Keep in mind as you read this story that the data now shows that the people within and among populations who eat the most omega-3s relative to omega-6s are the ones who reduce their odds of getting heart disease. (However, you DO need more omega-6s than omega-3s... at least 2 to 1, if not 3 or 4 to one.) From the book:
"They can have 78 percent of their HUFAs [highly unsaturated fatty acids] as omega-6s, as they do in the United States; 58 percent, as they do in Mediterranean countries like Italy and Greece; or 47 percent, as they do in Japan. Meanwhile, mortality from heart disease goes up linearly with the increase in omega-6s, from 50 deaths per hundred thousand people in Japan, to 90 in Mediterranean countries, and 200 in the United States." - p. 104
The First Theories On Fat and Heart Disease
Until the second half of the 20th century, people knew relatively little about fat. And for a long time - millennia - heart disease was not an issue among people like it is now. But then Eisenhower had a heart attack. THAT made the news. Heart disease was connected to diet after WWII. Prior to that we just thought it had to do with increasing lifespans. When heart disease went down in some countries during the war and up again after, people caught on that diet played a role.
For a while, we didn't even think it was necessary to eat fat at all. Sure, it tastes good. Mmm... fries, right? But can you live with no fat? We thought so. Maybe ALL fat was bad? That was until hospital patients who got all of their food through tubes for a long period of time started dying without any fat in their tube-fed diets. Oops... turns out we need SOME fat in our diet.
"Experiments" with tube-fed hospital patients continued. They weren't intended as experiments but when you've got someone on a tube for a while and their health declines, you gotta figure out how to make them better. You try a bunch of things and see what works. It's more or less an experiment. First we realized you need Omega-6 fatty acids. Later, we learned you need Omega-3 fatty acids too.
So what caused this heart disease? And why did European countries experience a decrease in heart disease during WWII and then a rise again after the war? Well, those countries ate a lot less animal products during the war. Was that it? Maybe the problem is animal fats? Or tropical fats? Saturated fats? Or cholesterol? And now we blame trans fats.
1950s: All Fat Is The Problem
As early as 1913, we already suspected serum cholesterol was a risk factor for heart disease. In the 1950's, a guy named Ancel Keys did tests to find out which foods caused cholesterol to increase. He wanted to find out if eating cholesterol raised your cholesterol. He found that dietary fat raised your cholesterol more than dietary cholesterol did.
Keys first told the incorrect version of the story we all know well today. He linked fat and heart disease with absolutely no nuances. But he was very dogmatic - in 1957, a young scientist pointed out the different effects of saturated and unsaturated fats to Keys and Keys responded, "Saturated, unsaturated. I don't think you understand this field, young man."
But Keys was in the right place at the right time. While other scientists working on this puzzling question knew they didn't have the answers yet, Keys always thought that whatever data he had was the complete story. When Eisenhower had his 1955 heart attack, Keys was there with answers.
He had a chart showing the correlation between amounts of fat in a population's diet and their rates of heart disease. His chart showed 6 countries with a perfect straight line "proving" that more fat leads to more heart disease. The problem? He had data for 22 countries and when you plotted them all, the straight line no longer worked.
Late '50s: Animal vs. Plant Fat
Another scientist, Ed Ahrens, began talking about the differences between saturated and unsaturated fat in the early '50s, and sooner or later, Keys acknowledged that Ahrens was right. From Allport's book:
Keys was also forced to amend his original thesis to acknowledge that dietary cholesterol has a small but significant effect on serum cholesterol and that the monounsaturated fats in olive oil are not neutral, as he first contended. For whatever reasons, physicians and health professionals followed loyally in the wake of these amendments. When Keys began to distinguish between saturated and unsaturated fats, the world divided fats into two camps, animal and vegetable, failing to recognize that no fat is totally saturated or unsaturated and that some of the most saturated fats - coconut and palm oil - are derived from plant sources. - p. 51
A Little About Fats
The conventional nutrition wisdom that we all learned really hasn't gone beyond what Keys said back in the 1950s and 1960s. I'm going to cut off the history lesson there and instead give you a very simplified chemistry lesson. All fatty acids are long chains of carbons with an acidic group on one end. And in all fatty acids, many or all of the carbons are bonded to hydrogens. In saturated fats, EVERY carbon has a hydrogen. It is saturated with hydrogen.
Monounsaturated fats have one double bond where instead of attaching to hydrogens, two carbons are double-bonded to one another. Polyunsaturated fats have more than one of these double bonds between carbons. Make sense so far?
Omega-3, Omega-6, and Omega-9's are all considered "essential" fatty acids or EFAs. Essential for LIFE, that is. No EFAs, no life. And in fact, if you don't get any 3s or 6s, your body CAN make 9s and that's not really good enough. What the "omega" and the number refers to is where the first double bonds are when you start counting from the end (omega - end of the Greek alphabet) of the molecule. Omega-3s have their first double bond if you count in 3 from the end, and so on.
