Strength and longevity are compatible

Growth and aging are thought to be processes that are mirror images of each other. When development has stopped and maturity reached, cellular and biochemical processes that promote growth in the earlier part of life then promote aging. Strength is part of growth, but in my opinion, strength and longevity are compatible.

There’s good evidence for the relation between growth and aging, and for an overview I recommend the paper by Mikhail Blagosklonny, who has written extensively on this, Aging is not programmed: Genetic pseudo-program is a shadow of developmental growth.(1)

According to Blagosklonny, aging is a “quasi-program”, the continuation of the growth program. Among the most important systems that promote both growth and aging is the cellular nutrient sensor mTOR.

Without getting bogged down in the theoretical reasons why this may be true, the immediate question that comes to mind is, do interventions that promote growth also promote aging?

If they do, then we may want to avoid them in order to slow aging.

For example, milk and other dairy products increase the activity of mTOR.(2) This makes sense: mammals use milk to promote the growth of their offspring.

Iron deficiency down-regulates mTOR.(3) If iron acts this way in a linear fashion with no threshold, as it does in other aspects of physiology, then increased iron activates mTOR, thus promoting both growth and aging. This also makes sense, as growing animals require large amounts of iron; after maturity, not much iron is required, and excess amounts promote aging through mTOR activation.

Is this the whole story? Do we all want to become vegans in order to slow aging?

Balance is the key to both strength and longevity

Probably not, because the growth program is needed in aging as well. The key, I believe, is balance.

Consider that levels of IGF-1, a growth hormone, were positively correlated with scores on an exam designed to test cognitive function.(4) Furthermore, the lower the IGF-1, the greater the thickness of carotid arteries.

Patients with AD [Alzheimer’s disease] and VaD [vascular dementia] had significantly lower IGF-1 concentrations and greater mean IMT [carotid artery intima-media thickness] than nondemented controls.

Low levels of IGF-1 are also seen in osteoporosis.(5)

Low levels of growth hormone and IGF-1 may be involved in the development of sarcopenia (muscle wasting) in the elderly.(6)

With this evidence we see that lower levels of growth factors could lead to frailty and cognitive decline in aging.

In aging, the ideal is to slow it or fight it as much as possible while remaining strong and vigorous. If you’re going to be confined to a wheelchair or be unable to read in your old age, that’s not going to be much fun.

How do we find balance in aging between slowing the aging process and maintaining strength and energy and a sharp intellect?

Protein intake

Adequate protein is necessary for strong bones, muscles, and brain. Too much, however, conduces to aging.

Trained bodybuilders need only about 1.1 grams of protein per kilogram of body weight to maintain muscle mass. Adding muscle may require somewhat more.

So, to promote strength but to slow aging as much as possible, don’t eat more protein than this.


The study cited above discussed how milk and dairy products activate mTOR and thus promote growth. One of the mechanisms through which dairy products do this is through their relatively large fraction of branched-chain amino acids (BCAAs).

Here’s the thing though: BCAAs increase lifespan in mice and enhanced physical endurance (exercise capacity).

So don’t forgo the dairy, would be my advice.


As we’ve discussed ad infinitum on these pages, excess iron promotes aging. Here, the link between growth and aging is less strong, since in the developed world, it’s difficult to get too little iron. In almost all stages of life, iron levels will be more than adequate enough to support strength in older age; it’s the excess we need to be worried about, and there are a number of things you can do about it.

Intermittent challenges / hormesis

To my mind, the best way to balance strength and energy with fighting aging is through emphasizing the natural cycles of buildup and breakdown, anabolism vs catabolism, that the body normally does on its own but the amplitude of which declines with age. Both catabolism (autophagy) and anabolism (synthesis of muscle and bone) are equally necessary for health.

I wrote up my program for this in my book Stop the Clock: The Optimal Anti-Aging Program.

Cycles of feasting and fasting, of building strength through weight training, and of hormetic challenges through dietary phytochemicals and other methods like cold showers should be a powerful program for both maintaining strength and health and fighting aging.

Strength and longevity are compatible

It’s simplistic to conclude that because certain interventions or factors cause growth, that we ought to discard them fully in order to counteract aging.

This leads to the conclusion of veganism, and that can conduce to frailty and dementia in older age.

Instead, the best way to be both strong and energetic, and to fight aging, is to challenge the body cyclically through exercise and fasting, and then with rest, protein, and anabolism.

It might be the way to have the best of both worlds: strength and a long life.


