Does the brain HAVE to have glucose?
 

In my anatomy & physiology class tonight, the teacher said that every organ in the body can use fatty acids as fuel except the brain. Now I'm confused. I've read before that the brain actually does better on ketones. Also, can't the body turn fat or protein (can't remember which) into glucose if necessary?

Do a search on here, and also look at the studies collected by the Atkins web site. Yes the body can turn excess protien into glucose. The brain however, can function on keotenes in the absence of glucose. One study even found the brain functioned better when keotenes were the energy source.

I agree. I have looked up other sites on the topic of glucagon. I have learned that the body/brain does indeed need glucose to function, however, it doesn't need Lays potato chips for glucose. All of that healthy protein that we eat can be converted into glucose.

I am listening to the morning news and they are talking about reducing the carbs in school lunches. Hmmm, me thinks they are beginning to get it.

From what I understand most of the brain can function on ketones but a small part of it near the stem must have glucose. The body can make this from protein. (And if you don't eat protein ie fat fast, it will make it from your muscle!)

Keep in mind that low carb does not equal no carb. So by doing Atkins or any other low carb regime you are still getting enough brain food.

Thanks y'all!:)

Ladybelle--I knew I had read that somewhere!

Quote:

however, it doesn't need Lays potato chips for glucose

:lol:

Black--I think it would be great if they would cut some of the carbs in school lunches. I remember what my typical lunch was at school--pizza with fries or breaded meat with fries and a roll--carb city!

RC--Maybe that's what the teach was saying--that it's onlya particular part (hmmm maybe I should pay more attention in class!) And no worries about the fat fast--that's is one thing I have NO desire to try!

Calvin--I've never tried to go no-carb--that can't be healthy. I am (for the most part) doing induction levels, although I have been as high as 35g in a day and am still losing.

Free Fatty Acids (FFA) and Ketones
Most tissues of the body can use FFA for fuel if it is available. This includes skeletal muscle, the heart, and most organs. However, there are other tissues such as the brain, red blood cells, the renal medulla, bone marrow and Type II muscle fibers which cannot use FFA and require glucose. The fact that the brain is incapable of using FFA for fuel has led to one of the biggest misconceptions about human physiology: that the brain can only use glucose for fuel. While it is true that the brain normally runs on glucose, the brain will readily use ketones for fuel if they are available.

Arguably the most important tissue in terms of ketone utilization is the brain which can derive up to 75% of its total energy requirements from ketones after adaptation. In all likelihood, ketones exist primarily to provide a fat-derived fuel for the brain during periods when carbohydrates are unavailable.
As with glucose and FFA, the utilization of ketones is related to their availability. Under normal dietary conditions, ketone concentrations are so low that ketones provide a negligible amount of energy to the tissues of the body. If ketone concentrations increase, most tissues in the body will begin to derive some portion of their energy requirements from ketones. Some research also suggests that ketones are the preferred fuel of many tissues. One exception is the liver which does not use ketones for fuel, relying instead on FFA.

By the third day of ketosis, all of the non-protein fuel is derived from the oxidation of FFA and ketones. As ketosis develops, most tissues which can use ketones for fuel will stop using them to a significant degree by the third week. This decrease in ketone utilization occurs due to a down regulation of the enzymes responsible for ketone use and occurs in all tissues except the brain. After three weeks, most tissues will meet their energy requirements almost exclusively through the breakdown of FFA. This is thought to be an adaptation to ensure adequate ketone levels for the brain. Except in the case of Type I diabetes, ketones will only be present in the bloodstream under conditions where FFA use by the body has increased. For all practical purposes we can assume that a large increase in FFA use is accompanied by an increase in ketone utilization and these two fuels can be considered together.


http://www.allyourstrength.com/nutrition_1002Fuel.html

If you are doing a high protein/fat diet, you will normalize your insulin which will activate glucagon. Glucgaon's job, in part, is to turn protein into glucose. Glucagon also enhances lipolysis ( ketosis ). My conclusion is-the brain functions best when insulin is normalized. Insulin rises when there is an access of blood glucose, caused by a high consumption of carbs.

I also agree. I read a lot on this and was supposed to be on DR. Phils show I was going to use this as my topic of discusion

1. Parts of your brain need glucose, and it must be within a certain range of concentration in the blood. That is why blood flows from the digestive tract through the liver before it gets to the brain.

2. According to the Eades` in the Slow Burn Revolution, some muscle fibres burn glucose and only glucose.

These are the only two situations I am aware of where glucose is a must.

I will say this much...since I added SOME carbs into my diet my memory..especially short-term...has been better. The first year I was on Atkins - strict low-carb - it was rough... At first I thought it was my age, maybe not enough sleep? - stress? but I now am convinced my brain needed a little bit more carbs (I eat between 35-55 on most days). Induction period was definitely the worst for me!