7 Things to Know about Aspartame, Phenylalanine, and Those Scary Warnings on Soft Drinks

Fooducate community member Skyler asks about a warning she saw on a pack of gum -

“Phenylketonurics – contains phenylalanine”

What is this? And what does it have to do with chewing gum? Or diet soda?

What you need to know:

1. Phenylalanine is an amino acid. Amino acids sounds scary, but they are actually the building blocks of protein.

2. Phenylalanine is actually an essential amino acid. This means the body cannot create any on its own, and thus must receive it as part of a diet, usually when consuming proteins.

3. So where can one find phenylalanine? In breast milk (for babies), and in most animal products (meat, dairy, eggs).

4. Oh, and in aspartame too. Yes, that cursed artificial sweetener breaks down into several components in our body, one of them being phenylalanine.

So what’s with the warning?

5. Turns out that one in 15,000 people in the world has a genetic disorder called Phenylketonuria. Their body can’t metabolize synthesize phenylalanine. As it builds up in the body, it causes all sorts of bad things to happen, such as mental retardation, seizures, and other brain damage.

6. People suffering from Phenylketonuria (or PKU) are called phenylketonurics. They need to constantly monitor their protein intake. They are also warned about consumption of products containing aspartame – hence the warning on labels – “Phenylketonurics – contains phenylalanine”.

7. If you don’t have PKU, you probably don’t need to worry about harmful health effects of phenylalanine. But that doesn’t mean that aspartame is healthy for you, or that diet drinks are a healthy choice. As for gum – choose those sweetened with Xylitol.

If anyone of our readers suffers from PKU, give us a shout and tell us of your experience making the right food choices.

Get Fooducated: iPhone App RSS Subscription or Email Subscription

Follow us on twitter: twitter.com/fooducate on facebook: facebook.com/fooducate

Get Fooducated

  • Sketch

    wow – an article that tells us the facts without any spin… its almost like you want us to decide for ourselves if we should choose aspartame or not… Whats the catch?

    Good Job, people!
    now if we could get one of these article thingies for saccharin….

  • Brooke

    I think you mean to say that phenylketonurics can’t *metaboloize* phenylalanine. As it is an essential amino acid, by definition, no human can synthesize it.

  • guest

    is that really a “warning”? no spin in the article, but the tweet made me think there was real concern for most people.

    • Erin

      Yes, it really is warning specifically for phenylketonurics like myself, but anyone may have eactions to it because of the high concentration phenylalanine and the fact that it is in isolation.

      BTW, I haven’t mentioned that I work for Wisdom Natural Brands, the makers of SweetLeaf Stevia, so that’s another reason I know about sweeteners.

  • http://twitter.com/mcnee McNee

    good info, but I think the title is a lil misleading. Really only a passing mention of aspartame, and don’t think that warning is any scarier than seeing “may contain nuts” on various products.

    • Jean

      Well, that “may contain nuts” label is also pretty scary if you (or your child) is severely allergic to nuts.

      • Nschmtiz2004

        I have to wonder what we did to peanuts through GM or selective harvesting to make peanuts cause the human body to freak out and send out the immune cells like that. I mean it has only been over the past 20 years peanut allergies have been on the rise. Any thoughts?

        • Leigha7

          My guess is that it has little to nothing to do that, but rather:

          1. Far more people have access to them. Up until relatively recently, people could only eat foods that grew were they lived, and only when they were in season (unless they were preserved in some way). Peanuts only grow in a few states in the southern US, northeastern Africa, and parts of Asia and South America (if my quick Google search is correct). So people from the rest of the world would likely never have eaten them, which means they would never have suffered from any sort of allergy (even though they may have been allergic).

          2. Anyone with a severe allergy would likely have died in the era before modern medicine. Now that we have the ability to recognize (and thus prevent) as well as treat allergies, this is no longer the case. Further, since allergies can be hereditary, the previous generation of allergic people who would otherwise have died are alive to have children who may very well also have allergies.

      • Keoki

        Or you have PKU Peanuts are a rich source of protein and with that said a rich source for phenylalanine as well.

  • Leanne

    Why is it, then, that some people (myself included) have instant headaches and dry mouth when anything with phenylalanine or aspartame is ingested?

    • karen

      Leanne, maybe you need to bring this article to a Dr. and asked to be checked for a problem with it. Good luck

      • seaotter

        Leanne, if you had untreated PKU you would have severe mental retardation due to eating phenylalanine. As the article states, phenylalanine is in many foods everyone eats including breast milk, eggs, etc. Do you get headaches and dry mouth when you eat eggs or drink milk (or eat anything with them in it)? I would be shocked if you had undiagnosed PKU and made it to adulthood without anyone noticing the associated problems.