There are a few types of Omega-6s you should know: Arachidonic acid (AA) and Linoleic acid (LA). And a few types of Omega-3s: Alpha-Linolenic acid (ALA), Eicosapentaenoic acid (EPA), and Docosahexaenoic acid (DHA). ALA comes from plants and DHA and EPA come from animals (and some seaweed). And while EPA and DHA are both crucial to human health, our bodies CAN make them out of ALA.
Here's a REALLY SIMPLE way to distinguish between Omega-3s and Omega-6s. Omega-3s come from the leafy parts of plants. If it's green, it's got Omega-3s. If it's an animal and it ate green stuff, it's got Omega-3s. Omega-6s come from seeds and animals that ate seeds. There are exceptions of course, and it's totally NOT black and white, but that's an easy mental shortcut to remember them.
Where Did the Omega-3s Go?
Before we knew anything about omega-3s, we knew how to make money. Mmm, money. That's our real favorite food here in the U.S. We like convenience, shelf-life, lower costs, and higher margins. That's how you get profit. And marketers like to play to whatever consumers think is the newest fad to get healthy - now they label everything "0 trans fat!"
So we had animals on pasture, eating grasses, at the beginning of the 20th century. By the end of the century they were all in feedlots eating grains. Meat's ratio of Omega-6 to Omega-3 changed as a result.
Now is a good time to note that absolute quantities of omega-3s and omega-6s are less important than the ratio of one to the other. It's OK to have more omega-6 than omega-3, but it's not good to have a LOT more (as we do). In fact, when the research on omega-3s and heart disease started, the native populations of Greenland had very low rates of heart disease or type 2 diabetes and they ate lots of omega-3s in whale and seal meat. They kept eating whale and seal but added foods from the normal Western diet to what they ate later in the century and they started to experience higher rates of heart disease. So it's not just about adding Omega-3s but eating less Omega-6s.
What about the ratios in grass-fed (pasture raised) animal products vs. grain fed animal products? Well, for one thing, it varies. But here are some numbers I found.
Ratio of Omega-6 to Omega-3
Egg yolks, pastured: 2:1
Egg yolks, grain fed: 52:1
Butter, organic and grass-fed: 1.5:1
Butter, grain fed: 9:1
Beef, grass fed: 3:1
Beef, grain fed, 17:1
(Note that a good Omega-6:Omega-3 ratio doesn't negate a high amount of saturated fat. At first I hoped this was all a good excuse to pig out on butter but sadly it is not. But if you want to eat some butter, this data says you should get some from a grass fed cow if you can.)
Then, when we brilliant humans decided that animal fats were bad, we started replacing butter and lard in our diets with seed oils and hydrogenated seed oils (trans fats). And keep in mind that about 50% of U.S. cropland has either corn or soy growing on it, so guess which kind of oils we're eating?
Omega-6 to Omega 3 ratios of various plant oils
Flaxseed or linseed: 0.2: 1
Canola: 2:1
Canola (for light frying): 3:1
Walnut: 5:1
Soybean: 7:1
Wheat germ: 8:1
Olive oil: 12:1
Hydrogenated soybean: 12:1
High oleic sunflower: 19:1
Corn: 46:1
Palm: 46:1
Sesame: 137:1
Less than 60% linoleic sunflower: 200:1
Cottonseed: 259:1
Safflower: No omega-3s at all
(This chart is from Allport's book)
Notice that hydrogenated soybean oil has a worse ratio than soybean oil. Well, omega-3s have a tendency to go rancid quickly. They aren't very shelf-stable. Flaxseed oil has to be stored in dark bottles in refrigerators and the bottles recommend you consume it within 6-8 weeks of opening it. We loooooved hydrogenated oils because they extended shelf life. We also loved them because they were solid at room temperature like saturated fat and could thus, replace it in our diets. When I was growing up, my family ate "healthy" margarine instead of "unhealthy" butter.
And what are we doing now that we're removing trans-fats? Often replacing them with palm oil. But we're also trying to come up with varieties of canola and soy with LESS omega-3s (to lengthen shelf life).
So What Should We Eat?
Right now, Allport notes, we tend to treat Omega-3s like supplements and at one point they were just a regular part of our diets. For example, baby formula with DHA is now FINALLY available, but you gotta pay extra for it compared to baby formula without DHA.
Allport recommends that we eat a LOT of vegetables and quit eating so many Omega-6s. I'm oversimplifying her advice here, AND I am not a registered dietitian or a clinician of any sort so PLEASE do not act on anything I say without consulting a medical professional or, at a very minimum, reading Allport's book. And before you read the advice below, note that you don't need zero omega-6s. Some are OK. In fact, it's even good to eat more omega-6 than omega-3. Just not A LOT more. Here are some of Allport's tips (paraphrased by me):
1. Lots of fruits and veggies. There's not much fat in leafy greens, but what there is is good for you. Eatup, as Sen. Grassley would say. (Note: Your body can convert the plant form of omega-3s to the animal forms, so pig out on your fruits and veggies.)
