Was Darwin lactose-intolerant?

October 19, 2015 • 11:56 am

by Matthew Cobb

The other week I gave a talk at the Ilkley Literature Festival, about my book Life’s Greatest Secret. It was a great event – although traffic problems meant I was slightly late, despite setting off with 45 minutes leeway – and was sold out!

Ilkley is a lovely town in Yorkshire, surrounded by fantastic hills and a moor which is the subject of a very well known English song (“Ilkley Moor Bar T’At”) which recounts what happens if you go walking on the Moor, and even courting Mary-Jane on the Moor, without your hat on (spoiler: it finishes badly. In worms, then ducks, then the singers of the song…)

This version of the song has the guitar chords, and a transcription, though give it’s still in Tyke, you may have a hard time understanding it:

Anyway, it is a little known fact that when The Origin of Species was published, Darwin was not at Down House in Kent, where he lived, but in Ilkley. I learned this because my talk was chaired by Professor Greg Radick of the University of Leeds. Greg is Professor of History and Philosophy of Science, and in  2009 he wrote a slim book called Darwin in Ilkley, which he co-wrote with a retired Professor of Gastrointestinal Pathology and local historian, Mike Dixon. (It’s available in the US and in the UK on Kindle – you can also read it with the Kindle app on the tablet of your choice).

Darwin was in Ilkley because of the local water-based health cure, and he was in search of relief from his mysterious debilitating illness, which dogged Darwin throughout his life. Radick and Dixon noticed that when Darwin was in Ilkley, eating a reduced dairy diet in the hotel where he was taking the ‘hydropathic cure’, his symptoms abated. When he returned to Down House, his malaise returned.

There’s a lot more to their story than a simple correlation, and if true, it would not only settle an issue that has concerned Darwin’s biographers down the decades – was his disease ‘real’ or psychosomatic, and if it had a recognisable cause, what was it? – it would also add an intriguing coda to the interaction between the man and his science.

Up until a few thousand years ago, humans did not drink milk after weaning and they did not have the necessary enzymes to be able to digest the key part of milk, lactose – they were lactose intolerant. Consuming milk products as adults would have made them ill.

However, in several communities around the world, which had begun to domesticate mammals, mutations arose which enabled some individuals to digest milk throughout their life. Presumably those mutations had occurred repeatedly in evolutionary past, but there was no animal milk to drink (try milking a mammoth!), so no advantage was gained and those mutated genes were not passed down.

Today, there are important parts of the world where lactose intolerance is prevalent – Japan and China, for example, although it is rare (but not at all absent) in Europe and parts of Africa. This map from New Scientist shows the distribution of intolerance:

If you want to know more about lactose intolerance, this New Scientist article is pretty good.

Maybe if Darwin had known, he could have made himself feel a lot happier…



43 thoughts on “Was Darwin lactose-intolerant?

  1. Hmmm, interesting. It passes a “sniff test” for credibility, what little I know of the symptoms of lactose intolerance.
    But … next flight looms …
    Ilkley Moor is one of the few songs I’ll attempt. But it takes an empty moor, and some good “wuthering” weather before I try it. (For those who don’t know, this is “Wuthering Heights” country too, hence the song’s line about “where the ducks fly backwards.”

    1. I assume you attempt it in the middle of the moor, at a safe distance from a critical audience?

      (I’m projecting, of course, my own attempts at serenading being best exercised on empty tracks)


      1. Distance – and deafness – definitely improves the experience for everyone. If only I could get away from my own voice …

  2. If I recall, Darwin does not mention having intestinal distress until his adult life. When on his voyage he had a lot of seasickness, but he was also ill while in South America, and he does mention encounters with the insect that causes Chagas disease which is one of the diseases that gets mentioned as a possible cause of Darwin’s illness. Other possible causes that have been proposed before include lactose intolerance, adult onset cyclic vomiting syndrome, Crohn’s disease, and a wide range of other conditions. His many symptoms were such that I wonder if he had more than one condition.

      1. I’m wondering if, in view of the mention of neoteny further down, his (presumed possible) lactose intolerance might have come on or intensified later in life. After his college days, that is.


      2. Lactose intolerance can come on later in life. It also depends on how much dairy you get in your diet. A period (such as aboard ship) where you don’t eat any dairy for a while can bring it on. I guess you don’t need the enzymes for a while and they decide to shut up shop. Mine didn’t assert itself until I’d spent 5 years in Asia eating almost no dairy from the age of 25-30.

      1. I do not know if he was embalmed, but no one this century is going to dig him up. But he has descendants, and one could look at DNA among them for inheritable genes of interest.

        1. I don’t know if examining his DNA would tell you anything. All mammals have genes that produce the enzyme that digests milk. It’s just that the expression goes away as the individual ages. This ability (in lactose tolerant populations) may be another example of humans neoteny.

          1. I’m pretty sure there is an identifiable, by genetic testing, genetic basis for lactose tolerance vs lactose intolerance. I think it would be possible to determine if Darwin were lactose intolerant given a viable genetic sample.

