Good fat & Bad fat

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BAT (Brown adipose tissue)   ::: WAT (White adipose tissue)

BAT is recognized as a regulator of whole body energy expenditure and body fat in humans and a hopeful target combating obesity and related disorders. Unfortunately BAT levels decrease as we age leading to an increase in weight gain Adipose tissue is a major metabolic organ and it has been traditionally classified as either white adipose tissue or brown adipose tissue. WAT and BAT are characterized by different anatomical locations morphological structures functions and regulations. WAT and BAT are both involved in energy balance. WAT is mainly involved in the storage and mobilization of energy in the form of triglycerides. Whereas BAT specializes in dissipating energy as heat during cold or diet induced thermo genesis.

WAT generally constitutes as much as 20% of the body weight of normal adult humans. WAT is normally characterized by an ivory or yellowish color as well as unilocular/large lipid droplets.

By contrast brown adipose tissue is recognized as the major site of sympathetically activated no shivering thermo genesis during cold exposure and after spontaneous hyperphagia thereby controlling whole body energy expenditure and body fat. Thus BAT is recognized as a regulator of whole body energy expenditure and body fat in humans and a hopeful target combating obesity and related disorders. In fact there are some food ingredients such as capsaicin and capsinoids which have potential to activate and recruit BAT via activity on the specific receptor transient receptor potential channels thereby increasing energy expenditure and decreasing body fat modestly and consistently.

. Sympathetic nerve activity in adipose tissues is increased in response to cold exposure and oral ingestion of food ingredients through the activation of transient receptor potential channels.

.Nor adrenaline binds to B-adrenergic receptors and initiates signaling cascades for triglyceride hydrolysis. The released fatty acids activate uncoupling protein 1 and are oxidized to serve as an energy source of thermo genesis..Activated UCP1 uncouples oxidative phosphorylation from ATP synthesis and dissipates energy as heat. .Chronic sympathetic activation is bad because this causes  not only brown fat hyperplasia but also an induction of beige cells in white fat thereby increasing whole body energy expenditure and decreasing body fat.

Formation of beige/brite adipocytes

White adipose depots have the ability to switch between energy storage and expenditure . Thus these depots can shift from a WAT phenotype  to a BAT like phenotype in terms of features such as morphology gene expression pattern and mitochondrial respiratory activity under some specific stimuli. As mentioned above this induction of the brown adipocyte like phenotype in WAT is called “browning “ and the beige/ brite cells of WAT are capable of this transformation. The beige/brite cells in WAT are derived from precursor cells that are different from classical brown adipocytes and are closer to the white adipocyte cell lineage. These beige/brite cells show a white adipocyte like phenotype. Including large lipid droplets and the lack of UCP1 expression under basal conditions. However in response to certain stimuli beige/brite cells transform into cells having BAT like characteristics such as multilocular /small lipid droplets and UCP1 expression.

Unfortunately BAT levels decrease as we age leading to an increase in weight gain . Because capsaicinoids can reactivate BAT into producing energy consumption  of capsaicinoids may help individuals maintain a healthy weight with aging.

A study concluded that capsinoids ingestion increases EE through the activation of BAT in humans.

Several research studies have looked at the impact of capsaicinoids on fat tissue within the body . Seven trials have found evidence of increased fat utilization or decreased fat stores. One study found a significant increase in fat metabolism as measured by a process called lipid oxidation among participants taking capsaicin supplements for four months.

“Beadlet” Technology

Capsicum extract loaded onto an inert central core and covered with a special coating that leaves no exposed capsaicinoids layer. This patented “beadlet “ technology allows for the active ingredient to be delivered within a capsule without the problem of gastric discomfort and burning .

Prevalence

Some recent WHO global estimates follow:

 .In 2014 more than 1.9 billion ,18 years and older were overweight of these over 600 million were obese.

.Overall about 13% of the world’s adult population was obese in 2014

.In 2014 ,39% of adults aged 18 years and over were overweight .

.The worldwide prevalence of obesity more than doubled between 1980 and 2014.In India states which topped the lists of rates of obesity are Punjab , Kerala and Goa .Though the percentage of obesity in India is less compared to United states of America and other developed countries , it is significant due to sheer size of population . Indians are genetically susceptible to weight accumulation especially around the waist.

In 2013 ,42 million children under the age of 5 were overweight or obese. Once considered a high income country problem overweight and  obesity are now on the rise in low and middle income countries particularly in urban settings. In developing countries with emerging economies the rate of increase of childhood overweight and obesity has been more than 30% higher than that of developed countries.Overweight and obesity are linked to more deaths worldwide than underweight. Most of the world’s population live in countries where overweight and obesity kill more people than underweight .

