Reports that the consumption of aspartame is associated with changes in mood, behavior and cognition, as well as very serious health conditions like fibromyalgia and Alzheimer’s disease are largely unfounded. In fact, a large body of scientific evidence has shown aspartame cannot be credibly linked to any of these health outcomes.
Mood, Behavior and Cognition
Clinical trials have included healthy adult volunteers who reported these symptoms after ingestion of aspartame (Schiffman et al. 1987), children with attention deficit disorder (Shaywitz et al. 1994), children with hyperactivity (Wolraich et al. 1994), male and female pilots (Stokes et al. 1995), male heterozygotes for phenylketonuria (Trefz et al. 1994), individuals with a history of seizures (Rowan et al. 1995), college students (Stokes et al. 1994) and non-aspartame sensitive controls (Spiers et al. 1998).
Randomized, double-blind, placebo-controlled, cross-over designs have been used in these studies and aspartame has been administered in capsules at varying doses (Spiers et al. 1998) and in beverages and compressed bars. The response to aspartame has been tested against glucose (Green et al. 2001), sucrose (Spiers et al. 1998), saccharin (Wolraich et al. 1994), alcohol (Stokes et al. 1991) and placebo. Laboratory measurements have included blood and urine assays, and neuropsychological measurements have included electroencephalogram (EEG), depression scales and tests of cognitive function, memory and spatial orientation.
During the 2013 revaluation of aspartame, the European Food Safety Authority (2013) concluded aspartame does not affect mood, behavior or cognition in children and adults. A good example of the strength of the evidence is the study by Sathyapalan et al. 2015. In this study, age and sex matched individuals that self-identified as either aspartame-sensitive or non-aspartame-sensitive were administered aspartame-containing (100mg) snack bars and control bars randomly over 7 days, and 14 symptoms commonly reported by aspartame-sensitive individuals were tested. The researchers found no difference in symptoms reported after aspartame ingestion and control treatment and no consequential differences between the aspartame-sensitive subjects and the non-sensitive control group. In a study designed to measure the effects of “expectancy,” Green et al. 2001 reported symptoms were more frequent when subjects knew which sweetener was being ingested, but not when the treatment was blinded. Also of note is the study by Walton et al. 1993 that found more symptoms in populations with pre-existing depression after aspartame ingestion (30mg/kg/d for 7 days), but not in those without a psychiatric history.
The cause of fibromyalgia remains unknown and there are no diagnostic laboratory tests for it. However, Vellisca and Latorre 2014 found elimination of aspartame and monosodium glutamate (MSG) in female patients with fibromyalgia did not produce any difference in their reported pain compared to controls. Cairns 2016 reviewed studies on pain associated with consumption of MSG, aspartame, arachidonic acid and caffeine and found decreased consumption of these ingredients did not consistently reduce pain.
A number of different factors are believed to be involved in the development of fibromyalgia, such as experiencing a physically or emotionally traumatic event or a repetitive injury. It can also occur spontaneously. People who have other rheumatic diseases such as rheumatoid arthritis or lupus are more likely to develop fibromyalgia and, for unknown reasons, it is more common in women. Thus, an experienced physician must base the diagnosis on criteria established by the American College of Rheumatology.
The chief symptoms of fibromyalgia are pain and fatigue, but patients also report cognitive and memory problems, headaches and numbness and tingling of the extremities, among other symptoms. Treatment may include the use of analgesics, alternative therapies like acupuncture, and changes in diet, exercise and sleep habits. No specific diet has been proven to influence fibromyalgia, but some people report feeling better when they avoid certain foods. As a result, healthcare professionals should discuss any dietary changes with their patients.
In dispelling myths about Alzheimer’s disease, the Alzheimer’s Association concurred with the U.S. Food and Drug Administration’s (FDA) 2007 Statement on European Aspartame Study that no scientific evidence has been presented to alter the FDA’s conclusion that the use of aspartame is safe.
The Alzheimer’s Disease Education and Referral Center of the National Institute on Aging states the cause of Alzheimer’s disease (AD) is unknown, but is likely a combination of genetic, environmental and lifestyle factors. The importance of any one of these factors in increasing or decreasing the risk of developing AD may differ from person to person.
The strongest dietary links with AD are the same as those related to other vascular diseases, such as heart disease, stroke, and high blood pressure. Diets high in saturated fat, trans fat, and sodium may increase risk of AD, while diets rich in antioxidants from fruits and vegetables and omega-3 fatty acids from fish and walnuts, or following the Mediterranean Diet Pattern, may lower the risk, but no single food or ingredient has been identified that causes it.