Archive for the 'omega-3' Category

An Unbiassed View of What We Should Eat . . . From a Rat

Wednesday, November 30th, 2011

In nature animals must choose a healthy diet based on what tastes good. This doesn’t work for modern humans — lots of people eat poor diets — but why it fails is a mystery. There are many possible reasons. Are the wrong (“unnatural”) foods available (e.g., too much sugar, too little omega-3, not enough fermented food)? Is something besides food causing trouble (e.g., too little exercise, too little attention to food)? Are bad cultural beliefs too powerful (e.g., “low-fat”, desire for thinness)? Is advertising too powerful? Is convenience too powerful? Lab animals are intermediate between animals in nature and modern humans. They are not affected by cultural beliefs, advertising, and convenience (the foods they are offered are equally convenient). Their choice of food may be better than ours.

Nutrition researchers understand the value of studying what lab animals choose to eat. In 1915, the first research paper about “dietary self-selection” was published, followed by hundreds more. The general finding is that in laboratory or research settings, animals choose a relatively healthy diet. There are two variations:

[1.] Cafeteria experiments with chemically defined [= synthesized] diets showed that some of these animals, when offered the separate, purified nutrient components of their usual diet, eat the nutrients in a balance that more or less resynthesizes the original diet and that is often superior to it. [2.] Other animals eat two or more natural foods in proportions that yield a more favorable balance of nutrients than will any one of these foods alone.

Both findings imply that housing an animal in a lab does not destroy the mechanism that tells it what to eat.

Which is why I was fascinated to recently learn what Mr. T (pictured above), the pet rat of Alexandra Harney, the author of The China Price, and her husband, liked to eat. It wasn’t obvious. “We tried so many foods with him and always thought it made a powerful statement that even a wild rat turned his nose up at potato chips,” says Alexandra. “He hated most processed food. He also hated carrots, though.” Here are his top three foods:

  1. pate
  2. salmon sashimi
  3. scrambled eggs

Pate = protein, animal fat, complex flavors (which in nature would have been supplied by microbe-rich, i.e., fermented, food). Salmon sashimi = protein, omega=3. Scrambled eggs = ??

He liked beer in moderation, but not yogurt. “Owners of domestic rats say they love yogurt,” says Alexandra, “but Mr T only liked it briefly and then hated it, even lunging to bite a friend who brought him some. [Curious.] He loved cheese, stored bread for future consumption (but almost never ate it). Loved pesto sauce and coconut.” Note the absence of fruits and vegetables. Alexandra and her husband have no nutritional theories that I am aware of. They did not shape this list to make some point.

For me the message is: Why scrambled eggs? I too like eggs and eat them regularly and cannot explain why.

More Alex Tabarrok’s Thanksgiving post shows the connection between libertarian ideas (economies work better when more choice is allowed) and dietary self-selection.

Flaxseed Oil Heals Bleeding Gums, Again

Friday, November 4th, 2011

In response to this post, which went up three months ago, a reader named Tara has just written:

I started taking 2 TB of flax oil daily about four days ago and now my gums are barely bleeding at all after I brush and floss. My gums were red, swollen and would bleed after I brushed and flossed and are now pink and healthy looking.

I’ve had this problem for years and I could not understand why it would keep happening even though I was consistent with my dental routine. I take the berry flavored Barlean’s flax oil mainly because it tastes good and so I look forward to taking it- if it was gross I would not be consistent with taking it.

Anyhow, thanks for the information! I wish dentists would look into this but they probably won’t so I’m glad that you do.

I agree about the Barlean’s, by the way. Their Omega Swirl flaxseed oil does taste good. The Omega Swirl webpage does not list healthy gums as one of its benefits. Instead it lists a bunch of benefits, such as “Heart Health” that are nearly impossible to verify.

