In springtime we seem to feel the urge to clean up not just our homes but also our bodies. Detoxes, cleanses, juice fasts… these are more or less synonymous and they all aim to purge your intestines of the encrusted layer of muck and accumulated toxins they have acquired. Then you can start afresh with a clean slate. But is this really so healthy?
Wellness tourism is hugely popular, thanks in part to influencers who tout it en masse. The claim is that a week spent juice-fasting by the pool or undergoing a macrobiotic detox, perhaps combined with a colon cleanse, will flush all the accumulated toxins out of your body.
Nonsense, says Ben Witteman, a gastroenterologist and professor of Nutrition and Intestinal Health. Your gut doesn’t need a cleanse. ‘People have the idea that all kinds of muck sticks to the lining of the gut and that you need to clean it out from time to time. But that’s not the case. The intestinal wall is clean and smooth and nothing sticks to it.’
According to Witteman, the gut’s self-cleansing capacity has been so well developed over millions of years of evolution that it cannot be improved on. Between them, the gut bacteria, the gut lining, the liver and the kidneys run a perfect waste disposal system. And if you want to give the intestines a helping hand, a juice fast is not the way to go. On the contrary: it will cause you to flush out the good bacteria as well. Witteman: ‘They do recover, but it takes them several days. And fruit juice also contains a lot of sugars and not much fibre, while fibre is good for the intestines.’ The gut bacteria convert it into free fatty acids, which in turn are good for the gut lining and the gut’s resistance to disease.
So juice fasts and colonic cleansing do not do your body much good, and yet people do feel better after them, as Witteman has to admit.
The intestinal wall is clean and smooth and nothing sticks there
Ben Witteman, gastroenterologist and professor of Nutrition and Intestinal Health
‘That can also be the effect of a week of relaxation and the idea that you have been working on your health. And at the hospital too, we notice that people often feel better after an enema: your bowels are empty so a bloated feeling may go away, for example. But that has nothing to do with toxins. That’s just a money-spinner. A laxative that you can buy at the pharmacy for 26 euros is sold for 600 euros by some spas.’
Every day, we are inundated with sometimes contradictory information. So what are the facts of the matter? In this feature, a scientist answers your pressing questions. Every question you ask makes you a little wiser. Do you dare to ask yours? Email us at: redactie@resource.nl
