US Omega-6 and Omega-3 Fat Consumption over the Last Century

Omega-6 and omega-3 polyunsaturated fats (PUFA) are essential nutrients that play many important roles in the body. They are highly bioactive, and so any deviation from ancestral intake norms should probably be viewed with suspicion. I've expressed my opinion many times on this blog that omega-6 consumption is currently too high due to our high intake of refined seed oils (corn, soybean, sunflower, etc.) in industrial nations. Although it's clear that the quantity of omega-6 and omega-3 polyunsaturated fat have changed over the last century, no one had ever published a paper that attempted to systematically quantify it until last month (1).

Drs. Chris Ramsden and Joseph Hibbeln worked on this paper (the first author was Dr. Tanya Blasbalg and the senior author was Dr. Robert Rawlings)-- they were the first and second authors of a different review article I reviewed recently (2). Their new paper is a great reference that I'm sure I'll cite many times. I'm going to briefly review it and highlight a few key points.

1. The intake of omega-6 linoleic acid has increased quite a bit since 1909. It would have been roughly 2.3% of calories in 1909, while in 1999 it was 7.2%. That represents an increase of 213%. Linoleic acid is the form of omega-6 that predominates in seed oils.

2. The intake of omega-3 alpha-linolenic acid has also increased, for reasons that I'll explain below. It changed from 0.35% of calories to 0.72%, an increase of 109%.

3. The intake of long-chain omega-6 and omega-3 fats have decreased. These are the highly bioactive fats for which linoleic acid and alpha-linolenic acid are precursors. Arachidonic acid, DHA, DPA and EPA intakes have declined. This mostly has to do with changing husbandry practices and the replacement of animal fats with seed oils in the diet.

4. The ratio of omega-6 to omega-3 fats has increased. There is still quite a bit of debate over whether the ratios matter, or simply the absolute amount of each. I maintain that there is enough evidence from highly controlled animal studies and the basic biochemistry of PUFAs to tentatively conclude that the ratio is important. At a minimum, we know that excess linoleic acid inhibits omega-3 metabolism (3, 4, 5, 6). The omega-6:3 ratio increased from 5.4:1 to 9.6:1 between 1909 and 2009, a 78% increase.

5. The biggest factor in both linoleic acid and alpha-linolenic acid intake changes was the astonishing rise in soybean oil consumption. Soybean oil consumption increased from virtually nothing to 7.4% of total calories, eclipsing all sources of calories besides sugar, dairy and grains! That's because processed food is stuffed with it. It's essentially a byproduct of defatted soybean meal-- the second most important animal feed after corn. Check out this graph from the paper:

I think this paper is an important piece of the puzzle as we try to figure out what happened to nutrition and health in the US over the last century.

Fat-ten-u

I recently bought the book Food in the United States, 1820s-1890. I came across an ad for an interesting product that was sold in the late 1800s called Fat-ten-u. Check your calendars, it's not April fools day anymore; this is for real. Fat-ten-u was a dietary supplement guaranteed to "make the thin plump and rosy with honest fleshiness of form." I found several more ads for it online, and they feature drawings of despondent, lean women and drawings of happy overweight women accompanied by enthusiastic testimonials such as this:

"FAT-TEN-U FOODS increased my weight 39 pounds, gave me new womanly vigor and developed me finely. My two sisters also use FAT-TEN-U and because of our newly found vigor we have taken up Grecian dancing and have roles in all local productions."

I'm dying to know what was in this stuff, but I can't find the ingredients anywhere.

I find this rather extraordinary, for two reasons:

• Social norms have clearly changed since the late 1800s. Today, leanness is typically considered more attractive than plumpness.
• Women had to make an effort to become overweight in the late 1800s. In 2011, roughly two-thirds of US women are considered overweight or obese, despite the fact that most of them would rather be lean.

A rhetorical question: did everyone count calories in the 1800s, or did their diet and lifestyle naturally promote leanness? The existence of Fat-ten-u is consistent with the idea that our bodies naturally "defended" a lean body composition more effectively in the late 1800s, when our diets were less industrialized. This is supported by the only reliable data on obesity prevalence in the 1890s I'm aware of: body height and weight measurements from over 35,000 Union civil war veterans aged 40-69 years old (1). In that group of Caucasian men, obesity was about 10% of what it is today in the same age group. Whether or not you believe that this sample was representative of the population at large, I can't imagine any demographic in the modern US with an obesity prevalence of 3 percent (certainly not 60 year old war veterans).

Here are two more ads for Fat-ten-u and "Corpula foods" for your viewing pleasure:

Dr. Kevin Patterson on Western Diets and Health

A few readers have pointed me to an interesting NPR interview with the Canadian physician Kevin Patterson (link). He describes his medical work in Afghanistan and the Canadian arctic treating cultures with various degrees of industrialization. He discusses the "epidemiological transition", the idea that cultures experience predictable changes in their health as they go from hunter-gatherer, to agricultural, to industrial. I think he has an uncommonly good perspective on the effects of industrialization on human health, which tends to be true of people who have witnessed the effects of the industrial diet and lifestyle on diverse cultures.

