Mattson research on ADF heart problems

This topic contains 5 replies, has 4 voices, and was last updated by Malcolm Charlton 10 years, 3 months ago.

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Damworker

12:19 am
25 Jul 14
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One of the contributors to the Horizon show, Mark Mattson did a study in 2010 which shows a rather worrying side effect – heart problems – in rats after prolonged alternate day fasting. The article is here http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2953475/#!po=43.1818

Anyone know about this? Did I fail to see the flaws in this research? It seems to be saying that whatever the short term benefits, there is an issue with using IF in the long term.

Mark says in a later video that IF is better for the heart which seems to contradict his 2010 study.

Thanks, David

Purple Vegie Eater

1:01 am
25 Jul 14
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Damworker, I guess there is a big difference between alternate day fasting and 5:2 (only 4 days fasting instead of 7 in a fortnight). Plenty of opportunity for healthy eating in between. Alternate day fasting was only used for the morbidly obese by Krista Vardy.
Also, were these the rats (nocturnal animals) who were woken to be fed in the daytime, to suit the researchers, and suffered anxiety as a result?
PVE

dlroseberry

12:10 am
30 Jul 14
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thanks for the link Damwowrker. It does say in the discussion section that the evidence overall is that IF rats live longer and healthier lives, including better heart health. Reduction in cardiomyocyte size and increased heart fibrosis resulted in less blood pumping capacity (by 16%) but this seems to not result in a shorter lifespan.

I would think that ADF is more stressful to rats than to humans because the rat energy reserves relative to base metabolic rate are much less. For this reason, I think it’s likely that humans won’t respond nearly as much to ADF as rodents do and 5:2 people will respond even less than ADFers. Nevertheless it is possible that fasting stress, while healthy overall, is not completely without negative effects for humans. So it is a warning. But I’m not clear that reduction in blood pumping capacity, unless it is large, is necessarily important to non-athletes.

dlroseberry

12:19 am
30 Jul 14
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This is also a very good reason to do HIIT. Exercising the heart should counteract this effect. I’ve been able to run now that I’ve lost so many pounds, and I count on this running to exert other health benefits, including heart health.

Damworker

8:53 pm
2 Aug 14
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Thanks for the replies.

If one discounts the study because rats are nocturnal then one would have to disregard many more positive studies too. Many people do 3:4 which is only 1 day less per fortnight than ADF and many of the claims made for IF come from ADF. I think Krista Varady even claimed that 5:2 had much less scientific backing than ADF because of this (though she has her own book out 🙂

The article itself makes plain that the findings are inconsistent with other studies showing long term benefit although there has been at least one other ‘negative’ article (concerning insulin response in women).

No treatment works perfectly even if the results are great for some (for example, many chemotherapy drugs have a complete remission rate of less than 20%).

Don’t get me wrong, i did 5:2 for nine months starting after Horizon first aired and I am an advocate having lost 2.5 stone. The weight loss alone is hopefully of benefit and I find it much more rewarding to exercise now but I find I need to do nearly 2 days fasting each week just to maintain (I note MM does one day fasting but also skips meals on other days so much the same).

As much as I am an advocate, I am starting to see this as a big experiment with us as the rats.

David

Malcolm Charlton

3:07 am
15 Aug 14
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Damworker, the article you have unearthed is interesting.
I wonder what Dr Michael Mosley has to say on it.
I saw his TV program only this week and I’ve started the diet with immediate effects and I’m sold on it.
As for Mosley;Ive never seen a more brilliant medical/scientific presenter who makes medical science understandable for non scientists.