Someone recently told me something fascinating about flaxseed oil: It made it much easier to kneel on the floor.  Before he started taking it, his knees would hurt after a few seconds. Now they don’t. I don’t remember my knees hurting quickly but I consume 66 g/day of ground flaxseed (= about 2 T flaxseed oil) and can kneel without pain for minutes.

The tiny fact reflected in Tara’s comment — an easily-available supplement (flaxseed oil) quickly cures a common problem (bleeding gums) but hardly anyone knows this — is  a devastating comment on our health care system.

1. Dentists haven’t managed to figure this out. Flaxseed oil is not an obscure supplement. Dentists are not making money giving people much worse advice (“floss regularly”).

2. Nutrition professors haven’t managed to figure this out. Omega-3 is not an obscure nutrient. Nevertheless, the 2010 USDA Dietary Guidelines says omega-3 fats are “essential” but says nothing about how much you need. Inflammation is believed to be the cause of many diseases, including heart disease. By getting this one thing  (minimum omega-3 intake you need to be healthy) right, the USDA could do a world of good. Instead they tell people to eat less animal fat (“consume less than 10 percent of calories from saturated fatty acids”).

To be fair, professional researchers are starting to figure this out.  A 2010 study of 9000 people found that “participants in the middle and upper third for omega-3 fatty acid consumption were between 23 percent and 30 percent less likely to have gum disease than those who consumed the least amount of omega-3 fatty acids.” With the right dose, I believe gum disease becomes 100% less likely. But at least they noticed a connection.


Brain Surprise! Why Did I Do So Well?

Monday, October 31st, 2011

For the last four years or so I have daily measured how well my brain is working by means of balance measurements and mental tests. For three years  I have used a test of simple arithmetic (e.g, 7 * 8, 2 + 5). I try to answer as fast as possible. I take faster answers to indicate a better-functioning brain.

Yesterday my score was much better than usual. This shows what happened.

My usual average is about 550 msec or more; my score yesterday was 525 msec. An unexplained improvement of 25 msec.

What caused the improvement? I came up with a list of ways that yesterday was much different than usual, that is, was an outlier in other ways. These are possible causes. From more to less plausible:

1. I had 33 g extra flaxseed last night. (By mistake. I’m not sure about this.)

2. The test came at the perfect time after I had my afternoon yogurt with 33 g flaxseed. When I took flaxseed oil (now I eat ground flaxseed), it was clear that there was a short-term improvement for a few hours.

3. Many afternoons I eat 33 g ground flaxseed with yogurt. Yesterday I ground the afternoon flaxseed an unusually long time, making made the omega-3 more digestible.

4. I did kettlebells swings and a kettlebell walk about 2 hours before the test. These exercises are not new but usually I do them on different days. Yesterday was the first time I’ve done them on the same day. I’m sure ordinary walking improves performance for perhaps 30 minutes after I stop walking.

5. I had duck and miso soup a half-hour before the test. Almost never eat this.

6. I had a fermented egg (“thousand-year-old egg”) at noon. I rarely eat them.

7. I had peanuts with my yogurt and ground flaxseed. Peanuts alone seem to have no effect. Perhaps something in the peanuts improves digestion of the omega-3 in the flaxseed.

8. I started watching faces at 7 am that morning instead of 6:30 am or earlier.

Here are eight ideas to test. Perhaps one or two will turn out to be important. Perhaps none will.

After I made this list, I read student papers. The assignment was to comment on a research article. One of the articles was about the effect of holding a warm versus cold coffee cup. Holding a warm coffee cup makes you act “warmer,” said the article. Commenting on this, a student said she thought it was ridiculous until she remembered going to the barber. She sees the person who washes her hair (in warm water) as friendly, the barber as cold. Maybe this is due to the warm water used to wash her hair, she noted. This made me realize another unusual feature of yesterday: I had washed my hair in warm water longer than usual. I think I did it at least 30 minutes before the arithmetic test but I’m not sure. In any case, here is another idea to test. I found earlier that cold showers slowed down my arithmetic speed.

