The Durk Pearson & Sandy Shaw®
Life Extension NewsTM
Volume 12 No.
2 • April 2009
Leptin, a Hormone Important in Satiety and
Food Intake, Decreases After Meals
Cooked at High Temperatures
Leptin was discovered not too long ago to be an important hormone released by adipocytes (fat cells) that regulates satiety and food intake, as well as aspects of immunity and inflammation. The hormone is synthesized and released in response to increased energy storage in fat. Obesity and diabetes are both associated with high leptin levels combined with leptin resistance. Hence, leptin signaling is impaired. Both hyperinsulinemia and hyperglycemia are responsible (but mainly the latter) for the modulation of leptin secretion. The authors of a new study hypothesized that not only meal composition, but the temperature at which it is cooked, would modulate postprandial leptin levels.
The study reports on the results of feeding type 2 diabetic patients with the same meal either cooked at high temperatures or at low temperatures. The high temperature meal (but not the low temperature meal) was associated with higher blood AGE (advanced glycation end-products) and TBARS (a measure of lipid peroxidation) levels. The meal prepared at a high temperature (but not at a low temperature) was also associated with a significant decrease in leptin levels. The reduced leptin levels may result in an impairment of the anorectic effect of leptin in type 2 diabetics.
Interestingly, short sleep was also associated with reduced leptin as well as elevated ghrelin (stimulates appetite). The authors suggest that this might explain the increased BMI (body mass index) observed in people with short sleep duration.
- Wang et al. A nutrient-sensing pathway regulates leptin gene expression in muscle and fat. Nature 393:684-8 (1998)
- Stirban et al. Leptin decreases postprandially in people with type 2 diabetes, an effect reduced by the cooking method. Horm Metab Res 40:896-900 (2008)
- Taheri et al. Short sleep duration is associated with reduced leptin, elevated ghrelin, and increased body mass index. PLoS Medicine 1(3):e62 (Dec. 2004) (http://www.plosmedicine.org)