Tuesday, 21 October 2008

Don't forget to keep fit, or vice versa

Fat levels contribute to Alzheimer's?

Interesting. The levels of fatty acids in the Brain contribute to Alzheimer's, or at least do in transgenic mice designed to show Alzheimer's like symptoms. That's an important distinction, because these mice don't actually have Alzheimer's, they have a certain pathology that shows the same symptoms. The article does point this out, but this article is slightly hit-and-miss with it's accuracy. Sometimes it specifically points out the facts, sometimes it glosses over them. For example:

"...in mice genetically engineered to have an Alzheimer's-like condition" - Correct. The mice don't have Alzheimer's, as discussed above. If we could give mice actual Alzheimer's, then that would mean we understood it precisely, which suggests we could do something about it, beyond just giving it to mice. The strain is called APPSWE Tg257, to be precise (Assuming they use the same ones as in my lab)

There are currently 700,000 people living with dementia in the UK, but that number is forecast to double within a generation" - Correct but misleading. This smacks of scaremongering, but potentially scaremongering to increase awareness of Alzheimer's, which is OK I guess. But well done on saying dementia rather than Alzheimer's, because last I heard, it was only possible to confirm Alzheimer's after death, which is too late if anything. (Also, because of the unknown origin of the disease, you can't leave your body to medical examination after death in case someone 'catches' it, which is ridiculously unlikely but can't be guaranteed. Of course, anyone suffering the disease won't remember that, no matter how many times you tell them). But this is mildly misleading because dementia affects around 50% of people over 80. And thanks to improved health care and medical advances, that's the most rapidly expanding age group, so the disease will increase with it.

""In general, fatty acid levels can be regulated by diet or drugs...But a lot more work needs to be done before this novel therapeutic strategy can be tested on humans" - Good, I like the cautious tone. Because given the way the media works, this could be taken by several types of scaremongers and twisted to deliver completely different messages. The anti-choice health Nazi's like McKeith and her ilk could use this as just another example of how eating a lot of fat is bad for you and you shouldn't eat anything other than muesli and tree bark, you ignorant overweight prole. This would lead to mixed messages, as if you eat too much fat you'll die of heart disease and get Alzheimer's. In truth, doing both is highly unlikely, what with dying young being possibly the best prevention of Alzheimer's, but since when did logic and actual science stop these shrieking harridans?
Then there's the anti-government brigade, who could argue that 'life saving treatment being withheld on the NHS', by not giving Alzheimer's patients diet drugs or some other cock-and-bull rationalisation. If there were such a thing as a pill that could prevent uptake of body fat, then it would be worth billions, much like Viagra is. There are some diet pills that prevent up to 30% of fat being digested into your system, but this means it passes straight through. And bare in mind fat is hydrophobic, which means after visiting the toilet you get a lot of 'floaters', which may result in being invited to less parties.

This is a massive generalisation, of course, seeing as one type of fatty acid is linked to the disease and there are many in our bodies, and they are useful. But one thing that's remarkable about diet is the extent to which it depends on memory. Although there are many internal systems in use, like stomach extension, blood sugar levels etc., our habits can often override these with no fuss. If we eat at 3pm every day, we'll be hungry at 3pm, this is habit forming and is a basic and powerful form of memory. As long as we know we've eaten we'll not be hungry. But the time when you eat is an episode, and episodic memory is the first thing to go when you have Alzheimer's (trust me, this is my field). So it's around 3pm, you don't remember eating, you'll eat. You might eat half a dozen meals before someone stops you, it's a problem with people who suffer from anterograde amnesia (can't make new memories, the guy in Memento had it).

People who suffer from Anterograde amnesia have a problem with weight gain, as they forget that they've aready eaten. One of the most common causes of this is Alzheimer's, which is apparently worsened by fat consumption. Vicious cycle. But don't forget that not eating enough, like with sufferers of eating disorders tend to do, can cause memory loss too. Lack of thyamine shrivels the mammilary bodies (small brain nuclei, not breasts, although they lose mass too,m come to think of it) and these are part of the diencephalon, which controls memory. Korsakoff's syndrome, where you can't remember anything, but tend to make it up without realising it. These people have dull lives but exciting memories. So you could say you suffer memory problems if you eat too much or too little. What's the point of all this ranting? Buggered if I can remember.

Alzheimer's mentioned = 16 times.


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