A central concept behind my thinking is that it's possible to benefit simultaneously from both:

• The sanitation, medical technology, safety technology, law enforcement and lower warfare-related mortality that have increased our life expectancy dramatically relative to our distant ancestors.


• The very low incidence of obesity, diabetes, coronary heart disease and other non-infectious chronic diseases afforded by a diet and lifestyle roughly consistent with our non-industrial heritage.

But it requires discipline, because going with the flow means becoming unhealthy.

Spiced Lentils with Mushrooms and Greens

I'm always on the lookout for a way to incorporate lentils into my diet as well as more greens. So this recipe for Spiced Lentils with Mushrooms and Greens from the February, 2011 issue of Food and Wine magazine is perfect, especially since I think nothing with mushrooms can ever be bad. And there is nothing I love better than when foods that seem somewhat boring on their own (i.e. dry lentils and Swiss chard) get tossed together with some spices and end up super tasty as a result! And this is exactly what I got with this one. In fact, it was so good I didn't eat it as a side-dish as suggested in the recipe, I ate it stand alone as a light meal.

Spiced Lentils with Mushrooms and Greens 4 side-dish servings 1/2 cup brown or green lentils 3 Tbsp extra-virgin olive oil 1/2 pound shiitake mushrooms, stems discarded and caps sliced 1/4-inch thick Salt 1 garlic clove, minced 1/4 tsp ground cumin 1/4 tsp ground coriander 1/4 tsp freshly ground black pepper 1/8 tsp turmeric 1/2 pound Swiss chard or other tender greens, large stems discarded and leaves coarsely chopped 1 Tbsp chopped parsley

In a small saucepan, cover the lentils with 2 1/2 cups of water and bring to a boil. Cover and cook over low heat until the lentils are tender, about 30 minutes.

Meanwhile, in a medium saucepan, heat 2 tablespoons of the olive oil. Add the shiitake and season with salt. Cover and cook over moderate heat, stiffing, until the mushrooms are tender and starting to brown, 5 minutes. Add the remaining 1 tablespoon of olive oil along with the garlic, cumin, coriander, pepper and turmeric and cook, stirring, until fragrant, 1 minute. Add the greens and cook, stirring, until wilted, 2 minutes.

Add the lentils and their cooking liquid to the mushrooms and simmer for 3 minutes. Add up to 1/4 cup water if the lentils are too dry. Season with salt. Ladle the lentils into bowls, garnish with parsley and serve.

My Legume Love Affair (MLLA) was originally started by Susan of The Well-Seasoned Cook. This month's MLLA #33 is being hosted by Ammalus Kitchen

Scarlet Barley with Mushroom & Cannellini Paprikas

I admit that the main reason I made this recipe is so that I could shred a beet. I have had a thing with beets this past fall but so far I have only tackled roasting them. I found the concept of peeling the raw beet and then shredding it and using it as an ingredient intriguing. And when I learned this month's Monthly Mingle theme is "Think Pink" I decided this recipe for Scarlet Barley from Isa Chandra Moskowitz's "Appetite for Reduction" would be a fun contribution.

The Scarlet Barley along with the Mushroom & Cannelini Paprikas came together in about an hour. Shredding the beet for the Scarlet Barley was harder than I thought. I used the shredder on my mandolin and since the beet is naturally hard it was a bit difficult to get a good position for the shredder to shred it. And of course my hands turned all red. But once that was done the rest was simple. And it wasn't too difficult that I wouldn't do it again to use for other recipes if the ingredient is called for.

I prepared this dish prior to an evening appointment and let it sit on the stove for at least two hours before I ate it. Unfortunately I think it lost some flavor. The end result was somewhat bland to me. I think if I would have tried the barley after letting the fresh lemon sit for about 10 minutes it would have been much better.

The next day I sauteed some Swiss chard with green onions and garlic (like the way it is done for the Miso Udon Stir-fry with Greens and Beans recipe) and then threw the leftovers into the pan to reheat. I mixed it all together and after it was plated I squirted on a bit of sriracha. It was a really great combo to be eaten this way!

Scarlet Barley Serves 6 1 tsp olive oil 2 cloves garlic, minced Freshly ground black pepper 1 bay leaf 1 cup pearl barley, rinsed 2 1/2 cups vegetable broth 1/4 tsp salt 1 beet (about 3/4 pound), grated Juice of 1/2 lemon Fresh dill, for garnish (optional)

Preheat a 2-quart pot over medium heat. Saute the garlic in the olive oil for about 30 seconds. Add several pinches of pepper and the bay leaf. Add the barley, broth, and salt; cover and bring to a boil. Once boiling stir and lower the heat to low. Cover and cook for about 20 minutes, stirring occasionally.