Leave a Comment:

Rob H says December 20, 2015

Hi Dennis, another great article, I’m definitely with you on accentuating the body’s cycles of anabolism/ catabolism, acute stress/ rest etc. That article you reference (2) relating to the effects of dairy products on MTOR is fascinating. However, I have to admit I found it a little hard to follow in parts… It seemed to be saying that whey protein caused fasting levels of insulin to rise (not a good thing I believe, as opposed to acutely raised insulin, which can be beneficial after a workout?) Also, at the start it seemed to indicate that whey raises hepatic/ systemic IGF-1 (not a good thing I assume?), but then later on says that other studies seem to indicate that it is actually the casein that raises IGF-1? From what I have read from other sources, I do feel that on balance it may be prudent to drop regular casein/ cheese etc from the diet. But I am still struggling with whether to take whey OR BCAAs + post-work-out meal immediately after strength/ HIIT training. Could I ask Dennis, what was your take from this article in terms of the net effect of whey on systemic IGF-1 and fasted (as opposed to acute) insulin? I’m confused!

Rob H says December 21, 2015

Just to be a bit more specific, please see below the particular paragraph that I struggled with. It seems to be saying that it is actually the amino acid Tryptophan that causes the increase in hepatic IGF-1 levels (when combined with insulin). Tryptophan is apparently found most abundantly in whey, but I am assuming NOT in BCAAs. But the paragraph then goes on to say that in epidemiological trials, it was actually found that casein and not whey raised IGF-1 (in obese adolescents). What’s your take on this apparent conflict Dennis?:
“IGF-1, formerly called somatomedin C, is the most potent growth hormone that activates mTORC1 [21,22,23,27]. Milk consumption enhances hepatic synthesis and secretion of IGF-1 [71]. Growth hormone and amino acids, especially tryptophan, synergistically induce hepatic IGF-1 gene and protein expression [81,82]. Notably, the major whey protein α-lactalbumin has the highest tryptophan content among all other protein food sources [83] and after oral intake substantially increases human plasma tryptophan levels [84]. Epidemiological evidence confirms the relation between milk consumption and serum concentrations of IGF-1 [85,86]. A 20% increase in serum IGF-1 levels has been reported in prepubertal children previously not used to milk consumption after daily intake of 710 mL of ultraheat-treated (UHT) milk for 4 weeks [87]. A recent study including 193 overweight adolescents aged 12–15 years drank either 1 L/day of skimmed milk, whey, casein or water for 12 weeks [88]. All milk-based-drinks contained 35 g milk protein/L. IGF-1 significantly increased with skimmed milk and tended to increase with casein compared to the pre-test control group [88]. Casein in comparison to whey protein has been shown to differentially enhance serum IGF-1 levels [71]. Notably, per capita cheese consumption, the major dairy source of casein, increased in Germany from 5 kg in 1950 to 24.4 kg in 2013 [89]. Recent evidence indicates that glutamine controls the activity of the β-cell IGF-2/IGF1R autocrine loop by increasing the biosynthesis and secretion of IGF-2 [90]. This stimulatory effect of glutamine necessitates its metabolism but not mTORC1 activation.”

    P. D. Mangan says December 21, 2015

    Hi Rob, I think whey does not raise systemic IGF-1 levels (fasting levels) because it’s a “fast” protein, in and out of the system in a few hours. Casein is a better candidate for doing so. As for mechanisms (as in your quote from the paper) I tend to take these things with a grain of salt, since there are always so many things going on physiologically that it’s hard to say in the real world what process predominates.

    Re dropping cheese/casein from the diet, I can only speak for myself when I think I’m already restricting my diet a whole lot and soon I’ll have nothing left to eat. Cheese and other dairy has very little iron, and also inhibits the absorption of iron from other foods. (This latter fact I failed to mention in any of my iron articles.) So at least for now, I’m going to continue to eat it.

    Re your question whether to take BCAAs or whey after a workout: BCAAs can be effective if combined with other sources of protein, such as a complete meal, scrambled eggs for instance. On their own, they will decrease protein breakdown but won’t increase protein synthesis. The reason is that muscle requires all the essential amino acids to grow, and BCAAs provide only 3 of them.

    Therefore I recommend that you take whey after a workout.

