By Grant Jacobs 25/01/2017 5


New Zealand agricultural scientists have learnt that the calves of a cow modified to have less allergenic milk also have less allergenic milk, raising hopes of developing a variety of cattle that those will one type of milk allergy can drink.

Jamie Morton writing in the New Zealand Herald has the story, GE cow’s offspring show ‘super-milk’ potential.

For those reading Jamie’s piece, ‘hypo-allergenic’ simply mean less allergenic. Hypo- is a Greek prefix scientists use to mean under or less. Hyper- is the enlarging counterpart.

Milk allergy is not lactose tolerance. Apparently confusing the two is a fairly common mistake.

A number of us are allergic to milk, in a similar way that a number of us are allergic to other types of foods.

β-lactoglobulin is regarded as the main allergen in milk.* (β is the Greek letter, beta; you’ll also see it written beta-lactoglobin.) β-lactoglobulins is considered an important allergen in part because there’s no β-lactoglobulin in human milk.

Around 2-3% of children are allergic to milk. Those with milk allergy can show any of the symptoms of allergy; skin, gastric and breathing problems, including, in rare cases, acute allergic reaction (anaphylaxis).

Usually kids grow out of the allergy, but they carry a higher risk of eczema, egg allergy or allergic asthma in adulthood.

One way to tackle this allergy might be a little prevention: to breed cows that don’t make β-lactoglobulin – without this protein, the allergy problem isn’t there.

What the New Zealand researchers did was to block the gene that makes β-lactoglobulin – this way you get just the thing you’re wanting, and you can try it out on a small scale using a small research team. One of the great values of genetic engineering is that it enables small teams to do stuff that might otherwise need very large-scale projects.

A catch with the technique they’ve chosen to use, known as RNAi, is that you want to know if the offspring also doesn’t make the protein – is it inherited?

That’s the latest news – they’ve succeeded at that, as you can read in Jamie’s report.

You’ll also see in his report that this work started with a study in mice! It’s often most practical to test the initial ideas on animals that have shorter life cycles, are less costly to breed, and which you can more easily control their environment (including what they are fed).

There’s still a long way to go, but less-allergenic milk might give an option to those who have developed milk allergy.

A thought here for those opposed to GM: if those that don’t want to use milk from cows that were bred to make modified milk, they don’t have to — but there’s no need to block that option for others that do want to.

One thing I’d like to learn is to what extent the caseins in low β-lactoglobulin milk provokes allergic reactions. Presumably this milk would be for those allergic to β-lactoglobulin, but not those allergic to caseins.

One line of research suggests that people are allergic to β-lactoglobulin when it lacks iron.** β-lactoglobulins can bind a number of organic molecules, including siderophores. One thing siderophores can do is strongly bind iron. Research has shown that when the β-lactoglobulin protein carries an iron, by holding onto siderophore binding iron it triggers an immune response (e.g. inflammation).

The more widely-known lactose intolerance is because as adults many of us can’t break down & absorb the lactose sugar in milk. It’s more common in non-European people. Since humans starting drinking milk, we’ve started to produce lactase, the enzyme that breaks down lactose, as adults — adaptive evolution in humans as a result of farming!   Adapting to produce lactase as an adult has happened several times independently in different parts of the world. I’ve previously touched on how it arose among in North Africa, probably through camel milk, in an article about tracking disease and human migration through genetics.

Featured Image

Remember glass milk bottles?!

Source: Wikimedia Commons, GNU Free Documentation License.

Footnotes

* Caseins in milk can also cause allergic responses. Caseins are found in the solid part of the milk, the curd. β-lactoglobulin is found in the liquid part, the whey. Some people are allergic to one of these, a few to both. If you’re allergic to cow’s milk, you’ll likely be allergic to other animal’s milk too. There are also a few people who are allergic to cow’s milk that are also allergic to soy milk. (Source: Mayo Clinic.)

 ** The Major Cow Milk Allergen Bos d 5 Manipulates T-Helper Cells Depending on Its Load with Siderophore-Bound Iron

Roth-Walter et al., PLOS ONE, August 12, 2014.

http://dx.doi.org/10.1371/journal.pone.0104803


5 Responses to “Towards tackling milk allergy”

  • Probably the easiest way to tackle cow’s milk allergy is to focus on camel’s milk, rather than to try to twist mother nature once again. Moreover, camel milk is hormone free!
    In regards to GM: maybe those with allergies should have that option to use “modified” milk. But I’m still opposed because of a possibly much bigger danger: cross contamination through male calves born from bred cows. One day, the vast majority who won’t use modified milk may no longer have that option. And no, the strictest regulations won’t prevent mishaps and unscrupulous farmers from gaming the system.

    • Maybe camel milk is of use to some people who can get it easily and cheap enough, but a few thoughts.

      A very quick (!) spot of research suggests that camel milk isn’t a sinecure for safe milk, unfortunately as there are people with allergies to that too. This article, for example gives a case history of anaphylactic shock due to camel milk protein and notes,

      “[…] there is no universal hypoallergenic mammalian milk (17). Thus, camel milk should not be considered constantly safe.”

      http://onlinelibrary.wiley.com/doi/10.1111/j.1398-9995.2010.02421.x/full

      (Taking nothing away from your point here, but this seems worth bearing in mind; esp. as advertising for camel milk might down play this as advertising tends to want to.)

      Hope you don’t mind, but I can spot a few problems with your objections.

