Oral rehydration therapy at home #2

Following up my last post on oral rehydration therapy, it was pointed out to me that coconut water is a rich source of potassium. So much so that it can be used to make an alternate home recipe for Oral Rehydration Solution. The recipe, illustrated above, is:

  • 3 metric cups (750 ml) of water
  • 1 metric cup (250 ml) of coconut water
  • 8 metric teaspoons (40 ml) of lemon or lime juice, as a source of citrate
  • 1 metric teaspoon (5 ml) of honey, to supply additional glucose
  • ½ metric teaspoon of salt, to supply additional chloride and sodium
  • ½ metric teaspoon of baking soda (sodium bicarbonate), to supply additional sodium, and as a way of neutralising the acidity in the lemon or lime juice


Oral rehydration therapy at home

Oral rehydration therapy is one of the most cost-effective lifesavers in the history of medicine. It stops people dying from cholera and other diarrheal diseases. It works because of the sodium-glucose co-transport mechanism in the intestines, discovered by Robert K. Crane around 1960.

The WHO has guidelines for Oral Rehydration Solution, and the recipe pictured at the top of this post is my attempt to approximate these guidelines using ordinary kitchen ingredients and easy measurements (doing a computerised search through the space of valid options). The mix actually tastes OK too. The recipe is:

  • 1 litre of water
  • 8 metric teaspoons (40 ml) of lemon or lime juice, as a source of citrate (10 millimoles, by my calculation)
  • 3 metric teaspoons (15 ml) of honey, as a source of glucose and other sugars (90 millimoles)
  • 1 metric teaspoon (5 ml) of cream of tartar (potassium bitartrate), as a source of potassium (19 millimoles)
  • ¾ metric teaspoon of salt, as a source of chloride (73 millimoles) and sodium
  • ¼ metric teaspoon of baking soda (sodium bicarbonate), as an additional source of sodium (giving 87 millimoles in total), and as a way of neutralising the acidity in the lemon or lime juice

The total osmolarity here is just under 300 millimoles, which is above the optimum of 245, but under the upper limit of 310. The specific WHO criteria for glucose (between the sodium level and 111 millimoles), sodium (60–90), potassium (15–25), citrate (8–12) and chloride (50–80) are also satisfied.

Possible substitutions are 13.5 grams of glucose powder for the honey and 2.1 grams of citric acid monohydrate for the lemon juice. The three other ingredients can also be replaced by ½ teaspoon “lite salt” (which provides sodium and potassium), ¼ teaspoon ordinary salt, and ½ teaspoon baking soda.

What makes Australians happy?

Lately I’ve been exploring demographic and social data, including looking at the Australian data in the World Values Survey. Of particular interest are data on self-reported happiness. Among women, financial stress and poor health contribute to unhappiness, as might be expected. Socially conservative women report being happier, and single women report being less happy. Finally, women who attend religious services once per week or once per month are happier than those who do not attend religious services, or those who attend religious services more than once per week. This is broadly consistent with literature on the effects of religion on mental health.

Among men, financial stress and poor health act in the same way as for women. In terms of marital status, however, it is separated men who are the least happy. Male happiness is also closely tied to employment status, with unemployed (and, to a lesser extent, self-employed) men reporting more unhappiness.

Gender and Health

Lately I’ve been exploring demographic data related to women’s health. Among other things, this involved looking at the Australian data in the World Values Survey, which includes a self-reported measure of health. For women, this depends on a number of other variables, including age:

For men, the age effect is weaker:

Presumably, this is because male health problems are more likely to be fatal, which is why there is an excess of women amongst the elderly, as indicated by Australian census data:

Why vaccinate?

Why do we vaccinate children? To prevent some horrific diseases that have haunted the human race for centuries. These diseases have not gone – they are still lurking in the darkness, and have already started to reappear in towns with low vaccination rates. Here is a brief reminder of five diseases that no sane person would want to see return.


Diphtheria is caused by a toxin-producing bacterium. It kills between 50 and 200 out of each thousand people who catch it.


Measles is caused by a virus. In the US, it kills about 2 out of each thousand people who catch it (in the rest of the world, more like 7 out of each thousand). However, it can also cause brain damage, deafness, blindness, and other complications in the survivors. It is extremely infectious – far more so than Ebola or the flu. And cases are trending upwards in the USA as a result of non-vaccination.


