The FastDay Forum

[carorees]

The original Horizon programme by Dr Mosley focussed a lot on the importance of lowering IGF-1 (insulin-like growth factor 1), but this was because it is something that can be measured in a blood test. What is more important is how what we eat/don't eat affects activation of the FoxO transcription factor.

This paper from 2008 is a good starting point for trying to understand the role of FOXO in ageing.

The FoxO family of Forkhead transcription factors functions at the interface of tumor suppression, energy metabolism, and organismal longevity. FoxO factors are key downstream targets of insulin, growth factor, nutrient, and oxidative stress stimuli that coordinate a wide-range of cellular outputs. FoxO-dependent cellular responses include gluconeogenesis, neuropeptide secretion, atrophy, autophagy, apoptosis, cell cycle arrest, and stress resistance. This review will discuss the roles of the mammalian FoxO family in a variety of cell-types, from stem cells to mature cells, in the context of the whole organism. Given the overwhelming evidence that the FoxO factors promote longevity in invertebrates, this review will also discuss the potential role of the FoxO factors in the aging of mammalian organisms.

Fellow nerds, enjoy!

PS, while the first part of the paper is impenetrable, later on where the authors discuss FOXO in the context of the whole organism it becomes more understandable!

Thank you Caroline for all your research and informative stuff I am finding it fascinating. There certainly seems to be a lot of ongoing studies on IF. I suppose we are all Guinea pigs in this!
Margaret (Isis)

Caroline, this great for us nerds, but if FoxO can't be measured except by cutting us up, isn't it still logical for us to focus on IGF-1, which can be (and is, by some, being) measured? Or is it irrelevant?

[carorees]

Hi dominic

Yes, I think it is the fact that IGF-1 can be measured that has driven the focus onto that molecule. The reason I mentioned FOXO is that the nutrients we consume (or don't) affect many systems that feed (!) into the nutrient-sensing pathways and this is very important in the way our bodies work so it is worth understanding how fasting affects these pathways (if we can)! Also because IGF-1 is not the whole story, I don't know how valuable testing for it actually is...

Thanks Caroline, at a practical level my concern about IGF-1 has led me to experiment with cutting back on milk intake (and not replacing it with soya either) - on feed days too. But maybe I am getting a bit paranoid!

The evidence of the Laron syndrome people in the program was pretty compelling, although I don't doubt there are controlling pathways between fasting and IGF1 falls. It may be just an intermediate stage, but at least one we can measure.

Thanks Caroline, at a practical level my concern about IGF-1 has led me to experiment with cutting back on milk intake (and not replacing it with soya either) - on feed days too. But maybe I am getting a bit paranoid!

Hi Dominic,could u expand on your milk intake concerns pls?

Thanks,
FL

Hi FL

• From here:
  
  Dairy foods increase growth hormones: In addition to calories and nutrients to support growth, cow’s milk increases hormones that directly stimulate the growth of the calf. The most powerful of these hormones is called insulin-like growth factor-1 (IGF-1). When cow’s milk is fed to people, IGF-1 levels also increase. Studies funded by the dairy industry show a 10% increase in IGF-1 levels in adolescent girls from one pint daily and the same 10% increase for postmenopausal women from 3 servings per day of nonfat milk or 1% milk. [4,5] This rise in IGF-1 level is an important reason for the “bone-building” effects of cow’s milk.
  
  IGF-1 promotes undesirable growth too—like cancer growth and accelerated aging. IGF-1 is one of the most powerful promoters of cancer growth ever discovered for cancers of the breast, prostate, lung, and colon. [6] Overstimulation of growth by IGF-1 leads to premature aging too—and reducing IGF-1 levels is “anti-aging.” [7]
  
  4) Cadogan J, Eastell R, Jones N, Barker ME. Milk intake and bone mineral acquisition in adolescent girls: randomised, controlled intervention trial. BMJ. 1997 Nov 15;315(7118):1255-60.
  
  5) Heaney RP, McCarron DA, Dawson-Hughes B, Oparil S, Berga SL, Stern JS, Barr SI, Rosen CJ. Dietary changes favorably affect bone remodeling in older adults. J Am Diet Assoc. 1999 Oct;99(10):1228-33.
  
  6) Moschos SJ, Mantzoros CS. The role of the IGF system in cancer: from basic to clinical studies and clinical applications. Oncology. 2002;63(4):317-32.
  
  7) Rincon M, Rudin E, Barzilai N. The insulin/IGF-1 signaling in mammals and its relevance to human longevity. Exp Gerontol. 2005 Nov;40(11):873-7.
  
  
• Another article here says, among other things:
  
  Drinking too much milk may increase your risk of developing certain types of cancer, such as prostate and ovarian, according to the Physicians Committee for Responsible Medicine. Milk contains a hormone called insulin-like growth factor-1 which may help stimulate the growth of cancer cells. According to a 1998 study published in "Science," men with the highest levels of this hormone were four times more likely to develop prostate cancer.
  
  
• And lastly (as this post is already long enough!) another from here:
  
  In conclusion, the research shows that nutrition has an important role in determining serum IGF-1 levels (Yaker et al., 2005). Whether the increase in IGF-1 caused by cow’s milk occurs directly (by IGF-1 crossing the gut wall), or indirectly (as a result of the action of other factors), the research is clear. The consumption of cow’s milk and milk products is linked to increased levels of IGF-1, which in turn are linked to various cancers.

Hi Dominic,am I right to conclude that other milk 'types' such as Soya or rice are ok then....?

Caroline and PhilT can advise better, but unfortunately I think Soya milk is just as bad if not worse. See the thread here from the breastcancercare.org.uk forum. From this thread I believe that Koko (coconut-based, widely available e.g. from Tesco) is okay (formerly called Kara).

P.S. there are other concerns about soya milk for women - phytoestrogens?

Thanks Dominic-really interesting if not slightly confusing ! I don't drink lots of tea/coffee (usually no more than 3 cups of either/or per day) and maybe every other day with cereal.I think I might try rice milk and see how much difference it makes. Although I do like my fruit and fat free Greek yoghurt though....

[carorees]

Unless you are getting through lots of dairy (several bowls of cereal and milk, milk shakes, lattes, custard etc every day) I wouldn't stress about it. Very low IGF1 is also bad for us so no need to go all out to change your diet.

I'm so glad you've said that Caroline, you are the voice of reason yet again ! I really don't have loads of dairy and TBH sometimes I think we can have a tendency to over-analyse some stuff regarding what's 'good' or 'bad' don't you ?

Thanks Dominic for posting all that info! I usually take ss milk in tea/coffee - probably average 10cups total per day, also take milky porridge every day, tho that's cut to 5 days a week now of course

I also take on board what u are saying Caroline, nonetheless certainly food for thought...if you'll pardon the pun

Also interesting to see that Koko (Kara) contains only 8.4% coconut milk


Filtered Water,Coconut Milk 8.4% ,Grape Juice Concentrate ,Calcium Phosphate ,Emulsifier: Sucrose Ester ,Sea Salt ,Colour: Natural Carotene ,Vitamin D2 ,Vitamin B12