Brent Pottenger Comments

I asked Brent if he had any comments on his experience (after he adopted an ancestral diet, his migraines and sinus infections stopped). He wrote:

The quality of my life (mental + physical health) improved even further when I started eating slices of butter throughout the day awhile back. For awhile, I was using spoonfuls of coconut butter/coconut oil and/or Greek yogurt for this satiation role, but once I added butter slices to the mix, I beefed up my nutritional ‘bag of tricks’ quite a bit. Of course, I had cooked in butter for a few years, but I never made the link to simply eat it in slices, despite enjoying its taste so much. And, a little bit goes a long way. I eat cultured butter from a few different brands and a few different locations of the world (hoping this diversification may carry extra beneficial side-effects: different strains of micro-organisms, etc.). I try to find brands that are pastured too (more naturally-occurring Omega-3’s, evidently). I usually suck on/chew on the butter slowly because I’ve found this has improved my oral health too: animal lipids (plus coconut oil) are good for epithelial tissue health (that’s why I rub coconut oil on my face and skin and rub butter, coconut oil, and yogurt on my hands). Pairing butter and coffee (I eat the butter; I don’t put it in my coffee; I drink my coffee black) has become a nice start to my day (Dave Lull even found a study speculating on the benefits of coupling hyperlipidity and anti-oxidants together in this way; I think it’s also a useful approach to detoxifying the liver), particularly when I know I am going to workout that morning–this little hyperlipidity kick seems to help in the gym too (when I am not fasting). Using butter slices in this manner is a nice compliment to fasting intermittently–these two practices allow me to enjoy low-caloric intake periods pleasantly. They set up my “feasts” nicely. Whenever I have a “grumbling” stomach, or I feel a “biting” sensation in my stomach, I eat a small piece of butter, and my mood and body tend to stabilize. And, like bacon and yogurt and eggs, it’s cheap. Butter has certainly been an excellent ‘cheap health option’ for me.

He later added:

Now I am working intently on Meta-Rules. Meta-Rules are simply ‘rules for making rules’ to live by. Three dynamics concern me deeply: (1) The problem of induction; (2) biochemical individuality; and, (3) factoring for the unseen. For instance, one of my nutritional Meta-Rules is: “Don’t consume anything that causes a negative physiological reaction.” From this Meta-Rule, I have deduced the following rule to live by (as one example): “Don’t consume high-fructose corn syrup.” A marker for monitoring this rule could be facial inflammation and ‘puffiness’ post-consumption, as one possibility. That’s an example of a higher-level precept empowering an individual to deduce for him or herself how that concept applies (or does not apply) in his/her own specific case (I like the term: Patient of One). Over time, I suspect that something like William Baines’ Biomedical Mutual Organization (BMO) could emerge if enough people were self-experimenting with Meta-Rules and interacting about their experiences and results. Amongst this cohort of parallel n=1 clinical trials, some convergence of Meta-Rules may occur, indicating ways that our bodies are the same, and also showing how our bodies differ individually when it comes to things like diet, exercise, and lifestyle design.

To explain why headaches can be due to inflammation, he pointed me to this.

Why Do Inmates Hide Butter?

When Marion Jones, the Olympic athlete, was in prison, “several inmates befriended her and showed her . . . how to hide sticks of butter.” Just as others carry water bottles so they can drink throughout the day, I carry butter in my backpack in a jar so I can eat small amounts throughout the day. As far as I know, no one else does this. I value butter so much because it makes my brain work better. If anyone reading this knows why inmates value butter so much, please let me know.

Science in Action: Mysterious Mental Improvement (part 3)

Previously on Seth’s Blog: A few weeks ago, during a brief test, I did simple arithmetic (e.g., 3+8, 4*0) substantially faster than usual. The next day, under the same conditions, it happened again. I thought of four possible reasons for the improvement:

  • 30 g of butter I’d eaten a few hours earlier.
  • A cobblestone mat I’d stood on earlier for 5 minutes.
  • Walking for 10 minutes before the test.
  • Standing (rather than sitting) during the test.

I guessed it was the walking.

Since then I’ve been gathering data to choose between these possibilities. I’ve been eating butter regularly to see if there’s a chronic speed-up. And I’ve been doing pairs of tests 20 minutes apart. The first test provides a baseline against which to judge the results of the second test. To measure the effects of the cobblestone mat I stood on the mat between the tests. To measure the effect of walking, I walked during the time between the tests. To measure the effect of standing, I stood during the second test but not the first.

