Why low-carb hypos are less severe

[BlueSky]

I noticed that I wasn't getting the typical distress signals with dropping blood glucose some time ago. I didn't make the connection at the time, but it happened after I switched to a low-carb way of eating. I was puzzled at the apparent reduction in hypo-awareness, because I was having hardly any hypos. This is supposed to improve hypo-awareness, but with me it was having the opposite effect.

It is beginning to make more sense to me now. Low-carb/high-fat eating increases the supply of keytones to the brain, and the following study, described in Larry McCleary's blog, provides a logical explanation for my experience :
... During hypoglycemia associated with prolonged fasting or strenuous exercise, circulating ketone body levels increase many-fold. Ketone bodies (acetoacetate and beta hydroxybutyrate) are products of partial fat metabolism which are generated in the liver and are secreted into the circulation. They constitute a fuel source that is easily burned by the brain and is able to provide the energy the falling blood glucose can't. This study was designed to investigate whether ketones would provide similar protection under insulin-induced hypoglycemia. The experimental conditions were chosen to model what happens when diabetics become hypoglycemic due to injection of too much insulin.

Infusion of precise amounts of insulin was performed in two groups of subjects, one who had shortly before received an infusion of ketone bodies, and one group who had received a placebo (inactive infusion containing no ketone bodies). Blood samples were then drawn and cognitive function testing was performed.

Compared to the group that received insulin plus placebo (no ketones), the group that had insulin plus ketone bodies had reduced signs and symptoms of hypoglycemia. They remained asymptomatic until blood glucose levels fell to the 40 mg/dl range compared to the production of symptoms in the more typical 50 mg/dl range of blood sugar in the other group. These remarkable findings suggest that ketones help protect neurons from severe hypoglycemia. While such therapy may not be useful in all circumstances, it is expected to expand the safety margin of tight glucose control in a large number of diabetic patients.

Ketone body therapy is not currently available. However, when taken as a supplement to the diet MCT oil (medium chain triglyceride) is rapidly turned into ketone bodies which would be expected to produce the same beneficial effect.
Dr. Larry McCleary - Saving Diabetic Brains (http://www.drmccleary.com/2007/09/25/SavingDiabeticBrains.aspx)

It makes a lot more sense to me now. Because the brain has ready access to keytones from high fat food, hypo's are not as much of a problem for it as they used to be. For me, this has had other major implications. Since switiching to high-fat eating three years ago, I haven't had any seizures (this used to be a big problem) and I have been able to stop the anti-convulsant medication entirely. Having said that, crossing that critical low blood sugar threshold is no doubt just as hazardous, allbeit at a much lower level.

[ant hill]

It makes a lot more sense to me now. Because the brain has ready access to keytones from high fat food, hypo's are not as much of a problem for it as they used to be. For me, this has had other major implications. Since switiching to high-fat eating three years ago, I haven't had any seizures (this used to be a big problem) and I have been able to stop the anti-convulsant medication entirely. Having said that, crossing that critical low blood sugar threshold is no doubt just as hazardous, allbeit at a much lower level.

Hello Bluesky, I find that fat will slow down glucose although high BG for a good piriod of time. Take chocolate for instance, We know that there is sugar in it and there is also fat witch will slow the spike that sugar will normaly do buy it'self.
Now there are two types of fat that we should look at and they are the LDL the good fat and the HDL the bad and I find that more of the killer than the hypos that we have to whach for and just about anything that is white will rase BG's.
The fats may be different than what I have just said so I will stand corrected if need be. :)

[AliB]

Hi BlueSky.

I have been doing a fair bit of research on the effects of Omega 3 oils on the body.

Fats, particularly the Omega 3 types as found in Fish, Sesame, Flax and Olive apparently help to reduce the effects of insulin resistance.

If the body is less affectd by the insulin resistance then better overall glucose control is maintained.

I found it interesting that when my levels were high (over 11 [200]) on the very rare occasion that I would get a hypo I could only get down to around 5.5 (100) before experiencing the symptoms of the hypo. Since I started the Vitabase and have brough my levels down to around 'normal', I have had a couple of hypos with my levels actually going down to 3.5 (63) before experiencing the symptoms.

