Leptin is a hormone secreted from adipocytes (fat cells) and functions to suppress appetite and increase energy expenditure. Leptin is a proinflammatory cytokine. In contrast, ghrelin, a protein known to trigger feeling of hunger, increases during periods of fasting and decreases after a meal. The discovery of leptin in the 1990s created a furor, because when injected into rodents it caused them to eat less and lose weight. As of 2011, there is no leptin supplement available over the counter.
Role of the hormone
Leptin has a wide range of effects on physiological
functions related to the regulation of body energy balance. Many of
leptin's effects are mediated through neuropeptide-containing neurons and
neuropeptide receptors in the hypothalamus. The melanocortin system
includes both agonist (alpha-melanocyte stimulating hormone, alphaMSH) and
antagonist peptides (agouti related peptide, AGRP). Increased melanocortin
receptor stimulation following leptin administration plays an important
role in leptin-induced hypophagia and increased sympathetic nervous system
activity and is partly responsible for leptin -induced weight loss.
However, melanocortins do not appear to mediate some of the more striking
centrally-mediated effects of leptin on adipose tissue, including adipose
tissue apoptosis, that lead to the extensive depletion of fat.
Leptin regulates energy balance and female reproductive function, mainly through its action on hypothalamic-pituitary-ovarian function, whose molecular and cellular aspects are progressively being deciphered.
Natural supplements that
help with appetite control
There are several supplements that have an influence on appetite
including the following:
Hoodia reduces
appetite in some people
Green Tea extract
Garcinia cambogia is an herb that has
hydrocytric acid
Carraluma
5-HTP which converts
into serotonin
Acetylcarnitine
is the acetyl form of carnitine.
Dietary supplement over the
counter
Is there a safe or effective leptin supplement
available or soon to be on the market?
Where can I buy a leptin supplement?
To the best of my knowledge, such a supplement is
not currently available. Leptin is a hormone and I would think the FDA may not
allow such a hormone to be sold over the counter. Therefore, I doubt
if there are legitimate over the counter leptin diet pills available.
I came across a product that claims to control leptin. Is there research on
such pills that control it? Is there an herb that
can lower leptin levels or prevent its resistance?
I have not seen any studies on leptin control supplements
that have been evaluated in humans. Therefore, the claims of control or
resistance supplements appear to be misleading at this time. There may be
herbs or supplements that lower leptin levels, but we don't have the research at
this time to support such claims.
Leptin given to obese patients reduces appetite
Giving leptin hormone to morbidly obese volunteers de-activates their
brain's response to tasty food. When given leptin hormone, the centers in
the brain involved in self-control are more activated. When given leptin
injections, there is activation of the cerebellum -- a section of the
brain at the base of the head.
Leptin, diet, obesity, and heart
disease
Emerging evidence from both animal and human studies indicates that
leptin may play an important role in
obesity -related
cardiovascular disease. Besides modulating
appetite and metabolism, leptin has also been shown to increase sympathetic
nerve activity, stimulate generation of reactive oxygen species, upregulate
endothelin-1 production and potentiate platelet aggregation. These effects of
leptin may contribute to hypertension, endothelial dysfunction and
atherosclerosis in obese individuals. Better understanding the mechanisms of leptin resistance should facilitate therapeutic approaches to reverse the
phenomenon of selective leptin resistance.
Recent observations suggest that the cardiovascular
actions of leptin may help explain the link between excess fat mass and
cardiovascular diseases. Leptin is an adipocyte-derived hormone that acts in the
central nervous system to promote weight loss by decreasing food intake and
increasing metabolic rate. Leptin hormone causes a significant increase in overall
sympathetic nervous activity, which appears to be due to direct hypothalamic
effects and is mediated by neuropeptide systems such as the melanocortin system
and corticotropin-releasing hormone. Renal sympathoactivation to leptin is
preserved in the presence of obesity, despite resistance to the metabolic
effects of leptin. Such selective leptin resistance, in the context of
circulating hyperleptinemia, could predispose to obesity-related hypertension.
Atherosclerosis. March 2014. Leptin and coronary heart disease: A systematic review and meta-analysis. Leptin, an adipose tissue-derived hormone, plays a central role in regulating human energy homeostasis. The role of leptin in regulating blood pressure, activating the sympathetic nervous system, insulin resistance, platelet aggregation, arterial thrombosis, angiogenesis, and inflammatory vascular responses suggests that leptin may have a close relationship with the development of coronary heart disease (CHD). However, no conclusive data are available to determine the association between leptin and CHD. Although the associations of leptin and CHD were not statistically significant both in male and female overall, males with high levels of leptin should be paid more attention to. Our findings highlight the need for additional well-designed and gender-specific prospective studies to evaluate the role of leptin on the development of CHD.
