Are Ketones a Neurotoxin in Bodybuilding?

[.ryan.]

I know this isn't really a health-type forum, but I guess it would be appropriate since it does have to do w/ physiology which is a branch of biology.

I've always been on the heavy side. 2 years ago, I was 250lbs. After 8 months of dieting, I got down to a very lean 170lbs. My weapon of choice during this period was the Atkins diet. I didn't know about any of the 'dangers', but when I had to type a research paper about it, I found out something that alarmed me at this website - http://www.paralumun.com/diabetesketone.htm

particularly this-

Ketone bodies can poison and even kill body cells

However, this is from a diabetes website. I've read that there's a difference between diet-induced ketosis, and the state of ketoacidosis that people with diabetes can enter.

I found further information that stated that ketones were a neurotoxin. I wish I could find the article that stated that, but it seems to not exist anymore

I later found this, however-

Higher ketogenic diet ratios confer protection from seizures without neurotoxicity.

Bough KJ, Yao SG, Eagles DA.

Department of Biology, Georgetown University, Washington, DC 20057-1229, USA.

The present study was designed to establish a dose-response relationship for the efficacy of the ketogenic diet (KD). Sprague-Dawley rats were fed ketogenic diets containing varying ratios of fats; (carbohydrates + proteins) whereas control animals were fed rodent chow. Unless otherwise indicated, all animals were fed calorie-restricted, isocaloric diets beginning at P37 and ketonemia, seizure threshold and neurotoxic effects were determined. Despite being provided isocaloric quantities, animals fed lower ketogenic ratios gained weight relative to those fed diets having greater proportions of fats. A significantly increased metabolic rate was noted for animals fed a high-fat diet, suggesting a basis for the weight differences. Results also showed that the animals fed calorie-restricted high-fat diets exhibited significant ketonemia and protection from pentylenetetrazole (PTZ)-induced seizures. There were no detectable neurotoxic effects for any diet group. For animals of the same age, there was no correlation between beta-hydroxybutyrate (beta-OHB) and seizure threshold. These findings suggest that beta-OHB is not directly involved in the anticonvulsant mechanism of the diet. Also, data presented here show that the conventional 4:1 ketogenic diet does not confer the greatest level of seizure protection. We conclude that a 6:1 ketogenic diet, which shows no evidence of neurotoxicity, may be maximally efficacious in rats.

PMID: 10604602 [PubMed - indexed for MEDLINE]


Now I'm more inclined to believe the above, since it seems to be from a very credible resource.

If you don't want to wade through all that, then here's the main point of this post-

Are diet-induced ketones a neurotoxin? Was I spending that 8 moths killing brain cells? If yay or nay, can you please provide some information backing your reply? Thanks. This really has me worried

 

[pattylou]

First off, don't panic. We kill brain cells when we sneeze, for example. (That may be an urban legend, I don't know.) But don't panic.

I searched around on PubMed for a while. It looks like diabetics are put on ketogenic diets on purpose, to control seizures. If there was significant risk of neuron loss, this therapy wouldn't be so widely used. So - I think you're OKAY.

That being said, many articles question the health benefits of Atkins. For example, blood cholesterol may go up, on Atkins. Here are a bunch of articles on Atkins and health (I didn't see any mention of brain cell death):

http://www.ncbi.nlm.nih.gov/entrez/...md=Display&dopt=pubmed_pubmed&from_uid=711091

Click on a title to get the abstract - Not all articles have abstracts. You can also select "Related articles" at the right to broaden your search on any given title.

Here is a similar pubmed search on Ketosis and brain metabolism.:

http://www.ncbi.nlm.nih.gov/entrez/...=Display&dopt=pubmed_pubmed&from_uid=15888376

And an oddball search string, that came up in my surfing, linking Transcendental Meditation with ketosis.

http://www.ncbi.nlm.nih.gov/entrez/...=Display&dopt=pubmed_pubmed&from_uid=15893151

As far as weight control, exercise and calorie control are the old tried and true. I don't think there have ever been any nasty side effects (aside from injury) from increased exercise. I know lots of people who have used Atkins successfully, and so congratulations on such a great weight loss! Maybe you could introduce some carbs and exercise to maintain your current weight?

 

[.ryan.]

Thanks a lot. I've been off the diet for 5 months now. I've got the carbs up to 300g a day, and run 3 miles every other day with 4 weight lifting sessions a week. I'll probly never low carb again since I started going crazy for carbs toward the end. Thanks for the help and I would appreciate any other info from anyone.

 

[pattylou]

Hey - weights are phenomenal. They're the best kept secret for staying fit. I didn't mention it because most people have their own thing when it comes to exercise, but I am sure if you keep up the weights, you'll do fine with some carbs. (Of course, I'm not a physician :) )

 

[Moonbear]

In situations of starvation, formation of ketone bodies supposedly helps preserve neural function as an alternative fuel source. In the situation of ketoacidosis (the extreme case of too many ketones formed), cardiac arrest is what you'd worry about most. It's difficult to know the effects on otherwise healthy people except in cases where starvation is documented. Most of the literature on ketoacidosis addresses the problem in diabetics or alcoholics where other health problems complicate things.

There are healthier "low-carb" diets that are not "no carb" diets. However, from watching what people eat when on those diets (I don't know if they are really sticking to their diets or not), they seem to be just not over-eating carbs and are also choosing healthier whole grains rather than processed, refined foods.

 

[.ryan.]

Thanks for the help guys. On another forum, someone provided me with this study which really set my mind at ease-

Prostaglandins Leukot Essent Fatty Acids. 2004 Mar;70(3):287-92. Related Articles, Links

Ketone body synthesis in the brain: possible neuroprotective effects.

Guzman M, Blazquez C.

Department of Biochemistry and Molecular Biology I, School of Biology, Complutense University, 28040 Madrid, Spain. mpg@bbm1.ucm.es

Ketone bodies make an important contribution to brain energy production and biosynthetic processes when glucose becomes scarce. Although it is generally assumed that the liver supplies the brain with ketone bodies, recent evidence shows that cultured astrocytes are also ketogenic cells. Moreover, astrocyte ketogenesis might participate in the control of the survival/death decision of neural cells in at least two manners: first, by scavenging non-esterified fatty acids the ketogenic pathway would prevent the detrimental actions of these compounds and their derivatives (e.g. ceramide) on brain structure and function. Second, ketone bodies may exert pro-survival actions per se by acting as cellular substrates, thereby preserving neuronal synaptic function and structural stability. These findings support the notion that ketone bodies produced by astrocytes may be used in situ as substrates for neuronal metabolism, and raise the possibility that astrocyte ketogenesis is a neuroprotective pathway.

 

[.ryan.]

I have another question-

I've been lifting weights for 2 years now. I get at least 200g of protein a day to maintain a positive nitrogen balance. However, while I was searching for info regarding ketones and neurotoxins and a study was talking about L-phenylalanine being a neurotoxin. One article said that it was only dangerous when consumed as part of aspartame and that when it is consumed with other amino acids, it has no negative effects. I would guess that I get around 4-5g of L-phenylalanine from protein shakes, chicken and turkey. Any danger here?

and yes, I realize I'm pretty dang paranoid about stuff :P.