2. Switch from very high omega-6 oils to ones with a healthy balance. Skip on safflower, sunflower, corn, cottonseed, and peanut oils when you can. Switch to flaxseed, walnut, organic canola, and organic soybean oils. (For canola and soy, as Paula pointed out in the comments, go organic because everything else is GMO. Or just stick to flaxseed oil.) Small amounts of butter are OK (get butter from grass fed cows if you can - great info on various organic dairies can be found at http://www.cornucopia.org in their Dairy Scorecard). Olive oil is good too - it might not be the world's greatest omega 6/3 ratio but it has other good stuff in it and it's a foundation of the proven-healthy Mediterranean diet.
3. Eat a wide variety of fish. I cringe at this advice. It's a good way to get omega-3s into your diet but we're killing our oceans AND many fish have toxins like PCBs and mercury in them. So use an online reference to which fish are best and look for Marine Stewardship Council certified fish like American Tuna (available at Whole Foods). If you want more info about fish, read the book Bottomfeeder. I have yet to read it but I've heard that it is amazing and can give you a basic foundation in what you need to know about fish.
4. Eat Omega-3 enriched eggs. The BEST thing to do - for the environment and for the sake of the chickens - is to find pastured eggs from a farmer near you on a site like http://www.eatwellguide.org or http://www.localharvest.org - and if you buy eggs at a farmers' market ASK the farmer if his chickens are raised on pasture. The goal is to get chickens that eat grass and bugs as part of their diet, not just grain. Chickens fed flax have high omega-3s too, but chickens kept in factory farm conditions and fed flax don't benefit the environment the way chickens raised on pasture do. Plus, factory farms are cruel. The best recommendation I have is to get some chickens of your own (info here). Then you know for sure that your eggs are healthy, they'll eat bugs for you, they'll fertilize your lawn, and they are really cool pets.
5. Eat pasture-raised meat if you eat meat. The same 2 sites I gave above for eggs should work to find good meat. Whether you're going for beef, pork, chicken, turkey, lamb, or anything else, pasture-raised is best. Don't just settle for stuff at the store that is labeled "free range." If you can't find a farmer and the best you can do is store bought, then look for the words "grass fed," "grass finished," or "pasture raised." I'd add wild game to the list of good meats.
6. Be careful with supplements. You don't NEED extra Omega-6s but many supplements include them. You need LESS omega-6s, not more. So be wary of things that say "high omega," "complete omega," "complete EFA," and stuff like that. I'm a believer of getting nutrients from whole foods in my diet instead of from supplements (and again, I am NOT a dietitian or doctor and NOT someone to take dietary advice from) but if you do go the supplement route, make sure your supplements give you omega-3s ONLY.
Really briefly, the other stuff to do is to skip on processed foods and trans-fats (hydrogenated oils), and cut down on saturated fats.
What Does the Government Do Wrong
Very simply, it's following flawed science - and there are a LOT of interests that want it to continue to follow flawed science. Just this week, the Senate held a hearing in which they (and Tom Vilsack) reinforced how safe U.S. pork is to eat. Well, it might be safe from swine flu but a recent study found that people who eat beef or pork daily have a significantly increased chance of dying in the next 10 years.
Step one of bad policy are the policies we have that promote growing lots and lots and lots of corn and soy and make them really cheap. Most of the corn and almost all of the soy goes to feed factory farmed animals here and abroad. (The soy is crushed for oil, which humans eat, and the resulting meal goes to animals.) The next 2 major crops are hay (animal food), and wheat (mostly human food, including lots of exports, and about 20% or so animal food). Together, those 4 crops make up 90% of our cropland.
The corn and soy, etc, are so cheap, that it's cheaper to put animals in factory farms and feed them corn and soy instead of letting them graze on pasture. And we allow factory farming. It's totally legal. I think it should not be. I think factory farmed meat is like cigarettes. It's bad for the environment and when factory farmed beef and pork and tobacco are used as directed, they lead to increased mortality rates.
We also allow fish farming. Fish are so healthy not only because they REQUIRE omega-3s to live in water as they do (and thus, farmed fish cannot have omega-3s 100% removed from their diets), but also because they are one of the last wild foods we eat. So what are we doing on fish farms? Feeding them less natural diets. We basically feed 'em the cheapest crap we can get away with.
And then, after we've created all of this totally junky food, we eat it. And we make policies that help us eat it, like the National School Lunch Program that allows all of this food in school cafeterias. In fact, as part of the program, the government provides factory farmed meat and dairy to schools FOR FREE. And what do you think budget-crunched schools feed the kids?
Oh - and what do we base the school lunch program on, as well as the WIC program (women, infants, and children), the Thrifty Food Plan that establishes how much money food stamp recipients get, and every single food label on every single packaged food sold in stores? The USDA's dietary guidelines, which totally DO NOT distinguish between omega-3s and omega-6s at all.
Is this backwards? Screwed up? Yeah, totally. The best thing to do right now is to write your legislators about school lunches and other child nutrition programs because a bill reauthorizing those will be passed this year and they are already debating it. Also, write in about the 2010 dietary guidelines because those are already in the works too. The guidelines SHOULD include all of this science about omega-3s and omega-6s.
What I've left out here is all of the science showing WHY omega-3s are so good for you. You have to read the book to get all of that. I know that's kind of a central piece of important information to this subject but I found it less relevant than the story about how flawed theories and profit motives shaped our eating and how you can eat well now. |
