It's really possible: weight loss with aromatherapy
Some time ago we wrote about an obscure Japanese animal study, which showed that exposure to the scent of grapefruit strengthened the electrical nerve impulses to fat tissue in mice. In theory this might be a way for the animals to lose weight – and, if this is the case, that aromatherapy using grapefruit oil could be interesting for humans wanting to lose weight. This theory gains credibility from a follow-up study that the Japanese published in 2005.
The Japanese performed experiments on male rats. In one experiment they recorded the electrical activity in the nerve pathways to the epididymal fat tissue in the lower abdomen [epididymal], the brown fat between the shoulder blades [interscapular], the adrenal glands that produce adrenalin [adrenal] and the stomach [gastric].
When the researchers laid a cloth impregnated with a 1:100 solution of grapefruit oil in water on top of the cage, they observed that the activity in the nerve pathways to the fat tissue and the adrenals increased, but that the activity in the pathway to the stomach decreased. The activity was measured for 90 minutes.
After the aromatherapy started the glycerol concentration in the rats' blood rose, which indicates that the fat cells were releasing their contents into the blood.
For a period of six weeks the researchers laid a piece of gauze soaked in a 1:1000 solution of grapefruit oil in water on the cloth three times a week. The gauze was soaked in a 1:1000 solution of grapefruit oil in water [GF]. Gauze soaked in water was laid by above the cage of the control group [Water]. Exposure to the grapefruit oil inhibited the increase in bodyweight.
This was to some extent due to the fact that grapefruit oil reduced the intake of food, according to the figure below.
The researchers discovered that aromatherapy raised the body temperature of the rats from 37.23 degrees [when the 15-minute exposure started] to 38.02 degrees [3 hours later].
The researchers repeated their experiment with limonene, a prominent component of grapefruit oil, and obtained the same results. "We conclude that the smell of grapefruit oil, especially limonene, affects autonomic nerves, increases lipolysis and heat production (energy consumption), and reduces appetite and body weight."
More effective in humans
It may be the case that aromatherapy using grapefruit oil is more effective in humans wanting to lose weight than in rats, the Japanese speculate. They cite work done by researchers at Creative Nesus, who, in an unpublished study, exposed people for thirty minutes to the smell of a grapefruit that had been cut in half. At the start of exposure the skin on their back had a temperature of 31 degrees. Ninety minutes later the temperature had risen to 34 degrees.
"The reason why humans show a much more dramatic change (about 3 degrees Celsius) in temperature than mice (about 0.8 degrees Celsius) is not clear", the Japanese write.
Neurosci Lett. 2005 Jun 3;380(3):289-94.
Slim faster with aromatherapy 27.04.2013