Nutrition: Fats Chapter 9
- What are Fats? (VIDEO)
- Facing the Fats
- Not all Fats are Equal
- Fiber & Lowering Cholesterol (VIDEO)
- Two Sources of Cholesterol: You Eat It & You Make It
- "Good" Fats: Unsaturated & Omega-3 (VIDEO)
- Saturated Fat & Its Effects (VIDEO)
- Fats in Nature: Good Fats & Bad Fats
- "Good" Fats: The Big Omega's!
- Trans Fats (VIDEO)
- Trans Fats: Plaque Attack
- Building a Body with Fat
- Your Brain is Built on Fat
- When Fats Take Revenge
- Reading Your Fats is Not So Tough
"Good" Fats: The Big Omega's!
Fats in White Hats: Which are the Good Ones?
In the past few years, a dietary war has broken out between the two families of fatty acids. Dueling experts, health and diet books, not to mention outspoken websites and bloggers have made the battle of the omegas the subject of very heated discussion. The most zealous proponents of omega-3s claim that omega-6s, in fact, are responsible for much of the country’s ill health. READ MORE
What is going on here and how do we make sense of this debate?
Essential fatty acids are fats that must come from our diet because our bodies cannot make them on their own. They play key roles in every system in the body, including our cardiovascular, reproductive, immune, and nervous systems. They are also important in the regulation of many physiological processes and are crucial for the health of cell membranes and the neurological development in infants.
There are two essential fatty acids: linoleic acid (LA), an omega-6 fatty acid, and alpha-linolenic acid (ALA), an omega-3 fatty acid. There are several other fatty acids in both the omega-6 and the omega-3 families, but the body can assemble these other fatty acids as long as LA and ALA are present in the diet.
At least the body can to some degree. In reality, the efficiency with which the body converts LA and ALA into other fatty acids is unpredictable. Therefore, there are other omega-6 and omega-3 fatty acids that are also important to get from dietary sources, even though they are not strictly “essential” by definition. This includes the omega-3 fatty acid DHA (docosahexaenoic acid), which is found in fish oil, and the omega-6 fatty acid ARA (arachidonic acid). Both play key roles in neurological development.
A Question of Balance
Scientists simply do not know what the optimum ratio is of omega-3 and omega-6 fatty acids. There is growing evidence, however, that most Western diets have too little omega-3 and that may affect inflammation and immune system function. According to Dr. David Katz, anthropologists believe that the ‘native’ (or natural) ratio of omega-3 to omega-6 fatty acids in the human diet is probably between 1:1 to 1:4. In the typical modern American diet, however, the ratio is between 1:11 and 1:20. That’s a big difference.
Why is the ratio of omega-3 to omega-6 so one-sided in our modern diet? One factor, explains Katz, is that we have inadvertently shrunk our natural sources of omega-3s. “We tend to refer to omega-3 as fish oil these days because fish is one of the few places we can reliably get it. But that’s our doing. When animals grazed on a wide variety of wild plant foods, they were a source of omega-3s too. So we have basically domesticated fish oil out of everything but fish.” LESS
Balancing the Omega’sREAD MORE
Has that dietary approach been upended? No. While nearly all experts would agree that Americans could certainly benefit from getting more omega-3 fatty acids into their diets, most would be very reluctant to suggest that people should reduce their intake of omega-6s from healthy sources. As Katz cautions, “the total amounts of these essential fatty acids in the diet may be more important than the ratio.” To reduce omega-6s in the American diet could wipe out hard-won progress already made.
The American Heart Association, in fact, published a science advisory paper to avoid that very outcome. Entitled, Omega-6 fatty acids: Make them a part of heart-healthy eating, the advisory made it clear that “omega-6 fatty acids, found in vegetable oils, nuts and seeds, are a beneficial part of a heart-healthy eating plan.”
The report was accompanied by a comment by William Harris, lead author of the advisory, which applies to most health news reported by the media. “As with any news about a single nutrient, it's important to remember to focus on an overall healthy dietary pattern. One nutrient or one type of food isn't a cure-all,” said Harris. “Our goal was simply to let Americans know that foods containing omega-6 fatty acids can be part of a healthy diet, and can even help improve your cardiovascular risk profile.”
For now, let the bloggers battle it out. Eat more omega-3, not less omega-6. LESS
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