Regular readers of this site will know I tend to give my blog posts quite literal and descriptive titles: Why is the dietary advice given to diabetics so often so woefully inadequate?�, that sort of thing. So, I promised to write about sunlight and beta-carotene today (which I will, give me a moment�), but thought I’d use a less obvious title today because it might just lure the attention of the individuals who have taken great issue with the fact that I believe that the evidence used to vindicate MMR with respect to autism is ‘shoddy’ (and don’t mind saying so). The evidence does no such thing. Not even close. And seeing as this is a matter of extreme importance in terms of people’s lives, those who maintain that the evidence proves that MMR is safe with regard to autism I believe are misleading the public in a way which may be having grave consequences. Let’s hope not, but we just don’t know.
The scientific evidence these people cite is like a two-legged stool: every time they put it up, it falls down again. If you’ve been following the ‘debate’ unfold over the last few days you may now be of the view that the only thing to admire those who keep attempting to put the stool up again is their persistence.
But, it’s a pointless, exercise, I reckon, and these individuals need putting out of their misery. And the fact remains that we need more evidence to know beyond reasonable doubt that MMR is not responsible for a whole different sort of misery, in the form of regressive autism and the lives it can blight.
So, the title above is partly a reference to the whining that’s been coming from a group of individuals who know the game’s up, but still proclaim MMR’s innocence.
But the title is also a reference to what this blog is really about, which is about beta-carotene, and its ability to help prevent sunburn (geddit?).
Those that read my blog on Monday may remember that I was due to write about this subject then, but the weekend had been grey and drizzly, and I was diverted by the MMR/autism thing anyway. Now, right on cue (where I am anyway), the sun is out, and it therefore seems like an ideal time to deliver on my promise from Monday.
Beta-carotene (the nutrient that is responsible for the orange colour of carrots) comes from a family of nutrients known as the carotenoids (I wonder why). Beta-carotene has what is known as antioxidant action, which means it helps neutralise damaging, destructive molecules known as free radicals. Now, free radicals have a role to play in sunburn (sunlight exposure increases free radical production in the skin). So, in theory at least, more beta-carotene in the body and specifically the skin may help prevent sunburn.
Several studies have looked at whether beta-carotene does do this in the real world, and the study I’m focusing on today took 7 such studies, and lumped them all together in the form of what is known as a ‘meta-analysis’. In the individual studies, beat-carotene dosing ranged from 15 ” 180 mg per day. The conclusion of the study was that beta-carotene did indeed have the capacity to offer protection against sunburn. This study also looked at how long individuals need to take beta-carotene for before their skin is ‘primed’. A minimum of 10 weeks is the answer. So, sorry, if you live in the UK and haven’t been dosing up on beta-carotene then you’ve missed the boat rather. On the plus side, there is always next year.
Beta-carotene is not the only nutrient that might help prevent sunburn. See here for a recent blog which looks at this, as well as giving an account of the nutrients which may actually promote tanning.
References:
1. Kopcke W, et al. Protection from sunburn with beta-carotene ” A meta-analysis. Photochemistry and Photobiology. 2008;82(2):284-288
