Going green – will eating a bag of watercress a day banish wrinkles?

 

 

 

I came across an article in the Daily Mail online a few days ago and was intrigued by a couple of aspects of it. Firstly its claim that “If you want to roll back the years, forget expensive lotions and potions and instead reach for something more natural (and cheap): a bag of watercress”. It claimed that 10 out of 11 female volunteers experienced visible improvements to their skin after just four weeks of adding one handily packaged bag of watercress a day to their diet.

 

As usual in these type of stories, it all seemed a bit too good to be true. It had a few obvious flaws: the sample size of 11 women for starters – no serious scientific study would be happy to claim such definitive results based on such a small number. But it did carry a couple of quotes from a couple of scientists to back up its claims. So I googled them – I was particularly interested in “Watercress Alliance member Dr. Steve Rothwell, who holds a PhD in watercress” and that’s true – he does indeed have a PhD in watercress! But what the Mail article fails to note is that Dr. Rothwell is also the managing director of a company called Vitacress, who just happen to be the “world's leading watercress producer.”Whilst this fact alone doesn’t necessarily mean that this groundbreaking research into the anti-aging properties of watercress is flawed, it does mean that its findings may be biased by the fact that Dr. Rothwell’s company paid for the study carried out and that its in their interest if the story shifts an extra couple of million bags of watercress.

Sadly so far I’ve been unable to track down the original published research that formed the basis for the Daily Mail story so I started to think that this story was just another company press release converted into a health story by a busy journalist. But when I looked again at the Vitacress website I came across a story which was far more interesting - and more scientifically valid - about why watercress really may be good for your health - and it’s for a far more important reason than ironing out a few wrinkles.

The Daily Mail article states (in a direct quote from a Vitacress press release) that “gram for gram, watercress contains more vitamin C than oranges, four times more beta-carotene and vitamin A than apples, tomatoes and broccoli, more vitamin E than broccoli, more calcium than whole milk and more iron than spinach” .But it’ s the fact that watercress is the richest natural dietary source of a substance called PEITC (phenylethyl isothiocyanate) which is of real interest. In 2010 the University of Southampton reported research where the phenylethyl isothiocyanate found in watercress may have the ability to suppress breast cancer cell development by 'turning off' a signal in the body and thereby starving the growing tumour of essential blood and oxygen.

Research carried out by the University of Ulster, Coleraine, and published in Feb 2007 edition of the American Journal of Clinical Nutrition, found that “eating watercress daily can significantly reduce DNA damage to blood cells, which is considered to be an important trigger in the development of cancer, and that in addition to reducing DNA damage, a daily portion of watercress also increased the ability of those cells to resist further DNA damage caused by free radicals”. But as this research team noted in the conclusion to their paper, their results do not necessarily give us a green light to eat more of the green stuff to definitely keep cancer at bay. They state that “it should be noted that lymphocyte DNA damage is only a surrogate marker of whole-body cancer risk, and the effects of watercress on cancer risks at different sites could well be different to that observed in lymphocytes. This, among other things, could depend on tissue exposure, bioavailability of watercress phytochemicals in the various tissues, or both.” They also note that other researchers working in the field did not find the same results as did this study. This is means that while the evidence in favour of watercress looks promising its anticancer qualities remain unproven – further research is needed. (The Vitacress press release left this section out).

But I shouldn’t leave you with the impression that Vitacress set out to deceive – they didn’t. And it’s not necessarily a bad thing that they are funding research into the possible anticancer effects of their product. It’s just that when a press release on a research finding gets turned into scientific fact by a journalist – and other “facts” quoted in previous press releases become treated as scientifically proven when they have yet to be , the result is that once again the general public gets misleading information on nutritional matters.

 

So by all means eat more watercress – it contains significant amounts of iron, calcium, iodine and folic acid in addition to Vitamins A and C. It’s unlikely to harm you and to preserve its nutritional content, it’s better to eat it raw but one word of warning - where ever you get it from I’d recommend you wash it carefully before eating. I’ve found references to commercial crops being treated with a solution of bleach before packaging - I’m not sure or not if that’s true – but washing it is probably wise. And one thing to note if you’re into wild foraging, is that patches of watercress found close to rivers and streams, if they have been exposed to manure from sheep and cows in the water, can harbour snails infected with a parasite - the liver fluke Fasciola hepatica which can potentially infect humans – so again wash very carefully before eating. Another point to note is that apparently it’s not recommended to eat watercress if you are taking Chlorzoxazone – a muscle relaxant drug – the two don’t mix.

One last point about the Daily Mail article – and strictly for fun – amongst the many skin improving benefits it cites for watercress is the fact that levels of “porphyrins - said to be levels of bacteria on the skin” were much improved. I’ve looked them up : “Porphyrins” appear to be blood pigments ...I’m not really sure you’d want too many of those on your face –indeed in Hamsters and gerbils they can cause a very nasty skin condition – perhaps the Gerbils need to eat more watercress too?