        Many people do have unfavourable reactions to artificial sweeteners (including myself..I also get headaches). Instead of worrying about phenylalanine specifically I would focus more on avoiding artificial sweeteners.

        • Erin

          seaotter, the chemical make-up of aspartame is different than the phenylalnine in regular foods we eat.  It is quite common for people to have reactions to aspartame who don’t have reactions to the foods you mentioned. (and you don’t have to have PKU to have reactions to it)

    • Erin

      Leanne, like I said I have a PKU variant, so I would know.  Trust me, you don’t have PKU.  You simply cannot go through life without knowing it, and babies are tested for the disorder shortly after birth.  However, that does not mean that you would not have reactions to aspartame even though you don’t have reactions to other foods, because of the specific chemical make-up of aspartame.

    • Ilovepdsr66

       It is because aspartame is very well known to cause headaches, not necessarily phenylalanine. If you get headaches from phenylalanine then you would get headaches from any animal products as well. So its more than likely just the aspartame.  

    • happygirl

      Like most other genetic diseases, PKU involves the inability to produce a certain protein correctly, or at all. Those with PKU do not produce an enzyme (a type of protein) that is essential for breaking down phenyl. Therefore, it builds up in the brain and causes retardation. So, your body either makes the enzyme or it doesn’t, according to the set of instructions in your DNA. Hope this helps.

  • Shelly

    Would like to hear a whole lost more about these artificial sweeteners!

  • Schwartzjon44

    1 in 15,000? Got it. Thanks.

  • http://www.thefrugaldietitian.com Nancy – The Frugal dietitian

    Nice review is here (you can click on the pdf form): http://www.eatright.org/About/Content.aspx?id=8363

    • Joshh

      Good review. I’m an RD too, and even though the ADA and FDA say that aspartame and other non-nutritive sweeteners are ok to include in our diet, I’m skeptical.

      Studies as the one below, which says drinking three servings of diet coke, aspartame, per day increases the risk of cancer should be eye opening for dietitians and the leaders of the ADA and FDA.

      http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1964906/

      Bottom line, just because the FDA labels something as “generally recognized as safe”… doesn’t make it ok it consume.

      Joshh, RD

      • http://www.facebook.com/marcus.beier.3 Marcus Beier

        Monsanto Chemicals (the original patent holder for Aspartame) donates large sums of money to Diabetics foundations and the FDA so i would take anything not from a trusted doctor with 10 grains of sea salt!

  • Kristina A Reed

    I get, what I refer to as, ‘the shakes’ when I consume anything with aspartame. It’s almost an instant effect on me so I steer clear of almost anything thing sweet and on the occasion i feel the need i definitely won’t do a ‘diet’ or ‘light’ any product

    • happygirl

      that sounds like an affect of caffeine. have you tried testing that?

  • http://www.facebook.com/profile.php?id=1229199146 Tara Gray Burkholder

    Something I learned in my college biology lab: some people are born with the ability to taste phenylalanine and some aren’t, it’s genetic. If you can taste it, it makes anything sweetened with aspartame taste horribly chemical & leaves a bad aftertaste in your mouth. If you can’t taste it, diet drinks don’t taste all that different than regular drinks.

    • Rosey B.

      Wow! That would explain a lot of things for me. I am constantly freaking out cause stuff tastes “chemically” to me…People think I am a freak or just overreacting, but I can almost not eat anything anymore because I get that chemical taste

    • Evan Grantham-Brown

      Yup, this is me. To me, anything with aspartame in it tastes absolutely awful. It’s a real pain if you’re trying to keep your sugar consumption down; anything that says “No added sugar” has about a fifty-fifty chance of having aspartame in it.

    • Ashley

      I get headaches really bad if I have anything with aspartame in it. Anytime I go to get anything I make sue there is no aspartame because I can fast it all to well. Its a very noticeable taste and so I stay away from it accept today when I realized it has phenylalanine in it. So now I have a headache. I also know a manager at our local tool store who has severe memory lose due to drinking a lot of diet soda. So yeah stay away from it all people.

