You can’t swing a dead fish these days without hearing about its good fats. The term “omega-3” is now well known throughout the world of nutrition, but this wasn’t always so. Science writer Susan Allport accomplishes the task of chronicling the discovery and rise to stardom of omega-3 oils in The Queen of Fats: Why Omega-3s Were Removed from the Western Diet and What We can Do About Them.
Omega-3s, specifically long-chain omega-3s DHA and EPA found naturally in fish, have overtaken the world of nutrition as one of the most exciting areas of research in the last few decades. They are now recognized as essential for cardiovascular health and guarding against heart disease; DHA for being the most abundant fat in our brains and a key nutrient for infant and brain development as well as long-term brain health in adults; and EPA because it acts to replace other fatty acids in eicosanoid pathways to reduce inflammation in joints and the body overall.
No one would have predicted these facts half a century ago. Back in the 1960s, fats were all considered evil. There was no distinction between what fat was “good” or “bad”, writes Allport. Out of this type of thinking was born the American Heart Association’s low-fat recommendation, which was a recipe for disaster in eating.
As Allport puts it: “… that’s what happens when the center doesn’t hold, when the marketplace is full of such absurdities as overly sweetened breakfast cereals, such as Cocoa Puffs and Lucky Charms, being endorsed by the American Heart Association (because they have no cholesterol or saturated fat)—when the overly simplistic, low-fat mantra of the 1980s and 1990s made the Atkins craze almost inescapable. As a dieter in Texas confides, ‘Eating low-fat guarantees that I will binge on fried foods. Eating low-carb guarantees that I will binge on a bag of chips.’”
All this back-and-forth advice on nutrition has led millions of Americans to binging in and out of diets such as Atkins and terrible eating habits that include uncontrolled portion sizes, too many calories, too many high-glycemic carbs, too much trans fats and too little exercise. Wrong advice has led to epidemics in obesity, diabetes and, soon, Alzheimer’s disease.
Omega-3s removed from food
In her book, Allport seeks to highlight another aspect of what happens when ignorance in nutritional advice food processing lifts out a key nutrient from our diets. Despite what most people might think, omega-3s are not at all rare in nature and were not even rare in what people ate only half a century ago. In fact, omega-3s are the most abundant fats on the planet, making up a part of all plant cells. However, over time, omega-3s have been purposely removed from foods completely.
Why? Because omega-3s turn rancid quickly, getting them out of vegetable oils and out of processed foods increases their stability over time. Canola oil, for example, was once high in omega-3 alpha linolenic acid (ALA) and is still one of the greatest sources of omega-3s over the last few decades in the diets of Americans. However, plant biologists have been developing lower-ALA versions for years. The same thing has happened to soy oil and other oils.
To improve shelf life of processed foods, vegetable oils included in them were also often hydrogenated to improve shelf life. They still are. Hydrogenation—whether partially or fully hydrogenated oils—drastically improves stability of the oils, but completely destroyed omega-3 content. Too often enough, partially hydrogenation also introduces harmful trans fats.
At the same time, omega-3s have been removed from the diets of the animals we eat. As Allport explains it, plants accumulate oils in form of omega-3s in their leaves while concentrating the more stable omega-6s in their seeds. As the diets of animals, such as cows, switched from one that was grass-fed to one of grains, the content of omega-3s in their flesh diminished. For example, cows that ate grass were diverted to a diet of mostly corn in their animal feed. When the animals stopped receiving sufficient omega-3s in their diets, humans as consumers also had omega-3 levels in their bodies diminish.
Giving our food an extended shelf life of food and our meat plenty of flavor through the marbling effect of feeding animals corn are an understandable goal for food producers, but, unwittingly, the removal of omega-3s from our diet, not to mention the addition of high amounts of omega-6s and trans fats, have high implications on our health.
In a “stroke of luck”, writes Allport, two Danish researchers, Dr. Hans Olaf Bang (now deceased) and Dr. Jørn Dyerberg, led the world back onto the path of eating heart healthy fats. Had it not been for their discoveries, we may still be avoiding omega-3s today.