So it seems that the body, when used to higher numbers actually seems to work on a higher threshhold than normal.

As an experiment, I stopped the Vitabase the day before yesterday, but my levels are still remaining low. I have been reading Nicholas Perrigone's book (good book, worth reading) this morning and he mentions that om trials, the benefit of taking cinnamon has continued for some time even when the cinnamon is not eaten. Apparently the active substance for glucose lowering is in the water-soluble part of the cinnamon.

The more I read about natural unadulterated food, the more I understand what wonderful stuff it is and the incredibly intelligent design behind it! All the time, information is coming out about the properties and values of different foods and their benefits.

[AliB]

Plus, the brains' predominant substance is fat (like a lot of other organs in the body). If it doesn't get enough, particularly of the type of fat that supports it then it cannot function optimally.

Apparently too, obesity and insulin resistance can also not only mean that the body has to use more amino acids in order to function but it can also prevent the body from utilising the amino acids properly that it does get. Therefore, muscle wastage can be a problem for the obese, particularly diabetics, and can be even further exacerbated when dieting. So whilst some weight loss may well be from fat, there can also be loss from muscle, which is not so good, particularly for the heart.

I have a friend who is very worried about losing weight as her Mum lost over 3 stone (45lbs) then dropped dead from a heart attack!

I have been feeling my heart beating for at least 5 years which is worrying (well, it's good from the point of view that it is still beating!) considering that it used to be something I was totally unaware of. The thumping may be something or nothing, but the fact that I feel it is not normal must surely, it would seem to me, indicate that it is having to work harder than it should be. I have had it checked and it is working 'normally'.

[Gary_W]

BlueSky - Interesting reading; if you badly miscalculated an injection so you had a whole load of insulin floating around that wasn't being mopped up by carbs, is this saying that the fat would keep the hypo at bay or that the hypo would happen just the same but you'd feel it later?

It's also interesting what you're saying about the seizures. I'm glad the eating has had a positive effect in this respect. Just a thought in that regard is had you considered gluten intollernence as a factor? I seem to remember in one of your posts that you used to eat at least 6 rounds of bread each day etc. If you go on Wikipedia, one of the possible links with coeliacs disease is epilepsy. Not an experiment you'll do (for the obvious reason that what you are doing is working well for you) but I wonder how the seizure side of things would work for you if you ate a 'regular' amount of carbs but avoided the bread?

Glad it's making sense for you; I'm always a little more wary of research that comes from a chap who is keen to flog a book than I would something that came out of a uni etc with less immediate financial gain, but that could be me being overly sceptical :)

Ali - You're friends mum was already putting herself at risk of a heart attack by being 3 stone + overweight, and the time spent at the higher weight will have done far more harm to her system than the weight loss. Whilst sudden weight loss isn't good for your system, weight loss in a gentle and sensible manner towards a healthy weight is far more likely to prolong your life than it is to shorten it.

Gary

[xMenace]

Some other thoughts to consider:

- less carbs means less insulin and less margin for error and less potential for a severe hypo.

- more fat & protein means slower and steadier release of sugars into the system and a smoother ride through the insulin's cycle.

[Gary_W]

Some other thoughts to consider:

- less carbs means less insulin and less margin for error and less potential for a severe hypo.

- more fat & protein means slower and steadier release of sugars into the system and a smoother ride through the insulin's cycle.

That's all well and good in theory, but it's not a theory my body likes much. If your body uses the insulin injected very quickly then you don't really want the smoother ride from the food otherwise you go hypo despite having just eaten.

With plain and simple carbs, carb counting works perfectly for me on the vast majority of occasions. Apidra works very quickly for me, 80% + will be gone by hour 2 and the whole lot will have vanished by hour 4. For this reason in me, meals based mainly on 50% + carbs witha bit of protein and fat work well. I don't spike too badly, and will usually be down to a sensible level at hour 2. The low GI carbs and protein flesh out the tail end of the Apidra and all tends to be well with the world. If I've had slightly too much meat or fat then I'll rise at hour 4 or so and may need a mild correction shot.