The results so far suggest, to my surprise, that two of the four factors helped: butter and standing. How wrong I was!
At Berkeley, one of my students did a self-experiment that compared different ways of studying. She measured how long she stayed awake while studying foreign vocabulary. Worst turned out to be the conventional way: sitting at her desk in silence. Best was lying on her bed listening to hard rock. My new results are sort of a bigger version of the same thing: conventionally we avoid butter and sit while doing intellectual work.

Chairman Mao’s Brain Food

Hoping to learn why Chairman Mao, like me, considered pork belly “brain food”, I found just this:

The local government in Hunan [where Mao was from] has sought to standardize the cooking of the dish [Mao’s favorite pork belly dish], in order to stem the tide of imitations that crowd Chinese restaurants.

According to stringent instructions from the government’s food quality supervision and testing institute, true hong shao rou [red braised pork] can only be made with the meat of rare pigs from Ningxiang county. Officials have designated the pig, which has been bred for nearly 1,000 years, as an “agricultural treasure”.

I tried pork belly from different sorts of pigs (e.g., black pigs) but never noticed a difference.

Hunan Province is also the location of West Lake restaurant, one of the largest restaurants in the world. I’ve been watching “The Biggest Chinese Restaurant in the World,” a wonderful BBC documentary about it. The owner attributes her success to her first husband, who made her furious.

Assorted Links

Thanks to Vic Sarjoo, Anne Weiss, and Marian Lizzi.

Science in Action: Mysterious Mental Improvement (part 2)

Yesterday I blogged about a sudden improvement in how fast I could do arithmetic. The improvement was much larger than normal variation and happened after I did four things that I rarely did. In chronological order:

1. Ate about 30 g of butter.

2. Stood on a cobblestone mat (for 5 minutes, which was all I could bear).

3. Stood during the test.

4. Walked for 10 minutes just before the test.

To find out which mattered, I did them again in the same order and at the same times of day, but with tests before and after each one.  If performance suddenly improved after one of them, then I’d know.

Here’s what actually happened.

2010-03-10 arithmetic time vs time of testThe last six points are the relevant results. The first of the six points (627 msec) was before everything. The second (613 msec) was after butter but before the cobblestones. The third (630 msec) was after the cobblestones but before standing. The fourth (610 msec) and fifth (603 msec) were while standing but before walking. The final one (581 msec) was while standing after walking.

I was surprised and pleased how closely the first and last scores repeated the earlier difference. The first score was close to the previous baseline; the last score was close to the previous outlier. A big improvement seems to be under my control.

Before doing these tests, my best guess about what caused the improvement was the walking. But the scores were improving before the walking so that’s unlikely. Perhaps the walking was one of several factors that helped. The data suggest, if anything, a shocking conclusion: butter made my brain work better. An alternative, less consistent with Occam’s razor, is that butter, standing, and walking all produced smaller improvements, which together added up to the big improvement. The cobblestones produced a short-lived decrement.

That pork fat improved my sleep obviously supports the butter interpretation. I should be less surprised than anyone else, but still . . . Last week I noticed something else that supports the butter explanation. At a restaurant with a friend, the waiter brought bread and olive oil. I asked for butter. I spread all of it on a piece of bread, then asked for more butter, and spread all of that on another piece of bread. (About 30 g butter total.) It was the first time I’d eaten a large amount of butter at a meal. An hour or so later, I felt unusually good, some combination of calm and warmth. I never noticed this after eating pork fat, but butter may be to pork fat as hamburger is to steak: Easier to digest. The pork fat is within cell walls; the butter fat isn’t.

The Need for Animal Fat

If you read Good Calories Bad Calories you may remember that the Arctic anthropologist Vilhjamur Steffanson spent a year on an all-meat diet, with no ill effects. (In an earlier post about Steffanson, I stressed the fermented food that the Eskimos ate.) You may not know that animal fat was crucial for his health during that year, which began with a brief attempt to eat lean meat (meaning meat without fat):

On February 26, 1968, [Stefansson] was admitted to the ward and on February 28, started on the meat diet. At our request he began eating lean meat only, although he had previously noted, in the North, that very lean meat sometimes produced digestive disturbances. On the 3rd day nausea and diarrhea developed. When fat meat was added to the diet, a full recovery was made in 2 days.

