An alternative to the Kyoto Protocol? Photo: Breville USA / Flickr
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Study finds broccoli-sprout juice helps the body flush carcinogens (but don't call it a "detox")

New study suggests broccoli-sprout beverages help the body detoxify airborne pollutants, though it's not quite a "detox".

It’s hard to avoid health fads. It took Google just ten minutes since I read this study in Cancer Research Prevention to begin bombarding me with adverts. ‘7lbs in 7 days Juice Diets‎’ and ‘Coreflush colon cleanses’ are just some of the regimes proclaiming salvation from ill health, but nothing gets pushed as much as the detox. According to The Internet, the detox diet might as well have descended from Heaven as it's so effective at solving everything from bad breath to erectile dysfunction.

This latest obsession with internal body cleansing has flourished over the last couple of decades. The diet industry, of which detox plays an important role, is rapidly expanding. It’s already worth tens of billions of dollars, despite coming under severe criticism from leading scientists. Author and blogger Dr. Ben Goldacre – famous for calling out examples of ‘bad science’ – once described detox as “meaningless, symbolic, gimmicky short-lived health gestures with a built-in expiry date”. Yet this doesn’t stop the media touting every new superfood or miracle-diet as a panacea for all our ills. News outlets pounce at the first sign of a study purporting to have identified a medical breakthrough, often misrepresenting the author’s original findings in order to grab flashy headlines. (Take a quick look at the A-Z of things the Daily Mail thinks will cause and cure cancer – broccoli has 14 entries).

The trick is not to get carried away by the hype. Look at this latest study. Researchers in the US and China have found broccoli-sprout juice appears to "remove" airborne pollutants from the body, but this isn't a "detox". Unlike the fleeting 'cleanse-your-body-in-5 days' type programmes (which unsurprisingly peak after the Christmas holidays), this research looked at the effects of longer-term consumption of broccoli-sprout juice on removing three specific carcinogens.

In the randomised-study of 291 participants from a highly polluted township in rural China, the team analysed daily urine samples from two groups: the first group was given a daily drink of broccoli-sprout juice, but the others were given a placebo beverage. The multi-institutional collaboration included researchers from the John Hopkins Bloomberg School of Public Health and the Qidong Liver Cancer Institute. The team were looking at how the levels of three carcinogens – benzene, acrolein, and crotonaldehyde – changed in participants’ urine over the three-month period.

The substances involved have been linked to increased risk of cardiopulmonary disease, arguably the second biggest killer in China. As the township in the study is located in the heavily-polluted Yangtze River Delta region (a tiny area of eastern China responsible for a monstrous 15 per cent of the country’s greenhouse gas emissions) there is a huge need to combat the dangers of air pollution.

Did the concoction work? On the face of it, yes. The authors found that juice-drinkers excreted more pollutants than the control group. In particular, they noted:

Rapid and sustained, statistically significant (p ≤ 0.01) increases in the levels of excretion of the glutathione-derived conjugates of benzene (61 per cent), acrolein (23 per cent), but not crotonaldehyde were found in those receiving broccoli sprout beverage compared with placebo.”

So far so good. Juice-drinkers weed out larger quantities of two of the three substances under consideration - but this still doesn’t mean broccoli-sprout juice “prevents against lung and heart disease”, as it might have you believe. 

The big question here – does drinking broccoli-sprout juice decrease your risk of disease by causing you to excrete higher levels of carcinogens? – needs lots more research. Without analysing numerous studies alongside one another (and taking sample size into account) you can’t really draw conclusions. A single study of 300 people is evidently not enough to justify claims of preventing lung cancer.

In an article published in The Journal of the American Medical Association, health-policy expert Dr John Ioannidis famously argued that a large amount of research is highly misleading. By comparing publications of “highly cited original clinical research studies” with subsequent papers where a larger sample size was used, he found a third of effectiveness claims to be either contradicted or highly exaggerated. Taking a single study to be gospel truth is foolish.

Let's go back to the broccoli. Research emerges linking this juice with enhanced excretion of pollutants; other studies have already linked those same pollutants to cancer. Extrapolating those statements to claim detoxing with broccoli-sprout juice will prevent disease is understandable, and perhaps even inevitable, but undeniably wrong. We mustn't connect dots to form patterns that aren't there.

This highlights a real problem with the supposed 'science' behind detoxing and other miracle-cures: subtly inviting us to form our own conclusions from the selective evidence they present, which, without comparative studies, is effectively meaningless. In detox diets this manifests itself by ignoring the body's own capabilities for disposing of toxins. Andrew Wadge, former Chief Scientist at the Food Standards Agency, expressed his scepticism that we need extra help cleansing out our insides:

There's a lot of nonsense talked about 'detoxing' and most people seem to forget that we are born with a built-in detox mechanism. It's called the liver. So my advice would be to ditch the detox diets and supplements and buy yourself something nice with the money you've saved.”