The problem comes for me on the rare occasions where I include a whole bunch of protein or fat. Protein does raise my BG, but it does it over a much longer period and in a far less predictable way. A dual bolus helps, but when I'm trying to second guess the delaying action of fat then I get it wrong as often as I get it right. I am guessing if I pumped it might be more 'do-able' for me, but my body does not appreciate high protein / high fat as far as keeping the old BG on an even keel goes. I appreciate for a lot of people it makes it easier, but I'm not one of them :)

Gary

[BlueSky]

.... I pumped it might be more 'do-able' for me, but my body does not appreciate high protein / high fat as far as keeping the old BG on an even keel goes. I appreciate for a lot of people it makes it easier, but I'm not one of them :)

Gary
Not being on a pump makes changing the insulin duration difficult. I have simplified my life by only eating low-carb/high-fat meals at home (breakfast and dinner), and I bolus with Actrapid (Regular insulin). When I go out, I only take the Novorapid pen with me and I generally eat more carby meals.

[soso]

Thanks for this BlueSky... Yesterday I found myself at 1.9 ( unexpected, but I worked out why..combo of small things) I was particularly upset as the only sign I had was a slightly bizarre sensation when I turned my head... I did not feel bad at all, certainly did not think I would be low and had a shock when I saw how low.. wondered if it was the meter, but numerous tests as I carbed my way back up seemed logical and when I tested the meter against others that night it was slightly higher not lower...
I was thinking.. crikey... hypo unawareness, as I have had a few other hypos that I hardly felt recently..though I usually get the shakes below 3, but not this time..
I do lowish carb, 15-30g per meal mostly and don't snack between meals.. I do not limit my fat intake though except for trans fats of course which I never eat...

[REDLAN]

this is an interesting theory...

I think however that lack of awareness of a hypo is not the same as "symptoms of hypoglycemia" as defined by the study - the study specifically measured cognitve functioning - i.e. how much the low blood sugar affected the brain, and discovered that ketones can be used as an alternative food source when glucose is low - all the way down to 2.2 mmol (40).

the typical symptoms of a hypoglycemia - shakes, tremors, sweats - is adrenergic in nature (brain function is usually not affected at adrenergic hypo levels), and dependent on BG level (not sure how ketones affect this response - if at all).

second question to ask yourself is how many ketone bodies do I have in my body?

And I would suggest that for the average low-carber, hardly any at all (you could ketostix yourself and see if you are producing any).

Fat metabolism by itself does not necessarily produce significant ketones. Fat is broken down into acetyl CoA and then oxidised in the citric acid cycle (this pathway is how cells get most of their energy). As long as there is sufficient capacity in the citric acid cycle then no significant ketones will be produced from burning fat.

however...

gluconeogenesis uses a key component in the citric acid cycle (oxaloacetic acid), and so reduces the citric acid cycle's capacity to burn fat. The excess fat is diverted into ketogenesis to supply the body with energy (both these processes occur within the liver)

so....

ketogenesis occurs as a result of gluconeogensis, which occurs in response to low glycogen/low glucose.

significant ketogenesis occurs in starvation, and after strenuous exercise.

so...

the amount of ketones you would have in your body to protect your brain from hypos, would depend on how much gluconeogenesis was occuring at the time.

(unfortunately I can't find a reference for how low-carb you have to go to induce significant ketogenesis - which would be useful to know).

Oh and one further fact...

insulin switches off gluconeogenesis, which means that it will also stop ketogenesis...

[BlueSky]

.... second question to ask yourself is how many ketone bodies do I have in my body?.....
I would think quite a lot. If I understand this correctly, fat has to be broken down into keytones before it can be used for energy. If a low-carber only eats 50 grams of carbohydrate a day (200 calories) but requires, say 1800 calories a day to maintain body weight, the remaining 1,600 calories must come from keytones. And these keytones are available to the brain as well. I was suggesting that, because the brain has ready access to this source of energy, it is not as vulnerable to shortages in glucose. My experience certainly seems to back that up.

[REDLAN]

If I understand this correctly, fat has to be broken down into keytones before it can be used for energy

I think this is where there is misunderstanding about the role of ketogenesis and fat metabolism.

