Re Diabetes UK

[graham64]

Some interesting data in the link.

As noted above, ketone bodies, including β-hydroxybutyrate, that are produced during consumption of the ketogenic diet may serve as an alternative source of energy in states of metabolic stress, thus contributing to the neuroprotective activity of the diet. In fact, β-hydroxybutyrate may provide a more efficient source of energy for brain per unit oxygen than glucose

http://www.pubmedcentral.nih.gov/articl ... d=16940764

Graham

 

[Dr H]

http://www.cincinnatichildrens.org/about/news/release/2000/7-diet.htm

http://www.targetwoman.com/articles/ketogenic-diet.html

http://www.mdconsult.com/das/article/body/151849769-2/jorg=journal&source=&sp=21519617&sid=0/N/671007/1.html?issn=0887-8994

For the last one you can sign up for a 30-day trial

 

[Aadrgon]

EDIT: If you didn't realise it, the Kreb's Cycle is incredibly inefficient. It can cope with supporting the body in the short-term but experiments and clinical trials haven't shown if it can support the body for a lifetime.

The Krebs cycle may not be efficient at converting amino acids to glucose but then again - how much glucose does a brain need.

The human race has been around for quite a few years and initially would have been hunter/gatherers rather than farmers. This would probably have meant a low carb diet. Admittedly their life cycle was shorter than ours but I doubt if any clinical trial will ever last that long.

You have still yet to show even a single reasonable point that carbs = high blood sugar. Which they don't, or carbs = bad, which they aren't.

Hanadr asked what advantage there would be to eating more starch if your BG was steady and high - the answer of course is none at all since the idea is to maintain a normal blood glucose by whichever diet suits you best regardless of the carb content.

Carbohydrates are readily converted into sugar therefore a high carb diet CAN cause high BG if your insulin levels are either too low or you have insulin resistance.

 

[Dr H]

The Krebs cycle may not be efficient at converting amino acids to glucose but then again - how much glucose does a brain need. .

Surprisingly a lot...

Brain Energy Demand


Your brain cells need two times more energy than the other cells in your body.

Neurons, the cells that communicate with each other, have a high demand for energy because they're always in a state of metabolic activity. Even during sleep, neurons are still at work repairing and rebuilding their worn out structural components.

They are manufacturing enzymes and neurotransmitters that must be transported out to the very ends of their– nerve branches, some that can be several inches, or feet, away.

Most demanding of a neuron's energy, however, are the bioelectric signals responsible for communication throughout the nervous system. This nerve transmission consumes one-half of all the brain's energy (nearly 10% of the whole body's energy).

http://www.fi.edu/learn/brain/carbs.html

 

[sugarless sue]

OK is it therefore safe to say that the brain can function using both Glucose and converted ketones?

 

[timo2]

http://www.springerlink.com/content/w46r8p2v7j874258/

Found this, Sue, but it's only a text preview.

 

[sugarless sue]

Can't get link to work Timo!

 

[sugarless sue]

OK so what does that actually mean?

 

[phoenix]

The question is can the brain run without glucose or not,simple!!!

If only it were!
As a type one it is very clear that hypoglycemia requires the fast action of glucose to reverse it (and its effect on brain function) This has been found to be the case in a small study.
Post-hypoglycaemic hyperketonaemia does not contribute to brain metabolism during insulin-induced hypoglycaemia in humans Diabtologia 1993 Fanelli C, et al

Human breast milk has about 35/45% carb content so one would imagine that this is the optimal proportion of carbs for development... including that of the brain which develops rapidly in early life, but the energy requirement is high and babies also use lactate and ketones.

There is increasing evidence that glucose and /or carbohydrate ingestion has an effect on cognitive functioning. This is a relatively new area of research and much of it contradictory.
It may be that some functions, particularly some memory functions require rapid replacement of fuel therefore glucose is optimal. (See research by Gold and McNay, C. Greenwood, Kaplan )
On the other hand there is for example evidence that adults with poor glycemic control have some memory impairment and that the ingestion of high gi carbs compounds the problem.(Greenwood et al [ Carbohydrate-Induced Memory Impairment in Adults With Type 2 Diabetes

:!: :!:
For those who really want to investigate further, or are doing a literature search for a post grad degree! (ignore otherwise)
This extract from
METABOLIC ADAPTATIONS
JR Skoyles - precedings.nature.com
. Skoyles 1 Human metabolic adaptations and prolonged expensive
neurodevelopment: A review John R. Skoyles
discusses the matter, (but not always clearly) I've put in some underlining. The references are in the original text.