Exercise influence
Plasma leptin is associated with satiety and that it stimulates lipid
metabolism, and increases energy expenditure. These effects implicate leptin as
a major regulator of energy homeostasis, which may serve to limit excess energy
storage. As plasma leptin concentrations are tightly coupled with fat mass in
humans, decreases in adipose mass with weight loss coincide with decreased
concentrations of circulating leptin. However, due to many confounding factors,
the effects of exercise on circulating leptin are less clear. The data from
investigations examining single exercise bouts suggest that serum leptin
concentrations are unaltered by short duration (41 minutes or less),
non-exhaustive exercise, but may be affected by short duration, exhaustive
exercise. More convincingly, studies investigating long duration exercise bouts
indicate that serum leptin concentrations are reduced with exercise durations
ranging from one to multiple hours. These findings raise speculation that
exercise-associated reductions in leptin may be due to alterations in nutrient
availability or nutrient flux at the level of the adipocytes, the primary site
of leptin production and secretion.
Hormonal effects
Leptin hormone plays a critical role in the
control of appetite and energy balance, with mutations in the genes encoding the
hormone or its receptor leading to profound obesity in both rodents and man.
Leptin regulates appetite primarily through an interaction with hypothalamic
neuroendocrine pathways, inhibiting orexigenic peptides such as neuropeptide Y
and orexin A, and stimulating anorexigenic peptides such as proopiomelanocortin.
The presence of higher leptin levels in boys with pubertal gynecomastia
indicates that leptin hormone may be involved in the pathogenesis of pubertal
gynecomastia. The role of circulating leptin in pubertal gynecomastia is
probably related to increase in estrogen and/or estrogen/ androgen ratio by the
stimulating effect of leptin on aromatase enzyme activity in both adipose and
breast tissues, or a direct growth stimulating effect of leptin on mammary
epithelial cells, or increase in sensitivity of breast epithelial cells to
estrogen with inducing functional activation of estrogen receptors by leptin in
breast tissue.
Elderly and seniors
Some healthy elderly individuals experience a decrease in appetite and
consequently eat less than they normally ate when they were younger. Part of
this decrease in appetite may be due to hormone alterations that reduce hunger
and increase feelings of fullness. The elderly have higher leptin levels under
fasting conditions than younger individuals, but both groups have similar levels
of the hormone after eating. American Journal of Clinical Nutrition, May 2006.
Asthma
High levels of leptin hormone, an inflammatory compound produced by body
fat, may raise the risk of
asthma in
premenopausal women. Because previous reports have linked leptin levels
with asthma in children, Dr. Akshay Sood, from Southern Illinois
University School of Medicine in Springfield, and colleagues decided to
see if it held true in adults as well.
Using data from 5876 participants in the Third National Health and
Nutrition Examination Survey, the researchers found that elevated leptin
levels did, in fact, correlate with asthma in adults. This association was
stronger in women than in men and stronger in premenopausal women than in
postmenopausal women. There appears to be evidence from animal studies
that leptin plays a pro-inflammatory role in the airways. Source: Thorax,
April 2006.
Brain function
The hormone leptin signals information regarding the status of fat stores to
hypothalamic nuclei, which in turn control feeding behavior and body weight.
However, leptin and its receptor are widely expressed in many extra-hypothalamic
brain regions, including hippocampus, brain stem and cerebellum. Leptin has
other neuronal functions that are unrelated to its effects on energy
homeostasis. Leptin-deficient rodents display abnormal brain development and
leptin actively participates in the development of the hypothalamus. In the
hippocampus, leptin is a potential cognitive enhancer as genetically obese
rodents with dysfunctional leptin receptors display impairments in hippocampal
synaptic plasticity. Direct administration of leptin into the hippocampus can
facilitate hippocampal LTP (long-term potentiation) in vivo and improve memory
processing in mice.
Menstrual cycle
A lack of leptin contributes to the absence of menstrual periods in women with
extremely low levels of body fat, but treatment with a synthetic form of the
hormone may restore both the menstrual cycle and fertility.
