Pseudoscience about glutathione and nitrate

Glutathione, and other supplements purported to boost our bodies’ ability to make more of it, are touted in the March 2018 issue of the flier from Natural Grocers, here in Las Cruces.  It’s another case of looking for a magic bullet for health.  Actually, they propose a fusillade of magic bullets – turmeric, a raft of vitamins, and more.

Let’s look at glutathione, a known antioxidant, and the claims made by Natural Grocers.  First, they say that glutathione is the most abundant single molecule in our bodies, after water.  Not so!

  • Glutathione: it’s a soluble peptide (simply, three amino acids, linked together).  Its concentration averages about 2.5 mM in cells, higher in liver, lower in other tissues; here, “mM” stands for “millimolar,” thousandths of a mole per liter of solution.  For glutathione  a mole is comprised of 307 grams.  How many moles does that indicate are in our bodies (variably by our size and genetics, etc.)?  Well, a 70 kg person at 70% water contains about 50 liters.  Multiply that by 0.0025 moles per liter and you get 0.125 moles, or about 38 grams.  Now for comparisons to more abundant molecules:
  • Cholesterol:  it’s vitally important in every tissue, especially in the brain, as a component of the membranes in every cell.  I talked about this on my radio show published on YouTube (first and second segments on 19 December 2017).  Consider the brain, alone.  The fresh mass of the brain is about 1.3 kg, and 2.5% of that is cholesterol, or about 32 g.  The brain holds 1/5 of the cholesterol in the body, so the body’s total is about 160 g.  That’s more than four times the mass of glutathione.  It’s also more molecules; the molecular mass of cholesterol is 387 g per mol, so the body contains about 0.42 mol of cholesterol.
  • ATP, adenosine triphosphate, the energy currency of the body.  There’s about 0.2 mol of ATP in the average human body, which is about 100 g, nearly three times as much as glutathione.  Note that we use up and regenerate each ATP molecule about 200 times each day!  Lot’s of energy trading.
  • Myoglobin, the oxygen-storage protein in muscle: It’s about 2.5% of dry muscle mass.  Dry muscle mass is about 30% of fresh muscle mass.  Fresh muscle mass is about 42% of the body in a fit person, or about 29 kg.  Thus, dry muscle mass is about 8.7 kg, and myoglobin is about 220 g, or 0.012 mol.  The mass is about 6 times greater than that of glutathione.
  • The myosin heavy chain, a protein that’s a  major component of muscle, is about 1/6 of dry muscle mass, or about 5 kg or 0.3 mol.  That’s over 130 times the mass of glutathione.
  • Collagen, a mixed protein, is about 25% of dry muscle mass, or about 7 kg.  That’s about 180  times more than glutathione. Collagen holds us together, as it functions also in other mammals; it’s the tough sinews and membranes, familiar to hunters as also to anyone who cuts up chicken for dinner.


    Glutathione is important as an antioxidant.  It’s not as abundant as Natural Grocers would have us believe.  It’s also a compound we can and do make naturally in our own bodies, with any normal or even near-normal diet.  Remember, taking hominids as starting 2 million years ago, we survived at least 100,000 generations without supplements in pills.  Sure, our ancestors died much at much younger ages than do most of us, but it was very, very rarely from just lacking glutathione; big predators, infectious diseases, and simple broken bones that hampered both escape and foraging were among the causes.  They didn’t die looking for a Natural Grocers store.

    Natural Grocers recommends that you eat lots of the brassicaceous vegetables – kale, broccoli, cauliflower, brussel sprouts, cabbage, kohlrabi.  Problem: these foods contain abundant goitrogens that interfere with iodine uptake by your thyroid gland.  You can get hypothyroidism!  People have been getting hypothyroidism on eating lots of kale.  Check out a reliable book that covers diet and nutrients, such as the eminently readable On Food and Cooking, by Harold McGee.

