The things you learn in class. Well, this week we went over digestion and the blood flow into the liver. Your liver, in case you don't know, is the major filter and processor of your body. It gets first crack at anything you digest (called "first pass", and here I should state, this is if you have a healthy liver). This is why many (most) drugs can cause liver damage. Before the drug can get to it's targeted tissue, it must pass through the liver. And here's the secret, most drugs are poisonous to some extent (the trade off is that hopefully it will help more than it hurts).
So, we had a discussion about digestion of certain "new foods." One of those is aspartame (formerly known as Nutrasweet) which is found in a lot of products. No, really, go look. I've tried to eliminate it from my diet for over a decade now (it gives me headaches, one of the side effects, it also lead to a loss of memory in my case, but that's another story). But this is not a good chemical for you to ingest.
Aspartame is an artificial sweetener (which means it doesn't occur naturally). That's not the bad part. It's composed of two amino acids, aspartic acid and phenylalanine dipeptide, connected by an ester bond. So far, okay, better living through chemistry, right? However, some people have a reaction to phenylalanine, so those might want to avoid it. But this still isn't the bad part.
Here I'm not going to go into the various medical side effects and proposed health issues (like MS and other diseases). Our discussion just kept to how your body processes nutrients (read a chemicals in the blood stream). You body does process aspartame (unlike other artificial sweeteners, or other "made" foods like olestra). And when it digests aspartame, that's when the problems occur.
Digestion is a process of breaking food down to usable chemicals. So the first thing that happens is that the ester bond is broken which releases the two amino acids (and here I won't follow those anymore, although, not all amino acids are good, but that's another discussion). That leaves the ester that was used to hold them together. That's an alcohol. Specifically, it's methanol (or at least, that's what your body turns it into). You may remember methanol by another name, wood alcohol. (Also, there is now some evidence that aspartame starts breaking down in the can/bottle, so you ingest the ester as methanol)
Now, this is a pretty small dose, so it's not going to make you blind (methanol attacks the optic nerve and it's connections). And it's for this reason that aspartame is considered safe. That is, you don't drop over dead or have serious immediate medical problems. (Or, at least, most people don't, see my comment about headaches, it also makes me feel like I'm drunk, but without the euphoric effects of alcohol)
We're not done, because your body, well, your liver, keeps on trying to package the methanol (because it's a poison, so the liver deals with it). Methanol processes to formaldehyde and then formic acid. The major liver damage comes at this point. Formaldehyde, as I'm sure you know, is an embalming fluid (used because it slows tissue breakdown and kills bacteria).
There's plenty of back and forth over what aspartame may or may not do, what it may cause or enhance, etc. That's not where I'm going right now. I'm going to talk about something else.
As your liver processes methanol (well, any alcohol, but more so with methanol) it stops packaging fats into triglycerides (which makes them usable by your body) and instead stores the fat (for later processing, but the liver never does get back to it, ever).
You may have heard of cirrhosis. Cirrhosis means you have a fatty liver. This is one of the problems that alcoholics have when their liver shuts down. Also, while there is no direct link shown, I can tell you that there is a rise of NAFL (non-alcoholic fatty liver disease).
This also means that your body stops processing or metabolizing fats while digesting aspartame. Aspartame is widely used in dieting materials. Why? Because it's cheap and it isn't sugar. However, it directly contributes to greater fat storage and lower fat processing.
How many people do you know trying to lose weight, who drink the diet pop and complain they can't lose the weight? They can't. Now you know why. What they're consuming is affecting their ability to metabolize fat, and increases their storage of fat.
As we were told, the tipping point for having problems is comparable to drinking a quart of diet soda a day. Understand that that point doesn't meant that the methanol isn't causing problems before that. Also, a quart sounds like a lot. There are over 2 quarts in a 2 liter bottle. How many kids do you know who drink a 2 liter bottle a day?
So why does industry still use it? Because it's cheap. Why doesn't the government stop them? Welcome to deregulation. See, the government did try back in the 90s, but then it was government interference. And people aren't dropping over dead from consuming it (yeah, that's pretty close to the standard). Some other governments have banned or controlled its sale. Does the industry know it affects you this way? Yes. That's why they have a PR campaign to stop having it pulled from the market (and to win you over, you can compare this to the tobacco PR of the 60s-80s). So why do they still use it? It's cheap.
Another example of when people tell me how companies only have the best interests of their customers at heart I just laugh.