This illustrates a big advantage of personal science (science done for personal gain) over professional science (science done because it’s your job): The random variation in my life may suggest plausible new ideas. As far as I can tell, professional scientists have learned almost nothing about practical ways to make your brain work better. You can find many lists of “brain food” on the internet. Inevitably the evidence is weak. I’d be surprised if any of them helped more than a tiny amount (in my test, a few msec). The real brain foods, in my experience, are butter and omega-3. Perhaps my tests will merely confirm the value of omega-3 (Explanations 1-3). But perhaps not (Explanations 4-8 and head heating).

Assorted Links

Friday, October 28th, 2011

Thanks to Navanit Arakeri and Casey Manion.

New Source of Omega-3?

Sunday, October 9th, 2011

I used to get my omega-3 from flaxseed oil. Then I encountered problems with the flaxseed oil going bad, in the sense of losing potency. (It did not smell bad.) I switched to flax seeds, which I grind and eat with yogurt. This is more difficult than drinking flaxseed oil.

From Peter Spero I have learned of a possible new source of omega-3: camelina oil. Camelina oil, unlike flaxseed oil, contains high levels of anti-oxidants, which protect it from going bad. Camelina is cheap to grow and can be grown where other crops cannot.

Flaxseed in Various Units.

Monday, October 3rd, 2011

I eat 66 grams of flaxseed per day. (I eat it with yogurt in two batches. For each batch, I weigh out 33 g of whole flaxseeds then grind them.) Not everyone has a scale, so I found that 100 ml of whole flaxseed weighs about 64 grams. Assuming 1 tablespoon = 15 ml, that’s 6.9 tablespoons/day whole flaxseed. If you are interested in weight/volume conversion, that’s 9.5 g of whole flaxseed = 1 tablespoon. I checked this using two different volume spoons and a scale that matches another scale.

This website says there are 15.02 g of whole flaxseed in a tablespoon. I am measuring brown flaxseeds. Perhaps their golden flaxseeds are smaller and therefore more dense. The overprecision suggests this shouldn’t be trusted.

This website says there 14.17 g of “dry” flaxseed in a tablespoon. Again with the overprecision.

According to this website, there are 7.5 g of whole flaxseed in a tablespoon.


Arthritis Relief From Flaxseed Oil

Tuesday, September 20th, 2011

From the Shangri-La Diet forums:

I have just been doing the flaxseed oil for a few days and I am experiencing a dramatic decrease of my arthritis pain! It is a wonderful benefit. . . . My doctor friend who told me about the SLD told me that the flaxseed oil would help my arthritis as well, but I never expected anything this dramatic or quick!

A friend of mine noticed something similar: his sore back stopped hurting shortly after he started taking flaxseed oil. If he skipped a day or so, the pain returned. Update: Reminded of this, he said, “I had forgotten all about that. When people ask me how my back is I tell them it never bothers me anymore since I stopped going to the gym.”

Update 2: At first the arthritis sufferer took 4 1200-mg capsules 3 times/day — that is, 12 capsules per day. Then she increased her dosage to 6 capsules 3 times/day (= 18 capsules/day).

Update 3. ” Yesterday, I was off to work and could not find my oil capsules.  I didn’t have time to look for them, so I resigned myself to doing sugar water during the day.  . . .  I did notice a small but significant worsening of the pain in my knees.  When I got home, I found the capsules, and began taking them again.  By the time I woke up this morning, I noted that my knees are again feeling better.”


Flaxseed Oil Reduces Healing Time

Friday, August 19th, 2011

A few days ago, Dominic Andriacchi, a 25-year-old law student living near Detroit, told me that he mentioned some of my self-experimentation (my discovery that postponing breakfast reduced insomnia) in an Amazon ebook (Law School Livin’) he’d just published. He added that something he read in this blog really helped him:

Thank you for introducing me to flaxseed oil.  Recently, I re-injured my back (a injury that occurred during college football).  While I’ve never seen a doctor for the injury, I did a little internet searching and figured that I had herniated a disk in my lower back.  I also had pain in my leg due to, I presume, pressure on the sciatic nerve from the herniated disk.