That March 2018 issue of Natural Grocers’ sales flier also pushed eating vegetable high in nitrate.  What a twist.  Knowledgeable food experts have warned for years about the dangers of high nitrate levels, which can cause methemoglobinemia, a condition in which the iron atom in the center of the hemoglobin molecule in your red blood cells oxidized to the ferric state, which has low affinity for oxygen.  Eat red beets, turn blue?  Not really, unless you eat a lot of beets.  Note also that high nitrate in vegetables is generally a result of overuse of chemical fertilizers (nitrate itself, or ammonia that gets oxidized to nitrate in the soil), and beets (and lettuce, …) are particularly good at taking up nitrate while not reducing it to biochemically useful ammonia internally.   I’ve done a significant amount of research on the cycling of nitrogen in various forms around the globe, where the ability of different kinds of plants to reduce nitrate to ammonia that usable by the plant (e.g., to make proteins), is a rich and diverse subject. Sure, nitrate is one source for our bodies to make nitric oxide, the molecule critical for signaling among organs – in really small amounts.  Nitric oxide in large enough amounts is toxic, particularly to infants; it’s a free radical, having an unpaired electron ready to make bonds with, well, almost anything, which is not good.

You can also damage yourself with excess vitamins A, D, and B12, or even die, as a British food faddist did recently by overdosing on vitamin A (extreme liver damage).  Excess vitamin C is harmless; you just excrete the excess (and the dollars it represents).

A little knowledge is a dangerous thing. — Attributed to various commentators

Education: that which discloses to the wise and hides from the foolish how little they know. — attributed in various forms to Mark Twain

Subjective time: does time seem faster as we get older?

Here’s a simple (simplistic?) argument that we experience time in logarithmic fashion.

Intro: When we were young, it seemed to take ages to get older – to the next grade in school, to the next stop on a long drive, to wait till Christmas or another holiday.  There are so many cliches about the change in the experience of time as we get older.

The math, with a few graphs: follow this link

Adventures in light propagation – teaching and research

This multilayered post can be followed from one PDF document, or by the explicit links given below in the description of the whole study.  The post covers:

  • Teaching:
    • Working with students to make a light intensity detector using a photodiode.  It measures photon flux density in the visible portion of the electromagnetic spectrum.
    • We went on to use it as the detector in a (spectro)photometer for measuring the concentration of methylene blue dye illuminated with light from a high-intensity yellow LED.
  • Research:
    • The main point I just completed writing up is the use of radiative transport equations that I developed for estimating scattered light within a uniform canopy of plants.    The solutions for the fluxes of a direct beam and diffuse light together are analytic, in term of algebraic and exponential quantities.
    • The model also is useful for simulating the propagation of light inside leaves for modeling photosynthetic rates of leaves with different structures and pigmentations.  I have a number of publications on this (which I can link later, when I find PDFs of them.  One interesting prediction I made is that leaves with half-normal chlorophyll content should allow sharing of light with leaves deeper in a dense canopy, ultimately giving an 8% increase in biomass and yield.  John Hesketh’s group at the University of Illinois tested this in the field and got an 8% increase over fully green leaves! (Pettigrew WT, Hesketh JD, Peters DB, et al. (1989) Characterization of canopy photosynthesis of chlorophyll-deficient soybean isolines. Crop Science 29:1025-1029).
    • Recently (Nov.-Dec 2017) I extended it to multiple layers of different optical properties.  The challenge was testing it rigorously and making a comprehensive explanation with text and equations.

Back toward teaching: I wanted to verify that the photodiode circuit responded linearly to flux density.  I made a simple error in using layer scattering media too close to the detector, invalidating Beers’ law for the direct beam alone.  However, I then dove into the propagation of direct and diffuse light for its inherent interest.