During the year, he got about 80% of his calories from fat.

Via Inhuman Experiment.

Animal Fat, Sleep, and the Ketogenic Diet

Kathy Tucker draws my attention to a recent article about the ketogenic diet, which is essentially a very-high-animal-fat diet, used to treat childhood epilepsy. I’ve blogged about the ketogenic diet (here, here, and here) but that was before I was on a similar diet. Kids on the diet didn’t develop high cholesterol (“very few children actually end up with cholesterol or lipid problems on the diet”). I slept better when I ate more animal fat, which suggests that animal fat makes the brain work better overall. The success of the ketogenic diet supports that idea. My results suggest that it is the animal fat, not the other fat, that makes the diet effective.

That many kids with epilepsy get better when put on the ketogenic diet can be seen as a canary-in-the-coal-mine phenomenon. Canaries are more sensitive to bad air than miners; children with ketogenic-responsive epilepsy are more sensitive to lack of animal fat than the rest of us. That lesson was lost on me when I first learned about the diet and its success. The broader lesson is that almost any disease has something to teach us about what the best environment is.

How Bad is Animal Fat?

After learning that animal fat improved my sleep, I happily ate much more of it. I wasn’t worried that it made something else worse (e.g., heart disease). I believe that all parts of our bodies have been shaped by evolution to work well on the same diet, just as all electric appliances are designed to work well on the same house current.

A to-be-published meta-analysis in the American Journal of Clinical Nutrition supports my view that animal fat is nowhere as bad as we’ve been told a thousand times. It says:

During 5–23 y of follow-up of 347,747 subjects, . . . intake of [more] saturated fat was not associated with an increased risk of CHD [coronary heart disease], stroke, or CVD [cardiovascular disease]. The pooled relative risk estimates that compared extreme quantiles of saturated fat intake were 1.07 (95% CI: 0.96, 1.19; P = 0.22) for CHD, 0.81 (95% CI: 0.62, 1.05; P = 0.11) for stroke, and 1.00 (95% CI: 0.89, 1.11; P = 0.95) for CVD.

Emphasis added. One aspect of the results suggested that studies that found an positive association (more fat, more disease) were more likely to be published than those that didn’t find an association or found a negative association. Which means these numbers may underestimate the good effects.

Thanks to Steve Hansen and Michael Pope.

“The 11 Best Foods You Aren’t Eating”

There isn’t one fermented food on a list of “the 11 best foods you aren’t eating” compiled by Tara Parker-Pope, author of the world’s most visible health blog. Nor do any of the listed foods contain animal fat. One of them (sardines) is high in omega-3, so the list gets a D instead of an F. Fermented foods and animal fat (in sufficient quantity) have easily-noticed benefits, in contrast to every food on the list. Parker-Pope and the nutritionist she consulted (Jenny Bowden) have large gaps in their understanding of nutrition.

The Unwisdom of John Mackey

John Mackey is the founder of Whole Foods, a business I greatly respect. But he’s not always right.

“You only love animal fat because you’re used to it,” he said. “You’re addicted.”

(From a profile of Mackey in The New Yorker.) I discovered that animal fat improved my sleep when I overcame my (learned) repulsion and ate a lot more than usual.I think it’s obvious that fat tastes good for unlearned reasons. For reasons not based on experience. (Babies like fat. Animals similar to us, who have never eaten fast food, like fat.) Mackey’s comment is an example of a larger disregard of this. Professional nutritionists, including nutrition professors, have ignored the general point that our food preferences must somehow be good for us. I’m not saying all fat must be good for us — just the fat we ate when our liking of fat evolved. The idea that evolution would shape us to like and eat a food component that’s bad for us makes no sense.

James Michener Anticipates Me

In James Michener’s Poland (1983), a Polish peasant in a concentration camp tries to survive by thinking about food (p. 532 of the paperback):

He then transferred his imagination to a supper served at the wedding of a well-to-do farmer, where huge platters of sauerkraut, sausage, boiled pork and pickles had been provided, one to each of six tables, and he had helped himself piggishly, moving from one to the other so as not to reveal his gluttony.  He recalled this particular feast for two reasons: as a peasant, he knew that the acid bite of the pickled kraut was good for him, all peasants knew that and it was one reason why they survived so long; and he could see in the rich fat of the meats the strength that came from them.

