Today’s question, by Caroline, is asking whether eating parasitic worms can protect against asthma, diabetes, gut problems, and even multiple sclerosis.
Shall I go and eat worms?
Don’t worry I’m not feeling like Johnny-no-mates today, this question refers to a pub discussion a couple of weeks back about using parasitic worms as therapy for various diseases. The worms in question, helminths, are a broad group of species some of which live in the gut of their host and feed off the food they are ingesting or alternatively the host’s blood. Parasitic worms infect about a quarter of the worlds populations and although infection is not usually fatal the malnutrition or anaemia that follows is often debilitating. In children the situation is more serious since the worm can affect intellectual development and growth.
So why would someone deliberately infect themselves with parasitic worms? Well there is evidence that they help with certain immune diseases, particularly those of the gut such as Crohn’s syndrome, ulcerative colitis and inflammatory bowel disease but asthma, multiple sclerosis and type 1 diabetes also improve. These are all ailment that involve some aspect of inflammation where the immune system becomes over-zealous to a relatively harmless trigger.
The most likely explanation for how the worms reduce inflammation lies in their influence on the immune system. There is an immune ‘stem cell’ that, when it matures, can become one of two types of cell: type 1 which promotes inflammation and allergy or type two which fights parasitic infection. Infection with worms increases the number of type two cell as the immune system tries to rid the body of the parasites. Consequently the number of type 1 cells decreases leading to a reduction in inflammation and improvement of the immune based diseases.
So should I take them for asthma? Inflammatory diseases usually involve some irreversible scarring which eventually leads to health problems. Asthma, for example, is not just a series of transient attacks that are alleviated by an inhaler, the scarring caused by inflammation leads to permanent damage and constant problems with breathing in later life. Scarring is also a feature of inflammatory disease of the gut and leads to permanent problems with digestion. So I should consider anything which prevents inflammation, no matter how odd.
Before you rush off to your doctor I should tell you these worms are not available from GP’s just yet because they are not a licensed therapy. And this is my quandary, because they are available on the internet. After a brief health questionnaire and a fee, you, or me, could be host to a worm or two or twenty.
If time was not an issue then the course of action would be clear – don’t take them because it is not clear they will work or worse, be harmful to health (see the table below for more details). But time is an issue and the sooner I take something that will probably work and is probably not very harmful, the less scarring on my lungs (which I know will be harmful).
A recent study (1) has identified the specific protein in the worms that causes the immune switch away from type 1 inflammatory cells. That is exciting news because it opens the way for more conventional pill based therapy without the need for whole worms. It will take time: ten, fifteen, maybe even twenty years but I’m willing to wait because if I’m truly honest the idea of swallowing live worms is just too gross. I’d rather wheeze.
Table 1. Health therapy options – licensed through pharmaceuticals company or bought from the internet.
|Taken under medical supervision
||Not taken under medical supervision but in the UK you can go to your doctor if something goes wrong
|Medical claims on the packaging regulated: all claims must be backed by strong scientific evidence
||Claims made on the internet or by word of mouth not always substantiated with data or strongly underpinned by law. Little or no regulation
|Monitored for false or exaggerated claims
||Exaggerated claims frequent, little monitoring
|All side effects observed during trials listed
||Side effects not clear
|Medical trials done in large groups to examine safety and identify side effects.
||Data taken from smaller medical trials in medical literature. Indicative but not comprehensive. Side effects not written up and shared with the scientific or medical community.
|Medical trials give indication of whether it works and who it works for.
||Safety issues expressed but vulnerable groups not prevented from obtaining it. Not clear who should take what.Not clear if it works.
|Expensive, drug companies charge a lot for new treatments
||Relatively cheap although more expensive than a UK prescription
|Takes a long time 10-20years
||Have it now
Thanks to Caroline Bell for the question.
Whip worm image from Wikimedia: http://commons.wikimedia.org/wiki/File:Trichuris_trichiura.jpg