Rubella (German measles) is of concern not only because of the harm it can do to those who catch it, but because it also causes miscarriages and birth defects in pregnant women.


Pertussis (whooping cough) can leave children weak for a long time. It is particularly deadly in young infants, and low vaccination rates are responsible for the deaths of babies in some areas. See here for a rather disturbing video of a baby in intensive care.


Poliomyelitis (polio) is caused by a virus, which can cause permanent paralysis of various muscles. The 1950s saw serious epidemics that have now been largely forgotten. Unfortunately, attempts to eradicate polio have stalled in certain parts of the world.

Polio survivors (photo: RIBI Image Library)

Worldwide, each minute of every day and night, three children under five die from vaccine-preventable diseases like these. So “jab for life,” mums and dads!

The dose makes the poison

Some time ago, someone pointed me at a “natural health” site which expressed shock that “Big Pharma” was putting “toxic copper” into baby formula. Those poor babies! Now the copper was there, all right, but only because copper is an essential mineral. Indeed, copper is present in human breast milk, at a concentration of about 0.36 milligrams per litre, and inadequate copper intake has terrible consequences, especially in premature babies. The copper was necessary. The key idea here, which the diagram below is intended to capture, is sola dosis facit venenum (“the dose makes the poison”).

Many essential vitamins and minerals, like copper, transition from a “no effect” dose (blue) to a beneficial dose (green) to a toxic dose (red). In the upper three bars of the diagram, the black dot indicates the recommended daily intake (which we should ingest), and the white bar marks the recommended upper limit, which we should not exceed (disclaimer: this diagram may contain inadvertent errors; please take your medical advice from official sources).

Something similar happens with medicines, like paracetamol (acetaminophen). Small amounts do nothing for your headache; in adults, one or two tablets (0.5–1 gram) safely ease mild pain; but exceeding the dosage indicated on the packet can cause liver failure and death.

Paracetamol tablets (photo: Mateus Hidalgo)

For toxic heavy metals like mercury, cadmium, lead, or silver, there is no beneficial level – the transition is from a “no effect” dose (blue) to progressively greater harm, up to and including death. In the lower four bars of the diagram, the white dot indicates the daily intake of the average person (which generally seems to have no observable effect), and the white bar marks the recommended upper limit.

When people are exposed to levels above the white bar, health authorities start to get worried. For example, shark meat can contain 1 mg of mercury per kg or more. Australian authorities recommend that if shark meat is eaten by pregnant women or children, it should be limited to 1 serve per fortnight (with no other fish eaten that fortnight). But even there, it is the dose that makes the poison.

Mercury and formaldehyde in vaccines?

The anti-vax community runs regular scare campaigns regarding “toxins in vaccines.” Mercury and formaldehyde are the two most often mentioned. Mercury occurs in the form of the antibacterial thiomersal (thimerosal), but not in vaccines routinely administered to children. Thiomersal is present in multi-dose vials (not in single-use vials) of influenza vaccine, typically at a level of 25 micrograms (0.025 milligrams) per dose. For comparison, though, the normal mercury intake is about 2410 micrograms (2.41 milligrams) per year, so an annual “flu shot” adds very little extra. And even that exaggerates the risk, because thiomersal breaks down into ethylmercury, which is less dangerous than other forms.

Formaldehyde, though toxic in moderate to large quantities, is naturally produced and consumed as part of human metabolism, with a turnover of about 50 grams of formaldehyde per day for a person weighing 50 kg. Formaldehyde occurs naturally in blood at levels of about 2.6 milligrams per litre. Even for a 3.5 kg newborn baby (with 85 mL/kg of blood), that comes to 0.77 milligrams of formaldehyde (and there’s more in body tissue). Vaccines contain at most 100 micrograms (0.1 milligrams) of formaldehyde, and so add very little to the blood (and that is very quickly eliminated). That’s even more true for older children, with their much greater blood volume.

Part of the problem here, I suspect, is widespread confusion between grams, milligrams, and micrograms. At the other end, of course, some people also have problems in economics with understanding the difference between millions, billions, and trillions.