Life, the Universe, and Everything

Book review: Nutrient Power: Heal Your Biochemistry and Heal Your Brain, by William J. Walsh.

Nutrient Power is an eccentric book about nutritional problems and their effects on the brain. It’s full of information that’s somewhat at odds with conventional wisdom.

It’s a short book, and I wasn’t tempted to read all of it. I usually don’t review books unless I’m willing to read the whole thing, yet this time I can’t resist the temptation.

I expect that it’s important reading if you’re building your own model of how nutrition affects cognition, you’re frustrated about how little you’ve found in peer-reviewed publications, and you’re interested enough to treat this as something closer to a career than a hobby. If, like me, you’re less ambitious than that, you should expect to find at least parts of the book frustrating. And if you just want easy-to-follow or rigorously proven advice, this is definitely not the book you want.

I’ll guess that a bit more than half of the unusual ideas are correct and valuable, and that less than 10% of the others are harmful. Don’t expect it to be easy to distinguish the good ideas from the bad.

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Some links to information sources that I’ve been using:

Food delivery is erratic in Berkeley. GoodEggs seems to have major food shortages, and maybe some labor shortages. Model Meals has been working almost as smoothly as normal, providing I place my order a day before their deadline – they are selling out of most things near their deadlines. I tried Instacart for the first time, and it seems substantially degraded by high demand – I had problems with getting 2 apples when I ordered 2 3-lb bags of apples (no that wasn’t listed as a substitution – the intentional substitutions worked fine). I’m guessing I’ll want to go back to shopping at grocery stores in person in a week or so. Infection rates are almost certainly dropping here now that the shelter-in-place rules have been around for a while, but it will likely be a week before much evidence confirms that.

I hiked in Briones Regional Park on Friday. I expect to see no more than 5 cars at the trailhead on a weekday; this time there were more than 30! People seemed unusually friendly. Most were making a decent effort to keep a 6 foot distance from me, but a few of the younger ones seemed to not care.

I think OPEC just collapsed, and nobody celebrated. I suppose the climate change implications might be a bit bad, but most effects will be pretty good.

Will auto sales be up or down a year from now? Loss of wealth will delay some purchases, and a fair number of existing drivers will drive less. But some people will switch from public transport to owning a car; others will switch from UberPool to UberX.

A modest number of maids will be replaced by Roombas [disclosure: I just bought stock in iRobot].

Politicians are talking about bailing out airlines, with terms that prevent them from stock buybacks. I expect that restriction to be purely symbolic – it will be a while before airlines are tempted to do buybacks anyway. If politicians were really upset about buybacks, they would instead deny the bailout to a single airline that was the most reckless in buybacks (maybe the one that achieved the worst debt to tangible equity ratio? I think that’s Delta). Alas, politicians won’t do that. After all, it might help people see that bailouts are somewhat targeted at helping bond and stock holders, and that the planes, workers, etc., don’t just vanish in the (somewhat unlikely) event that bankruptcy proceedings cause one company to shut down.

Some senators are under fire for insider trading on some sort of COVID-19 insights. If they profited from improved analysis of public information, I think that’s great! I’d like them to have an incentive to listen to experts. It would be suspicious if they profited from secret data, but I can’t find much reason to think that’s what happened – as far as I can tell, the relevant evidence was made public fairly quickly, and what mattered was competent evaluation of that evidence. And the most important question is what else they did to prepare. If, as the news storytellers vaguely imply, they did little else to warn people, then either they were more confused than the reports suggest, or they were recklessly negligent.

Shutting borders can hurt:

One issue has been restrictions on travel intended to stem the spread of coronavirus, which has affected [U.S. ventilator maker] ResMed’s Singapore factory which employs many workers from neighbouring Malaysia. He said ResMed has appealed to the Malaysian government for an exemption so its workers can travel to Singapore.

