Cellulite reduction appears to be the holy grail of the cosmetics world illustrated by the plethora of cellulite treatments currently on the market. Although the exact mechanism behind the condition is not known, previous studies suggest that blood and lymphatic circulation in the skin may play an important role. Caffeine is thought to have a lipolytic effect on fatty tissue reducing the size of fat cells, ultimately providing a good candidate in the treatment of cellulite. A new study performed by researchers at the University of Rio de Janeiro tested a caffeine containing formulation, currently on the market as a cellulite treatment, finding that although it had significant reductive effects on thigh circumference it did not affect the microcirculation in the tissues. The team, led by Professor Omar Lupi, used orthogonal polarization spectral imaging (OPS), which allows the investigation of the behaviour of the blood vessels in the skin non-invasively. The team measured the number of flowing capillaries per unit area, the diameter of the dermic papilla and the capillary diameter, as well as measuring the circumference of the thigh in two places. In total ninety nine women were included in the study (participants were excluded if their exercise levels or weight changed during the study in an attempt to control for these factors), and told to apply a 15g dose of the cream, twice daily to one leg, leaving the other as a control. After a month of treatment the researchers found that in more than 80 percent of the participants there was a reduction in circumference in both the upper and lower portions of the thighs. This led to a mean reduction on the upper thigh of 2.1cm and 1.7 cm on the lower thigh. However, the caffeine solution did not significantly modify the microcirculation in the skin; the capillary number and diameter were not significantly altered. Lupi and colleagues conclude this 'suggests that a 30-day treatment might not be enough to show significant dermic microcirculation effects of the drug, or that its action might not be measurable in the dermic microcirculation'. The research also aimed to show whether the effectiveness of the treatment was altered by factors such as diet, exercise and smoking. According to the researchers there was no association between smoking and alterations of circumference in the thighs and hips. Similarly, no statistically significant relationship could be found between either exercise or alcohol consumption and the efficacy of the treatment.