Friday, 22 April 2011

Blueberries are yummy

I read The Week because it amalgamates and distills the past weeks news and events down to bite size chunks which are much more palatable than reading 7-days worth of newspapers etc. I normally trust what it says because it doesn't have it's own agenda; it attempts uncouple the weeks events from the spin and speculation presented in other media. But, this week, when its science page reported a story from the Daily Fail which claimed that "Slimmers should start snacking on blueberries, as they slash the number of fat cells in the body by up to three-quarters (!), say scientists", this was my face:

The story originates from a press release (which I can't find: science-blogging n00b) from Texas Women's University where Dr. Shiwani Moghe has apparently shown that a chemical found in blueberries could prevent fat cell precursors from forming mature fat cells. Here is the abstract: Clicky!

The data are* yet to be published, but from what I can glean from the abstract, I can see that the Daily Mail's reporting of it is completely FUBAR. 

Here's what Dr. Moghe did: she cultured some cells from mouse embryos. The cells normally form fat cells (or at least cells which resemble fat cells in vitro). Then she added various amounts of blueberry extract to the culture medium (that's the juice that the cells grow in). Then she measured the rate at which the cells differentiated, the amount of fat in the cells and the rate at which they broke down the fat. Now, regardless of what her results are, its clear that this study cannot tell us what will happen to the fat cells in humans who eat blueberries.

There are a few things that I want to know before I'd encourage any portly-people up my blueberry intake. Firstly, how efficiently do out gastrointestinal tracts absorb these polyphenols? Secondly, how long do they last in our blood stream before they are metabolised or excreted? Thirdly, what concentration of polyphenols do fat cells see in vivo and how many blueberries would I have to eat to reach the concentrations that Dr. Moghe exposed her rat cell culture to? And finally, is the fat-cell precursor maturation model a good representation of how we gain weight?

And that is before we even consider whether or not the same effect would be seen in the much more complicated environment of a living organism or what other effects these polyphenols might have, especially at high doses. I'm not slating Dr. Moghe's work because it is a valid piece of research (if not very profound) , which I will read when it's published properly, but it doesn't even hint at the sort of extrapolations that the Daily Mail (and others) have hinted at: but nevertheless, these vultures will benefit from it.

A bit of a higgledy-piggledy post, I know, but hopefully I made my point. Thank you, and goodnight.

* using 'data' properly, as a plural, is one of life's little pleasures.