The lead PDF document here has several sections:

  • The most recent inquiry: is the photodiode responding linearly to photon flux density?
  • The radiative transport equations
  • A few notes about extensions to nonuniform canopies

Within the lead document are links to several others.  The links are imbedded within the lead document; the links are also noted directly here:

  • A short write-up of the electronic circuit for the photodiode detector
  • Fixing-approximations.pdf:” A set of notes on improving a whole-canopy flux model (light, CO2 uptake and respiration, transpiration) in the representation of:
    • The enzymatic model of photosynthetic carbon fixation, bridging the cases of high light and low light
    • The equations for radiative transport, with their full derivation and some numerical results
    • A discussion of extensions of the model for leaves varying in absorptivity with depth in the canopy, or that are clumped, or that vary in temperature as they transpire water at different rates
    • In turn, this PDF references a short Fortran 90 program I wrote to solve the radiative transport equations
    • Also, a link to a 2013 publication I had with Zhuping Sheng, modeling all the fluxes of a pecan orchard.  The relevance is that I cited in this second PDF the modeling of light in a regular array of tilted, ellipsoidal canopies of individual trees.  Sheng did the experimental measurement of fluxes with eddy covariance equipment. I modeled the results, with one surprising finding that pecan trees, unlike every other plant I’ve studied, do not reduce its stomatal conductance and thus its transpiration in very dry conditions.  They operate at high transpiration rates and poor water-use efficiency in these conditions.
    • A couple of references to publications:
      • A model of radiative transport in layered plant canopies represented by finite layers (a finite-element model), as an integral equation that’s readily solved numerically.   I cite this publication because within it I discuss the changing angular distribution of diffuse light with depth.
      • The clever method of colleague and friend Michael Chelle and his former advisor Bruno Andrieu for radiative transport in an arbitrary assemblage of light-scatters.  The method is called nested radiosity, accounting essentially exactly for nearby scatterers affecting light at a given leaf and then via a nice smoothing approximation (mean field) for more distant scatterers.


Radio show, Science: let’s take a look

Science: let’s take a look, on radio KTAL LP FM, Las Cruces, New Mexico:

I host an hour-long show each Tuesday at 12-1 PM, Mountain Time.  Find it at 101.5 on the FM dial if you’re in Las Cruces, or stream it live on or

I cover a great variety of topics in all the shows,, extending from many branches of science to engineering to math to implications for society.  Guests appear about every other show.

I record each show, edit the audio into distinct segments (cutting it at station breaks), add some imagery, and created videos for YouTube.

Here are links:

Coming up:

  • Have you thanked a bacterium today?
  • Proxima Centauri b: not really habitable; how ’bout keeping Earth habitable?
  • Carbon nanontubes: useful; don’t inhale!
  • How far is it worth driving for cheaper gas? Some algebra
  • Many more guests from near and, I hope, far (scientific colleagues calling in)

Star Talk, with Neil deGrasse Tyson

Neil deGrasse Tyson is one of my favorite persons.  I imagine myself at times traveling with him, John Oliver, and Bill Bryson.  Still, we all put out some stuff that needs comments or corrections.  I just went through Star Talk with Neil deGrasse Tyson, Abridged Edition (National Geographic, 2016).  He had co-authors and editors, so I don’t know who wrote or edited individual items, but here are my notes:

p. 56, about life possibly originating on Mars and being transported to Earth on tektites blasted off the Martian surface by an impactor. Others have proposed this, too. Several ideas militate against this.  First, as Neil (may I use his first name?) admits, live organisms surviving the intense heat and shock of both exiting Mars and landing on Earth is extremely problematic.  Second, the idea that Mars was warm and wet before Earth has less and less support.  The evidence for water on Mars is, well, evaporating in favor of sand having sculpted features.  Third, the whole idea violates Occam’s Razor, which is that the simplest explanation is favored over all complex ones, in the absence of strong evidence to the contrary.

