The FastDay Forum

[Tracieknits]

Anthony - I think one needs to be careful of studies, and see who is funding them. In the US,the dairy lobby is incredibly strong and are known to finance studies that have the intent of proving how healthy milk is, rather than seeing if it's healthy.

But also, "healthy" is such a general term, isn't it? In this thread, what was being discussed was the production of a particular hormone, IGF-1 and the effect of protein and dairy on that hormone. Now it may be true that the studies you cite do show that those particular amino acids are increased to repair muscles after the consumption of whey protein. But that's actually beside this point about IGF-1. Both things could very well be true - but many people who are interested in IGF-1 are interested because of the effects this hormone has on cancer risk and diabetes risk, as well as this particular diet's effect on obesity.

I can see that IGF-1 (also sometimes called IGF1 or IGF-I, I think they are all the same thing) is a hot topic, maybe it needs forking into a new thread but as there is already discussion here (especially and very helpfully by carorees), and at the risk of going over some ground that was already covered earlier, I'll continue...

We can all agree about the medical benefits of losing weight, for those of us who are or have been overweight. The 5:2 diet delivers these as do other diets. But the 5:2 diet (and other IF regimes) may offer something more and that 'more' seems connected with this mysterious IGF-1, an endocrine hormone mostly produced by the liver.

There is a positive correlation between IGF-1 levels in the bloodstream and prostate cancer risk, see http://jnci.oxfordjournals.org/content/92/23/1910.abstract?ijkey=3f3ecd08353d260c941a424eca6f3688b52f49b6&keytype2=tf_ipsecsha (2000). There is also a positive correlation between levels of intake of animal fat/animal protein and IGF-1 levels http://jnci.oxfordjournals.org/content/93/8/649.full [2001]. Note that there is no correlation between obesity or high BMI or total protein intake or total energy intake and prostate cancer risk.

The problem is knowing whether IGF-1 level is a merely an indicator of risk or whether there is a causal link. If it is only an indicator then targeting its reduction is at best a distraction and at worst may be damaging.

However more recent research http://www.ncbi.nlm.nih.gov/pubmed/22520978 (2012) says that 'IGF1 and IGF2 can promote cancer growth', so it seems that the idea that IGF-1 is a cause and not just a positive correlative for cancer is now in the research mainstream.

If this is the case, then avoiding raised IGF-1 would seem to be a good thing (for adults), and this is what the 5:2 diet might achieve (see the original Horizon programme, which of course is anecdotal evidence only). I think Dr Michael Mosley is pretty persuaded of the connection because lowering his IGF-1 seems to be one of his key aims in the programme. He achieves it (and it is clearly not just a function of the weight loss which he also achieves).

He also seems quite keen to reduce milk consumption, including on fast days, recommending black tea and coffee. I suspect this is because of the link between milk and raised IGF-1; dairy milk is a particularly strong source of IGF-1 (much more so than most other animal products), and unfortunately soya milk seems to be the same (http://www.breastcancercare.org.uk/community/forums/yes-or-no-soya-milk). There are some alternatives such as coconut-based milk (http://www.kokodairyfree.com/) and rice milk which apparently do not raise IGF-1 - I can't say I have tried them.

Dominic (not a medic...)

Seen as everyone is obsessed by IGF-1 on this thread I thought I would share something I read yesterday. Remember the Laron people from Ecuador who featured in the Horizon programme. Mosley went his length to say how they were free from diabetes and cancer because their IGF-1 levels are naturally low. What he didn't say is that their life expectancy is no different from anyone else. So what does this say? First of all it says to me that Mosley isn't presenting the full story. I certainly assumed from what he was saying that if you didn't get diabetes or cancer than you would live longer! It also shows that a life time exposure to low IGF-1 levels doesn't extend life.

Well said Echo. I fully believe the link between igf-1 and cancer but am very interested to know more about the implications of low igf-1 levels.