Ketone bodies. Ketone bodies (β-hydroxybutyrate and acetoacetate) are the major energy
supply to the brain during lactation being created from blood brain boundary impenetrable
free fatty acids (Nehlig, 2004). During famine, the brain can subsist with 60% of its energy
needs being supplied by their hepatic conversion via lipid mobilization from adipose tissue
(Bougneres, Lemmel, Ferre, & Bier, 1986). It has recently been suggested that when the
equivalent of two alcoholic drinks (0.5 g kg-1) of alcohol depresses glucose measured brain
metabolism by 23%, acetoacetate makes up the deficit (Volkow et al., 2006)20. However,
ketone bodies have pharmacokinetic properties that are distinct from those of glucose. This is
most evident in the ketogenic diet treatment of epilepsy for which these differences provide
its neurological effectiveness. The specific effects of the ketogenic diet and a high use of
ketone bodies by the brain are not well understood but seem to link to alterations in the
metabolism of the major excitatory neurotransmitter, glutamic acid (Yudkoff, Daikhin,
Nissim, & Lazarow, 2001). Such alternations could have a potentially disruptive role in
neurodevelopment since key glutamate receptors, such as AMPA and NMDA are closely
involved with the regulation of the stability of synapses (Adesnik et al., 2008; De Paola,
Arber, & Caroni, 2003).
There is evidence from hippocampal slices that ketone bodies cannot maintain neural activity
comparably to that of glucose (Arakawa, Goto, & Okada, 1991). Consistent with this,
weaning rats fed a ketogenic diet grew up to have impaired visual-spatial learning and
memory defects and reduced brain size (Zhao, Stafstrom, Fu, Hu, & Holmes, 2004). In one
study, the production of ketone bodies that are produced in hypoglycemia were inhibited by
the drug acipimox: the absence, however, of hypoglycemia induced ketone bodies due to
acipimox did not increase the cognitive and effects of hypoglycemia (Fanelli et al., 1993).
This suggest that ketone bodies do not compensate the brain for the plasma glucose deficit in
hypoglycemia (Fanelli et al., 1993). It has been suggested that ketone bodies “spare glucose
for the emergence of various functions such as audition and vision as well as more integrated
and adapted behaviors whose appearance during brain maturation seems to critically related
upon active glucose supply and specific regional increased use” (Nehlig, 2004, p. 265). Thus,
ketone bodies and glucose are not equivalent in their effects upon the brain, particularly
during its development, and this might, if high in percentage contribution, make it a
suboptimal replacement.

A second place to find multiple references to follow up is
http://www.fao.org/docrep/W8079E/w8079e08.htm#carbohydrate and behaviour

 

[sugarless sue]

So therefore glucose is the best brain food but ketones can be used for a short while then?

 

[Dr H]

According to a neurologist out here in the wastelands. Glucose is the optimum fuel, ketones can be converted but the process itself needs to be kick started.

However, ketones are needed simply because they use up excess glucose (I think he mentioned a ratio of about 3 glucose molecule used in the production of one). This keeps the water potential of the blood at the optimum level for osmosis. Too much glucose can actually dehydrate the brain (as well as other organs, but the brain is more susceptible).

(I had him write most of it down on a piece of paper)

 

[timo2]

Here's another abstract for neither of us to understand, Sue.

circulating ketones were discovered to replace glucose as the brain's major fuel during the marked hyperketonemia of prolonged fasting. Until then, the adult human brain was thought to be entirely dependent upon glucose.Ketones: Metabolism's Ugly Duckling

 

[Dillinger]

Doesn't gluconeogenesis produce sufficient glucose for the brain and for gylcogen production, if you are eating sufficient protein and fat instead of carbohydrate (and also have sufficient serum insulin)? Genuine question, by the way, not sarcastic one... :?