p. 57, that life needs a steady heat source, water, and a critical set of chemicals. This is wholly inadequate. I outline what keeps Earth friendly to life in another essay.  The most egregious error here is the claim that life can use heat, not just to keep water liquid, but as an energy source.  No!  Organisms have to perform biochemical reactions of high energy, several electron-volts’ worth in common terminology (e.g., 1.8 eV for photosynthesis).  Thermal sources in the physiological temperature range are far, far too low in energy, only several percent as large.  The “tail” of the energy distribution, in the eV range, is vanishingly small for thermal sources.  Some physical chemistry or chemical physics needs to be accounted here.

p. 96, about heavy water (D2O) not being toxic, only slowing a host of biochemical reactions. Sure, the isotope effect on chemical reactions is well understood (the zero-point energy of chemical bonds with heavier atoms is lower, making more energy needed to break bonds for chemical reactions), and the effect on rates is rather modest, in most cases. However, animals from flatworms to mammals die when a large fraction of their ordinary protium (hydrogen) is replaced by deuterium.  In mammals, bone marrow and intestinal functions are changed, lethally.  Humans have only been exposed to minor amounts of D2O and then survived.

p. 97, a positive note from me: the profligacy of making and disposing of plastic bottles, especially for water. I may add that tap water is purer than many bottled waters, as analyses have shown! Bottled water is, by and large, a tax on ignorance.  I did verify the calculations about barrels of oil used and number of cars that could be fueled.

p. 99, on water consumed for electric power generation: The only water mentioned her is the steam in the turbines….but water in the turbines is consumed very infrequently; mostly, it’s recirculated, unlike that in old steam locomotives. The major use of water in electric power generation in thermal power plants (still our biggest source, vs. photovoltaics and wind turbines and hydropower) is in cooling the recirculating water. I have an essay on that, in which I also debunk the idea that 40% of our water supply is consumed in power plants.  There are two types of cooling using water – towers that vent evaporating water, which are true water consumers, and once-through flow of water with rejection of warmed water to streams and other bodies of water.  The warmed water evaporates more than in its original, cooler state, but only to the extent of about 8% of the passed-through water or 3% or so of total water use.  We should publish more accurate accounting about power generation.

p. 116, on planting more trees to take up (sequester) carbon from the air and reduce climate change from the business-as-usual scenario (which is horrifying!). The author of this text points out some caveats, about losing competing plants and inviting more diseases and pests in big monocultures. A bigger issue, for me, is water use.  Plants transpire (lose) several hundred molecules of water for each molecule of CO2 taken up…and that’s inflated by the need to maintain tissues and regrow some tissues.  One must also consider that most plant biomass decomposes back to CO2 and other products unless it gets buried well or charred – that’s a lot of work.  Another caveat is that standing biomass, not buried, that we might grow adds up to only about 2 years of CO2 emissions, ever – I’m grateful to Rob Jackson, now at Stanford, for the quantification.  The author(s) of this page rightly point out that more trees is only one part of the solution to climate change, one “wedge.”

p. 117, showing an electric car with a photovoltaic panel on the roof. This is misleading about how much PV area we need, for cars or any other power usage. Covering, say, half the top area of a car with modern panels, about 6 square meters, would provide around 1.2 kW at peak or around 8 kWh over a clear day, maybe 1600 kWh over a year with average weather.  A typical small car used for 15,000 miles of driving a year.  At the normal mix of speeds, it might run at 20 hp or 15 kW for 400 hours to cover those 15,000 miles.  That means it uses 6000 kWh.  Panels on cars don’t make it.

p. 128, bottom, about most oil having come from (decomposed and heat-processed) vegetation. Let’s say that most of it came from plankton in water bodies, especially oceans. Modern taxonomy has these organisms very distinct from vegetation, taken as meaning green higher plants.