Pathophysiology of obesity

.The afferent system generates humoral signals from adipose tissue pancreas and stomach

.Acting in the brain leptin and to a lesser extent insulin decrease food intake and increase energy expenditure promoting weight loss. They are consequently termed catabolic adiposity signals.

.Impinging on the same neuronal targets ghrelin exerts opposite effects and is thus an anabolic hormone.

.The amount of leptin is  direct proportion to adipose stores. Weight gain evokes proportionate increases in catabolic hormones and decreases ghrelin whereas weight loss causes the opposite.

1 Afferent system generates signals released fro adipose tissue pancreas and stomach.

2 Central processing unit present in hypothalamus having two set of neurons: orexigenic and anorexigenic neurons

3 Efferent system carries out anabolic and catabolic signals by modulating feeding behavior or energy expenditure.

APY/AgRP =NeuropeptideY/Agouti related peptide;

POMC/CART= Pro- opiomelanocortin/cocaine and Amphetamine Related Transcript

NPY Rec=Neuropeptide receptor; MCH = Melanin Concentrating Hormone

MSH = Melanocyte stimulating hormone; Mc4R=Melanocortin receptor

TRH=Thyrotrophin releasing hormone ;CRH=Corticotrophic Releasing hormone.

Cardiovascular Disease

Obesity is an independent risk factor for CVD as including CHD myocardial infarction angina pectoris congestive hear failure stroke hypertension and atrial fibrillation. Overall results from large prospective and observational studies confirm the marked adverse effects of obesity on CVD.Intima media thickness a noninvasive marker for early atherosclerotic changes was found to be significantly increased in the obese children as compared with nonobese children of similar age sex and pubertal stage.Not only is obesity linked with hypertension but weight loss in obese subjects is associated with a decline in blood pressure. The anti hypertensive effect of weight loss is independent of race or gender  . Furthermore chronic obesity reduces the efficacy of antihypertensive medication.

Bad fat turnover as man ages :-: Unfortunately BAT levels decrease as we age leading to an increase in weight gain . Because capsaicinoids can reactivate BAT into producing energy consumption of capsaicinoids may help individuals maintain a healthy weight with aging. Coming to Obesity and Reproductive Health the followings are relevant :-

Obesity during pregnancy is associated with an increased risk of complications including gestational diabetes pre -eclampsia and delivery complications such as macrosomia shoulder dystocia and higher rates oc caesarean sections and infections, Obesity is now estimated to be responsible for 6% of primary infertility. Obesity and insulin resistance are closely related with PCOS and insulin resistance has a pivotal role in the pathogenesis of this syndrome. Body weight and body fats are considered to be significant physiological triggers of menarche. Hence obese girls often present with menarche before the age of 10 years.

In men there is a link between impotence and increasing infertility with abdominal obesity a particular risk.

Obesity in men can result in both physical changes and hormonal changes. These changes in turn contribute to oligozoospermia azoospermia an increase in the DFi and a decrease in semen volume.

Available data suggest that a little as 5%-10% weight loss can improve fertility outcomes.

Dyslipidemia

Obesity is associated with an unfavorable lipid profile . Lipid abnormalities related to obesity include an elevated serum concentration of cholesterol low density lipoprotein cholesterol very low density lipoprotein cholesterol triglycerides and apo lipoprotein B, as well as a reduction in serum high density lipoprotein cholesterol . Insulin resistance and hyperinsulinaemia stimulating hepatic triglyceride synthesis from an increased adipose tissue undergoing enhanced lipolysis. This leads to postprandial hypertriglyceridemia smaller and denser LDL particles and reduced HDL cholesterol concentrations.

Dyslipidemia associated with obesity no doubt plays a major role in the development of atherosclerosis and CVD a life threatening diseases in obese individuals.

Lifestyle modifications weight loss exercise dietary fibers and with weight loss medications can improve this dyslipidemia reducing CVD risk.

Management of obesity 

Obesity results from a prolonged small positive energy imbalance and treatment needs to reverse this imbalance. The relationship between energy intake and expenditure is shown in

Appropriate goals of weight management emphasize realistic weight loss to achieves a reduction in health risks and should include promotion of weight loss; maintenance and prevention of weight regain.

Many different diets have been tried to treat obesity and weight loss occurs with all of them. The principal effect seems to be the degree of adherence to the prescribed calorie reduction.

Obesity drugs have been developed that tap brain mechanisms for controlling feeding and the gastrointestinal tract and its peptides.

One of the key messages for obese patients is that when caloric intake is reduced below that needed for daily energy expenditure ; there is a predictable rate of weight loss.

Patients should understand that since obesity is a chronic disease weight management will need to be lifelong.