Later he thinks about animal fat:

He imagined himself luxuriating with platters of butter, or grease, or pork drippings, or oil that rich people bought from Spain, or the golden globules at the edge of a roast, or plain lard.

According to Wikipedia, Poland was based on “extensive study of Poland’s history and culture.” Thanks to Nadav Manham.

Sometimes Black Really Is White

Jenny Holzer, the artist, says, “I get up about four times a night and go back to sleep, or not.” I suspect she’s not eating enough animal fat. At my local Beijing supermarket yesterday, I asked a butcher to cut the meat off a piece of pork fat. Reverse trimming. At the moment, I think about 180 g of animal fat/day is a good dose. I’m much less concerned about amount of meat. Another instance, I thought to myself, where I want the opposite of everyone else. But that’s far more true in America than here. In China but not America, I can buy pork belly at any supermarket; in China but not America, there is vast selection of pickles and yogurt at any supermarket.

More Animal Fat, Better Sleep

After I wrote about eating a lot of pork fat and sleeping better, David Shackelford commented that he had had a similar experience: After he started eating much more animal fat and meat, he too slept better. (He posted about this before he read my post.) I asked him for details. He answered:

About three weeks ago, I started a carnivorous diet. I did this primarily for its supposed benefit to insulin sensitivity, energy levels, and general health, and also because I wanted to see if it was really possible to thrive on nothing but meat.

Immediately after starting, I noticed that I was sleeping easier, longer, and deeper, and having more vivid dreams than usual. I’ve had a hard time falling asleep for my entire life, usually taking 45 minutes to two hours after going to bed, and occasionally not being able to sleep at all, so this was a very pleasant surprise.

At first I thought that this was due to standing on one foot, which I had started a few days prior, but I stopped one-foot-standing and the effect persisted. The all-meat diet has been pretty great all around-food is delicious, I’ve got a ton of energy, and I’m rarely hungry-but the sleep has been the best part.

21 years old (senior in college)
130-ish lbs
12-15% body fat
Moderately active, fairly good shape.

My diet
-Breakfast of 3-4 egg omelette, with 1-2 oz cheese and occasionally bacon.
-Lunch: chicken breast, sausage, or eggs.
-Dinner: 1lb+ steak.
-Snacks: nuts and/or cheese.

Approximate macronutrient composition
Before: 50% carbohydrate / 30% protein / 20% fat (at least half unsaturated olive oil)
After: 60-70% fat (all animal fat), 30-40% protein;10% carbohydrates (nuts and the occasional glass of wine, plus trace amounts in sauces and cheeses). Unsure of my caloric intake; I think it varies between 1500 and 2000 a day.

-I cook chicken, beef, and eggs in butter.
-I drink coffee 1-2 times a day, and tea about once a day.
-I take a multivitamin (I don’t know why), 5,000 IU Vitamin D (I live in Oregon, which gets very little sunlight), and 2.5g fish oil (the grain-fed beef I eat has low 3:6 ratios; if I could afford grass-fed, I probably wouldn’t need the fish oil).
-I let the diet go on weekends, for the sake of social life. I probably have 3-5 drinks on Friday and Saturday night, as well as some junk food (pizza/chips/fries). I feel like I don’t sleep quite as well on these days, but there are so many confounding variables (alcohol, staying up later than usual, seeing faces later into the night, sex) that isolating a cause of the difference is tough.

-I lift weights for about 30 minutes, twice a week.
-I go out social dancing for about four hours, once to twice a week.
-Sleep does not seem to vary with whether I exercise or not.

He blogs about this at His story is more evidence that the animal fat/sleep connection is cause and effect (animal fat –> better sleep), and suggests that the effect is not limited to me.

My self-experiment about this.

Saturated-Fat Epidemiology

Here, at Free the Animal, are three scatterplots that show better health (less heart disease, less stroke) correlated with more saturated fat (= animal fat) in the diet. Each point is a different European country (Albania, Bulgaria, etc.). Small and large countries show the same relationship.

The obvious confounding is with wealth — rich people eat more meat than poor people. Were this data submitted for publication, I imagine someone would say how dare you fail account for that! and reject the paper. That would be a mistake. Because it is hard to look at this data and continue to think that saturated fat is the evil it is made out to be. And of course whatever the weaknesses of my sleep/fat experiment (which showed animal fat improved my sleep), confounding with wealth was not one of them.