When most of the water has absorbed, mix in the grated beet. Cook for about 20 more minutes, stirring occasionally. Turn off the heat, mix in the lemon juice, and taste for salt. Cover and let sit for about 10 mire minutes. Remove bay leaf and serve topped with fresh dill.


Mushroom & Cannellini Paprikas
Serves 4

1 1/2 tsp olive oil
4 cloves garlic, minced
1 pound cremini mushrooms, sliced
Several pinches of freshly ground black pepper
1/4 tsp salt
1/2 cup dry red cooking wine
1/4 cup vegetable broth
2 tsp smoked paprika
2 Tbsp fresh chopped thyme
1 (16-ounce) can cannellini beans, drained and rinsed
1/4 cup chopped fresh dill
1 recipe Scarlet Barley

Preheat a 4-quart pot over medium-high heat. Saute the onions in the oil until lightly browned, about 7 minutes. Add the garlic and saute for about 30 seconds. Add the mushrooms, pepper, and salt; cook until lots of the moisture has been released, stirring occasionally, for about 5 minutes.

Add the wine, broth, smoked paprika, and thyme. Turn up the heat and bring the mixture to a low boil. Boil for about 3 minutes. Lower the heat and add the beans. Cook to heat through, about 4 more minutes. Use a strong fork to lightly mash some of the beans, to thicken the sauce. Just mash a few against the side of the post and then mix 'em back in. Taste for salt and serve.

Serve over Scarlet Barley with plenty of fresh dill.

This month's Monthly Mingle theme is Think Pink and is being hosted by Sarah at Maison Cupcake.

Randy Tobler Show: Welcome

This morning, I had a conversation with Dr. Randy Tobler on his radio show "Vital Signs", on 97.1 FM News Talk in St Louis. Dr. Tobler is an obstetrician-gynecologist with an interest in nutrition, fitness and reproductive endocrinology from a holistic perspective. He asked me to appear on his show after he discovered my blog and found that we have some things in common, including an interest in evolutionary/ancestral health. We talked about the history of the American diet, the health of non-industrial cultures, what fats are healthiest, and the difference between pastured and conventional meat/dairy-- we took a few questions from listeners-- it was fun.

The show is available as a podcast here (3/26 show), although as far as I can tell, you need iTunes to listen to it. My section of the show starts around 8:20.

To everyone who arrived here after hearing me on the air this morning: welcome! Here are a few posts to give you a feel for what I do here at Whole Health Source:

The Coronary Heart Disease Epidemic
US Weight, Lifestyle and Diet Trends, 1970-2007
Butter vs. Margarine Showdown
Preventing and Reversing Tooth Decay
The Kitavans: Wisdom from the Pacific Islands
Potatoes and Human Health, Part I, Part II and Part III
Traditional Preparation Methods Improve Grains' Nutritional Value
Real Food XI: Sourdough Buckwheat Crepes
Glucose Tolerance in Non-industrial Cultures
Tropical Plant Fats: Palm Oil
It's Time to Let Go of the Glycemic Index

Safflower Oil Study

A few people have sent me a new study claiming to demonstrate that half a tablespoon of safflower oil a day improves insulin sensitivity, increases HDL and decreases inflammation in diabetics (1). Let me explain why this study does not show what it claims.

It all comes down to a little thing called a control group, which is the basis for comparison that you use to determine if your intervention had an effect. This study didn't have one for the safflower group. What it had was two intervention groups, one given 6.4g conjugated linoleic acid (CLA; 50% c9t11 and 50% t10c12-CLA) per day, and one given 8g safflower oil. I have to guess that this study was originally designed to test the effects of the CLA, with the safflower oil group as the control group, and that the interpretation of the data changed after the results came in. Otherwise, I don't understand why they would conduct a study like this without a control group.

Anyway, they found that the safflower oil group did better than the CLA group over 16 weeks, showing a higher insulin sensitivity, higher HDL, lower HbA1c (a marker of average blood glucose levels) and lower CRP (a marker of inflammation). But they also found that the safflower group improved slightly compared to baseline, therefore they decided to attribute the difference to a beneficial effect of safflower oil. The problem is that without a control (placebo) group for comparison, there's no way to know if the improvement would have occurred regardless of treatment, due to the season changing, more regular check-ups at the doctor's office due to participating in a study, or countless other unforeseen factors. A control group is essential for the accurate interpretation of results, which is why drug studies always have placebo groups.

What we can say is that the safflower oil group fared better than the CLA group, because there was a difference between the two. However, what I think really happened is that the CLA supplement was harmful and the small dose of safflower oil had no effect. Why? Because the t10c12 isomer of CLA, which was half their pill, has already been shown by previous well-controlled studies to reduce insulin sensitivity, decrease HDL and increase inflammatory markers at a similar dose and for a similar duration (2, 3). The safflower oil group only looked good by comparison. We can add this study to the "research bloopers" file.

It's worth noting that naturally occurring CLA mixtures, similar to those found in pastured dairy and ruminant fat, have not been shown to cause metabolic problems such as those caused by isolated t10c12 CLA.