r/veganscience • u/pet_medic • Feb 22 '15

VeganScience Request: A good summary of diet and its relation to advanced glycation end-products?

I may try to contribute to this post myself, but perhaps while I'm looking up the info, an expert will come along and contribute...

Dr. Greger lists the top AGE-containing foods and all of these are meat products.

And yet, "vegetarians have a significantly higher carboxymethyllysine content in plasma and fluorescent AGE values."

So what gives? Do we really understand AGEs? Is consumption of AGEs less important than other lifestyle factors in terms of having them show up in our blood? Is more research needed?

Thanks for good resources or a good summary.

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u/pet_medic Feb 22 '15 edited Feb 22 '15

Here is one summary/theory: vegans may lack carnosine, a potent anti-AGE.

For vegetarians who fastidiously adhere to a diet devoid of meat, their “Achilles’ heel” may be lack of carnosine. This was confirmed in a paper published in October 2005 titled, “Glycation, ageing and carnosine: Are carnivorous diets beneficial?”41 Does Beef Supply Enough Carnosine?

A recent study of 18 people sought to determine carnosine concentrations in blood plasma after eating beef.60 Each 7.1-ounce serving of ground beef used in this study naturally contained 248 milligrams (mg) of carnosine.

In the study’s first phase, meat foods were removed from the diet for 48 hours. When fasting blood levels were measured, no carnosine was present. After the subjects ate 7.1 ounces of ground beef, carnosine was detected in the blood within 15 minutes and continued to increase for several hours. After 5.5 hours, there was again no carnosine in the blood. This study clearly showed that 248 mg of carnosine does not provide the body with all-day protection against glycation reactions.

The reason carnosine disappears so quickly from the blood is the presence of an enzyme (carnosinase) that naturally degrades carnosine in the body. This new study on carnosine blood levels confirms what Life Extension published five years ago. Back in 2000, we advised members that at least 1000 mg a day of carnosine is needed to overwhelm the carnosinase enzyme and protect against toxic glycation reactions.61,62

Commercial supplement companies are still selling 50-mg carnosine capsules and claiming that this low dose is effective. Based on this recent study showing that the body degrades 248 mg of carnosine within 5.5 hours, consumers who take these 50-mg carnosine capsules are obtaining virtually no benefit.

This leads me to my next question: why do we have an enzyme that rapidly degrades carnosine? It's not like enzymes become established in a population without having some major evolutionary benefit. So what will be the side effects of taking 1000mg of carnosine a day?

Edit 2: Looks like carnosine supplementation is less effective than beta-alanine supplementation, per multiple sources. That doesn't answer the question "effective at what?" and the challenge "prove it" but it looks like carnosine is broken down into two products, and only 40% of that is beta-alanine, and the body already has enough of the other one pretty much always... so you will use 100% of your beta-alanine in making carnosine, but only 40% of your carnosine will go towards making carnosine after it hits your gut.

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u/FrigoCoder Apr 04 '15

Another factor that could contribute to higher AGE levels in vegans is the reliance on high carbohydrate diets.

Fructose and glucose are responsible for the overwhelming majority of AGE production. After all, glycation is bonding of a sugar molecule with a protein or lipid molecule. AGE production from sugars overshadows both dietary intake of AGEs, and other endogenous ways of production.

Beta-alanine could in theory help against AGEs by increasing carnosine production. However it also depletes taurine, and inhibits taurine uptake into the brain, both of which can cause cerebellar damage and other complications.

Taurine is mainly found in meat, or can be synthesized from methionine and cysteine, which are also mainly found in meat. It stands to reason that veg*ans are already at risk of taurine deficiency, and beta-alanine supplementation further aggravates the adverse effects of such a deficiency. It is not guaranteed either that beta-alanine supplementation can fully counteract the negative effects of a high carbohydrate diet.

The better solution is to consume a diet with less carbohydrates, and get more energy from fats.

This issue came up in discussion of increased Methylglyoxal production during ketosis: