speculations on keto diet and longevity

V

virtualcyber

New Member
It has been known for some time that decreasing caloric intake has beneficial effects, in terms of longevity. It also has been shown that this effect exists for all mammals that were tested. So, the likely conclusion from these studies is that, for a human being, decreasing caloric intake to its subsistence level will increase the lifespan.

What is interesting to me is, that the ketogenic diet causes body to "simulates" semi-starvation states, the state found during decreased caloric intake (which is likely to foster longevity).

Could it be possible that the ketotic states are actually healthful, and help you live _longer_?
 
Interesting... I don't have anything useful to add other than some observations.

My bro is on a keto diet (the Greenwich diet) and it had had a tremendous effect. He's lost weight, a chronic skin condition disappeared, and his hair is thicker and fuller. The transformation is almost comical.

The arguments behind the Greenwich diet are mainly that our diets have deviated sharply from the meat-laden paleo diets our bodies are "built" for by evolution. Mainly we've increased the starchy, processed carb content of our diets.

No question this diet is more healthy for him. Greenwich also allows small amounts of fibrous carbs like broccoli -- which turns out to be more veggies than he'd get on a self-selected diet.

People freak about keto diets because they assume you are eating bacon and pork rinds all day. You don't have to eat like that -- you can choose wise protein and fat sources.

Anyway, I am curious about this topic too. My gut tells me that this style of eating is healthy long-term. The only reason I'm not doing it myself is that I lost weight during my short flirtation with it. I'm trying to put on more mass, so I upped my carbs again.
 
I don't believe you're right. . .  it's not inducing a ketogenic state that offers the benefits of calorie restriction.

Rather, I believe the ongoing research is pointing to increased efficiencies in the body at lower calorie levels being the key benefactor.

When the body's supply of anything is low, it tends to get more efficient with it.  When you are getting the minimum supply of all macronutrients, the body acts very conservatively with them, and nothing is wasted.  

The wasteful processes that we experience when we consume excess fat, protein, and carbs all tend to have negative side effects.  Excess fat get stored as fat, increasing blood pressure. . .  excess carbs can cause insulin spikes and crashes, can raise the metabolism (which we want to lose weight, but which makes the body's energy system work hard), and can end up stored as fat. . . excess protein is among the worst -- it not used as protein, it is broken down into toxic sub-components which must be broken down by the liver and/or captured and passed by the kidneys.  (That's why cats have enormous kidneys compared to people -- to deal with all the protein by-products they eat.  And they still tend to die of renal failure at old age.)

Incidentally, the beneficial effects of calorie restriction are not limited to mammals.  Some of the earliest research confirming the effect were performed on flies.  Fat, well-fed flies breed and die quickly.  Thin flies live longer, "healthier" lives. (I put healthier in quotes, because of the purpose of a fly is to breed, the fat flies succeeded faster, which improves the health of the species, as opposed to the health of the individual fly.)
 
edzui

You are probably right. But a few observations:

The first interesting observation is that _pure_ (what does that mean??) carbohydrates have carcinogenic properties. I was thinking that perhaps ketogenic diets avoids this.

The second thing I was wondering is whether it is the hormonal imbalances that influence mammalian longevity. I was thinking that perhaps it is insulin spikes that tax our bodies the most. From what you said about flies, though, that does not seem likely. [I cannot imagine flies producing insulin-like body chemicals].

Finally, ketotic states "simulates" the starvation mode to certain extent. I was hoping that the simulation is "good enough" to increase lifespan. In ketosis, many parts of human body goes into "savings" mode.

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In any case, the most likely conclusion is that if one is to live longer, one probably should give up BB. I am not sure if living 150 years as a skinny, shrivled up, wimp appeals to me.
 
VC, see the other thread I've started in nutrition for a good link on calorie restriction.

I went to look up more recent info than I'd last read.

It seem you may be on target -- preliminarily, the strongest positive calorie-restrictive effects in primate trials seem to be insulin-related; a restricted diet inhibits the progression of insulin resistance and related problems.

A keto diet may help in that regard, but I still feel it has other drawbacks.

I speculate that the diet of a bodybuilder who is going for a lean condition -- but not necessarily the greatest possible bodymass -- may give much or most of the benefits of straight calorie restriction. It's a subject I'd like to pursue.
 
Pardon me for my ignorance, but from what i understand about ketogenic diets, it cuts out all carbs and lets you eat only protein and fats?

i was wondering, carbs is the main source of energy for the brain and every other organs in the body, so how do you survive on this kind of diet? Wouldnt all your daily activities be hampered, as in you will become "mentally" slow?

From a bodybuilding perspective, does it really work in burning off the fat? Whats the belief behind the ketogenic diet?

From a health perspective, i am assuming this kind of diet isnt suitable long term and not very healthy.


Hope you guys can correct me if i am wrong. :)
 
Ketones are usually present in the blood at all times, a ketogenic diet is one that raises blood ketone levels substantially. Usually this requires <100g carbohydrate per day.
A ketogenic diet is not unhealthy per se, it is the food choices one makes within a ketogenic diet that would be the problem. If you eat large amounts of saturated fats and avoided all fruits/vegetables it is possible that long term health is compromised. There is also a little research that confirms keto diets affect the cognitive function, but this is usually limited to the adaptation period, where the subjects brain alters from 'predominantly' carb oxidising to mainly keto (with some carbs included) oxidising. Once this has happned everything generally ok. I found the problem being cyclical keto diets as you are constantly going into and outof ketosis.

In terms of bodybuilding/fat loss, a keto diet works. But it also works the same way that every other diet on the planet works, it requires caloric restriction. Fat loss does not occur without it. It offers very little (to none) advantage over any other diets, but seems to suit some people in providing increased satiety and appetite supression (something that it never achieved for me)
They are nothing magical, although there are some people who go all cult like over them (just checkout alt.support.diet.low-carb) but then again their are over zealous nuts on both sides of the fence.
 
You know, anecdotal "evidence" is not really evidence, but merely an indication of possibility.

Anecdotally, people (some) claim that, while in ketosis, they actually function _BETTER_ than when they were not in ketosis.

One interesting thing: when one is in carb based metabolic state, one is burning glucose. But, as it turns out, it is the oxidation of glucose that is harmful to the cells. When one goes into ketosis, you are burning different fuel (Free fatty acid and ketones), so one does not get the harmful effect of glucose burning. Of course, there is a difference between someone who is calorie restricted and someone who is in ketosis: one in ketosis is still burning FFA and ketones, while the person under calorie restriction is hardly burning anything. Who knows, FFA and ketones over long period of time maybe harmful like glucose.

For someone in the ketogenic diet, there are two more things which can _possibly_ be harmful: excess protein and fat. I personally have not seen any research that supports the view that the level of protein and fat intake necessary to sustain ketogenic diet is harmful to the body. Edziu mentioned cats which die of renal failure, but I am not sure if those cats live ketogenic life and had consumed excess protein throughout their lives. I am assuming that those cats' lifestyle is relevant to homo sapiens.

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Spencer

Most organs in the body can burn one of two things: FFA (free fatty acid) and ketones. Some glucose is needed, but if you take in a few grams of carbs and protein, liver will synthesize the necessary amount.
 
</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (virtualcyber @ June 16 2002,08:50)</td></tr><tr><td id="QUOTE">Edziu mentioned cats which die of renal failure, but I am not sure if those cats live ketogenic life and had consumed excess protein throughout their lives.  I am assuming that those cats' lifestyle is relevant to homo sapiens.  [/QUOTE]<span id='postcolor'>
Cat physiology may not be very directly comparable to human physiology, but we are both mammals, and basic similarities are there.

Cats are an oft-studied animal because of their domesticity and abundance. They're an example of mammal that has evolved specifically to eat a very high-protein, high-fat diet, and their natural diet has virtually no carbs.

The way their organs have evolved to deal with that kind of diet is telling, to me, about the strains of such a diet. Cats have (if I recall) kidneys that are roughly 12 times the size of a humans, in terms of relative body mass. They have to process large amounts of protein break-down products. They also have an ability we don't have -- their kidneys can filter cholesteral from the bloodstream so they can urinate it out.

We, as omnivores, are in the curious situation where we are capable of subsisting on a WIDE variety of diets. Which is actually optimal for health is, therefore, a difficult question to answer.

Hey, we may someday learn that the healthiest thing is to cycle several months of keto diet and several months of vegan diet, with a fast in between! (winter/summer diets) Who knows?
 
</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (virtualcyber @ June 17 2002,12:50)</td></tr><tr><td id="QUOTE">    One interesting thing: when one is in carb based metabolic state, one is burning glucose.  But, as it turns out, it is the oxidation of glucose that is harmful to the cells.  When one goes into ketosis, you are burning different fuel (Free fatty acid and ketones), so one does not get the harmful effect of glucose burning.   Of course, there is a difference between someone who is calorie restricted and someone who is in ketosis: one in ketosis is still burning FFA and ketones, while the person under calorie restriction is hardly burning anything.  Who knows, FFA and ketones over long period of time maybe harmful like glucose.[/QUOTE]<span id='postcolor'>
Any energy source can be oxidised through the electron transport chain.
All ketones get converted back into pyruvate, so they all end at the same point as glucose/fatty acids/protein when being oxidised.

The process of oxidative phosphorylation produces masses of free radicals (the usual factor blamed), whether it comes from fat etc

All systems in the body rely on free radicals to do a large number of processes, including repair from exercise.
 
Hi, Aaron

&gt; All ketones get converted back into pyruvate, so they all
&gt; end at the same point as glucose/fatty acids/protein when
&gt; being oxidised.

Do you mean that ketones and glucose &quot;end up&quot; as identical molecules? But it seems logical to me that as they are chemically different, so they would not produce the same waste material? (I don't know).

What about Free Fatty Acid utilizing body parts? Do they generate the same waste material as glucose?

&gt; The process of oxidative phosphorylation produces masses
&gt; of free radicals (the usual factor blamed), whether it comes
&gt; from fat etc

Are they the same type of free radicals though? Some molecules should have greater affinity to attract or donate electrons to other molecules. Do they all end up as material of equal toxicity?
 
Here I go being all Libran again!

But it seems alot of people want to go to extremes. Insulin is bad. Ketones are bad. n6 fatty acids are bad. saturated fats are bad.

There needs to be balance between all of them. Too little insulin is just as bad as too much.
 
Sorry, cold weather and lack of sleep must be creating brain fade.

Glucose is broken down into pyruvate, which is then converted further (oxidative decarboxylation) into acetyl-CoA, which is fed into the citric acid cycleto produce high energy intermediates for use in the electron transport chain. (NADH FADH).

Beta-Oxidation is the process where fatty acids are broken down into Acetyl-CoA (the CH3-CO-SCoA molecule in the link above) This ends in the same place citric acid cycle to produce the high energy intermediates. When there is an excess of Acetyl-CoA from beta oxidation, they are broken down to form ketones
Specifically 2 AcetylCoA molecules are joint, junk the CoAs adn are left with a Acetoacetate molecule, which can interconvert into the other ketones or Acetone and Beta Hydroxybutyrate.

Ketones then used in other tissues are directly taken up into the mitochondria where they are converted back into acetyl coA and fed into the citric acid cycle etc.
So generally all fuels go through the same process to get oxidised (yes glucose can also produce energy in glycolysis but small amount)
Oxidative phosphoylation is a massive producer of free radicals, which is why when people take DNP they always say to increase antioxidants, because its activity is massively increased.

In essessense all free radicals are the same thing, but they have different producers. Remember free radicals or ROS (reactive oxygen species) are important for life, the immune system, oxidative metabolism, yada yada yada all require them.

Its not just lipid peroxidation that is the only source of ROS, that is just one of the more popular ones, especially for those interested in vitamin E/C protection of lipids.

I have a couple of nice charts at home that i may scan in and post at a later point.
 
If all oxidative process generates free radicals, then what is important would be anti-oxidants? By consuming anti-oxidants, how much of the free radicals can you remove from cell nucleus? Aaron, edziu?
 
</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">If all oxidative process generates free radicals, then what is important would be anti-oxidants?  By consuming anti-oxidants, how much of the free radicals can you remove from cell nucleus?   Aaron, edziu?[/QUOTE]<span id='postcolor'>

Because free radicals are potentially damaging, there are many antioxidant systems in the body (SOD GSH etc) and antioxidant nutrients that limit their damaging effects.
The main problem is when there is too large of an amount of free radicals, and they overload the capacity of hte body.
This has been related to cell and mitochondria damage, lowered immune function, ageging, cancer atherosclerosis.
 
Which relates to one of the prevalent theories of why Calorie Restriction prolongs healthy lifespan; with the body running efficiently, fewer free radicals are produced which the body's antioxidant systems have to deal with, and they don't get overwhelmed.

In this sense, taking ephedrine and caffeine to increase your metaboslism are BAD for your longevity (although, if your fat level is high, they are probably good short-term in that they help bring it down.)

One problem with taking antioxidants as supplements is that there are probably areas which they can't reach. For example, they certainly get into the bloodstream, and are known to protect the eyes and the vessels. . . but can they get into the nucleouous of a cell? Can they protect the DNA inside mitochondria? The body's antioxidant systems can, but only if they're not overloaded.

E
 
I have taken another look at the links that edziu provided, http://www.infoaging.org/b-cal-6role.html.

It speaks of two effects of metabolic process. The first effect, which we have already covered, is about the generation of free radicals.

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The second effect of metabolic process is known as &quot;glycation&quot; which we have not covered, and which I want to address.

What is interesting about glycation is this: glycation is the addition of insertion of sugar molecules into DNA. It is irreversible. In other words, due to the presence of glucose, our DNA is altered irreversibly.

As it turns out, restricting calories reduces glycation damages in tissues.

Why is this interesting? Because the ketogenic diet eliminates carbs from body, thus, decreasing glucose metabolism. This means the ketogenic diet has one effect that is identical to caloric restriction: reduction of glycation.

If it turns out that glycation is the major cause of aging, then it is possible that the ketogenic diet will have the same positive effect on aging as calorie restriction.
 
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