Savoury snacks can be as bad for your teeth as sweet ones, says a dental
researcher who has fed his experimental rats with an assortment of crisps
and crackers. Of the crisps, cheese and onion flavour seemed most harmful
to teeth, while some highly processed snack foods were almost as damaging
as sweet biscuits and sugar. Salted peanuts proved the safest snacks to
eat.
Trevor Grenby, who carried out the experiments at the Department of
Oral Medicine and Pathology at Guy鈥檚 Hospital, London, says that the pattern
of tooth decay in the rats is likely to reflect that in people (Chemistry
in Britain, July 1991).
鈥楴ext to sucrose, rich tea biscuits were the most cariogenic of the
foods, but only just ahead of two varieties of crisps 鈥� cheese and onion
and Square Crisps,鈥� says Grenby. These were followed by the other savoury
snacks, with the lowest scores of all from the salted peanuts.
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Grenby attributes the unexpected harmfulness of the cheese and onion
crisps to glucose in the flavouring powder. He blames most of the other
high scores on processing techniques such as extrusion, which break down
the structure of starch in the food. Saliva in the mouth continues the process
to produce sugars such as maltose and glucose which, unlike starch, contribute
to tooth decay.
In this respect, Square Crisps and Monster Munch, both made by Smiths
Crisps of Reading, scored badly. Square Crisps caused almost as many caries
in the rats鈥� teeth as sucrose.
A spokesman for Smiths Crisps said: 鈥楽miths takes the view that it is
a responsible company, so if it was proven (that extruded products harm
teeth) then we would look at ways around it, but it鈥檚 just hypothesising
at this stage.鈥�
The Snack, Nut And Crisp Manufacturers鈥� Association pointed out that,
as tests have been performed only on animals, they considered that the results
are as yet 鈥榰nproven鈥�. Other types of experiments were needed to verify
Grenby鈥檚 results 鈥� for example, tests to see how easily snack foods dissolve
tooth enamel.
鈥楾he findings are a bit of a surprise. It鈥檚 something worthy of further
consideration by some of those companies that make the extruded snacks,鈥�
said Keith Nightingale, the director-general of SNACMA.