            Yes, taking a quick google-look quick and easy genetic testing for lactose intolerance was developed in 2009. Testing was possible before that but was more involved.

            1. Agreed. And i think this is how the map of lactose tolerance / intolerance was made. I think — but maybe imagining — that there are different lactose tolerance alleles, marking their separate origin in different cultures that kept dairy animals.

      2. Darwin is entombed in the floor of Westminster Abbey, close to Sir Isaac Newton. Rather than exhumation, it would be possible to take a core sample using a mining drill and test his DNA. Sir Isaac could serve as a control sample.
        But seriously, CD has numerous descendants alive today, including pure maternal line descendants, a potential source of mtDNA.

        1. ‘core sample’

          For some reason, I find that a far more disconcerting image than ripping up the floor of the abbey and digging up Darwin.


            1. No forgiveness needed, my sense of humour is sufficiently bizarre that I’m not about to cast aspersions at anyone else’s.


              1. I hope no one thought the core sample was a serious proposal. I know CD would not want anyone to take a core sample; I am sure he would say ‘Take the b’ lot’. (He never wanted to finish up in Westminster, anyway.)

              2. haymanj, I assumed you were joking. 😀

                But the “never wanted to finish up in Westminster” is true?

              3. Darwin intended to be buried in St Mary’s Churchyard in Downe, Kent, with his elder brother, Erasmus.

              4. @haymanj

                I must admit I thought it was a serious possibility. My sense of the absurd is no longer a reliable guide these days since the needle is permanently stuck in the red.

                You did flag it as non-serious with your ‘but seriously’, but this is the Internet. Whatever you write, somebody will take it the wrong way. In this instance the body was me. No worries.


  3. I bet many of the people with lifelong illnesses, or who were “a sickly child”, or died young, just had food intolerances.

    In retrospect its weird that food intolerances only became “a thing” so recently.

    My Dad was a martyr to ulcers for 60 years, but back then experimenting with cutting things out of your diet wasn’t really something you did. However, when he cut out sugar they cleared up pretty much overnight.

    1. A lot of them died of cholera or diptheria, certainly. A classic bit of research was the discovery that the proximate cause of ulcers was bacteria.

      1. One of the guys (Barry Marshall) who established that proved it by giving himself the infection (H. pylori). He and his coworker Robin Warren won the 2005 Nobel Prize in Physiology/Medicine. Heroic science.

  4. It’s easy from the perspective of our so-called “enlightened” era to judge our ancestors for their lack of tolerance. But let’s be honest. If we had been born in such a time and place would we have been any better?

  5. I generally have an iron stomach and am not remotely a snowflake about what I eat (except that it has to be good- real food!), but it seems that just over the last few years milk and things like crème caramel (which I love)and ice cream seem to unsettle my stomach. Bummer and surprising for a quarter-Norwegian and the rest mainly British Isles. Cheese and yoghurt seem to be OK.

      1. Yeah, milk chocolate and ice-cream are lethal. I check labels for the words, “milk solids”, anything with that written on is going to be not worth the suffering.

  6. Darwin may have had lactose intolerance but this was part of a wider disorder. Lactose intolerance might explain some of Darwin’s gastrointestinal symptoms but not his cardiac symptoms, his atopic dermatitis, his asthma, his visual disturbances,his headaches, his attacks of fear, his episodes of lethargy, his hysterical crying (dacrystic seizures) and his stroke-like episodes in later life. The seasickness he experienced throughout the voyage of HMS Beagle was part of this illness. The boils that he suffered at Ilkley are a recognized complication of atopic dermatitis.

    Darwin had a pathological mtDNA mutation inherited from his maternal Wedgwood forebears. Such a mutation explains all of Darwin’s symptoms including his cyclic vomiting; it also explains the symptoms of his elder brother Erasmus, it explains the illnesses of his mother Susannah, her younger brother Tom and in particular the illness and early death of the youngest sibling of that generation, Mary Ann.

    Darwin inherited more than wealth from his maternal Wedgwood ancestors.

  7. Nilotic Africans drink a lot of milk in various forms. The Maasai of Kenya and Nuer in South Sudan among others are “pastoralists” and drink mixtures of milk and blood as well as a really good yogurt. Yum.

    1. He only went once; while there he suffered a sprained ankle, multiple boils, and sudden swelling of his face and one leg (?carcinoid reaction). He described the proprietor (Dr Edmund Smith) thus: ‘… he constantly gives me impression, as if he cared very much for the Fee & very little for the patient’.

      Darwin returned home in a worse state than when he went; he would probably agree with your opinion of Yorkshire

    2. “I’m just shocked that Darwin went to Yorkshire for a cure, worst county in England”

      Must… not…rise….to…..bait…

  8. As someone who has found that (at least subjectively) milk products have gotten harder to eat as I age, I have a question:

    Can the mechanisms for lactose digestion be *partially* active so that lactose tolerance comes in degrees?

  9. For purposes of studying the genetic bases if lactose intolerance, that is possibly the worst map I have ever seen. It has some vague correlation with current areas of lactose intolerance, but many of the most interesting parts are missing, and some of the others are just flat wrong.

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