# Risks Associated with Artificial Sweeteners: A Closer Look
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Chapter 1: Understanding Artificial Sweeteners
When consuming products like Diet Coke or other items containing the artificial sweetener aspartame, you may notice a warning for individuals with phenylketonuria, a genetic metabolic disorder.
Unlike natural sugars, artificial sweeteners such as NutraSweet and Equal are not carbohydrates. Aspartame, specifically, is a methyl ester formed from two amino acids: aspartic acid and phenylalanine (Phe)—a detail that is crucial for later discussion.
The safety of aspartame has been under scrutiny since its discovery in 1965, but so far, no substantial evidence links it to harmful effects in the general population. The warning on aspartame products is targeted only at those with phenylketonuria.
Genetic Factors and Phenylketonuria
For an individual to have phenylketonuria, they must inherit faulty copies of the gene responsible for breaking down Phe from both parents. Generally, these parents are carriers who possess one normal and one defective gene but do not exhibit symptoms themselves.
The primary issue in phenylketonuria is the body's inability to metabolize excess Phe, which is one of the amino acids present in aspartame. Here’s where it gets intricate.
Amino acids can link together and fold into complex three-dimensional structures, forming functional proteins that fulfill various roles in our body. While we can synthesize some amino acids, others, such as Phe, must be sourced from our diet. The body cannot store excess amino acids (in contrast to fats and carbohydrates), necessitating a continual intake.
When we consume too many amino acids, they can't be directly excreted; instead, they must undergo a series of breakdown steps. The initial stage of Phe degradation involves its transformation into tyrosine, which plays a critical role in neurotransmission. This reaction requires an enzyme and a co-factor, both produced by specific genes.
However, mutations in these genes can lead to the production of an altered enzyme that may not effectively facilitate the breakdown of Phe. As a result, Phe levels in the body can rise, leading to neurotoxic effects. Early identification and intervention for elevated Phe levels are crucial to prevent severe cognitive disabilities.
Diagnosis and Management of Phenylketonuria
Phenylketonuria was first recognized by biochemist Asbjorn Folling, who noted an unusual odor in the urine of certain individuals with developmental issues. This smell results from a compound produced when Phe accumulates in the body.
In the late 1950s, a reliable diagnostic test that could be administered from around eight weeks of age was developed. However, by this time, many untreated infants had already experienced brain damage.
Fortunately, a more sensitive method emerged a few years later, allowing for detection just three days after birth. The Guthrie test, also known as the heel-prick test, involves taking a drop of blood from a newborn. This blood is placed on a growth medium that only supports bacteria unable to produce Phe. If the bacteria grow, it indicates a positive result for Phe in the blood.
This heel-prick test is now standard in neonatal screening. Modern diagnostic techniques include tandem mass spectrometry, which screens for various conditions.
Since the 1950s, a low-Phe diet has been the mainstay of treatment for individuals with this disorder. Given that Phe is present in most food sources, patients typically obtain most of their calories from a formula, supplemented by low-protein foods like fruits and vegetables.
Due to the restrictive nature of this dietary regimen, researchers are exploring alternative treatments. Possibilities include synthetic forms of the enzyme co-factor, enzymes that can break down Phe, and gene therapy.
The reason individuals with phenylketonuria must avoid aspartame-sweetened foods is that during digestion, aspartame breaks down into its constituent amino acids, including Phe, which poses a serious risk for these individuals.
Chapter 2: Health Risks of Artificial Sweeteners
The first video titled "Artificial sweetener linked to risk of blood clots: study" discusses the potential health risks associated with consuming artificial sweeteners like aspartame and their connection to blood clotting issues.
The second video titled "Artificial sweetener linked to increased health risks, study finds" explores further studies that reveal the various health concerns tied to artificial sweeteners and their long-term effects on health.