      “rather than to try to twist mother nature once again”

      Variations on this line are common enough from those concerned about GM, so you’re not alone, but if you look a little closer they don’t work! All of our crops, farmed animals, pets, pigeons!,* etc. are “twisted” – they’re nothing like their original forms. (There’s a good chance it’s the same for domesticated camels too.) We’ve selectively bred away from the “natural” version to suit us. And things that are “natural” aren’t always good for us either.

      “But I’m still opposed because of a possibly much bigger danger: cross contamination through male calves born from bred cows.”

      You’re written that as a danger, but it’s not a danger; no-one would get hurt.

      Best ask agricultural types, but I imagine it’s pretty straightforward to control the breeding if you wanted to. After all, farmers already want particular breeds as it is & use artificial insemination and whatnot if they need to.

      Might also be worth noting that 2-3% of the population isn’t that small a number.

      In any event, it’s really is a matter of letting people choose what they want for themselves.

      (* This one because Charles Darwin used pigeon breeding as one of his examples of creating variation.)

  • Just a stray thought while I’m writing –

    This is an example of a product that reduces potential harm.

    Someone wrote to me the other day saying they were “pro safe food” rather than ‘anti-GMO’. (Long story short, their messages said otherwise, though!)

    This is an example of a new food that should increase food safety; if you’re “pro food safety” you ought to be happy with it work being down towards it.

  • Thanks Grant for commenting and sharing your insights.

    1. There are indeed people allergic to camel milk. I met one in Dubai. She said she was part of an unfortunate group representing less than 10% of the milk allergic people. I am talking about milk allergy, not milk intolerance. Many people with lactose intolerance can often eat small amounts of milk products without noticing any symptoms. I feel sorry for this allergic group but I am still opposed to GM milk just to accommodate this tiny portion of the population. There are tons of foods out there that are healthier sources of protein and calcium.

    2. Indeed some veggies/fruits and animals are “twisted”. The twist is sometimes the result of the evolution. We humans are the “twisted” version of apes. Also, there is a fine line between a basic modification such as breeding a plant with the strongest traits or cross breeding two dog races and in vitro GE. Actually, most of the GE tests fail. The GM industry relies heavily on trials and errors. It is telling of the nature’s DNA rejecting such hazardous engineering.

    3. This problem is not even as critical as cross contamination. “it’s not a danger; no-one would get hurt”? Really? Ask those who were told so and then died of poisoning/complications when DDT was introduced and “recognized as safe”. You don’t know. Precaution should prevail. Another example: BPA in plastics. We didn’t know… until we found out.

    4. RE the industrial farming industry, there has been many reports of abuses, outbreaks and collateral damages in the past (mad cow, MERS virus, bird flu outbreak, explosion of birth defects rates in all Argentinean and Brazilian villages surrounding GM crops…). The type of breeding we are dealing with here is not as straightforward as you “imagine”. You are too prompt in dismissing the risks, relying too much on the farming industry’s goodwill and underestimating what you may not know yet but are likely to find out in the future.

  • ‘Fred’

    re 1. –

    You are free to choose what you want – and others should be able to, too. If those who would like to use a milk they are not allergic to, they should be free to without others disrespecting their choice. (This applies to all sorts of other choices we make too.)

    re 2. –

    “Actually, most of the GE tests fail.”

    I’d disagree, but lets take it for a moment to illustrate a point. Most of anything new fails while it’s being developed (including attempts at “conventional” breeding, inventions of any kind, etc) — cue a very famous Edison quote. Pointing would be moot.

    The reason I disagree is that GM product that gets to the market has been through a lot testing (especially compared to non-GM food products), and what happens before the final product is moot – think about it. [If what happened to trial versions of the product mattered you’d have to reject every invention that had an early trial model not work, which wouldn’t make sense, and would probably include every product released!]

    “The GM industry relies heavily on trials and errors.”

    So does any type of breeding. Fundamentally “conventional” breeding has trial and error to a (much) greater extent than GM because it isn’t able to create a particular thing wanted (as GE does), but has to try randomly mix then select what looks to be heading in the right way, and keep on at that until they get what they were after.

    “It is telling of the nature’s DNA rejecting such hazardous engineering.”

    I can’t make sense of what you trying to say here. That said, it might pay to remember that almost all ‘conventional’ breeding ‘goes across the grain’, too. The techniques used aren’t ‘natural’ and wouldn’t work unless people intervened. It also might help to remember that most bred things are weak, that if they were stuck out into the wild they’d quickly die out – they work in a farming setting because humans babysit them – in that sense nature would ‘reject’ nearly all of our farmed animals and crops!

    re 3. – This isn’t a case of adding something and not knowing what effects it might have. It’s a case of knowing something that causes unwanted effects (the allergen beta-lactoglobin) and removing it, but not changing anything else. The only thing being done is to remove something that is known to cause problems for some people.

    (Aside from that this is not a case of adding something and not knowing the effects, more generally you can’t directly compare what might be true for small molecules to proteins, what most genes make.)

    re 4. – The infectious diseases have no relevance here.

    “explosion of birth defects rates in all Argentinean and Brazilian villages surrounding GM crops” doesn’t turn up in Google, and has obvious signs that you’ll want to check your sources more closely before waving it around! (Loaded language, never mind the extra-ordinary claim.) I’m suspecting you’re read an account of one of the more wayward pieces of “science” in this area. There are a handful of absolutely terrible papers out there making claims of nasty harm, but the research is too shoddy to take seriously. A few of these papers have been retracted because of the poor standard of the work. (Worth remembering, too, that there are diseases that cause birth defects, like Zika does for example.)