Dietary Fat and the Brain

Over the last six months I’ve come to believe that animal fat improves my sleep. Because sleep is controlled by the brain, this suggests animal fat may also improve other measures of brain function, just as omega-3 turned out to improve brain function in a wide range of ways. I didn’t know about a recent experiment done with airplane pilots that supports that idea. This was the design:

A total of 45 pilots (mean age, 20.8 years; 87% male) from the [University of North Dakota] commercial-aviation program were enrolled in this 14-week repeated-measures crossover trial.

During the first week, participants were randomized to receive 1 of 4 diets (3 full meals and 2 snacks) for 4 days: a diet high in carbohydrates, a diet high in fat, a diet high in protein, or a control diet. After a 2-week “phase-out” period, all pilots then randomly received a different study diet. This process was repeated until all pilots had received all 4 diets.

I haven’t been able to find out much about the high-fat diet. Here are some of the results:

The response time on the Sternberg test of short-term memory was significantly faster for participants who ate the high-fat diet (P < .05) than for those who ate the protein and control diets, especially at higher memory loads.

With sleep, however, the high-carb diet produced the best sleep.

Here is the abstract.

Thanks to Paul Sas.

Effect of Animal Fat on Sleep (more)

After the striking correlation I described earlier — I ate lot more animal fat than usual and slept longer and had more energy the next day — I started eating much more of what had produced the correlation: pork belly (which is used to make bacon). I couldn’t get uncured pork belly, so I ate bacon. I usually ate it raw. I tried several brands; the only one I liked was from Fatted Calf ($10/pound).

In Beijing I discovered pork belly for sale in every meat department. It is used to make a dish said to be Chairman Mao’s favorite. I bought a soup cooker, an appliance I haven’t seen in America, which made it easy to cook the pork belly. I seemed to sleep better when I had it for lunch.

Finally I did an experiment. I ate pork belly for lunch some days but not others. I ate the pork belly in miso soup, with vegetables. I always ate a whole package of pork belly, which was about 0.7 lb and perhaps 80% fat, 20% meat. On baseline days I ate my usual diet, which was already high-fat by people’s standards. (For example, I ate a lot of whole milk yogurt, a fair amount of nuts, and ordinary amounts of meat.) I tried to alternate baseline and pork-belly days but this wasn’t always possible.
Here are the results on ratings of how rested I felt when I awoke (100% = completely rested = the most rested I have ever felt, 0% = not rested at all).

The lines were fit separately to each set of points (red line to the red points, etc.). The difference is is very consistent (t = 5). Differences in how long I slept were much less clear. I will discuss them in a separate post.

The fascinating thing about this effect isn’t just how clear it is; it’s also how fast it goes on and off (within a day). With most nutrients you’d never see an effect like this. For example, scurvy takes months to develop and a few weeks to recover from. The omega-3 effects I’ve studied have a fast onset but take days to go away.

Sleep is controlled by the brain, of course. The brain is more than half fat, but determinations of how much fat the brain has have measured structural fat. This effect is so fast, both on and especially off, that it must involve circulating fat. Apparently my brain works better when there is a certain amount of animal fat in my blood. This supports Chairman Mao’s idea that pork belly is “brain food” but is a new idea for American intelligentsia. I think the chance that a nutrient that is good for one part of the body is bad for another part is zero — the same as the chance that the electrical appliances you own work best with widely-different currents. The obvious conclusion suggested by this data is that we need plenty of animal fat to be healthy. The only novel element of these lunches was the animal fat. Miso soup with ordinary meat has no effect on my sleep, as far as I know.

I think the science of nutrition proceeds in four steps, repeated over and over for each necessary nutrient: 1. Figure out that we need it. 2. Determine a way to measure how much of it we need. 3. Figure out the optimal amount. 4. Check your answer. With animal fat, conventional nutrition science hasn’t quite reached Step 1. Before this data, I’d say the clearest evidence that we need animal fat is that fat tastes good and long ago we had very little plant fat so it must have been the benefits of animal fat that produced the fat-tastes-good linkage. But conventional nutrition scientists never think this way — never take what we want to eat as meaning anything. And the mere fact that fat tastes good is no help figuring out how much is best.