IF so then, I guess the question is does that cause any short or long term complications? As far as short term complications go I use my brain quite a lot and haven't noticed any deterioation whilst cutting back on carbohyrdates (although to be honest it did take me a while to figure out how to spell 'deterioation' there...)

All the best

Dillinger

 

[Celtic.Piskie]

Trouble is sue, if it were that simple, there wouldn't be this much controversy lol.
Human's have been eating meat, carbs, veggies for thousands upon thousands of years. Myself, and a lot of other diabetics, can manage on a healthy, higher than low-carb diet without permenantly high blood sugars.
We don't even know precisely when diabetes is diabetes, and when someone just has a higher than normal blood sugar, that is normal for them, because if there is a range, someone has to be at the top end.
It's hugely complicated, and at the end of it no-one knows.

So i just do the best, and enjoy the pizza.

 

[sugarless sue]

Well I understand that protein turns so much percentage into glucose as well so logically,if you are on a low carb diet and eat a fair bit of protein then the glucose from this could be fuelling the brain along with the ketones??

 

[Dr H]

Yes, but if you think about it logically, if 3 ketones are equivalent to 1 glucose molecule. Then you'd have to eat 3 times as many ketones as you would have to each carbs.

So, I'm unsure as to how much food this is. But I suppose that it's a lot of meat...

In response to Dillinger's question. The honest answer is that I don't know. Low-carb diets have only been linked with long-term problems, especially in cells that require more glucose than most. The brain and heart.

However, the eskimos live on high fat diets and it's their diets that most modern low-carb diets are modelled on. They have far higher rates of chronic heart disease than normal, but that could be genetic or have other environmental factors.

 

[timo2]

The brain gets its energy from ketone bodies when insufficient glucose is available (e.g., when fasting). In the event of low blood glucose, most other tissues have additional energy sources besides ketone bodies (such as fatty acids), but the brain does not. After the diet has been changed to lower blood glucose for 3 days, the brain gets 30% of its energy from ketone bodies. After about 40 days, this goes up to 70% (during the initial stages the brain does not burn ketones, since they are an important substrate for lipid synthesis in the brain). In time the brain reduces its glucose requirements from 120g to 40g per day.

http://en.wikipedia.org/wiki/Ketone_bodies

So, under ketosis, the brain's glucose requirements are significantly (66%) lower, Sue.

 

[Celtic.Piskie]

In time the brain reduces its glucose requirements from 120g to 40g per day.

Now, I'm no expert and don't claim to be. But a brain that should be running on 120g, only running on 40g, that doesn't seem to me to be a good thing long term.

 

[graham64]

The honest answer is that I don't know. Low-carb diets have only been linked with long-term problems, especially in cells that require more glucose than most. The brain and heart.

Dr Richard Bernstein, has had Type 1 diabetes for over 60 years, having viewed his podcasts I can't see any negative effects of his low carb diet. He comes across as a very intelligent and articulate man.

Closer to home we have our own kentishman a board member.

kentishman wrote:I have been a Type2 Diabetic for over 40 years. I am now 86. For some considerable time I have been battling against the high carbohydrate advice. There is no doubt in my mind whatsoever that a low carbohydrate diet gives better control. Eat a high carbohydrate diet and your readings will elevate accordingly.
The advice for a high carbohydrate diet is given in the belief that it will mean a low fat diet but this is not necessarily the case It is possib;e to have a low carbohydrate diet and a low fat diet.
This means an unhealthy diet? Rubbish!!!
At my age I play golf four times a week and walk round the course. I have very little in the way of complications. I think eventually I may have to go onto Insulin but that isn't too bad after all these years.
Type1 is a different illness and I have no knowledge of it.

Graham

 

[Dr H]

It's rarely good, that would suggest either a decrease in brain activity or fewer mitochondria. Both of which are bad. But then again, we are only extrapolating the data.

In response to Graham's post. Two people doesn't make for conclusive evidence. However, a whole population living on low-carb diets having higher rate of chronic heart disease carries some weight. Whether or not it is down to the diet or other factors.