A new US study has found consumption of the popular artificial sweetener aspartame – marketed as Equal, Nutrasweet and Sugar Twin – may contribute to anxiety-like behaviour.
Researchers at Florida State University found consumption of aspartame (an artificial sweetener found in thousands of drinks and food products globally) produced anxiety-like behaviour in mice, along with epigenetic changes in the amygdala (a part of the brain associated with regulating anxiety and fear) – and these changes persisted for up to two subsequent generations through males.
The study, published in the journal PNAS, noted the anxiety in mice was the result of consuming the equivalent of ‘just 15% of the US FDA’s maximum daily recommendation’. Lead author Dr Pradeep Bhide told medicalnewstoday.com: ‘The amount of aspartame consumed by the mice in our study was representative of the amount consumed by some individuals: 2-4 small 8-ounce cans of aspartame- sweetened diet soda per day.’
Dr Bidhe explained their laboratory ‘is interested in examining how environmental exposures influence traits – behavioural, cellular, molecular, etc – not only in the directly exposed individuals, but also in their descendants.’
After determining nicotine and artificial sweetener saccharin produce heritable behavioural effects, the researchers turned their attention to the ‘even more popular sweetener than saccharin: aspartame’. The study’s male and female mice received aspartame in drinking water, then, to assess anxiety levels, researchers gave the mice an ‘open field’ test.
Fellow lead author Sarah Jones said the strong anxiety-producing effect of aspartame ‘was definitely an unexpected finding’.
Dr Bhide noted the anxiety ‘appeared to be robust, and I would not rule out that smaller amounts could produce anxiety in mice and men, if consumed daily over a period of several weeks.’
The researchers also found the drug diazepam could successfully alleviate anxiety, and that both changes in mice amygdala and their response to diazepam were retained in the male mice and persisted for up to two subsequent generations.
Dr Bhide explained: ‘Epigenetic changes produced by aspartame or other environmental influences in germ cells are believed to mediate transfer of the epigenetic changes to somatic cells (eg brain, liver, heart, etc) and germ cells (egg and sperm) of the descendants in the next generation.’
If such a change is inflicted on just one generation, ‘the heritable epigenetic changes and traits would dilute – or attenuate – with each successive generation and eventually disappear’.
By Dr Bhide cautioned: ‘Our data from mice suggest similar outcomes may obtain in humans. Studies in human subjects would need to verify this suggestion.’
And colleague Jones added: ‘It would be interesting to see if aspartame’s affects can be passed down to further generations beyond the grandchildren of the exposed individual.’