Free fatty Acids are released continually by fat cells. Transport is mediated by albumen, and they passively diffuse into cells. Once within a cell, they are then broken down into acetyl CoA by beta oxidation. Acetyl CoA powers the conversion of oxaloacetate into citrate - the high energy bonds of citrate are then broken down in a multi step process until oxaloacetate is reached again.

in a muscle cell fat is metabolised via the citric acid cycle and is turned into energy, water and CO2.

it's only in the liver that significant ketogenesis occurs, and this is in response to gluconeogenesis. Gluconeognesis utilises oxaloacetate to convert pyruvate back into glucose again - this however reduces the capacity of the citric acid cycle to oxidise acetyl coA. So the acetyl CoA concentration will start to accumulate in the liver, and the liver responds by converting the surplus acetyl coA into ketones.

there appears to be a general belief that fat metabolism requires ketogenesis - I suspect from the experience of atkins dieters - however (theoretically at least) ketogenesis only occurs in response to gluconeogenesis, and gluconeogenesis occurs in response to glucagon (and lack of insulin) - i.e. low cellular glycogen or starvation - diets produce a similar physiological response - the greater the calorie restriction the greater the response.

It would also occur with very low carb diets, where the body is using protein for glucose synthesis - but this should only occur at discrete points - i.e. when glucagon levels are high - however I could not find any studies which looked at how low carb you have to go to induce ketogenesis.

there also seems to be a misconception about fat and carbs - fat can never be made into glucose (however the energy from fat metabolism can be used to synthesise glucose)

the wiki has some good explanations

Citric acid cycle - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Krebs_Cycle)

Ketogenesis - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Ketogenesis)

[REDLAN]

found a reference to a ketogenic diet (this is to treat epilepsy - which I thought you would find interesting), and here they were using 88% fat 10% protein and just 2% carb.

Ketogenic diet - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Ketogenic_diet)

translate this to a 2000 calorie diet, and your daily allowance of carbs would be 10g (an average daily allowance of vegetables would be more than this)

as a side note the 10% protein is only just enough to supply your daily protein needs - translates as 50g of protein in a 2000 calorie diet. This would be a very risky diet for anyone on insulin.

you can read the long list of side effects for yourself :)

[BlueSky]

I have never been on a ketogenic diet (keytones in the urine). I get about 65% of my calories from fat and keytones hardly ever show up in ketostix tests. But I suspect that, as far as the seizures are concerned, I am still benefiting from a ready supply of keytones to the brain. There are probably other mechanisms involved too. The link between epilepsy and gluten intolerance that Gary mentioned in his post could be another partial explanation. While I don't have Coeliacs, I certainly felt a lot better after I stopped eating bread.

I guess we will never know if the seizures would have stopped 40 years ago if I started eating like this back then. But there is mounting evidence that diet has a major bearing on the incidence of epileptic seizures.

[REDLAN]

there is a theory as to how a KD (ketogenic diet) can control seizures, but it is in rats (and rodents respond physiologically differently to high fat diets than humans - rats and mice were never meant to eat a high fat diet)

KD causes the hippocampus to produce more mitochondria - the researchers believe that this increases the stability of this part of the brain and hence provides the protection to seizures.

Ketogenic diet prevents seizures by enhancing brain energy production, increasing neuron stability (http://www.eurekalert.org/pub_releases/2005-11/euhs-kdp111105.php)

unfortunately it is only a press release - far too often the conclusions and theories spouted in the press release can not be supported by the experimental data to which they refer. AND it is in rats. However it is interesting.

I also found this article

Epilepsy Action: The Ketogenic Diet (http://www.epilepsy.org.uk/info/ketogenic.html)

apparently a ketogenic diet worked in around 1/3 of children.

so it could be that eating low carb has stressed your brain out, which has had to produce more energy factories because it can no longer rely on getting it's glucose fix or...

it could be that your epilepsy simply went into remission.

Prognosis : Epilepsy.com/Professionals (http://professionals.epilepsy.com/page/mrcp_prognosis.html)

it's rather technical and it does look at children with a developmental disability (whose prognosis is usually worse than the general population).

In the Sillanpaa study a remarkable 64% were in a 5 year remission at the point the study was conducted and 81% had experienced a 5 year remission at some point.

who cares why it works, as long as it does ;)