Editor—Briffa distorts the content of our editorial, his language demonstrating his fundamental distrust of the “artificial” and “synthetic”—in this case a sweetener.
We pointed out the difficulty of proving an absence of effects in research and suggested that the public is better served by independent scientific review than by anecdotes of sometimes unknown provenance.1 When public safety is at stake, all views should be evaluated and contributors' vested interests recognised.
Briffa cites an online review of studies on aspartame that merely lists study number and funding sources without any scientific content or systematic review.2 He highlights one study that reports catastrophic levels of mixed psychiatric symptoms in eight patients with histories of depression, necessitating premature study closure after seven days' treatment.3 No effects were noted in five non-depressed colleagues. To reconcile these (uncontrolled) results with everyday experiences among depressed people exposed to aspartame and draw confident conclusions is difficult. Potential for positive publication bias in studies funded by manufacturers undoubtedly exists, but this can also apply to studies designed by those seeking to prove a strong belief about hazards of food components.
Briffa mentions a report of 32 people with self diagnosed headaches that were related to aspartame.4 These subjects were evidently prone to headaches, reporting them on 33% of days with aspartame, compared with 24% with placebo. This result just reached significance (P = 0.04), but over half the subjects could identify which treatment they were receiving, and no significant differences occurred in terms of severity or duration of headaches.
Briffa also highlights a study highlighted by Lipton et al which found that 8% of people with headache believed that aspartame was a cause, although other foods (such as alcohol, 57%) were reported more frequently. Other published studies are inconclusive.5
Gordon also reports headache. Many common foods can provoke headaches or other minor symptoms in isolated susceptible individuals. It would not usually be considered a major safety issue, and measures to introduce warnings for aspartame would need also to consider common foods, such as cheeses and wines. Scarcely any food would be free from a warning if all possible symptoms in all people were to be included. It remains important for food labelling to inform consumers about the presence of constituents such as aspartame, which individuals with personal beliefs or suspected symptoms can avoid.
Competing interests: None declared.
References
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