30/11/2012 11:06 GMT | Updated 27/01/2013 05:12 GMT

Dairy Causes Cancer, Sure I Googled It...

It is rare to experience a situation that leaves you bemused and fearful in equal measure but, just such a scenario occurred this week. During a perusal of all things nutritional I stumbled upon a discussion on the role dairy plays in causing cancer. It became quickly apparent that I was the group misfit, an outcast from their 'nutritional enlightenment', as I committed an act deemed worse than heresy in interjecting with actual science. Milk does not cause cancer and if anything is protective. To say it caused outrage would be an understatement.

Here's the thing, there is legitimate concern that dairy is involved in cancer. You only have to take the bestselling book 'The China Study' which renounces dairy as a demonic perpetrator igniting the cancer fire in all who consume it. However, the evidence base for the argument is at best tenuous and the multitude of studies that have come out since then suggest otherwise. Indeed, despite a dairy free diet being widely propagated for combating breast cancer, a 2011 meta-analysis of 18 prospective studies found those who eat the highest amounts of dairy have a 15% lower risk of breast cancer [1].

The first reply from a nutritionist -with careful use of exclamation marks to express her sheer indignation- was to tell me that modern farming methods ensure 60-80% of dietary oestrogen (the female hormone) comes from dairy, which promotes hormonal receptive cancer growth i.e. prostate, testicular and breast cancer.

Oestrogen is definitely a risk factor for breast cancer, but this belief that milk is an oestrogen laden brew, effectively feminising a nation is a bit hard to swallow. And when you check the facts you see the concern of high oestrogen in milk is based on mere speculation; that pregnant cows are now being used for our milk -to give a higher milk yield- and thus introducing high oestrogen levels into our food supply.

But the truth is, most of our milk is from non pregnant cattle and rarely is it produced after 220 days of pregnancy when hormones are at their highest [2]. If we drank 3 glasses of milk a day from pregnant cows we would be exposed to an estimated oestrogen total of 9.6 ng (non pregnant cows, which are the majority, would provide many, many times less)[2]. It has been reported that prepubertal girls produce 54,000 ng of oestrogens per day and that prepubertal boys produce 100,000 ng of oestrogens per day [2]. So really, is 10 more units on top of already 10s of thousands really going to have an impact? When we spout out 'facts' we really must get them in context before we go spreading these neuroses to individuals who entrust us to give scientifically sound advice to improve one's health.

But, it was the second reply that was simply astounding. A reply that got the 'likes' from the other members in the group. It started with the 'de facto' statement that 'holding up science as a paragon of virtue is not a good idea'. Immediately the alarm bells are ringing. This is the favourite tactic of the self proclaimed nutrition expert. Because they have no merited scientific background, they dismiss science off hand to try and level the playing field, and then they bring out their own brand of attention grabbing sensationalism with not an iota of evidence to back it, but by golly it sure makes a good tale. I'm the first to admit that science does not have all the answers, that new findings are continually forthcoming and old beliefs being expunged. But to use this as an excuse to simply dismiss science and instead create whatever style of fairytale that takes your fancy goes beyond ludricous.

And, it only got worse from here as the scientific studies were further dismissed with the 'irrefutable' logic that of course we should be disturbed about the dairy and cancer link for 'you only need to search Google for dairy and cancer and see the amount of results that are returned.' And, surely, you can't argue with that, '"dairy" AND "cancer"' in a Google search returns a whopping 47.5 million results. So, it got me wondering, what other aspects of life are we not concerning ourselves enough with?

Using the Google barometer we find that fears over 'dairy' and 'cancer' pale in comparison to fears about a vampire attack ('"vampire" AND "attack"' brings in a whopping 69 million results). And with 12 million results we really shouldn't be taking the risk of an 'alien abduction' too lightly either. We all know Ireland is great place to holiday in, but with over 6 million returns for 'leprechaun and gold' you surely have added incentive to visit now.

It's easy to be facetious here, and throw in a few quips. We can take a lighthearted approach, safe in the knowledge that the take home message is always the sensible one, the one endorsed by hard science. However, in the murky world of nutrition, further contaminated by the advent of the internet, egregious opinions such as these can quickly gain credence in a culture which lusts for sensationalism, and supposed nutrition experts only too happy to give it its seal of approval. It is therefore imperative to analyse, not merely accept, the material that claims to improve your health, as sadly the facts often beg to differ.