Image: Omega-3 benefits of fish
Joe Raedle  /  Getty Images file
Scientists believe Americans are suffering from a widespread deficiency of fatty acids which are found in foods such as fish, leafy greens and grass-fed meats.
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updated 10/23/2009 4:43:35 PM ET 2009-10-23T20:43:35

When Lisa Kepp (*name has been changed to protect privacy) was 2 years old, she was diagnosed with a neurological condition. She had not said a word in her short life — and it wasn't for want of trying. Lisa was so frustrated at not being able to form the words she clearly wanted to say that she flew into temper tantrums four or five times a day. The family was on pins and needles waiting for the next time the little girl would explode.

A pediatric neurologist diagnosed verbal apraxia, a speech disorder, and recommended that she receive intensive speech therapy. He suggested no other treatment. Lisa's mother had heard, though, about studies linking omega-3 fatty acids to intelligence and healthy brains, and she thought she'd give them a try. She purchased a bottle of Nordic Naturals' Children's DHA in liquid form and began putting half a teaspoon in her daughter's orange juice every morning. Within a week, the young girl was babbling and her tantrums stopped. Amazed, her mother spoke to the doctors, but none of them would engage her, as she puts it, in a conversation about omega-3s. So Lisa continued speech therapy — and her omega-3s — for a year and will be starting preschool this fall with her peers.

A happy anecdote, to be sure. Ask any scientist, though, and he will admit that without testing, we can't be certain that omega-3s fueled Lisa's recovery. But he can point to a growing body of scientific literature that touts the benefits of omega-3 supplementation. Studies show that these special fatty acids accumulate in the brain and can aid children with learning disabilities, reduce violence in prison populations, and even improve everyday mood.

We can only obtain these fats through our diet. They are essential to the development of healthy brains and other metabolically active tissues. Indeed, research from the world's top universities shows that these fats do much more than regulate our brains: They can also lower risk of heart disease, arthritis, and cancer. They even help fight wrinkles and may block fat-cell formation.

How could omega-3s possibly be this powerful? Scientists believe it's because Americans are suffering from a widespread deficiency. A recent study conducted by Dariush Mozaffarian, MD, of the Harvard School of Public Health, found that the absence of these fatty acids in our diet is responsible annually for up to 96,000 premature deaths in this country. Scientists, however, are learning that fixing this nutritional deficiency is a bit more complicated than simply telling people to eat more fish.

Our collective omega-3 deficiency
Every once in a while, a discovery comes along that changes everything about the way we see the world. In the early 16th century, Nicolaus Copernicus had such a moment when he discovered that Earth was not the center of the universe. Our new understanding of essential fats is that kind of discovery, and I was lucky enough, as a science writer, to make a small-yet-key contribution. While researching a book on omega-3s, I realized that the essential fats — the omega-3s and their close cousins, the omega-6s — change with the seasons. It might sound like a small idea, but it may soon fundamentally change the way you think about food.

First, let's start with omega-3s, what I'll call the spring fats. These are likely the most abundant fats in the world, but they don't originate in fish, as many believe. Rather, they are found in the green leaves of plants. Fish are full of omega-3s because they eat phytoplankton (the microscopic green plants of the ocean) and seaweed. In plants, these special fatty acids help turn sunlight into sugars, the basis of life on Earth. The spring fats speed up metabolism. They are fats that animals (humans included) use to get ready for times of activity, like the mating season. They're found in the highest concentrations in all the most active tissues: brains, eyes, hearts, the tails of sperm — the flight muscles of hummingbirds. Because fish have so many of these fats in their diets, they can be active in cold, dark waters. These fats protect our brains from neurological disorders and enable our hearts to beat billions of times without incident. But they are vanishing from our diet, and you'll soon understand why.

Our omega-6 surplus
Next up are the omega-6s, what I'll call the fall fats. They originate in plants as well, but in the seeds of plants rather than the leaves. The fall fats are simply storage fats for plants. Animals require both — omega-3s and omega-6s — in their diets and their tissues. But omega-6s are slower and stiffer than omega-3s. Plus, they promote blood clotting and inflammation, the underlying causes of many diseases, including heart disease and arthritis. Omega-3s, on the other hand, promote blood flow and very little inflammation, which may prevent things like heart disease. The proper mix of these two fats helps create tissue with the right amount of blood flow and inflammation. But because they're in constant competition to enter our cells, if your diet consists of too many omega-6s, your body will be deficient in omega-3s. And that is what's been happening to us as we've been eating more and more seed fats in the form of soybean, corn, and other vegetable oils.

Since 1909, according to the USDA, Americans have more than doubled their daily intake of omega-6s — from about 7 grams to around 18. One hundred years ago, heart disease was much less common in this country. Over the past century, though, heart disease has risen in tandem with our increasing intake of these seed fats, or omega-6s, according to the American Heart Association (AHA). So have neurological disorders like Lisa's, as well as depression, arthritis, obesity, insulin resistance, and many cancers. While other dietary factors such as increased consumption of calories, trans fats, and sugar undoubtedly contributed, our essential fatty acid imbalance is a key player in most of these illnesses.

Over the same time period, omega-3s began disappearing from our food supply. Cows used to be raised on grass and other greens, producing meat, milk, and cheese with much higher concentrations of omega-3s. These were the animal products that our grandparents and great-grandparents grew up on, before industrial feedlots replaced family farms. Now these livestock are fed corn and soy, and their tissues are swamped with omega-6s. Chickens, too, used to eat grass and grass-eating bugs. Those chickens produced eggs and meat that were high in omega-3s, but now they're fed full of omega-6-rich fall fats.