This data pushes our knowledge toward Step 2. It doesn’t just suggest we need plenty of animal fat for best health, it also makes two methodological points: 1. Animal fat improves brain function. There may be better measures of the improvement than sleep quality. 2. The timing of the improvement — which as far as I know is unprecedented in the study of nutrition — makes it easy to measure.

Yesterday at a Carrefour I watched a pig being cut up. The butcher cut off the skin (with a thick layer of fat) and tossed it into a section of the display of pork for sale. I could buy the part of the pig I valued most for an incredibly low price (about 25 cents/pound). All other pork cost more. That’s how much Chinese shoppers wanted it. No one rushed to buy the newly-cut piece of skin. It reminded me of New York where I tried to buy food past its expiration date, ordinarily considered worthless.

Effect of Animal Fat on Sleep?

Recently I listened to Robert Spector discuss his book The Mom & Pop Store: How the Unsung Heros of the American Economy are Surviving and Thriving. He had a personal connection to the subject: His father was a butcher. “As I watched him trim the meat . . . ” he said at one point. I thought: Oh-oh. To “trim” meat is to cut fat off of it.

Last spring, I bought $80 of organic grass-raised pork from a farmer near Berkeley. My order included a variety of cuts.  I cooked the ones I was familiar with, leaving one I’d never seen before: pork belly. Pork belly is used to make bacon. I’ve never seen it for sale in America. Ugh, I thought. Fat. It’s 80-90% fat. I too trim the fat off meat. It sat in my freezer for a long time. Finally I decided I shouldn’t waste it. I cut it into chunks which I put in miso soup and had for lunch.

That night I slept much longer than usual (8.3 hr) and woke up feeling unusually well-rested. Here is a graph that shows my sleep duration for that night and several preceding nights:

2009-10-25 sleep duration and animal fat

Sleeping 8.3 hours was less common than this graph may suggest. I’d moved back to Berkeley in January and from then until the miso soup had measured how long I slept on 130 nights. I’d slept more than 8.3 hours on 2 of them (2%). Even rarer was how energetic I felt the day after the miso soup. I couldn’t quantify it, but it was very rare — once in 10 years?

Was it a coincidence — that on the very day I ate far more animal fat than usual I also slept much longer than usual and had much more energy than usual the next day? Or was it cause and effect? Here’s why the second explanation — which implies that for best health I need much more animal fat than I usually get — is plausible:

1. As Spector said, butchers cut the fat off meat. The odds that our Stone-Age ancestors, living when food was sometimes scarce, did the same thing: Zero. Perhaps our meat is unnaturally low in fat. If for a long time in our evolutionary past we ate a lot of animal fat it makes sense that our bodies would be shaped to work best with that much fat.

2. Many video games, which boys enjoy, resemble hunting. I think this reflects an evolutionary past in which men hunted. If so, for a long time humans ate meat. That they ate a lot of meat is suggested by the fact that when big game went extinct (probably due to hunting) human health got worse.

3. American culture demonizes animal fat. The conclusion that animal fat is bad rests on epidemiology. Once something becomes heavily recommended or discouraged, a big problem for epidemiologists arises: the people who follow the advice are likely to be different (e.g., more disciplined, better off) than those that don’t (the healthy-user bias). As I blogged yesterday, an example is vaccine effectiveness: Those who get vaccinated are different than those who don’t.

4. Fat tastes good. Which implies we need it. We like whipped cream, butter on toast, milk in tea, and so on. Butter vastly improves toast even with my nose clipped. Long ago, when this fat-pleasure connection evolved, dietary fat was mostly animal fat and fish oil.

All this makes it plausible that animal fat is good for us. That’s not surprising. Based on Weston Price’s observations plus these four arguments, I already believed this. Many people believe this. The interesting idea suggested by my data is the possibility of measuring its benefits quickly, by measuring brain function. My experience suggested that animal fat improves brain function quickly. Brain function is easier to measure than the functioning of other parts of the body. By measuring my sleep, my energy, or something else controlled by the brain, maybe I can figure out the optimal amount of animal fat. This is what happened with omega-3. The idea that omega-3 is good wasn’t new; the novelty was the ability to measure its benefits quickly. (At first I measured my balance, later other things controlled by the brain.) With a fast measure I could determine the optimal amount. It’s likely that what’s optimal for the brain is optimal for the rest of the body, just as all the electric appliances in your house work best with the same house current. If you figure out the best current for one appliance, you are probably simultaneously optimizing all of them.