Can ageing be prevented by dietary restriction?
Mech Ageing Dev. 2006 Dec 2; [Epub ahead of print]

This paper disputes the suggestion of Hipkiss [Hipkiss, A., 2006. On the mechanisms of ageing suppression by dietary restriction-is persistent glycolysis the problem? Mech. Ageing Dev. 127, 8-15], according to which dietary restriction by decreasing methylglyoxal production may prevent ageing. A list of arguments is given to support the refusal of hypothesis: (i) it has never been proven that the main source of methylglyoxal is its formation from triose-phosphate intermediates of glycolysis; (ii) the above note particularly applies to pathological conditions as acetone breakdown and amino acid metabolism also come into picture under these circumstances; (iii) glycolysis is of vital importance, thus its inhibition or a sharp restriction of carbohydrate uptake are unlikely beneficial for those tissues that are exclusively dependent on glycolysis in the regard of their energy production. Taken these concerns into account and considered all the promising attempts to influence the toxic effects of methylglyoxal, it is feared that the theory, as it is, cannot offer benefit to prevent ageing.

PMID: 17145073 [PubMed - as supplied by publisher]


Synergistic effects of caloric restriction with maintained protein intake on skeletal muscle performance in 21-month-old rats: a mitochondria-mediated pathway.
FASEB J. 2006 Dec;20(14):2439-50.

Caloric restriction (CR) delays the onset of age-related mitochondrial abnormalities but does not prevent the decline in ATP production needed to sustain muscle protein fractional synthesis rate (FSR) and contractile activity. We hypothesized that improving mitochondrial activity and FSR using a CR diet with maintained protein intakes could enhance myofibrillar protein FSR and consequently improve muscle strength in aging rats. Wistar rats (21 months old) were fed either an ad libitum (AL), 40% protein-energy restricted (PER) or 40% AL-isonitrogenous energy restricted (ER) diet for 5 months. ATP production, electron transport chain activity, reactive oxygen species (ROS) generation, protein carbonyl content and FSR were determined in both tibialis anterior (TA) and soleus muscle mitochondria. Myosin and actin FSR and grip force were also investigated. The ER diet led to improved mitochondrial activity and ATP production in the TA and soleus muscles in comparison with PER. Furthermore, mitochondrial FSR in the TA was enhanced under the ER diet but diminished under the PER. Mitochondrial protein carbonyl content was decreased by both the ER and PER diets. The ER diet was able to improve myosin and actin FSR and grip force. Therefore, the synergistic effects of CR with maintained protein intake may help to limit the progression of sarcopenia by optimizing the turnover rates and functions of major proteins in skeletal muscle.

PMID: 17142793 [PubMed - in process]

(originally posted on CRS list)

Al Pater "It seems that fasting/CR affects paraoxonase 1 activity. See, for
explanation in more detail for what is the function of paraoxonase 1:
http://www.clinchem.org/cgi/content/full/51/5/922 "Paraoxonase 1 (PON1) is
a HDL-associated enzyme that catalyzes the hydrolysis of lipid peroxides in
LDL and HDL and has been postulated as a member of the plasma antioxidant
system. Decreased PON1 activity has been associated with atherosclerosis in
persons with diabetes mellitus, familial hypercholesterolemia, and renal
disease (1)(2)." High-density lipoprotein (HDL) and low DL (LDL) oxidation
are negatives. The below paper that is pdf not availed examines the
CR-associated effect on the effects of the fasting/CR on stress with respect
to anti-oxidation."

Thomas-Moya E, Nadal-Casellas A, Gianotti M, Llado I, Proenza AM. Time-dependent modulation of rat serum paraoxonase 1 activity by fasting. Pflugers Arch. 2006 Dec 5; [Epub ahead of print]
PMID: 17146679

High-density lipoprotein-associated paraoxonase 1 (PON1) protects the
endothelium from the pro-oxidant activity of oxidised low-density
lipoprotein. Whereas fasting has been related to increased oxidative stress,
intermittent fasting and caloric restriction are associated to increased
resistance to oxidative injury. Taking into consideration that serum PON1
activity is modulated by a restriction of caloric intake and because there
is no evidence regarding PON1 response to total food deprivation, we
investigated whether PON1 activity is involved in the response aimed to
counteract the greater oxidative stress associated to fasting and whether
serum PON1 activity is altered by the length of food deprivation. Male
Wistar rats were randomly divided into five groups: fed and 6-, 12-, 24- or
48-h fasted rats. Serum PON1 activity increases within the first hours of
fasting, representing a prompt adaptation designed to attenuate blood lipid
peroxidation that cannot be sustained when fasting is prolonged. This PON1
response to early fasting could be part of the mechanisms triggered by
periodically repeated short periods of food deprivation-intermittent
fasting-which result in increased resistance to stress by stimulating
antioxidant defences.

