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EFA's: The importance of being balanced

MagazineJune 2009 (Vol. 20 Issue 3)EFA's: The importance of being balanced

A few decades ago, nutritionists and doctors discovered essential fatty acid (EFA) supplementation and, suddenly, every industry was on the 'more is better' bandwagon

A few decades ago, nutritionists and doctors discovered essential fatty acid (EFA) supplementation and, suddenly, every industry was on the 'more is better' bandwagon. Supplements were given for everything from heart disease to premenstrual tension, while the processed-food industry embraced the polyunsaturated fats in corn, soy and safflower oils as 'healthy'.
As a demonstration that the more-is-better mentality still prevails, 20 years ago, the US National Institutes of Health (NIH) recommended an upper limit of 6.7 g/day of omega-6 fatty acids-equivalent to around 3 per cent of the calories in the average person's diet.
In January this year, the American Heart Association (AHA) nearly tripled that recommended level, exhorting Americans to take at least "5 percent to 10 percent of their calories from omega-6 fatty acids". Depending on the level of physical activity, age and gender, this works out to 12-22 g/day.
But several decades of research into this relatively new field tells a more sober and complicated story. Far from aiding health, such high levels of one type of fat over the
other can create health problems as serious as those caused by the excess consumption of the 'fake fats'-trans fatty acids.
Researchers now blame the im-balance between omega-3 and -6 fatty acids for many cases of heart disease, high blood pressure, diabetes and obesity. Excessive omega-6 supplementation may even be a major cause of depression and bipolar disorder.

The basic omega fats
The basic EFAs are two families of fats: omega-3 and omega-6. Omega-3 fatty acids comprise alpha-linolenic acid (ALA; found in flaxseed, corn and soy oils), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (found in plankton and fatty fish). The omega-6 family includes linoleic acid (LA) and gamma-linolenic acid (GLA), both of which are converted in the body into prostaglandins, which perform many vital bodily functions.
Up until the turn of the century, doctors believed that omega-6 was the most important EFA because of its anti-inflammatory, blood-thinning and vascular-dilating properties.
In 1993, the World Health Organ-ization (WHO) sponsored an inter-national team of experts, who con-cluded that "desirable intakes of linoleic acid should provide between 4 and 10 per cent of energy" and "the ratio of linoleic to alpha-linolenic acids in the diet should be between 5:1 and 10:1 (omega-6 to omega-3)."
Those consuming a higher ratio of omega-6 to omega-3 could simply eat more seafood or greens to balance it out. Furthermore, people grew wary of too much omega-3, having heard horror stories of haemorrhages, reduced blood-clotting and even strokes.
Consequently, for several decades, Westerners-and Americans in part-icular-have been told to use poly-unsaturated fats whenever possible in place of saturated fats.
This has resulted in an average ratio for Americans these days of 20:1 and, in some cases, even 50:1, of omega-6 to omega-3 fats. And this ratio is increasing in favour of omega-6s, as Americans now eschew eating seafish because of the likelihood of contamination and pollution.

More heart disease
In the intervening decades, new evidence has emerged showing that, far from being protective, a high omega-6 consumption is linked to a massive increase in heart disease.
In the famous Lyon Diet Heart Study, French heart patients were given either the AHA's polyunsatur-ated fats-rich 'heart diet' or the Mediterranean diet, replacing poly-unsaturated fats with olive oil, which is rich in oleic acid, an omega-9 monosaturated fat. Those eating the Mediterranean diet had a 70-per-cent reduction in all causes of death, including heart disease and cancer (Circulation, 1999; 99: 779-85).
The ongoing Massachusetts-based Framingham Heart Study found that those at risk of heart disease were not protected by high omega-6 intakes. In fact, their atherosclerosis became worse (Circulation, 2006; 113: 2062-70).
It's now known that omega-6 fats can cause those with an inherited atherosclerotic tendency to blossom into disease: those with the 5-lipoxy-genase (LOX) genotype develop hardened arteries with high levels of omega-6, whereas omega-3 is protec-tive (N Engl J Med, 2004; 350: 29-37).
High intakes of omega-6 fats are also related to an increase in heart disease. A Finnish study found a link between high omega-6 consumption and increased oxidation of low-density lipoproteins (LDL; the bad, atherogenic type of cholesterol) (Am J Clin Nutr, 1996; 63: 698-703).

Blunts omega-3 benefits
What is most disturbing is that too much omega-6 appears to counteract the benefits of omega-3, at least in pigs. Canadian researchers found that the positive effects of ALA on the heart were only realized when the diet was also low in omega-6, as in the Mediterranean diet (Am J Physiol Heart Circ Physiol, 2007, 293: H2919-27).
Besides heart disease, no less than three large-scale studies have shown that too much omega-6 fatty acids-such as currently recommended by the AHA-have been linked to breast cancer.
Although early epidemiological studies suggested that high doses of omega-6 fatty acids were protective, the latest findings show the reverse. In a recent Swedish study, high omega-6 intakes-more than 17.4 g/ day-doubled the incidence of breast cancer among those women who were genetically susceptible (Cancer Epidemiol Biomarkers Prev, 2008; 17: 2748-54).
In such women, the LOX enzyme, which is commonly found in the body, converts omega-6 fats into leukotrienes, which increase inflam-mation and are involved in the development of numerous disorders -from asthma and heart disease to a variety of cancers (of the breast, colon, lung and others).
This evidence suggests that, far from reducing inflammation, excess omega-6s bring about chronic inflammation in the body, leading to a plethora of disease states.