We are now eating a diet that is supposed to fatten us up for winter, when weather is harsh and calories are scarce. But today food is never scarce for the average American. The base of our food supply has shifted from leaves to seeds, and this simple change means our bodies are storing more fat, leading to obesity and all its associated diseases.

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How we got here
This is all too simple to be true, you might say. But arriving at this understanding was anything but simple. In the 1930s, the first family of essential fats was discovered and mapped by George and Mildred Burr at the University of Minnesota. These were the omega-6s. It was another 40 years before omega-3s were also found to be essential, by a researcher at Hormel named Ralph Holman. A great deal happened to our food supply in those decades. Due to farm subsidies, the acres of soybeans, for example, grown in the United States exploded from about 4 million to 70 million. Oil processors like Archer Daniels Midland mastered the process of extracting oil from these and other seeds, and vegetable seed oils — thought to be healthy — began to dominate our food supply as they were added to the foods that make up the center aisles of the grocery store.

At the same time, food chemists discovered that rancidity in packaged foods was caused by the oxidation of some minor but pesky fats: omega-3s. Scientists extended the shelf life of processed foods such as cookies, chips, cakes, breads, and spreads by removing omega-3s — a nutrient that no one thought mattered. Health agencies, like the AHA, and the US government also promoted omega-6s, because seed oils are low in saturated fat and free of cholesterol. So omega-6 oils, such as corn and soybean, they thought, were good for the heart.

Scientists have known since the early 1970s, however, that omega-6s also promote blood clotting and inflammation, two immediate and direct causes of heart disease. But because omega-6s were essential, doctors thought you had to take the good with the bad. By the time they learned that omega-3s protect our hearts and fight inflammation, omega-6s were already the foundation of our modern food supply.

Then, in the 1980s, epidemiological studies published in prestigious journals like the New England Journal of Medicine showed that fish-eating populations in Greenland and Japan are much less prone to heart disease. Omega-3s became associated with fish (rather than with green leaves), and that became the method recommended by such organizations as the AHA for us to obtain our omega-3s. The only problem is that eating more fish isn't a sustainable solution, as many of the world's fisheries are at the brink of collapse, according to a major study recently published in Science. Literally, there aren't enough fish in the world's oceans.

Obesity’s real cause?
It wasn't until Australian researchers showed a clear difference between membranes full of omega-3 fats and ones full of omega-6 fats — a clear metabolic difference — that I explored the seasonal aspects of these two fats. When Tony Hulbert, PhD, at Australia's University of Wollongong, determined that the metabolism of a species — every species on the planet — is a function of the amount of omega-3s in its tissues, I began to connect the dots.

It is probably no coincidence, I realized, as I researched my book “The Queen of Fats,” that leaves are the most metabolically active tissues in plants, and brains and eyes are the most metabolically active tissues in animals: They are both full of omega-3 fats. Omega-3s speed up the activity of cells.

It is no coincidence, I realized, that omega-6s are simply a storage fat for plants. Both omega-6s and omega-3s play many vital, essential roles in animals, as I cannot emphasize enough. But in plants, the only role of omega-6s is to serve as a storage fat. Omega-6s are also the main polyunsaturated fat in the storage fat of animals: white adipose tissue — the belly fat of every overweight American.

It is no coincidence that hibernating animals such as the yellow-bellied marmot of Colorado do not go into hibernation when their diet is full of omega-3s, as it is in the spring and summer. Their diet must change to one rich in omega-6 seeds before these animals will slow down for the winter.

It is no coincidence that animals that migrate long distances — like the semipalmated sandpiper, which flies from Nova Scotia to South America — fill up on omega-3s for their long journey. These birds know what human athletes are just starting to learn: High omega-3 concentrations in muscle membranes lead to improved performance.

So it is no coincidence that as America shifted its diet — from one based on green leaves to one based on seeds — we became fatter and fatter and sicker and sicker. Our hibernation diet is exposing us to epidemics of obesity, diabetes, heart disease, cancer, and brain disorders. Even infants, according to the Child and Family Research Institute of the University of British Columbia, are getting fatter — long before they could ever be accused of overeating — when they are fed formulas high in omega-6s. Sure, America's seed-based foods are remarkably cheap, but we spend the lowest percentage of our income on food and more on health care than any other country in the world.

Since publishing “The Queen of Fats,” I've continued to comb the literature for studies that shed light on the role that the essential fats play in nature. I came across one not too long ago in the journal Lipids about the African kudu and impala, showing that these animals also experience a shift in the amounts of omega-3s and omega-6s in their diets over the course of the rainy and dry seasons — rather than our seasons based on day length. It made me realize that these shifts are universal signals, experienced and interpreted by animals all over the planet — at least until we humans came along and devised a way of eating a diet rich in seed fats all year long.

There's a solution to our imbalance, but change is difficult, and we must first accept that polyunsaturates — omega-3s and omega-6s — are not one big happy family; rather, they are two competing families — spring fats and fall fats— with very different effects on cells and health. Once we've accepted that, making the necessary dietary improvements is relatively easy.

Copyright© 2012 Rodale Inc.All rights reserved. No reproduction, transmission or display is permitted without the written permissions of Rodale Inc.

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