Biomerica has a new COVID-19 test with some apparently nice features that differ from the common PCR-based tests. However:

Biomerica is positioned to begin filling large international orders of this disposable one-use tests within weeks, assuming international product shipping channels remain open and active.

In addition, Biomerica has begun the application process with the FDA under the COVID-19 Emergency Use Authorization (EUA), aimed at the possible clearance and eventual use of the test in the US. At this time, the product is not available for sale or use in the US.

And finally, some related entertainment about flattening the curve of armchair epidemiology.

I’ve been using an Oura sleep tracking ring for six months.

In some ways it’s an impressive piece of technology. It’s small enough to not distract me much, and they went overboard in making the user interface simple. Simple, as in there basically aren’t any controls. I just put it on my finger, and occasionally put it on the charger.

Yet it does a poor job of what I expected it to do: track how long I sleep. It occasionally thinks I’m in bed when I’m not wearing it. If I get up to use the bathroom, it’s hard to predict whether it will decide that’s the start or end of my time in bed.

But the Oura reminded me that “8 hours of sleep” isn’t a good description of what I want – that’s just a crude heuristic for “slept well enough that further sleep won’t improve my productivity / health”. The Oura observes other relevant evidence: body temperature, breathing rate, heart rate, and heart rate variability. I.e. things I ignored because they were too hard to evaluate, rather than because I decided they weren’t important.

If I did a strenuous hike yesterday, it will tell me that 7.5 hours of sleep wasn’t enough, whereas if I’d spent yesterday relaxing, it might have told me that 7 hours was plenty, and that I should be ambitious.

It’s somewhat obvious that I need more sleep when a cold raises my body temperature. The Oura convinced me that there’s a much more general pattern of above average body temperature indicating an increased need for sleep.

I’ve tried comparing the Oura’s heart rate variability measurements with those of the emWave2, and I couldn’t see much correlation. I’m inclined to trust the emWave2 more, but I’m not aware of good evidence on the subject.

The Oura also helps track exercise, at least for hiking (it doesn’t seem to do much for weightlifting, but most of my exercise comes from walking/hiking). It reports slightly less calories burned than what I calculate from a cheap Garmin GPS and this calculator. I’m unsure which of those 2 measures is more accurate. If I were only using the GPS to measure calories burned, I’d give up on the GPS, because the Oura doesn’t have problems such as poor reception, or me forgetting to turn it on or off at the start and end of a hike.

It said I slept 3 hours on a red eye flight. My subjective impression was that it was somewhat debatable whether any of that ought to be classified as sleep. But what do I know? I have some evidence that I can sleep without being aware of sleeping (mainly from people reporting that I was snoring, at a time when I thought I was awake and not snoring).

My ring isn’t quite the right size for my ring finger. I ordered it based on prior information about what ring size worked for me, rather than using Oura’s measuring procedure. I’ve ended up wearing on the middle segment of my middle finger instead. That’s works well enough that the difference seems unimportant.

See this comparison with several alternatives for a more detailed analysis.

Mostly, the Oura simply reassured me that I don’t have significant sleep problems, other than the times when it’s obvious that I took too long to fall asleep, or woke up too early. I suspect that the Oura would have been moderately valuable if I had had sleep problems that were hard for me to detect.

Book review: Move Your DNA: Restore Your Health Through Natural Movement, by Katy Bowman.

Move Your DNA does for physical activity what paleo diet advice does for food.

The book is full of suggested movements to practice, making it look somewhat like a yoga book.

Bowman criticizes the common notion of exercise, because it leads to people repeating a tiny set of motions.

Most of us wouldn’t imagine that we had a healthy diet if we ate nothing but carrots, or nothing but liver, even though eating more of those is usually a good idea. Yet plenty of people seem to imagine that they can offset the risks of spending 60 hours per week in chairs by running for a few hours on a carefully maintained surface, repeating a single type of motion with no variation.