However, this doesn't mean we should automatically write off such supplements as useless. Given how few of us get our 5-a-day, you could argue that any initiatives promoting increased consumption of vegetables could only be a good thing. Co-author of the broccoli-juice paper Dr. Thomas Kensler tentatively suggested their findings could be used on a personal level, alongside state measures to improve quality of air.

This study points to a frugal, simple and safe means that can be taken by individuals to possibly reduce some of the long-term health risks associated with air pollution.

This while government leaders and policy makers define and implement more effective regulatory policies to improve air quality.”

Though Kensler might be over-estimating the benefits here, the price tag alone will probably put you off purchasing it. The juice – which weighs in at £16 a glass if you’re interested – may well end hitting supermarket shelves soon, but don’t hold your breath that it’ll save us from the dangers of air pollution. There are plenty of measure to solve that problem already.

Davide Restivo at Wikimedia Commons
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Scientists have finally said it: alcohol causes cancer

Enough of "linked" and "attributable": a new paper concludes that alcohol directly causes seven types of cancer.

I don't blame you if you switch off completely at the words "causes cancer". If you pay attention to certain publications, everything from sunbeds, to fish, to not getting enough sun, can all cause cancer. But this time, it's worth listening.

The journal Addiction has published a paper that makes a simple, yet startling, claim: 

"Evidence can support the judgement that alcohol causes cancer of the oropharynx [part of the throat], larynx, oesophagus, liver, colon, rectum and [female] breast"

So what's especially significant about this? 

First, scientists, unlike journalists, are very wary of the word "causes". It's hard to ever prove that one action directly led to another, rather than that both happened to occur within the same scenario. And yet Jennie Connor, author of the paper and professor in the Preventive and Social Medicine department at the University of Otago, New Zealand, has taken the leap.

Second, alcohol not only causes cancer of one kind – the evidence supports the claim that it causes cancer at seven different sites in our bodies. There was weaker evidence that it may also cause skin, prostate and pancreatic cancer, while the link between mouth cancers and alcohol consumption was the strongest. 

What did we know about alcohol and cancer before?

Many, many studies have "linked" cancer to alcohol, or argued that some cases may be "attributable" to alcohol consumption. 

This paper loooks back over a decade's worth of research into alcohol and cancer, and Connor concludes that all this evidence, taken together, proves that alcohol "increases the incidence of [cancer] in the population".

However, as Connor notes in her paper, "alcohol’s causal role is perceived to be more complex than tobacco's", partly because we still don't know exactly how alcohol causes cancer at these sites. Yet she argues that the evidence alone is enough to prove the cause, even if we don't know exactly how the "biologial mechanisms" work. 

Does this mean that drinking = cancer, then?

No. A causal link doesn't mean one thing always leads to the other. Also, cancer in these seven sites was shown to have what's called a "dose-response" relationship, which means the more you drink, the more you increase your chances of cancer.

On the bright side, scientists have also found that if you stop drinking altogether, you can reduce your chances back down again.

Are moderate drinkers off the hook?

Nope. Rather devastatingly, Connor notes that moderate drinkers bear a "considerable" portion of the cancer risk, and that targeting only heavy drinkers with alcohol risk reduction campaigns would have "limited" impact. 

What does this mean for public health? 

This is the tricky bit. In the paper, Connor points out that, given what we know about lung cancer and tobacco, the general advice is simply not to smoke. Now, a strong link proven over years of research may suggest the same about drinking, an activity society views as a bit risky but generally harmless.

Yet in 2012, it's estimated that alcohol-attributable cancers killed half a million people, which made up 5.8 per cent of cancer deaths worldwide. As we better understand the links between the two, it's possible that this proportion may turn out to be a lot higher. 

As she was doing the research, Connor commented:

"We've grown up with thinking cancer is very mysterious, we don't know what causes it and it's frightening, so to think that something as ordinary as drinking is associated with cancer I think is quite difficult."

What do we do now?

Drink less. The one semi-silver lining in the study is that the quantity of alcohol you consume has a real bearing on your risk of developing these cancers. 

On a wider scale, it looks like we need to recalibrate society's perspective on drinking. Drug campaigners have long pointed out that alcohol, while legal, is one of the most toxic and harmful drugs available  an argument that this study will bolster.

In January, England's chief medical officer Sally Davies introduced some of the strictest guidelines on alcohol consumption in the world, and later shocked a parliamentary hearing by saying that drinking could cause breast cancer.

"I would like people to take their choice knowing the issues," she told the hearing, "And do as I do when I reach for my glass of wine and think... do I want to raise my risk of breast cancer?"

Now, it's beginning to look like she was ahead of the curve. 

Barbara Speed is a technology and digital culture writer at the New Statesman and a staff writer at CityMetric.