The life-prolonging benefits of long-chain omega-3 fatty acids are hardly front-page news any longer. We have all heard by now that it is important to eat at least two servings of fatty fish per week for optimal cardiovascular health. After all, no less an authority than the American Heart Association recommended just such a dietary plan for all Americans in 2000, and again late last year, after reviewing years of research on the impressive health benefits of omega-3 consumption.1,2
The recommendation reflects the culmination of decades of research that began in the 1950s, when scientists first examined the traditional diets and lifestyles of the Inuit (Eskimos) in Greenland in an effort to understand the Eskimos’ almost startling absence of cardiovascular and other diseases. While heart and circulation disorders rank among the top killers in the industrialized world, they are virtually unknown among the hunter-fishers of the Arctic Circle. The Inuit’s amazing health, scientists eventually understood, is a direct result of consistently eating large quantities of fish and marine mammals, which are rich sources of long-chain omega-3 fatty acids.
But intriguing new research from around the globe indicates that the much-heralded heart benefits represent little more than the tip of the proverbial iceberg when it comes to this versatile and utterly essential nutrient.
A 21st Century Optimal Supplement
Exciting new studies suggest that omega-3s play an integral role in overall health. When deficiencies exist, as is alarmingly common in the industrialized West, supplementation with the right omega-3s, in the right balance, has the potential to improve everything from vision to brain function. Far from simply decreasing blood pressure, and protecting against heart attack and stroke,3-10 omega-3s may also prevent (or play a role in the treatment of) everything from depression to autism.11-24 Certain omega-3s are crucial to the optimal development of the brain and sensory organs in preterm infants,25-28 and omega-3s have been shown to reverse the symptoms of rheumatoid arthritis and possibly to play a role in preventing Alzheimer’s disease.29-34
And the list doesn’t stop there, as new research suggests even more potential benefits of omega-3s. Cutting-edge research from facilities all over the world indicates that omega-3s may also prevent age-related macular degeneration, suppress cancer cell growth (while simultaneously promoting cancer cell death), decrease susceptibility to the most common form of stroke, ameliorate complications of Type II diabetes, and even improve the health of those whose lungs have been damaged by smoking or diseases such as asthma, cystic fibrosis, and emphysema.35-45
But even that list fails to encompass the full scope of this essential nutrient’s absolute importance to virtually every aspect of health. About 60% of the brain consists of lipids, and the omega-3s are among the most important of these. They are key components of cell membranes throughout the body, and are richly invested in neural tissue.
The omega-3s are known as essential fatty acids (EFAs) because they are necessary nutrients that must be obtained from the diet. Unlike cholesterol, for instance, the body cannot manufacture the omega-3s it needs. While certain plant sources provide the building blocks of the most crucial omega-3s, they are most readily and plentifully obtained from marine sources.
Data gathered from populations around the world paint a clear picture: societies with the lowest fish consumption have the highest rates of suicide, depression, and violence. Conversely, among populations where fish is eaten frequently, these costly social ills are dramatically lower. The jury is still out on certain promising aspects of omega-3 supplementation therapy, but one thing is clear: omega-3s play a crucial role in maintaining health. What is equally clear is that the average American does not get nearly enough omega-3 fatty acids from the diet.
Some scientists have even speculated that the lack of adequate omega-3s in the Western diet may account for escalating levels of neurological disorders such as autism, depression, bipolar disorder (manic depression), and attention deficit hyperactivity disorder (ADHD).11-24 Others are investigating the benefits of omega-3 supplementation in the treatment of everything from asthma to inflammatory bowel disease and schizophrenia.46-48 Studies have shown that omega-3s can reduce the risk of sudden death from heart attack,5 improve vessel elasticity,49 lower serum triglycerides,50 and coax an unsteady heartbeat back into a stable rhythm.51-53 It is no fish story: Fish oil is beginning to look like a panacea for the 21st century.
Omega-3 vs. Omega-6– A Harmful Imbalance?
The human body has evolved to thrive on a roughly equal intake of omega-3 and omega-6 long-chain fatty acids. Although the important omega-3s, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are available only from marine sources, it is not necessary to eat seal meat, as the Inuit do, to reap the benefits of these ocean-borne nutrients. They are plentiful in fatty cold-water fish such as salmon, tuna, bluefish, sardines, herring, and king mackerel. A three-ounce serving of salmon, for instance, yields roughly 3 grams (3,000 mg) of combined EFAs.
