 oz serving
King Salmon – 3.9 gm
Albacore 3.0 gm
Sablefish (black cod) – 2.7 gm
Silver Salmon – 2.2 gm
Sockeye Salmon – 2.0 gm
Sardines – 1.7 gm
Halibut – 0.85 gm
Omega-3s in Sockeye Salmon Oil*
Per 1,000 mg capsule – 160mg (0.16gm)
3 capsules provide 48mg (0.48 gm)
6 capsules provide 96mg (0.96 gm)
*USDA database, except sardine figure from our own tests (which confirm higher levels than USDA’s), and the figures for Sockeye Salmon Oil, from our own tests.
In other words, Americans consume less than one percent of the amount of omega-3s needed for optimal health given their excessive intake of omega-6 fatty acids.
New advice supersedes AHA guidelines
The American Heart Association (AHA) recommends that everyone eat two servings of oily fish twice a week. A six-ounce serving of sockeye would provide about four grams of omega-3s per week, or 571 mg per day.
The AHA recommends that people with heart disease consume one gram of marine omega-3s per day, which is a whopping 43 times more than the average American eats.
The NIH team is not alone in concluding that the AHA's recommended omega-3 intake levels, while beneficial, fall short of being optimal.
A recent evidence review from New York’s Rockefeller University (Breslow JL 2006) notes that people probably need daily doses of omega-3s (EPA and DHA) higher thanthree grams per day to decrease cardiovascular disease risks.
Note: While a dose of three grams per day may increase the risk of hemorrhagic strokes (due to thinner blood), the NIH team points out that that risk is far outweighed by its ability to reduce the risk of far more common thrombotic (clot-driven) strokes and other causes of death or disability.
Reduce omega-3 requirements by cutting omega-6 intake
Americans could achieve the NIH team’s tissue-level goal with a far lower daily intake of omega-3s, if they could cut their intake of omega-6 fatty acids dramatically.
This is because the omega-3 intake required to keep tissue levels of marine omega-3s at 60 percent of total fatty acids also depends on a person’s intake of omega-6 fatty acids.
The NIH team estimated that if Americans' average omega-6 intake dropped by 80 percent, this would reduce the intake requirement for omega-3s from 3,500mg daily to just 350mg per day.
And this advice seems eminently practical since Americans’ average omega-6 intake was much lower until about 75 years ago.
Currently, Americans get about nine percent of their daily calories from omega-6 fatty acids (i.e., 20 grams of omega-6s per day), so they would need to cut omega-6 intake to two percent of daily calories (i.e., 4-5 grams per day) in order to reduce their need for omega-3s to an easily obtainable 350 mg per day.
This drop in omega-6 intake may sound drastic, but two percent of daily calories (4-5 grams per day) was the omega-6 intake level found safe and adequate at the 2004 meeting of the International Society for the Study of Fatty Acids and Lipids, whose membership consists of the leading fatty acid researchers in the world, including members of the US Institute of Medicine.
The NIH team noted that diets during the 4–5 million years of human evolution were likely abundant in freshwater and salt water animals and plants and other sources of omega-3s (e.g., leafy greens) but included very few calories from omega-6-rich seed oils.
The dose of omega-3s needed to greatly reduce the risk psychiatric disorders and cardiovascular disease in 98 percent of the population must be considered in the context of omega-6 intake.
Different populations need vastly different additional intakes of omega-3s to reach the target (60 percent of tissue fatty acids as omega-3s), depending on their current intake of omega-6 and omega-3 fatty acids:
Philipines - 278 mg/day
Denmark - 1,000 mg/day
United Kingdom - 1,600 mg/day
USA - 3,679 mg/day*
*The NIH team rounded this down to 3,500 mg (3.5 gm) per day.
Early hominids certainly ate seeds, but could not have consumed enough to match the enormous amounts of seed oil that modern diets deliver.
In contrast, omega-6-rich soybean oil delivers some 20 percent of all calories in the average US diet, which explains why a whopping nine percent of the calories in the average American’s daily diet now comes from omega-6 fatty acids.
So avoid high-omega-6 oils like corn, soy, safflower, sunflower, and cottonseed and foods made with them ... which include many if not most restaurant and takeout meals.
Instead, use olive, macadamia nut, or hi-oleic sunflower oils and fresh whole foods for home cooking, and cut back on eating out.
You may live longer, and you’ll almost certainly stand a much better chance of living in good health.
- Hibbeln JR, Nieminen LR, Blasbalg TL, Riggs JA, Lands WE. Healthy intakes of n-3 and n-6 fatty acids: estimations considering worldwide diversity. Am J Clin Nutr. 2006 Jun;83(6 Suppl):1483S-1493S.
- Hibbeln JR, Nieminen LR, Lands WE. Increasing homicide rates and linoleic acid consumption among five Western countries, 1961–2000. Lipids 2004;39:1207–13.
- Breslow JL. n-3 fatty acids and cardiovascular disease. Am J Clin Nutr. 2006 Jun;83(6 Suppl):1477S-1482S. Review.
- Wang C, Harris WS, Chung M, Lichtenstein AH, Balk EM, Kupelnick B, Jordan HS, Lau J. n-3 Fatty acids from fish or fish-oil supplements, but not alpha-linolenic acid, benefit cardiovascular disease outcomes in primary- and secondary-prevention studies: a systematic review. Am J Clin Nutr. 2006 Jul;84(1):5-17. Review.
- Gebauer SK, Psota TL, Harris WS, Kris-Etherton PM. n-3 fatty acid dietary recommendations and food sources to achieve essentiality and cardiovascular benefits. Am J Clin Nutr. 2006 Jun;83(6 Suppl):1526S-1535S. Review