      Rob H says December 23, 2015

      Thanks for clarifying back on that Dennis. I have just been through the article again and feel it is one of the most important (in relation to human health) that I have seen in a long time. Hormonal cancer runs in my family, and I feel strongly that I need to do all I can to reduce systemic IGF-1, since it seems to have such widespread negative consequences. This article really underlies to me the many negative impacts of dairy, so I will be dropping that from my diet – EXCEPT in the post-workout window which I believe allows (and actually necessitates) certain nutrients which would otherwise not be beneficial in a nutritionally deprived muscular state. So, yes, as you advise above I’ll continue to take Whey Protein Isolate immediately after a fasted strength work-out, but then no other dairy for me, I just don’t think its worth the longer term risks. My theory is that it will turn out to be most beneficial to have extremely low fasting IGF-1 levels (lowered cancer/ diabetes/ alzheimers risk etc), but to then acutely bump up insulin (and possibly IGF-1 too) with a very ‘fast’ protein immediately after a strength work-out. Again, comes back to a point I made previously about short/ sharp shock to the system. Fast/ acute (via limited & highly targeted doses of whey protein) as opposed to slow/ chronic (via regular, persistent consumption of cheese/ milk/ other casein containing dairy) IGF-1 elevation. So while I agree with you on the highly-targeted post-workout whey twice per week, I think we’ll need to agree to disagree re cheese, milk and other dairy! Thanks again Dennis, I know of no other blog pushing the boundaries and making us think quite like you do!
      PS I copied the article into Word (31 pages!) and highlighted all the key bits which makes a very convincing argument when you read it that way. Just let me know if you would like me to send it over to you.

        P. D. Mangan says December 24, 2015

        By the way, and in case it isn’t obvious, butter and cream have no casein or other protein in them, so even if one wanted to avoid dairy for the protein, these could be used freely. Whey also has no casein, though of course plenty of protein. That leaves milk, cheese, yogurt as dairy to avoid for the casein.

          Rob H says December 24, 2015

          Thanks for clarifying that Dennis: I forgot to mention I also take a large teaspoon of pastured Irish butter (Kerrygold, very easy to obtain here in the UK) each morning for the vitamin K/ saturated fats to help the absorption/ utlisation of my vitamin D supplement (4,000 IU/ day tablets now, after just having read your book). It does seem somewhat ironic that after being told for years to avoid dairy fat, its actually the casein protein I’m trying to avoid now: good quality pastured dairy fat on its own seems very beneficial. Another reason I decided to drop it was in response to Dom D’Agostino’s podcast with Tim Ferriss: where D’Agostino mentions adding in dairy to his keto diet, had a big negative affect on his LDL. Anyway, my kids will be waking up soon so merry Christmas all!!

José Carlos says December 23, 2015

I’m also very wary of dairy, especially coming from cows. If you are not vegetarian, I don’t see how dairy can really benefit you, but of course dairy adds a lot of taste to your diet, so it is not a bad idea to eat a little cheese or cream or even a piece of cheesecake one or twice in the week. It won’t kill you.

Rob H says December 23, 2015

Yep, I agree Jose Carlos: in fact having a few bits of cheese a couple or so times a week ( as a treat, as opposed to regular daily consumption) won’t be a problem. But as far as I’m concerned, if you look at the big picture, how can daily dairy consumption possibly be a good thing when dairy secretion evolved specifically to grow infant calves which develop at 4 times the rate of humans. Common sense tells you it cannot be right when you introduce a compound with such a singularly specific anabolic objective in a separate species as a DAILY part of our diet – something which was not a big part of the human diet pre-neolithic times. By the way, have you ever tried giving up cheese? Not as easy as it sounds (apparently there is something within cheese that gives it a morphine-like effect, I’d guess the tryptophan). If I find myself craving something for no good reason, I know that its probably a good reason to drop it from the daily diet and reserve it for treats only!

    José Carlos says December 23, 2015

    We’re probably in the same boat, Rob(ert?). I was only able to give up my daily portion of cheese after many years of failure. It’s really addictive. I think the main problem with dairy is not so much the fact that milk has a very particular goal (to help infants, whether human or not, to grow), but that it contains casein.

Rob H says December 24, 2015

Totally agree Jose Carlos: for me its the combo of too much casein & tryptophan which are both known to increase systemic IGF-1 (+ abolish autophagy whilst sleeping if consumed at night), high methionine (which has negative health aspects in the absence of supplemental glycine) and if you read the Godfather of Paleo, Loren Cordain, he comes down very hard on cheese for the high salt content (although I haven’t seen anyone else take that line). While some of this you could argue both ways (particularly Colin Campbell’s China Study linking casein + methionine to cancer) there’s clearly a few things going on here and for me its easy to substitute out cheese/ dairy from my daily diet (once I broke it’s crack-like effect on me!), with plenty other alternative sources of essential aminos out there: eggs, fish, poultry, nuts, seeds, occasional (weekly) red meat etc. For me, anything that is reputed to lower systemic/ fasting IGF-1 has to come first, and to then work around any knock-on deficiencies that may create, if that makes sense?! Rob (yes, Robert.)

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