He re-injured his back pulling a small tree uphill.

Usually, it takes at least a week for the pain to go away.  I have trouble sitting, walking, and so forth.  That day, because I [had] read the post of Tucker Max’s ankle injury and flaxseed oil, I immediately upped my flaxseed oil to a total of 15 1000mg capsules.  The next day, there was nearly no pain at all.  I could bend over and touch my toes with only the slightest pain.  The day after that, I was back to normal.

Later he added some details:

I took 15 capsules of flaxseed oil [the day of the injury] to see what would happen. There was no immediate benefit that I felt that day, but the next day it was great. Even sitting or the slightest bending can cause a lot of pain, but I was able to bend over and nearly touch my toes. I took another 10 capsules that day as well. The day after that, I was completely pain free. I took more flaxseed oil capsules even though I was experiencing no pain at all. I expected the pain to come back, but it didn’t. From then on, I would just take my normal two flaxseed oil capsules [per day]. I was spacing them out, 5 at a time in between meals.

Many Supplements Taken Together Reduce Depression/Dysthymia

Wednesday, August 17th, 2011

At the recent Quantified Self Meetup in Mountain View, Fenn Lipkowitz told me that he had started taking a long list of supplements and now felt much better. At last week’s QS Silicon Valley Meetup, he gave a talk about it. The graph above shows “wellness” ratings before and after the change. (more…)

A Happy Reader Writes: Yogurt, Butter, Flaxseed Oil

Sunday, August 14th, 2011

A reader of this blog started taking flaxseed oil, half a stick of butter daily, and yogurt. “This works wonders,” he wrote me. “It feels like lubricant to the mind.”

My Daily Dose of Flax Seed

Wednesday, August 3rd, 2011

Currently I eat 33 grams (= 45 ml = 3 tablespoons) of flax seed in yogurt twice a day. That’s 66 g/day (which contains about 2 tablespoons of flaxseed oil). I grind it for 30 seconds before adding it to the yogurt. I like yogurt with ground flax seed better than yogurt without it, leaving aside the health benefits.

Unlike flaxseed oil, which must be kept cool, flax seed can be stored at room temperature, which makes a huge difference. I discovered that Chinese flaxseed oil was worthless, presumably because it hadn’t been kept cool. To bring American flaxseed oil to China was a nightmare — lugging it, trying to keep it cool. Chinese flax seed is fine, and not hard to get in Beijing.

Flaxseed Oil Cures Bleeding Gums in Three Days

Sunday, July 24th, 2011

I am pleased by these results:

After a possibly overzealous dentist told me I need a gum graft [which may cost $3000], my husband encouraged me to start taking flaxseed oil. A few people online have reported that flaxseed oil dramatically improved their gum health, and we figured it was worth a shot.

My initial dose of flaxseed oil was two tablespoons a day, and my gums stopped bleeding and hurting within three days. This is pretty huge for me, because my gums have been bleeding since I was in junior high. [Emphasis added.] At the same time, I added using a Sonicare toothbrush and flossing a little more vigorously. Considering that I had tried these things in the past without the flaxseed oil and they only made me bleed more, I feel like the flaxseed oil is the difference maker.

I have subsequently reduced my flaxseed oil dose to one tablespoon, which I feel is more appropriate for a woman my size. I haven’t gained any weight from the flaxseed oil, which was a bit of a surprise. Taking it in the morning seems to help curb my appetite by at least the 130 calories it consumes.

The online reports she mentions are from this blog. A recap: Because of the Shangri-La Diet, one evening I took four or five flaxseed oil capsules. The next morning, I was surprised to notice that putting on my shoes standing up, which I’d done hundreds of times, was much easier than usual. This suggested that the flaxseed oil had improved my balance. I started to carefully measure my balance and varied my flaxseed oil intake. My measurements showed that variations in amount of flaxseed oil really did affect my balance. They also suggested the best dose. My balance improved up to a dose of 3 tablespoons/day of flaxseed oil. So the best dose was about 3 tablespoons per day. I blogged about this.