  • http://www.facebook.com/profile.php?id=1229199146 Tara Gray Burkholder

    Something I learned in college biology lab: Some people are born with the ability to taste phenylalanine, it’s genetic. If you can taste it, if you consume anything sweetened with aspartame in it, it leaves a horrible chemical taste in your mouth, which is why some people dislike the taste of diet drinks (like me). Other people, those who cannot taste the phenylalanine, think that diet drinks don’t taste all that different from regular drinks.

  • Erin

    You told me to give a shout out, so I am. I have PKU, but no longer follow the diet. Actually, I have a variant of the disorder that is even more rare. Growing up I was only 1 of 2 known in the world with my type of PKU–the other was my brother. As a child, following the diet stunk– it was a pain, although kids with classic PKU had it much worse. Even though I don’t follow the diet in other ways now, I still avoid aspartame like the plague. Just so everyone knows, it is true that if you have undiagnosed PKU, you would be severely mentally retarded by now. I have two adult cousins who have minds of children due to ingesting too mush phenylalanine. Babies are tested for the disorder not long after birth because a strict needs to be followed…believe me, take it from someone who knows, if you have PKU, you know it!

    Aspartame has the potential, though, to cause adverse effects in anyone because of the high amount of phenylalanine (50%). I’m sure the 40% asparctic acid, 10% methanol (wood alcohol) and the conversion into formaldehyde in the body doesn’t help either. The three substances are found in natural food we eat everyday, but they are in much lower concentratiions and/or are in compounds with other elements or substances that nullify any any negative effects. They are not meant to be ingested in isolation or in this combination.

    • http://www.fooducate.com/blog Fooducate

      Thanks Erin, for sharing your story

  • No1

    This Is soo confusing! Lol

  • 911Baby

    Wow This is soooo Infomational!

    • KJG

      Ya It Is!

  • John Peacemaker

    Bottom line…it is not food!
    It builds up in the human body whether you are a pku patient or not.
    It is detrimental to human health.

    • Keoki

      No if you do not have pku phenylalanine would not build up in your body. It is metabolized into tyrosine which is used by the body for energy. If you have ever had the energy supplement 5 hour energy you ingested concentrated amounts of l-phenylalanine, l- taurine, and l-tyrosine. Furthermore, Phenylalnine is in all foods, that is why there are companies like Cambrooke that have devoted themselves to creating mock foods that don’t have phenylalanine.

    • GFM2011

      You don’t know what you’re talking about. Don’t go making up “facts” which are really only your own false impressions.

  • sammy

    My brother has PKU and was luckily born to a woman who is a Dietician, works with WIC and has worked with PKU kids for most of her career (if that’s not luck I don’t know what is). He has stuck with his diet his entire life and suffers from no mental problems. He is a very smart and quick young man, and currently serving a two year mission for The Church Of Jesus Christ of Latter Day Saints. I remember a few years ago when we started noticing the labels discussed in the above article, the rest of us kids stopped chewing gum for awhile, but he accepted it just like he has the rest of his eating habits. Its always nice to hear other people talk about this disorder, because its always been a part of my life.

    • Erin

      Just wanted to say hi.  I have a PKU variant–weird, I know.  Anyway I served a mission for The Church of Jesus Christ of Latter-Day Saints too!  Your brother was very fortunate to be born to someone who knows so much about PKU.  There are so few people who truly understand it even today, but I don’t think it was luck…

  • maddy

    i am an 18 year old girl and i have PKU as well. it doesn’t really affect me very much i just follow my diet and drink the formula, out of all the genetic conditions to have, this one isn’t so bad, as long as it is picked up at birth

  • Keoki

    Keoki – I am 20yrs old and have PKU. It has been so hard for the last 10 years to find types of gum I can chew. I gave up chewing gum all together. I am so glad to see a there is a post that is educating the public. The only problem I have is the estimate is “About one in every 10,000 Caucasian babies in the United States is born with PKU.” (http://www.health.state.mn.us/divs/fh/mcshn/ncfu/cond/pku.htm#13)

    My doctor and I once sat down and did the math on the worlds population coming out with 2% of the world having pku.

    • Frank

      I have PKU too, I’m 24. About the gum, I’ve recently come across a great gum called “Pur” that proudly boasts the fact that its aspartame free! I like it a lot, here’s their site if you wanna know more. http://www.pur-gum.com/pur_home.php

  • thewayitis

    I like what the guy John Peacemaker said. THE BOTTOM LINE IS AS STATED THE CRAP IN NOT FOOD. NOT FOOD. we all in the world should put a stop to the making of the FOOD poisoning and selling it to us as food

  • kane

    was worried for a sec just ate like three sticks of 5 gum

  • Miro

    Wow! What an amazing site!! I got more information from this than the 6 other sites put together. Thanks guys.

