I have never hiked Mt Whitney, although that would be fun. I write this, because I have to comment about this outdated post concerning aspartame.
No matter the scientific evidence in opposition (as presented in two papers cited below DASRP's post), the fact is that this sweetener, like caffeine, is still a drug. Every drug has side effects and has people who are sensitive to it. This goes for aspartame too, but sensitivity (no matter the outdated list in DARP below) by no means indicates aspartame is unsafe for the majority of people, just as meat, milk, and peanuts are safe for the majority of people.
The question in the case of aspartame is why are some people sensitive to it, while the vast majority are not. The answer most likely comes from how aspartame is processed. Just as digestion breaks food constituents into their basic components, aspartame is converted into its two amino acid components (phenylalanine and aspartic acid) and methanol. All three of these components are present in virtually all the foods we eat, quite often at higher concentrations.
Nevertheless some people show sensitivity to certain of these components. People with phenylketonuria cannot handle the phenylalanine component. But these people have been told about this personal sensitivity early in life and a warning to this effect is provided on the label. Critics suggested there were issues with such intakes of phenylalanine based on an early report by Wurtman (which DARP cites). But Wurtman himself completely refuted his own earlier, but still widely cited allegation, that phenylalanine or aspartate caused any problem with their conclusion: (Quote) Large daily doses of aspartame had no effect on neuropsychologic, neurophysiologic, or behavioral functioning in healthy young adults (Unquote), see
http://www.ncbi.nlm.nih.gov/pubmed/9734727. The aspartic acid (aspartate) component of aspartame presents no recognizable issue.
And while methanol at the concentrations encountered in foods also presents no problem to most people, some people have insufficient vitamin (folate, B12) nutrition or have personal genetic issues that impair their ability to properly utilize the methanol metabolites. This was first realized clearly in the late 1980's and early to mid-1990's culminating in the 1998 mandated fortification of grain products with folate. That mandate was consequent to discovery of birth defects in children of deficient mothers (more here,
http://www.fda.gov/AboutFDA/WhatWeDo/His...y/ucm091883.htm). The problem existed in men, albeit with less dramatic impact.
This underlying problem causes inadequate availability of methionine (methylhomocysteine) or other methylated substances (thymine from uracil). It is now known to be responsible for cancer, many diseases or related issues that critics wrongly attributed to aspartame. That the underlying issue is unrelated to accrual of methanol metabolites formaldehyde or formate, which critics argue exert some type of toxicity, is very clear. This is, because these cancers, diseases, and related issues far more documentably stem from accrual of homocysteine (unmethylated methylhomocysteine called methionine), see
http://en.wikipedia.org/wiki/Homocysteine or from polymorphisms (altered enzymes) of methylenetetrahydrofolate reductase, (
http://en.wikipedia.org/wiki/Methylenetetrahydrofolate_reductase) or methionine synthase (
http://en.wikipedia.org/wiki/Methionine_synthase). For more visit PubMed,
http://www.ncbi.nlm.nih.gov/sites/entrez, and type homocysteine or these other issues above into the search line.
To make this point consider aspartame's most widely reported issue--migraine headaches. Migraines have been linked directly to the MTHFR (MethyleneTetraHydroFolate Reductase) C677T folate polymorphism, see
http://en.wikipedia.org/wiki/Methylenetetrahydrofolate_reductase and specifically
http://www.ncbi.nlm.nih.gov/pubmed/11121176). Two other papers deal with this issue,
http://www.ncbi.nlm.nih.gov/pubmed/19619240 and
http://www.ncbi.nlm.nih.gov/pubmed/19384265). Taken together these reports indicate complete resolution of migraines with added folate alone. While these investigations revealed that more than the normal daily recommended amounts are needed (2-5 mg), in these papers increased folate doses ALONE solved the migraine problem [and aspartame was not even involved]. That alone suggests a human sub-population that is even more deficient in folate for which resolution of their symptoms requires even more folate. And that is confirmed by science; up to 40% of some populations have these genetic folate polymorphisms that require added folate; most don't even know it. For more read
http://download.cell.com/AJHG/pdf/PIIS0002929707614001.pdf?intermediate=true.So in summary I have documented above why aspartame is perfectly safe used as directed in people without some pre-existing health issue.
John E. Garst, Ph.D. (Medicinal Chemistry, Pharmacology, Toxicology, and Nutrition)