Pancreatic function
Diabetes Care. Feb 4 2014. Effects of Leptin Replacement Therapy on
Pancreatic β-Cell Function in Patients With Lipodystrophy. Leptin administration
is known to directly modulate pancreatic β-cell function in leptin-deficient
rodent models. However, human studies examining the effects of leptin
administration on β-cell function are lacking. In this study, we examined the
effects (16-20 weeks) of leptin replacement on β-cell function in patients with
lipodystrophy. In a prospective, open-label, currently ongoing study we studied
the effects of leptin replacement on β-cell function in 13 patients with
congenital or acquired lipodystrophy. Insulin secretory rate (ISR) was
calculated by C-peptide deconvolution from plasma glucose and C-peptide levels
measured during oral glucose tolerance tests (OGTTs) performed at baseline and
after 16-20 weeks of leptin replacement. β-Cell glucose sensitivity and rate
sensitivity were assessed by mathematical modeling of OGTT. There was a
significant decrease in triglycerides, free fatty acids, and glycosylated
hemoglobin levels (A1C) after leptin therapy. Patients with lipodystrophy have
high fasting and glucose-stimulated ISR. However, leptin therapy had no
significant effect on fasting ISR, total insulin secretion during OGTT, β-cell
glucose sensitivity, rate sensitivity, or insulin clearance. In contrast to the
suppressive effects of leptin on β-cell function in rodents, 16-20-week
treatment with leptin in lipodystrophy patients did not significantly affect
insulin secretion or β-cell function in leptin-deficient individuals with
lipodystrophy.
Psoriasis skin disease
People with psoriasis have higher levels of the hormone leptin, which regulates
food intake, body weight, and fat stores and is also thought to play a role in
immune and inflammatory processes. Those elevated leptin levels may in turn make
them more likely to become obese or develop high blood pressure, diabetes, and
other heart disease risk factors.
Leptin, diet, and hormone
studies
Integration of endocannabinoid and leptin signaling in an appetite-related
neural circuit.
Neuron. 2005. Department of Pathology and Cell Biology in the Center for Neurobiology and
Behavior, Columbia University, College of Physicians and Surgeons, New York, New
York
Recently developed therapeutics for obesity, targeted against cannabinoid
receptors, result in decreased appetite and sustained weight loss. Prior studies
have demonstrated CB1 receptors (CB1Rs) and leptin modulation of cannabinoid
synthesis in hypothalamic neurons. Here, we show that depolarization of
perifornical lateral hypothalamus (LH) neurons elicits a CB1R-mediated
suppression of inhibition in local circuits thought to be involved in appetite
and "natural reward." The depolarization-induced decrease in inhibitory tone to
LH neurons is blocked by leptin. Leptin inhibits voltage-gated calcium channels
in LH neurons via the activation of janus kinase 2 (JAK2) and of mitogen-activated
protein kinase (MAPK). Leptin-deficient mice are characterized by both an
increase in steady-state voltage-gated calcium currents in LH neurons and a
CB1R-mediated depolarization-induced suppression of inhibition that is 6-fold
longer than that in littermate controls. Our data provide direct
electrophysiological support for the involvement of endocannabinoids and leptin
as modulators of hypothalamic circuits underlying motivational aspects of
feeding behavior. Leptin in food.
Plasma leptin concentrations in postmenopausal women
with osteoporosis.
Endocrine Research. 2005.
Osteoporosis is less common in obese individuals with increased bone mineral
density (BMD) and plasma leptin concentrations. The aim of this study was to
determine the correlation between leptin levels and BMD in postmenopausal women.
The study consisted of 90 postmenopausal women with a mean age of 53.45 +/- 0.87
years who visited our outpatient clinic for the evaluation of BMD. From this
study we conclude that circulating plasma leptin hormone level does not have a significant
direct influence on bone mass in postmenopausal women.
Therapeutic Effect of Puerarin on Non-Alcoholic Rat Fatty Liver by Improving
Leptin Signal Transduction through JAK2/STAT3 Pathways.
Am J Chin Med. 2009. Institute of Digestive Diseases, Longhua Hospital,
Shanghai University of Traditional Chinese Medicine, Shanghai, China.
In order to investigate the mechanism of the therapeutic effect of
puerarin
on non-alcoholic fatty liver disease, a non-alcoholic fatty disease male rat
model was induced by a high fat diet, all rats were randomly divided into a
blank group, model group, simavastatin group and puerarin group. All the results demonstrated that puerarin can exhibit
therapeutic effect on non-alcoholic fatty liver disease by improving leptin
signal transduction through JAK2/STAT3 pathways.
Questions
Does hoodia extract
influence leptin hormone levels?
I have not come across research regarding the
influence of a hoodia supplement on this hormone level, so I don't
know.
Is there leptin in food?
I don't think there's any in food but I'm not
sure.