Recognition of tobacco flavours at the brain level

In the EU, about a third of the adult population are smokers, and the number of
deaths from smoking per year is currently
about 500,000. According to the WHO, about 100 million people died in the 20th
century from tobacco use. According to
the WHO, the term *attractiveness* refers to factors such as taste, smell and
other sensory attributes, which are meant to
increase their use (1). Many compounds, mostly flavours, are added in minute
amounts (in ng or *g) to cigarettes For
example, flavours such as *sugars* and *vanillin* are intended to appeal to a
target population, and are believed to
promote starting smoking. The sugars in tobacco generate upon heating
caramel-like compounds, which have an
attractive smell and taste.

reference
1. WHO. The scientific basis of tobacco product regulation: Report of a WHO
Study Group. WHO Technical Report Series 945. Geneva, Switzerland: World Health
Organization Press; 2007b. Available from: URL:
http://www.who.int/tobacco/global_interaction/tobreg/9789241209458.pdf. 2011.

Considering the high prevalence of smoking and tobacco related deaths,
knowledge about the appealing function (attractiveness) of tobacco additives is
highly significant, because they promote the initiation of smoking. This part
of the investigation deals with sensory properties of two compounds frequently
used as tobacco ingredient: caramel and vanillin.
Using the MRI technique, responses in the emotional memory can be detected
(activation of amygdala, ventral striatum and olifactory bulb).
The main hypothesis to be tested is that subjects remember flavours from early
childhood which stimulated them to start smoking (a specific brand containing
these flavours).
Specific research questions are:
a) Is the recognition of vanilla and caramel experienced as positive or
negative?
b) Is recognition related to smoking particular brands (current or past
preference), which contain the flavour?
c) Do subjects recognise the flavour experienced as nice during exposure in
childhood, as indicated by brain DTIresponses?
d) Do the DTI-responses correspond to answers in the questionnaire about
remembrance of flavours?

Open single blind controlled study using questionnaires and DTI-scanning of
brain.

In the scanner, subjects will be shortly (2x5 min.) nasally exposed to low
concentrations (just above scent threshold) of
two flavours. The two flavours tested (caramel and vanilla) are routinely used
in tobacco and food manufacture.