A healthier lifestyle would include a wide variety of motion, ideally motivated by the need to accomplish a wide variety of tasks such as carrying wood, digging, pounding nuts, and walking on terrain with lots of little irregularities (she calls this cross-terraining).

How much does it matter? Bowman provides surprising hints, and good theoretical reasons for concern, but leaves me with a good deal of uncertainty about the magnitude of the harm.

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Convenient, affordable blood tests seem to be important tools for improving health. See my review of The End of Alzheimer’s for hints about why they’re important.

Talking20 and Theranos raised some hopes, then they failed.

Now comes Baze. They shipped me a device that I pressed against my arm. I waited a few minutes, took it off, and shipped it back. I was a bit uncertain about my ability to read the light that changed color to indicate the device had collected enough blood, but I seem to have gotten it right.

Half the time that it took to complete my test involved walking to the nearest FedEx drop box, which is a good deal closer than the nearest LabCorp or Kaiser lab. I had no need to worry about unpredictable delays waiting for a technician to be available to extract my blood.

I got 10 nutrient levels tested for a sale price of about $50. Many of those tests aren’t available on, and the ones that are available are around $50 per nutrient. Life Extension has more of the tests, including Selenium (list price $88, but I normally wait for their spring sale), and Omega-3: $79 for a test that requires me to extract blood from my finger on my own. I had trouble getting enough blood that way, and never got a result, presumably because I didn’t do it well enough. So if I tried to test those 10 nutrients without Baze, I’d have paid maybe $500 and only gotten 7 or 8 results.

Are Baze’s results accurate? I’ve been tested for several of the nutrients previously, and the Baze results for those are similar enough to be reassuring. Their technology seems to have a decent pedigree.

So far, it sounds almost too good to be true. Is there a catch? Maybe. Baze does have a business model that makes me a bit nervous.

Baze is part of Nature’s Way, and tests nutrients in part in order to sell us vitamins in order to correct any deficiencies that it detects.

That does bias Baze away from providing the tests that are most valuable for influencing health-related decisions.

It also biases Baze toward recommending more supplements than is optimal. I don’t see any clear signs that they’re erring in that direction. I also see a distinct shortage of strong arguments in favor of their recommendations.

For vitamin D, they classified my level of 58.3 as excessive, when it’s only about 10% above the level I was aiming for, and there are many people advocating higher levels. That’s a clear sign that they’re not pushing too many vitamins on us.

Yet for choline and omega-3, they classified my blood levels as optimal, yet are still sending me those supplements. There’s at very least something wrong with their explanation here. Yet in both cases, I see some plausible arguments from independent sources that my levels are a bit below ideal, and I had been mildly concerned that I wasn’t consuming enough.

Maybe they’ve got a good explanation hiding somewhere on their blog, but the easy-to-navigate parts of their website are written more for people who want simple and convenient answers from a respected authority. Something feels wrong with their attempt to act like such an authority without providing more evidence of competence than I’ve seen.

They’re also sending me vitamin E and magnesium. I’m pretty confident that I’m consuming a bit more than the RDA for both of those, yet my test results say I’m a bit low in both.

I’m concluding that they have not yet given into the temptation to sell too many vitamins, but they’re putting little effort into reassuring me about this.

Their choice of which tests to do reassured me a bit. They test B12 via methylmalonic acid rather than the less sensitive direct test, and they avoid some nutrients that are more risky to supplement (iron, B6, A, calcium).

Potassium is an important nutrient that many people don’t get enough of. Baze doesn’t do anything with potassium, because potassium supplements are heavily regulated, and because low potassium levels can have causes that ought to be treated by doctors.

Fiber is another important nutrient that many people eat too little of. But that’s rather tricky to evaluate via a blood test – insulin resistance measures say something relevant, but it’s hard to quantify the connection, and doing so might raise novel regulatory issues.

With pretty much all of the nutrients that Baze sells, the evidence for benefits from supplementing is underwhelming, resting mainly on correlations. Where I’ve seen RCTs that test supplementing, only vitamin D seems to show a clear benefit.