  • amy

    I have heart murmur, and I have this gum that I have been eatingmfor about 1 year now. It contains phenylalanine. I was wondering if phenylalanine has a greater impact on me or a lower impact on me?

    • erinvalynn

      It sounds like your gum contains aspartame (50% phenylalanine, 40% aspartic acid, 10% methyl ester). You may be having a reaction to aspartame, so I suggest laying off the gum and anything else you might be ingesting that contains aspartame to see if that helps. All the best!
      (employed by Wisdom Natural Brands, SweetLeaf Stevia)

  • GFM2011

    If you’re going to lift so much literally from the Mayo clinic, you should at least attribute…

  • David H

    I noticed the Warning: Contains phenylalanine on a pack of gum today, and looked it up, which brought me here. I’ve actually been taking Phenylalanine as a mood enhancing supplement for the past several months. This article kind of concerns me, but I guess it shouldn’t since I’m not a PKU. Anyone think I should be concerned?

    • erinvalynn

      50% of aspartame is phenylalanine, which is why there is a warning on products that contain it for phenylketonurics like myself. But keep in mind that in foods we eat, while phenylalanine is present as it is an essential amino acid, it is only about 4-6% of the protein chain, whereas, it’s an isolate, or in isolation, that is to say separate from its protein chain, and is a whopping 50% of the aspartame combo. In other words, we were not meant to ingest phenylalanine the way it is in aspartame, whether you have PKU or not, so I suggest not as a supplement either if it’s an isolate and/or it’s at a higher concentration than in natural foods. Perhaps you should bring this up with your doctor…
      (employed by Wisdom Natural Brands, SweetLeaf Stevia)

  • tia

    My daughter chews a lot of sugarless gum since it is recommended to avoid tooth decay, but over the years I have noticed she has a lot of trouble learning. When I was a kid aspartame or any of the artificial sweetners weren’t consumed by anyone in our family. Nor were diet sodas. I can definitely tell a difference in my kids and their overall health then when I was growing up. As a kid growing up we ate fresh food from the garden drank fresh cow milk without antibiotic treated cattle and consumed fresh beaf from our own cattle that were not treated with antibiotics or growth hormones. We were much healthily as kids. I do not consume diet sodas or sugarless gum and had good health until 5 years ago. It has been shown that soda diet or not leeches calcium from your bones so how can these artificial sweetners that make the gum and soda have an aftertaste be good for you. As many preservatives that are added to our food now, do we really know what they are doing to our health?

  • tia

    One more question about someone coming across a gum called pur. Is the only way you can gt it is online? And does anyone know what it contains? I chewed gum as a child always contsinted

    • erinvalynn

      I understand that Pur Gum contains xylitol as its sweetener, and other than online may be purchased at natural food stores like Sprouts, so may also available at Trader Joe’s or Whole Foods. Good luck!
      (employed by Wisdom Natural Brands, SweetLeaf Stevia)

  • tia

    Clicked before I was done. Chewed gum as a kid always had sugar in it. Only thing was hard on my teeth but who didn’t eat candy and sugar as a kid.

  • Angel

    I didn’t know I had an issue until I switched from mountain dew and went on a diet coke only diet bc I was ‘fat’ in high school. I have had several bone problems through life and in high school ended up with slight brain damage in my short-term memory center. I have a hard time, especially in relationships, bc I don’t always remember things, and we all know how bad it is to forget something your other half has asked of you… It’s very frustrating. If I’d known sooner, maybe I’d have been able to have a more normal life, but I don’t regret much. I am who I am bc of my past, so I am thankful and just try to push forward.

    And from other posts, I see other people can taste it too. I always thought I was alone in that. Never met someone, who with one sip, knew that a mystery drink was artificially sweetened. At least I can tell when we are about to consume something dangerous! How many of you can’t taste it?

    And for those of you who say aspartame is harmless if you don’t have PKU, think again. The ‘history’ may have been ..altered.. concerning it via internet, but the truth is that before the PENTAGON released it to the FDA for human consumption, they held it, classified as a chemical warfare agent, deadly to humans at a certain concentration. <-That, was committed to memory as soon as I found it, and it's funny, bc I've not been able to find that information so freely anymore. Ten years of cover-ups. That's a long time to get rid of the evidence that the government was behind all of this…

  • kreed14

    That is really creepy. I once ate gum with pku nothing happened but will some thing happen to me To My Brain.Answer The Question Please.