[carorees]

I'm sure I read or heard that the Laron mice just drop dead for no obvious reason. That is how I'd like to go...not bothered about living longer just living in good health for longer. Of course the whole living longer in other species thing is likely not to apply to humans because we live longer than we "should" anyway with all the medical interventions. I don't suppose that kind of medical care is offered to lab mice!

Dr Mosley said he wasn't interested in living longer; he just wanted to live free of the diseases that would stop him enjoying the life he had left. Therefore, living a longer life because we don't get certain diseases is not the point; living a disease free life that enables us make the best of the lives we have is.

Dr Mosley states clearly that there’s no fighting our genetic make-up.

I’m not obsessed with living longer, just living with all my faculties and free of cancer.

Remember the Laron people from Ecuador who featured in the Horizon programme. Mosley went his length to say how they were free from diabetes and cancer because their IGF-1 levels are naturally low. What he didn't say is that their life expectancy is no different from anyone else.

"Because of their striking freedom from cancer and diabetes, they probably could live much longer if they did not have a much higher than usual death rate from causes unrelated to age, like alcoholism and accidents."

http://www.nytimes.com/2011/02/17/scien ... .html?_r=0 and others

[Tracieknits]

I thought Dr. Mosley said that because they felt invincible, their diet was actually considerably worse than their peers and they ended up getting a lot of heart disease and having other problems.

[carorees]

People with Laron syndrome don't get cardiovascular disease as we know it; rather they suffer from too thin cardiac muscle which reduces the heart's ability to pump.

People with Laron syndrome also have too much growth hormone, but their tissues are resistant to the effects of growth hormone which makes them tend to become obese...I think this is occurs even if they don't eat a terrible diet...and this also makes them have reduced muscle bulk (as seen in the heart muscle) and of course stunts their growth.

What they do get is epilepsy and other convulsive disorders, which is a major cause of death, (along with accidents etc as Echo said), but they don't know why they tend to get epilepsy.

"Because of their striking freedom from cancer and diabetes, they probably could live much longer if they did not have a much higher than usual death rate from causes unrelated to age, like alcoholism and accidents."

They obviously have to die from something as everyone does but why didn't Mosley report this. Well because it didn't fit in with the story. Also if they don't die of cancer or diabetes then all other causes of death would appear to occur at a higher rate than the general population who do die of cancer and diabetes.

The big claim with the fasting is that it will reduce your IGF-1 level, decrease your chances of getting cancer or diabetes therefore result in a longer healthier life. I'm not saying that this isn't the case. All I am saying is why didn't they explain in the programme that the only people on earth to live their whole life with low IGF-1 didn't live any longer.

I agree that living a disease free life is more attractive than living a long life which is why I want to make sure that I am not doing any damage in the face of doing good.

Is there perhaps a link between laron syndrome heart problems plus the adf'ing rat study or am I adding 2 +2 to make 5?

[carorees]

I suspect you are right skippy. In the rat study, though, the problem was stiffness of the heart muscle whereas in Laron individuals it seems to be thinness of the muscle. Of course, lowering IGF-1 through fasting in the context of normal growth hormone responsiveness (the rats) will result in a different metabolic situation than having a genetic condition resulting in low IGF-1. But what we can see is that low IGF-1 levels can affect the muscles (including the heart muscle). And this is something that is also seen in very old age where people become frail with loss of muscle (and weakness of bones).

[carorees]

Dr M says to keep down to a daily target of 0.85g of protein for every kg of your body weight, which is around 60g protein.

The 0.85g per kg of body weight comes to 67g at my goal weight, which is 268 kcal, or 11% of a 2400 kcal/day diet (which I calculate to be pretty close to a weight-maintaining diet once I get there). This seems pretty low to me, but that aside, does Dr. M have a suggestion on how to split the other 89% of calories between carbs and fat?

[carorees]

No, I don't think so just that low GL is the way to go. There is some scientific evidence that long term low carbing or frequent fasting (ADF) can deposit fats in the heart muscle and cause stiffness and left ventricular dysfunction. So as with everything...moderation is needed! My guess is that the Mediterranean diet as expounded in the 2 day diet is best wrt fast and carb balance.