Tyler Cowen, inspired by my results, started taking 2 tablespoons/day. A month later, he no longer needed gum surgery. Knowing nothing about my flaxseed oil intake or Tyler Cowen’s results, my dentist told me my gums were in excellent shape, better than ever. My sister’s gums showed similar improvement. Tucker Max noticed his gums stopped bleeding after he started taking flaxseed oil. He’d had bleeding gums most of his adult life. Nothing else had helped. He also found training injuries healed faster. When he stopped drinking flaxseed oil, his gums soon got worse. Carl Willat noticed dramatic gum improvement. Joyce Cohen had excellent results (her gums were “in great shape — better than ever”). Tim Beneke and Jack Rusher had similar results. Gary Wolf, on the other hand, didn’t like the mental effects. A recent epidemiological study found a weak correlation between inflamed gums and omega-3 intake.

What have I learned? Above all, that such a pattern of results is possible. These results suggest there was/is a big hole in the usual nutritional ideas. Tyler Cowen, me, my sister, etc., were eating a conventionally “good diet” yet there was a lot of room for improvement, both in brain function and overall inflammation level. (I’m sure flaxseed oil heals gums because it reduces inflammation.) And improvement wasn’t hard — there was a simple fix. In other words, omega-3 deficiency is very common. The conventional deficiency diseases, such as scurvy and pellagra, were/are rare. They appeared only under extreme conditions with very limited diets (e.g., prison, long sea voyage). Yet just as scurvy and pellagra are easily cured, there is a simple cure for omega-3 deficiency: about 2 tablespoons/day of flaxseed oil. (Perhaps ground flaxseed is an even better source.)

Other facts support the idea of widespread omega-3 deficiency. When gums are very red, and bleed very easily, it’s called gingivitis. According to this article, ” estimates of the general prevalence of adult gingivitis vary from approximately 50 to 100%”. Heart disease is common. There’s plenty of evidence that heart disease is caused by inflammation (gated). For example, it’s well-known that inflamed gums correlate with heart disease. Statins may reduce heart disease — to the mild extent they do — because they reduce inflammation.

I also learned that psychology can help improve general health (too much inflammation causes all sorts of problems, as Tucker Max’s experience suggests). My background in experimental psychology made it easy for me to measure balance.  I also found other mental tests were sensitive to flaxseed oil. These mental tests were like an animal model in the sense that they made helpful experiments (e.g., different doses) much easier. My friend Kenneth Carpenter, in his book about the discovery of Vitamin C (gated), stressed the importance of an animal model of scurvy. Once the best dose of flaxseed oil (for me) was known, it turned out to be easy to take a dose that produced dramatic improvement (in others).

The idea that psychology and self-experimentation can improve overall health is new. I presented my flaxseed oil results at a meeting of the Psychonomic Society a few years ago. After my talk, one member of the audience, a professor of psychology at Illinois State University, angrily complained that my talk was “pop culture” — not even pop psychology — and said I shouldn’t have been allowed to speak. He thought I had made elementary mistakes.

Flaxseed oil better than fish oil. Bad results of flaxseed oil.

Tucker Max on Omega-3 and Writing Ability

Thursday, June 16th, 2011

Re-reading an old post recently, I found this comment by Tucker Max:

I took four tablespoons [of flaxseed oil] a few hours ago, instead of the regular two, thinking that maybe I could load up and it might help me get back to normal quickly. The pain is pretty much the same, and I just brushed and my gums bled, so obviously the flaxseed oil takes more than a few hours to affect those problems. But–and I haven’t measured this with reaction tests like you do–I feel considerably more mentally alert right now. I don’t know if I felt like this before, and maybe I didn’t notice it because it came on slowly, or maybe I need four tablespoons at once to see a difference, but I really do feel the difference.