The two researchers’ curiosity had been sparked by reports that the native Inuit of Greenland, or Eskimos (as they’re commonly called), had a mysteriously low incidence of heart disease in spite of a diet rich in meat and fat, or blubber.
Dr. Bang and Dr. Dyerberg knew the world was changing and that the Inuit were becoming more Westernized by the day. They had to act right away if they were ever going to find out what in the Inuit’s diet protected their health.
Once in Greenland, they collected dozens of blood samples hoping to support an educated guess that the cardioprotective factor was due to dietary polyunsaturated fats. Upon analyzing blood samples back home in Denmark, their hypothesis was confirmed.
Their original discovery was long-chain omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) and their cardioprotective benefits.
Later, research in total parenteral nutrition would reveal that omega-3s should be considered an essential fatty acid, joining omega-6. Omega-6 had beforehand earned itself the name, “the King of Fats” and omega-3s would then be its “queen”.
Both these families of essential fatty acids, as Allport discusses, appear to compete for the same enzymes in the body.
Why are DHA, EPA and ALA all considered part of the same omega-3 family? The concept of separating both omega-3s and omega-6s into families was the brainchild of Dr. Ralph Holman.
Because chemists often use the first letters of the Greek alphabet to indicate position of chemical groups, Dr. Holman came out with the idea that “omega”, ω, the last letter of the alphabet could be used to distinguish the tails of fatty acids to put them into families.
Writes Allport, Dr. Holman’s naming convention was to help bring more attention to the relationship between these oils by avoiding their chemical names and addressing them by the end of the fatty acid chain, their tails. When metabolized in the body, the tails didn’t change and it made sense to bring more light to this fact. It also allowed the writing of the name of the oil to be shorter. For example, the chemical name of alpha-linolenic acid would simply be “18:3ω3” instead of “cis,cis,cis-9,12,15-Octadecatrienoic acid”.
Dr. Holman worried about how other researchers would react to the new terminology, but after a while he found that more and more studies began to take on the new vocabulary. Later on, Dr. Holman would find it exciting to see his “omega-3” name be adopted around the world to educate the public about the oils.
Speedy omega-3s, slow omega-6s
As all things in nature, there is a balance to be associated with fats in the wild. It appears, for example, that in most cases the speedier animals contain greater levels of omega-3s, specifically DHA, while slower animals accumulated omega-6 oils and saturated fats.
For example, slow-speed lizards and toads have more saturated fatty acids than high-speed hummingbirds, which contain plenty of DHA. In addition, large, slow animals such as elephants would have much greater omega-6 fatty acids and saturated fats than fast animals such as mice.
Omega-3s and omega-6s may also have a role in hibernation, writes Allport. It turns out, for example, that the yellow-bellied marmot’s natural diet has more omega-3s in the summer and a great deal more omega-6s in the winter. This is a relationship between leaves and nuts. But when given a diet high in linseed oil, which is high in omega-3s, the marmot doesn’t’ go into hibernation and, when given omega-6 laboratory food, they fall asleep on schedule.
Despite differences in omega-3 content in the body, Michael Crawford was the first to discover that percent content of DHA was consistent in brains throughout the animal kingdom. DHA is also found in greater concentrations in the eyes of animals.
Bringing omega-3s back into the diet
Because of a high intake of fish, the Japanese currently have a much higher amount of omega-3 fatty acids in their diet and live longer than Westerners. How can everyone be sure they are getting enough omega-3s, especially if they don’t eat much fish?
Allport writes that it will take a concerted effort of education and working with food producers to put omega-3s back into the food we eat. Already, however, we are seeing a greater leaning toward offering foods higher in omega-3s.
Consumers can help to protect their health by following some steps that Allport has laid out, which include eating plenty of fruits and vegetables, consuming oils with a healthy balance of omega-3s to omega-6s, eating a wide variety of fish, eating omega-3 enriched eggs, avoiding trans fats, cutting down on saturated fats, choosing free-range meats, and using supplements.
In conclusion, Allport makes a startling, but healthy prediction—that omega-3 status will not join serum cholesterol, LDL to HDL ratio, and C-reactive protein, but replace these other indicators as a risk factor for heart disease.