Omega-3 protection
In stark contrast, the omega-3 fats have a stunning amount of research to support their protective effects. Fish oils have been shown to decrease the incidence of cardiovascular events such as hypertension and athero-sclerosis (Circulation, 2000; 102; 2677-9), and to prevent depression and cancer.
They've also proved helpful in combating a host of diseases, including diabetes, ulcerative colitis, arthritis and Raynaud's disease (Nutr Rev; 1996; 54: S102-8; Am J Clin Nutr, 1991; 54: 438-63; Am J Clin Nutr, 2000; 71: 171S-5S).

Wrong ratio
Researchers have now begun to question whether omega-6s are truly necessary for human health. New evidence suggests that the initial research on omega-6 was flawed by mistakenly assuming that the health problems in the animals on an EFA-deficient diet were due to the lack of omega-6 fats rather than omega-3 deficiency (Prog Lipid Res, 2003; 42: 544-56).
However, most scientists maintain that the problem isn't omega-6 fatty acids per se, which are necessary for human health, so much as a massive overdose of them, which virtually eliminates the body's store of omega-3. It is known that the two fats compete with each other for enzymes to be converted into useful products in the body.
This is a point of particular concern, as the average daily British or American diet is already low on omega-3-amounting to one-eighth of the 650 mg/day of EPA and DHA recommended by the US NIH.

Ancestral ratios
The diet of our ancestors was rich in omega-3, with a typical ratio to omega-6s of 1:1, compared with the average ratio now of 1:15 to 1:16.7.
Lowering the ratio to as close to 1:1 as possible may counter many of the damaging effects of too much omega-6 supplementation. A ratio of 4:1, for example, has been associated with a 70-per-cent decrease in total mortality.
Nevertheless, there may not be a one-size-fits-all ratio for everyone. Different diseases respond to different ratios of omega-6 to omega-3 fats, and the optimal ratio appears to depend on how ill you are-the more severe the disease, the lower the ratio (closer to 1:1) required.
Patients with asthma found that a ratio of 5:1 was beneficial (while a ratio of 10:1 worsened their asthma). For those with rheumatoid arthritis, a 5:1 ratio had no effect, whereas a ratio of 2-3:1 suppressed inflammation. An even lower ratio was able to reduce the spread of cancer:
- Attempt a ratio of 1:1 if you can, but the amount you take depends on your state of health and where you live. You probably don't need as much omega-3 if you live where it's sunny and warm most of the time.
- If you are ill, nutritionists recommend 300 mg of EPA and DHA for every 10 lb (4.5 kg) of body weight. This equates to 1 tbsp of your average cod liver oil, or 10 capsules, for a 130-lb (59-kg) person.
- Use olive oil instead of PUFAs for cooking and don't ever heat the oils.
- If your symptoms resolve, try lowering the dosage of omega-3s.
- Take them with other supplements. As EFAs are fragile and easily oxidized, leading to harmful free radicals, always take them in a supple-ment using naturally derived vitamin E.
- EFAs require other nutrients to be converted in the body. Ensure that you're taking adequate amounts of vitamins B and C, as well as magnesium, calcium and zinc.
- Ensure that your brand of fish oil is free of mercury and PCBs. This requires some detective work such as contacting the manufacturer and examining independent reports of the product.
- Buy products containing a therapeutic dose of vitamin E, which will prevent the oil from going rancid. tio of 2.5:1 reduced rectal cell proliferation in colorectal cancer whereas a 4:1 ratio had no effect (Biomed Pharmacother, 2002; 56: 365-79).
In animal studies, a ratio of 4:1 enhanced cognitive effects such as memory-although, as usual, these results may not necessarily apply to humans (Proc Natl Acad Sci USA, 1993; 90: 10345-9).
Although some researchers believe that taking omega-3s reduces the need for omega-6 polyunsaturates, the best course may be to follow the course of our ancestors and aim for equal amounts of both-and then to listen to your body and its symptoms.
Lynne McTaggart

How much to take?

- Attempt a ratio of 1:1 if you can, but the amount you take depends on your state of health and where you live. You probably don't need as much omega-3 if you live where it's sunny and warm most of the time.
- If you are ill, nutritionists recommend 300 mg of EPA and DHA for every 10 lb (4.5 kg) of body weight. This equates to 1 tbsp of your average cod liver oil, or 10 capsules, for a 130-lb (59-kg) person.
- Use olive oil instead of PUFAs for cooking and don't ever heat the oils.
- If your symptoms resolve, try lowering the dosage of omega-3s.
- Take them with other supplements. As EFAs are fragile and easily oxidized, leading to harmful free radicals, always take them in a supple-ment using naturally derived vitamin E.
- EFAs require other nutrients to be converted in the body. Ensure that you're taking adequate amounts of vitamins B and C, as well as magnesium, calcium and zinc.
- Ensure that your brand of fish oil is free of mercury and PCBs. This requires some detective work such as contacting the manufacturer and examining independent reports of the product.
- Buy products containing a therapeutic dose of vitamin E, which will prevent the oil from going rancid.

Flaxseed vs fish oil

If you are vegetarian, you can take flaxseed or walnut oil as your omega-3. However, you should be aware that both oils contain the precursor alpha-linolenic acid (ALA), which needs to be converted to EPA and DHA for optimal benefit. This conversion process is not particularly efficient and grows worse with age (Am J Clin Nutr, 1991; 54: 438-63), especially if you also have raised insulin levels, as these will inhibit delta-6-desaturase, the enzyme necessary to convert ALA to EPA and DHA.


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