By coincidence I had noticed the same thing the day before: I was distinctly sharper than usual a few hours after drinking flaxseed oil (two tablespoons), as measured by my arithmetic test. I had noticed the same thing twice before — years earlier — but had decided not to study it in detail because it was much easier to study the long-term effects of flaxseed oil.

I wrote Tucker to say he had been right. He replied:

Yeah, there’s zero doubt in my mind now that fish oil/omega 3 is crucial to brain function. If I don’t take it, I can’t write effectively.

That’s very interesting. Sure, drugs have short-term effects. If you ingest caffeine, for example, it will make you more awake for a few hours. But drugs are dangerous. The notion that a necessary nutrient has benefits that last only a few hours is new. (The notion that a necessary nutrient can make us distinctly sharper will also be new to most people, but not to readers of this blog.) Perhaps we should eat omega-3 every few hours. You’ve heard of RDAs (Recommended Daily Allowances). Perhaps the future will contain RHAs (Recommended Hourly Allowances).

If you haven’t been reading this blog for several years, see these posts for background. Flaxseed oil also will make you smarter long-term, e.g., the next day. The short-term effect is in addition to the long-term effect.


Assorted Links

Monday, June 6th, 2011

Thanks to Dave Lull and Alex Chernavsky.

Tucker Max on Paleo: “I Started Feeling So Much Better”

Friday, May 6th, 2011

In this interview, Tucker Max talks about eating paleo.

Once I started doing this, I started feeling so much better. My brain felt like it worked better. Everything about me improved. So I kinda went down the rabbit hole, and I started reading up on diet and nutrition from alternate sources. Art De Vany, Robb Wolf, and Loren Cordain, they didn’t invent it but they kinda popularized the concept of paleo eating. I realized that if you’re just a normal person, and you have the normal ideas about diet and nutrition, everything you know is wrong.

If you ask me, Tucker’s enthusiasm/support for paleo is huge. Max Planck said progress happens funeral by funeral.  I say it happens keg party by keg party — college students, more than anyone else, have open minds. A friend told me that when she was a freshman in college, her sociology professor criticized the textbook. Whoa! she thought. Textbooks can be criticized!? She had thought they were beyond criticism. As far as I can tell, American college students respect Tucker more than they respect anyone else. (My Tsinghua students may favor Nassim Taleb.) For example, this recent tweet: “TuckerMax is my idol. and he’s on this paleodiet…so i think im going to do it too.”  I found no tweets about the dietary influence of Michelle Obama (“coolest First Lady ever“).

In spite of what the interview was shortened to say, Tucker got the idea of eating flaxseed oil from this blog, especially Tyler Cowen’s experience. He wrote to me about it at the time. I posted his comments about dental health (here and here) and sports injuries (here, here and here) under the name Anonymous.

I am pleased to announce that Tucker will be talking at the upcoming Ancestral Health Symposium at UCLA. The title of his talk is::

From Cave to Cage: Mixed Martial Arts in Ancestral Health

Sorry Tucker Max fans, symposium tickets are sold out. But after the conference you will be able to see the talk on the website.

Tucker’s latest book is Assholes Finish First.

Root Planing Cancelled

Thursday, March 3rd, 2011

My friend Carl Willat writes:

Last June I went to the dentist for a checkup and cleaning, fully expecting my gums to be in great shape since I had been diligently using my Braun Oral B electric toothbrush.  To my surprise and disappointment the hygienist told me the pockets had actually become deeper and that she was seeing bleeding in many places, to the point where she was recommending I have my roots planed, a painful and expensive procedure I had undergone once before many years ago. So of course I went home and started taking the flax seed oil and ground flax seed ["a couple of tablespoons a day of oil, plus random amounts of ground flax seed"] as you had recommended.  I also started using a Sonicare toothbrush at that point so it’s hard to figure out the degree to which either variable might be responsible, but today she said my gums were much better, and had hardly bled at all during the measurement of the pockets. All talk of root planing was forgotten.