I hope Baze focuses more on increasing the variety of biomarkers that it tests for, and less on selling vitamins. I would like to use them for more testing, but not for getting more vitamins. Optimizing our vitamin pill consumption is far from the most valuable goal that this new technology can accomplish.

I suppose the more valuable uses of the technology work best with a fair amount of doctor involvement, and the medical system changes slowly enough that Baze might have needed to introduce the less valuable uses first.

Baze seems good enough now that most people with below-average health (that includes most people over 60) will get a bit of benefit from Baze.

Warning: they report results in different units than I’m used to, so I needed to look up several conversion factors to compare my Baze results to my prior results.

Book review: The Paleo Cure, by Chris Kresser.

I wish I had read this when I went paleo 7 years ago. It’s more balanced than the sources I used. Alas, it was published shortly after I finished a big spurt of learning on the subject.

It still has a modest number of ideas that seem new to me, and many ideas that I’d have liked to have known when the book was first published, but which I found through less organized sources.

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I’ve mentioned Blue Zones approvingly several times on this blog (here, here, and here).

Alas, there are reasons to doubt that they’re unusually healthy. The paper Supercentenarians and the oldest-old are concentrated into regions with no birth certificates and short lifespans makes a decent case that they’re mostly just areas where ages have been overstated. There are some relatively unhelpful arguments about who’s right on Andrew Gelman’s blog and on

As a consequence, I’m slightly decreasing my opinion of some foods that I was encouraged to eat by the Blue Zone memes: whole grains, beans, olive oil, and sweet potatoes. Sweet potatoes still seem likely to be quite healthy compared to the average American food, but I’m now uncertain whether they’re better or worse than the average paleo food (I previously considered them one of the best foods available). The rest of those foods seem no worse than the average American food, but I’m less optimistic about the safety of the average American food than I previously was.

I’ve also become less confident in the safety of a diet with less than 10% of calories from protein (Blue Zone Okinawans in 1949 got 9% of calories from protein), but I’d already decided not to pursue a low protein diet.

I’ve slightly decreased my opinion of Steven Gundry and Valter Longo

H/T William Eden.

Book review: The Good Gut: Taking Control of Your Weight, Your Mood, and Your Long-term Health, by Justin Sonnenburg and Erica Sonnenburg.

I had hoped this book would help me improve my gut health. Alas, their advice is of limited value, mostly focusing on changes that I’d already adopted based on other types of nutritional ideas, such as eating more fiber from diverse sources. That limited value is probably due mostly to the shortage of useful research on this subject, rather than to any failing of the authors. Research on these topics seems hard due to the complexity of the microbiome, and the large variation between people.

The book convinced me to eat more kimchi, and left me wondering whether to try consuming more bacteria in pill form.

The book repeats warnings that I’d read elsewhere about the dangers of antibiotics, and the problems that arise from having an insufficiently diverse microbiome, such as autoimmune diseases.

I have been placing heavy emphasis on fiber in my nutritional strategies, while having a gut feeling that the concept of fiber left something to be desired. The book pointed me to an alternative concept: microbiota accessible carbohydrates (MACs), which mostly means carbs that aren’t absorbed by the small intestine. A diverse set of MACs feeds a diverse set of microbiota, which at least correlates with good health.

Alas, it seems impossible to reliably measure MACs by analyzing food in isolation – different people’s small intestines absorb different substances. There are also complications such as erythritol, which is mostly absorbed in the small intestine (and is then removed without doing much), but about 10% of which ends up feeding microbiota in the colon. So I’m still stuck with estimating my MAC consumption via the standard fiber estimates, and taking care to get it from diverse sources.