So macronutrient ratio does matter in CR.

Wyv

One of the things I notice about this line of research and some of the conclusions that seem like they may go a little above and beyond what the research literally says, are things like this:



Eating every other day or one meal a day is not going to provide complete nutrition. Heck it's hard enough to get even decent nutrition eating three meals a day.

Now, I'd be thin if only eating once a day was the answer for everyone; I've been lowcarbing for nearly three months now and I've demonstrated clearly to myself, with careful tracking, that the more my calories drop, the more my weight gain slows, and vice-versa -- as long as no matter what the calories (up to 2500), the carbs are fairly low. In my highest calorie eating plan but which included eating 5-7 tiny meals a day, I lost the most weight by far. Of course, I'm seriously obese and my body seems to have a major protection metabolic-shutdown-starvation-response to not eating regularly, so I may not be a typical example.

But I am tempted to wonder if it's always fair to interchange "less overall calories" with "less overall food" or even "very infrequent meals". I suspect that research done side by side that kept the same calories but varied the quantity of food intake and the frequency of food intake would not have "eating only occasionally" as the winner of much; dunno, would have to see it.

So far all I see is research that suggests that reducing calories is good. Sure, hard to argue with that. But I don't think that research on its own merits any conclusions about intermittant fasting. Calories vs. quantity of food vs. frequency of food seem to me, to probably be three different variables.

You can see a VIDEO interview with both michael and april in this CNN video

http://dynamic.cnn.com/apps/tp/vide...nn/video.ws.asx

Fair enough, this was your experience... although the data shows that CR has beneficial effects without making the animal becoming real thin. Even overweight CR'd animals outlive thin exercised lean animals.

In Calorie Restriction the metabolic rate actually goes right back to normal not long after being CR'd.

All a human being needs to do to benefit from the projected TWO-PERCENT increase in lifespan is to become a sexless eunuch that must restrict strenuous activity because they wont have the energy. Being cold all the time and shopping in young men's or junior misses department for the rest of you life is just a bonus.

What a life! Where do I sign up?

No need to sign up mutant... just eat less

Stick around, lets see if those rhesus monkeys get more than 2-3 year increase in both mean and maximum lifespan

Now really, that's a bit disgenuous. You are undereating to the point where normal body functions are disturbed. That is the reason CRONbies compulsively measure different body functions like body temperature; ice cold hands are a sign that the CRONbie is successfully starving themselves. (Cold hands, warm heart?) Is male sexual disfunction considered a positive? I see it mentioned frequently among CRONbies but get the feeling that with the coincident loss of libido and general lethargy that ultimately it isn't an issue. I know from personal experience of raising various exotic fish and reptiles that getting them to breed was a positive as it showed you finally got all of the enviromental variables right (nutrition, light, water chemistry, etc) I find it curious that a direct result of 'Optimal Nutrition' is sexual disfunction and disinterest. Besides abnomally low testosterone in men are there other hormone levels that are abnormal? DHEA? Growth Hormone? What about brain chemistry?

Cool Mice Live Longer
http://www.livescience.com/animalwo..._cool_mice.html

Cool humans live longer
http://news.bbc.co.uk/1/hi/health/2167316.stm

"Men with lower temperature and insulin and those maintaining higher DHEAS levels have greater survival than respective counterparts,"





I don't know... I don't have that problem



Then so what? Isn't your problem is it?



IGF-1 is lower, Testosterone is lower, DHEA is lower and not sure about brain chemistry... I guess the lower testosterone helps keep away aggression -- Might keep us out of trouble or early death from doing stupid things.

All those hormones are also reduced in CR'd animals, including okinawans... its just they will decline will be much slower.

I guess you already seen it, if not then look

DHEA (okies vs americans)- http://img.photobucket.com/albums/v...82/000_1922.jpg

do NOT need to start off with a high DHEA level to have a better chance of survival. Rather its the rate of decline.

Well, the CRONbie cult has determined that having screwed up body chemistry is a 'good thing'. Having emaciated bodies that can't work as hard or long wether in labor or recreation is a 'good thing'. Chemically emasculating yourselves through diet is a good thing.

You do know that testosterone is what makes a man a man? The more I think about the CRONbie cult I imagine that it may really be a perverted sex cult focused on supressing their sexuality under the cover of health and longevity. (I use the word 'health' very loosely here, as the indignities they inflict on their bodies is hardly healthy) I just hope they don't come to eat my brains! (YES! I have some! ) Some of the effects of starvation (read 'CRON') on the mind have been studied. Are the mental issues of CRON (body dismorphia, obsessive compulsions and sexual issues) caused by the starvation or present before the starvation? Chicken or the Egg?

My hope is that the CRONbies will be self-limiting like the Shakers of days gone bye. Maybe we can get some of the clergy, Boy Scout leaders and day-care workers on the program? An outreach program!