According to this, root planing costs $400-$1600. After Tyler Cowen started drinking flaxseed oil (2 T/day), he no longer needed gum surgery.

It is hard to get well-preserved flaxseed oil in Beijing (it goes bad at room temperature) so I now take 66 g/day ground flaxseed instead of 2 T/day flaxseed oil. I add it to yogurt twice/day. I don’t know if ground flaxseed is healthier or less healthy than flaxseed oil but it is much less trouble. Preservation is no problem (flaxseeds can be stored at room temperature) and ground flaxseed requires zero willpower to eat with yogurt. I had to push myself a little to drink the oil.

Preposterous Health Claims of 2010

Thursday, January 6th, 2011

Katy Steinmetz, a writer for Time, made a list called “Nutty Health Claims of 2010″ and “2010: The Year in Preposterous Health Claims.” The list of 12 includes:


Marion Nestle, the New York University nutrition expert, has often said she thinks the health claims made for yogurt are bogus — at least when big companies make them. She recently called Dannon’s claims “a case study of successful marketing”.

Different Effects of Omega-3 and Omega-6 on Heart Disease

Monday, December 13th, 2010

You have probably read hundreds of recommendations to eat more polyunsaturated fatty acids (PUFAs), which in practice means omega-6 and omega-3. If you shop at Whole Foods, you may see Udo’s Blend, a blend of PUFAs which includes both omega-3 and omega-6, as if someone isn’t getting enough omega-6. It is unquestionable that omega-3 is beneficial but there is plenty of evidence that omega-6 is harmful, starting with the Israeli Paradox. Why are they lumped together?

A just-published paper in the British Journal of Nutrition makes several new points about the relation of PUFAs and heart disease. Its main point is a new look at experiments in which one group was given more PUFAs than another group.  Those experiments — there are only about eight — can be divided into two groups: (a) experiments in which the treated group was given both omega-3 and omega-6 and (b) experiments in which the treated group was given only omega-6. The two groups of experiments seem to have different results. In the “both” experiments the treated group seems to benefit; in the “only omega-6″ experiments, the treated group seems to be worse off. Suggesting that omega-3 and omega-6 have different effects on heart disease. They have been lumped together because experiments have lumped them together (varied both at the same time).
Experiments that try to measure the effect of PUFAs usually say they are replacing saturated fats. More PUFAs, less butter. The paper points out that studies of the effect of PUFAs have at least sometimes confounded reduction in saturated fats with reduction in trans fats. Benefits of the change may be due to the reduction in trans fats, not the reduction in saturate fats.

The paper also makes several good points about the Finnish study, a classic in the fat/heart disease literature. Supposedly the Finnish study showed that PUFAs (replacing saturated fats) reduce heart disease. It had hundreds of subjects but they were not randomized separately. The subjects were divided by hospital. Everyone in one hospital got one diet, everyone in a second hospital got a different diet. This meant it was easy for there to be confoundings (i.e., the treatment wasn’t the only difference between the groups). Indeed, there were big differences in consumption of a certain dangerous medication and margarine between hospitals. (Margarine is high in trans fats.)

Perhaps the first author, Christopher Ramsden, who works at NIH, is responsible for the high quality of this paper.
Thanks to Susan Allport.

Flaxseed Oil vs. Fish Oil

Sunday, November 21st, 2010

You can find statements like the following in a hundred places:

Both fish and flax are good sources of omega-3. Flaxseed oil is less expensive, which can be an important consideration. The main difference is that flaxseed oil contains only alpha-linoleic acid (ALA), which is the parent compound from which other omega-3 fatty acids are derived. This leaves it to your body to do the conversion to the other forms it needs, eicosapentaonoic acid (EPA) and docosahexaenoic acid (DHA). The problem is that the conversion is not always that efficient, and the body often uses the ALA for extra energy, leaving less for conversion to the other types. The body uses various enzymes to convert ALA to other omega-3s, and the process is not very efficient, especially as one gets older. Estimates of the rate of conversion range from 5% to 25%. In order to make sufficient amounts of EPA and DHA, one needs to consume 5-6 times more ALA than if one relies on fish oil alone. Fish oil, on the other hand, contains the other forms and delivers them directly to your body with no conversion necessary.