The Sonnenburgs explain that food preparation affects absorption. Flour is absorbed faster than less-processed grain, and the meaning of “flour” has changed over the past century or so, from something that was ground coarsely and eaten soon after, to something that is ground very fine, and stays on a shelf long enough to go rancid if it is whole-grain flour. That nudged me toward a more nuanced position on grains. The “grains are not food” rule was a simple way to improve my diet, but there are clearly big differences between the best whole grains and the worst grain-derived products.

It also helps me understand how grains, as typically used, gradually morphed into mostly being junk food without an easy way to detect the worst effects. More sophisticated machines to grind the grains led to a texture that was more quickly absorbed, leaving less for microbiota. The switch away from whole grain flour was likely, in part, a gradual adaptation to a system where the flour was ground at an increasingly distance from the home, and became more likely to go rancid if the germ wasn’t discarded.

The book has a section on how infants get a microbiome, which explains why it’s really hard to find or create a good substitute for human milk.

The Sonnenburgs have unusual heuristics about when they wash their hands, designed to reduce pathogens while welcoming good bacteria. They avoid washing after gardening or petting the family dog, but are careful to wash after going to places where they could get germs from many other people – malls, petting zoos, etc.

I’m discouraged by the news that microbiome treatments such as Fecal Microbiota Transplantation (FMT) may be regulated as drugs. It seems like regulations should be modeled somewhat more closely on food, or blood transfusion, regulation. Like food, FMT should have broader goals than just combating specific diseases, should provide diverse inputs, and should bear some resemblance to what naturally enters our bodies. Like blood transfusions, FMT should be reasonably safe unless there’s something unusual about the donor.

The book’s advice overlaps a lot with paleo-like advice to go back to how our ancestors ate, played, etc., with a rather balanced approach to borrowing from our grandparents’ lifestyle versus borrowing from hunter-gatherer lifestyles. The book is solid, often at the expense of being exciting.

Food Tidbits


Most fruits have been genetically engineered (via selective breeding, not via the methods that people have been complaining about) to have more sugar relative to fiber than wild fruit. So I seek fruits that have been neglected by agriculture and have nutrient levels that are more like the fruit that our ancestors ate … hmm, I’m probably oversimplifying dangerously there. I suspect there are a number of wild fruits that aren’t especially nutritious, but my heuristic of getting more wild-caught fruit is at least slightly healthier than eating exclusively factory-farmed fruit.

I’m currently trying to get a paleo level of fiber using the heuristics that good food should have at least 25% of its carbs as fiber, and more than 50g of fiber per 2000 calories.

Saskatoon berries (sometimes known as serviceberry, shadberry, or juneberry) are my favorite fruit.

I’ve seen some highly conflicting reports about their nutritional value, but the most reliable-looking version says 140 grams of fiber per 2000 calories (32% of total carbs). The most convenient way to get saskatoon berries is in pie filling that has too much added sugar, but still has around 67g of fiber per 2000 calories.

I recommend adding generous amounts of nutmeg and cinnamon, and a few walnuts, and eating without any further preparation.

Baobab fruit has about 320g of fiber per 2000 calories (64% of carbs come from fiber!). I find the taste to be slightly less pleasant than that of a typical fruit, so I mostly use baobab powder as somewhere in between food and medicine, and also eat various baobab bites from (alas, those contain fruit juice that dilutes their nutritional value a lot).

The Hadza get 7-15% of calories from baobab, and get little western disease.

Fruits that are less healthy, but have interesting taste:

Freeze dried durian

Freeze dried mangosteen

Freeze dried dragonfruit

A fruit that breaks my category system:
Avocados have a well rounded set of nutrients, and Trader Joe’s Avocado’s Number Guacamole is almost pure avocado, and more convenient than whole avocados.


Taro root:
if you shop at a grocery store that caters to asian customers, you should be able to buy taro roots that weigh several pounds, for a dollar a pound. It has more nutrition per pound (or dollar) than most other starchy roots, although not as much nutrition per calorie as sweet potatoes (I presume you already know that sweet potatoes are a good source of nutrition).