p. 129, Elon Musk’s quote about digital intelligence taking over. Musk is a smart person, but his scenario doesn’t ring true to me. Sure, AI and robotics are increasingly used to replace humans for economic reasons and with great economic consequences for humans.  However, live organisms make themselves, remake themselves constantly (we turn over all the elements in our body over our lifetime, some of them frequently).  Robots would need supplies of metals, the refining of semiconductor elements (silicon, e.g.), the ability to put together economic systems, and much more.  I’m worried about corporate and governmental use of AI and robotics, not autonomous self-reproducing robots.

p. 130, on cyanobacteria producing free oxygen as an atmospheric poison to other existing life forms 2.2 billion years ago, all anaerobes poorly tolerating oxygen of finding it lethal. The biggest part of the threat that cyanobacteria and their O2 production posed to other life forms was creating Snowball Earth. The oxygen oxidized methane that massively dominated over CO2 in the early atmosphere.  This severely reduced the methane greenhouse effect, which is more potent that the greenhouse effect from an equivalent amount of CO2.  At that time in Earth’s history, the Sun’s output was as low as 70% of current levels; only a methane greenhouse effect kept the Earth warm enough to be largely ice-free.  When the methane got oxidized, the Earth’s surface froze over almost entirely, as shown by many pieces of evidence, including drop stones from glaciers being found all over the Earth at that time, now buried for “reading” in sedimentary rocks of that age.

Did free oxygen accumulate in high-enough concentration to be itself a threat to other, anaerobic life forms?  I wasn’t there, but here’s a hypothesis, that O2 reached moderate concentrations only locally.  There were many geographic niches by depth and lat/long for anaerobes.  In general, O2 levels remained very, very low, because there were many other “users” of oxygen that scarfed it up even at those low levels.  I’d point to the ferrous iron that was in the then-green oceans and that precipitated out in highly insoluble ferric iron compounds as it got oxidized.  It formed the red bands that ae so thick and so striking – visit the Grand Canyon to see them.  Methane itself was another “sink” for O2, though one has to guess how it reacted at low levels of O2; catalytic sites might have helped.

p. 131, on solar flares threatening operations in our modern civilization. I’d elaborate on this. Taking out the electric grid in the US for more than several months would cause massive death.  Most people live in cities far from farms; little food would be reaching them with transportation stymied by a low level of fuel-pumping capacity for vehicles, plus a near absence of financial transaction capacity, and more.  The same factors affect the ability to grow food on farms, where much fossil fuel and electricity is used.  Severe fuel shortages also would prevent most people from migrating to food sources.  And so on.  Keep that electric grid up!  Don’t fail to protect it from solar flares, cyberwar, and plain old wearing out.

p. 139, on vegans doing better nutritionally in nonindustrialized countries. The author attributes better nutrition there to contamination with insect carcasses as protein sources. That’s a minor factor; while protein is in short supply in many countries, it’s pure calories that are in even shorter supply.  I point, instead, to microbial contamination as the benefit.  Only microbes make vitamin B12.  Really clean vegetable matter lacks vitamin B12, which we need but plants don’t.  Mix in some dirt!

p. 149, on visual thinking done by people, notably Dr. Temple Grandin, who is autistic. I am impressed by her abilities. On the other hand, I am sad at having seen so many university students who have severely limited abilities to think in words while claiming to be visual learners.  Tell me how you can reason by putting images together.

pp. 166 ff., Section Four, about science fiction, including so much on zombies and aliens. It may attract some readers, but I find it rather pandering to pop culture and attendant anti-intellectualism. Sigh.

pp. 198, 199, which I laud, on unrealism in many movies about space. Yes, let’s keep up the critical thinking!


The End



New Mexico Climate Conference, 28 Oct. 2017

30 November 2017.  My presentation at the New Mexico statewide climate conference on 28 October is up on YouTube.  I spoke about the biological effects of climate change, which have concerned me for decades.  The conference was organized by the Citizens Climate Lobby, as the first of its kind for the CCL.  It linked presenters and audiences by Zoom videoconferencing in 4 cities – Las Cruces, Albuquerque, Santa Fe, and Taos.  John Nelson and I organized the presentation down here.