It isn’t that simple. Here are three things I rarely see mentioned:

1. The conversion rate is not fixed. It depends on the amount of the conversion enzyme, which increases with ALA exposure. The body makes the enzymes it needs and doesn’t make the enzymes it doesn’t need. You don’t have enzymes to digest food you don’t eat — but if you start to eat them you will build up the enzymes. The measurements of ALA conversion rate I have seen measured the conversion rate without giving the subjects extensive exposure to ALA before the test. (Measurements of glycemic index have the same problem.) They should be considered lower bounds of what would happen with long exposure.

2.  Time release is good not bad. When you take a dose of flax oil, its ALA is converted to DHA and EPA, which takes time, thus smoothing out the supply versus time function. If you take a dose of fish oil, the brain receives a sudden burst of DHA and EPA. It is likely that a smoother supply is better.

3. ALA (omega-3) conversion blocks AA (omega-6) conversion. Omega-3 fatty acids and omega-6 fatty acids are almost identical. The enzyme that converts short-chain omega-3 to long-chain omega-3 also converts short-chain omega-6 to long-chain omega-6. Long-chain omega-6 probably has bad effects in your brain, at least in large amounts, because it displaces long-chain omega-3. For industrial reasons, our diets are high in short-chain omega-6. Having ALA in your system, which flax oil provides but fish oil does not, slows down the conversion of short-chain omega-6 to long-chain omega-6 by occupying the conversion enzymes.

Thanks to Gary Skaleski.

Effect of Flaxseed Oil on Arithmetic

Friday, November 19th, 2010

After I moved to China in September, I was surprised that my arithmetic speed went down. (That is, I got faster.) I had lowered it from about 630 msec/problem to 600 msec/problem by eating lots of butter. I had no idea how to lower it further. I didn’t deliberately change my diet in China but it was quite different. I kept some things the same: the amount and brand of butter/day, the amount and brand of flaxseed oil/day.

I failed to figure out why I had gotten faster. I reduced the amount of flaxseed oil from 3 T (tablespoons) per day to 2 T per day. It made no difference. (In the beginning of my interest in flaxseed oil, change from 2 T/day to 3 T/day had made a difference.) Perhaps because of the butter.

Surprised that the change from 3 T/day to 2 T/day hadn’t made a difference, I went down to 1 T/day for two weeks, then back to 2 T/day. Both changes made a difference:

2010-11-16 2T vs 1T flaxseed oil

Each point is a separate test. Each test had 32 arithmetic problems (e.g., 3+4, 11-3). In the beginning of the data shown in the figure I tested myself once per day. After 12 days I started doing two tests/day, one right after the other. I was curious about the repeatability of the numbers; it wasn’t hard; it was a way to get better measurements. Averaging over the tests for each day to get one value per day, combining the 19 2-T/day (before) days and the 11 2-T/day (after) days, and comparing the combination to the final 7 1-T/day days, t(38) = 6.5. If you’re not familiar with t values, t = 2 is a barely reliable difference, t = 4 is a very clear difference.

This is more evidence that flaxseed oil improves brain function. It interests me because it implies the optimum dose is close to 2 T/day. It cost about $20 and took 1 person-month. In contrast, the DHA-Alzheimer’s study I mentioned two days ago cost about $1 million and took about 7000 person-months. And used (a) a cruder something-versus-nothing comparison, b) a less-sensitive between-subjects comparison, and (c) a more ethically-problematic placebo-controlled design.