I just slice off a piece, microwave it, and add salt/potassium chloride. I find it especially valuable for feeling full/getting plenty of fiber on days when I’m doing protein fasts, as it’s unusually low in protein.

Nomato sauce:
is made primarily from carrots and beets. It’s mainly a tomato sauce substitute for those who are allergic to tomato. It’s likely a bit healthier than tomato sauce, but if you’re currently satisfied with tomato sauce, then nomato sauce is likely not tasty enough to get you to switch (but it’s fairly close to being that tasty). I use it for paleo-friendly versions of pizza (crust: shredded carrot, egg, olive oil, and various flours) and spaghetti (with sweet potato noodles).


I use a variety of flours in baking that are generally healthier than grain-based flours:

  • Almond
  • Arrowroot
  • Baobab
  • Cassava
  • Chestnut
  • Coconut
  • Cricket
  • Garbanzo
  • Green Banana
  • Green Pea
  • Potato
  • Sweet Potato
  • Tigernut


Baru nuts:
interesting, and backed by some trendy sounding hype. I don’t know whether there’s any reason to prefer them to other nuts. I eat a modest amount, for variety.

I’ve moderated my anti-grain stance a bit, and now cook millet occasionally. It’s got the nutritional features of a whole grain, and tastes more like a refined grain.

Popped sorghum:
like popcorn, but with more fiber and other nutrients.

yet another legume, that isn’t particularly remarkable compared to familiar legumes. It’s a bit like a lima bean or soybean. Brami sells a lightly fermented version that’s a bit more convenient than a typical bean, and fermenting likely adds some nutritional value.

For canned beans, I recommend Eden Foods, since they’re soaked overnight and pressure cooked, eliminating some possibly harmful lectins.

Milked Almonds:
like almond milk, but with a higher nut to water ratio, and minus the vitamins/minerals that get added to almond milk in order to make its nutritional profile more infant-oriented.

Processed foods

Not whole foods, but likely still fairly healthy:

Pegan thin bars, chocolate lava:
Each of these bars has a whopping 26 g of fiber. It probably a good omega-6/omega-3 ratio, but I can’t find good evidence about that – it uses de-fatted Sacha Inchi seeds, which have a great percentage of omega-3 in any fat that remains, but I don’t see any info about whether the de-fatting leaves much fat compared to the poorer sunflower oil that they add.

Perfect Keto Bars – fiber, and plenty of collagen from grass-fed cows:
if you get most of you protein from animals, you likely have a poor glycine to methionine ratio. If you eat lots of milk or eggs (Mealsquares?), that ratio is even more likely to be poor. It only takes a little collagen to fix that ratio. (The Pegan thin bars also have a good glycine to methionine ratio).

Swerve or pure erythritol:
fairly natural ways to sweeten foods while adding almost no digestible calories. It’s hard to know whether these are as safe as not using sweeteners. They taste fairly similar to regular sugar, maybe cause mild digestive problems in some people, and work in some but not all baked goods.

Potassium chloride:
Most people should be getting more potassium relative to sodium (with important exceptions for people who take some trendy(?) drugs). Regulations restrict many convenient ways to do this, but it’s pretty easy to replace table salt with potassium chloride salt.

Green mussel pills:
if you want something healthier than a vegan diet without causing animals to suffer, but don’t like oysters, green mussel pills seem convenient.

Liver pills (from grass fed beef):
a relatively natural way to get some B12, B2 (riboflavin) and folate.

Wink Frozen Deserts:
taste a bit like ice cream, but have almost no calories. They’re mostly water, with some inulin and pea protein.


I bought a scale that weighs food to the nearest gram for my alternate day calorie restriction diet, and that has been better than measuring by volume for a variety of cooking tasks.

Finally, one food that I likely won’t get around to trying: Hákarl (aka rotten shark). It apparently takes months to make it non-poisonous. How did someone have the patience to discover that process?