For those who do not like fish or prefer the convenience and safety of supplements, fish oil is available in capsule form. But even fish do not generate these essential polyunsaturated fatty acids. They get them courtesy of their own diets, which include marine algae or seaweed. Humans can too, of course, although it seems unlikely that the average American will be able or willing to order fresh seaweed at McDonalds any time soon.
A third essential fatty acid, alpha-linolenic acid (ALA), is available from certain plant sources, most notably flax seed, avocados, and walnuts. The body can convert ALA into EPA and DHA, but the process is slow and the rate of conversion probably varies according to age, gender, and other factors.54-56 Fish and fish oil thus remain the best sources of vital DHA and EPA.
For millions of years, humans evolved on a diet rich in natural omega-3 food sources, including free-range game, fish, marine mammals, nuts, and fresh seaweed. In the early 20th century, however, food manufacturers in the industrialized nations began literally pouring soybean oil—a source of omega-6 fatty acids—into the food chain. A concurrent decline in fish and wild game consumption, accompanied by the heavy use of grains (another omega-6 source) as feed for livestock, conspired to drastically alter the balance between omega-6s and omega-3s in the Western diet. While an omega-6 to omega-3 ratio of roughly 2:1 is optimal, most Americans consume far more omega-6s than omega-3s, yielding a ratio skewed at least 10:1 in favor of omega-6s. Some estimates put the ratio as high as 40:1.
One researcher calculates that consumption of omega-6s has increased 1,000-fold since the early 20th century, literally changing the composition of our brains and bodies. Studies have shown that when cells are deprived of vital omega-3s, they attempt to compensate by incorporating saturated fats in cell membranes. The result is a stiff and ineffectual structure that must serve as the cell’s means of “commerce” and exchange with the rest of the body. Because omega-6s break down into arachidonic acid in the body, and arachidonic acid is converted to highly inflammatory chemicals, a huge increase in the availability of arachidonic acid translates into a huge increase in the potential for inflammatory and autoimmune diseases. Omega-3s, on the other hand, are converted by the body to series 1 and 3 prosta-glandins which serve to counterbalance the inflammatory effects of the series 2 prostaglandins, derived from arachidonic acid.
Here’s a look at some of the diverse ways in which omega-3s can improve health and extend life.
Promise Shown Treating Arthritis
Arthritic complaints are rare among the Inuit, and the omega-3s in their diet are evidently the reason. Clinical trials have examined the effectiveness of omega-3 supplementation in a variety of inflammatory and autoimmune diseases, including rheumatoid arthritis, Crohn’s disease, lupus erythematosus, psoriasis, multiple sclerosis, and migraine headaches. Many of these placebo-controlled trials have demonstrated significant benefits. In some cases patients have been able to reduce reliance on anti-inflammatory drugs, such as non-steroidal anti-inflammatories (NSAIDs), for relief from painful symptoms.32
Arthritis is actually a range of diseases, all of which have joint inflammation in common. Omega-3s excel at quelling inflammation. Although experts have recognized this beneficial effect for years, recent research has shed light on the exact mechanisms involved.
A number of diseases are associated with a high level of interleukin-1B (IL-1B), a pro-inflammatory cytokine. Arthritis is associated with an increase in IL-1B and the pro-inflammatory leukotriene LTB(4), which is indirectly produced by the body from arachidonic acid. Arachidonic acid is derived from omega-6 fatty acids and gives rise to a class of immune system compounds that promote pain and inflammation. Studies have shown that when omega-3 and omega-6 fatty acids are balanced (that is, when the ratio of omega-6 to omega-3 in the body is about 1:1 to 4:1), far less arachidonic acid is available for conversion to harmful eicosanoids and cyto-kines. Fewer of these compounds in circulation means less inflammation.
Besides “crowding out” excess arachidonic acid, the omega-3s aid the body in other ways, too. They have been shown to act on intracellular signaling pathways, to influence transcription factor activity, and to modulate gene expression. All of these effects may combine to alleviate inflammation and disease. As one researcher noted: “Many of the placebo-controlled trials of fish oil in chronic inflammatory diseases reveal significant benefit, including decreased disease activity and lowered use of anti-inflammatory drugs.”32 Another scientist reviewed nearly two decades of published research on the use of fish oil in the treatment of rheumatoid arthritis and concluded: “Treatment with fish oil has been associated with improvement…in rheumatoid arthritis.”34