Written by Tatjana Djakovic, Staff Writer. A herbal formula with 5-HTP resulted in a 29.2% increase in feeling full in a study with 77 healthy women.
An important regulator of appetite and weight control is a natural compound 5-HTP (5-hydroxytryptophan). In the body, 5-HTP is synthesized from the essential amino acid, L-tryptophan which must be obtained from the diet. 5-HTP is then utilized in order to make serotonin, a neurotransmitter which is a contributor to well-being and happiness. The conversion of 5-HTP to serotonin can be inhibited by stress, insulin resistance, increasing age, and magnesium or vitamin B6 deficiency. (1) The ratio of tryptophan to other amino acids in the body is reported to be low in obese subjects, suggesting that it may be an important factor for managing weight. (2)
The purpose of this double-blind parallel study was to test the effectiveness of 5-HTP in the management of weight. The treatment was supplied as a sublingual (under the tongue) spray which contains natural plant extracts rich in 5-HTP consumed five times per day for 2 months. The study also tested the bioavailability (the amount of the ingested dose that is absorbed) of the supplement. The study consisted of 77 healthy women aged 25-45 years with a body mass index (BMI) greater than 25 kg/m2 and less than 35 kg/m2. The subjects were instructed to restrict their daily energy intake by a moderate amount. Subjects were randomized to receive three sprays of an herbal product containing 5-HTP five times per day or a placebo for 8 weeks. The 5-HTP herbal product was composed of these extracts; 39 mg of G. simplicifolia, 11.7 mg of C. asiatica, 11.7 mg of Taraxacum. officinale, 9.75 mg of Cynara. scolymus, 4.55 mg of Paullina sorbilis, 39 μg ofAlga Klamath. Visual analog scale (VAS) was used to assess appetite sensations in patients. Fullness was assessed numerically, using a scoring system graded 0 (represent extreme hunger) to 10, to represent extreme fullness.
The participants in the group that received 5-HTP experienced a 29.2 % increase in feeling of fullness after a meal by compared to the placebo (p=0.007). After a period of 2 months, the concentration of 5-HIAA (a known 5-HTP metabolite) in the blood increased by 98.7% more in the treated group (1.70 mg to 4.08 mg) in comparison to the control (1.77 mg to 1.97 mg) p value = 0.005. The body mass index (BMI) was decreased by 2.7% more in the treated group (29.36 kg/m2 to 29.34 kg/m2) in comparison to control (29.86 kg/m2 to 29.65 kg/m2) p value =0.008. The hip circumference was decreased by 1.93% more in the treated group (108.31 cm to 105.62 cm) in comparison to control group (113.68 cm to 113.05 cm) (p = 0.033 (3). Regarding evaluation of health-related quality of life, the results showed that the treated group did not show changes in general physical, mental, social or emotional functioning. Hopefully longer term studies will be done to see if the reductions in BMI and hip measure continue.
Previous studies have shown that appetite increases after a body weight loss due to changes in hormone and neurotransmitter levels such as serotonin (4). The synthesis of serotonin in the brain is limited by the availability of 5-HTP and maintaining correct levels of 5 HTP was found to decrease appetite and cravings after weight loss when compared to placebo group.
Source: Rondanelli, M., et al. “Satiety and amino-acid profile in overweight women after a new treatment using a natural plant extract sublingual spray formulation.” International Journal of Obesity 33.10 (2009): 1174-1182.
© 2009 Macmillan Publishers Limited All rights reserved
Posted February 13, 2013.
References:
- Obtained from Medline Plus “5-HTP”.
- Ashley DV et al., Evidence for diminished brain 5-hydroxytryptamine biosynthesis in obese diabetic and non-diabetic humans. Am J Clin Nutr 1985(42): 1240-1245.
- Rondanelli, M., et al. “Satiety and amino-acid profile in overweight women after a new treatment using a natural plant extract sublingual spray formulation.” International Journal of Obesity 2009;3(10): 1174-1182.
- Doucet E., et al., Appetite after weight loss by energy restriction and low-fat diet exercise follow up. Int J obes Relat Metab Disord 2000 (24): 906-914.
