SpectraCell Blog

Leptin Resistance: Everything You Need to Know

Posted by SpectraCell Laboratories, Inc. on Wed, Aug 09, 2017 @ 02:26 PM

Overeating.jpgLeptin, often called the “satiety hormone,” is an adipokine (signaling molecule produced by fat cells) whose main function is to regulate energy and fat stores. In a metabolically healthy person, a temporary increase in caloric intake (such as after a big meal) corresponds to an increase in leptin production. This prompts the hypothalamus to send signals that promote satiety, which cues one to stop eating.

Leptin was the first adipokine to be discovered (in 1994) and changed how scientists view fat tissue. Fat stores were previously thought to be inert tissue that did not cause any direct harm. Upon the discovery of leptin and its related genes, scientists learned that excess adipose tissue is actually metabolically active, releasing several hormones (adipokines) and inflammatory enzymes. Consequently, it is now considered an endocrine organ.

Although leptin suppresses appetite, one can become leptin resistant, feeling hungry even when one consuming enough calories to maintain metabolic requirements. In a way that is analogous to insulin resistance, leptin resistance occurs in obesity: the higher the fat stores, the more leptin produced. In fact, leptin varies exponentially (as opposed to linearly) with adipose tissue. This means that changes in fat mass profoundly affect leptin levels. Over time, as leptin increasingly circulates in blood, the brain eventually becomes resistant to its effects. As a result, one becomes inclined to overeat, unable to experience satiety and therefore feeling hungry even when leptin levels are high! This is referred to as leptin resistance. 

An increase in leptin (in the short term) follows an increase in caloric intake. This promotes satiety and signals one to stop eating. However, in the long term, a chronic increase in leptin can be attributed to excess body fat, estrogen (endogenous and exogenous), insulin (leptin is released dose-dependently in response to insulin), stress, and some steroid medications such as dexamethasone.

Loss of fat tissue, reduction in caloric intake via dieting and fasting, testosterone (which is anabolic – this increases appetite), and ghrelin (the hunger hormone) are all factors that lower leptin. Sleep deprivation, which upregulates appetite, is a reason why sleep loss is linked to cravings, and also impacts levels.

Factors that impact leptin sensitivity include:

  • Excess body weight
  • High Fructose Corn Syrup (this blocks leptin receptors)
  • High Triglyceride levels block leptin’s ability to reach the hypothalamus
  • Estrogen deficiency: the leptin-estrogen link may cause menstrual cravings
  • Lectins in grains bind to leptin receptors, inducing leptin resistance 

Leptin receptors are found in several tissues besides the hypothalamus, including endothelial, muscle, placental, and liver cells. Although its appetite-regulating effects are well established, it is known to play a role in fertility and puberty; however, its other functions are not fully understood.

SpectraCell’s CardioMetabolic test offers a clinically relevant evaluation to help define risk for atherosclerotic cardiovascular disease (ASCVD), progression toward Type 2 Diabetes, and inflammation.
Whether you are at high risk of heart disease or managing an existing metabolic condition, SpectraCell’s CardioMetabolic test is appropriate and recommended.

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Topics: cardiometabolic, Weight Management, Leptin, Leptin Resistance

Vitamin A: Functions and Benefits

Posted by SpectraCell Laboratories, Inc. on Mon, Jul 31, 2017 @ 11:30 AM

vit A.jpgVitamin A was one of the earliest vitamins to be discovered – hence its top rank in the alphabetical vitamin nomenclature.Vitamin A is a family of fat soluble compounds that play an important role in vision, bone growth, reproduction, and immune system regulation. Most people associate vitamin A with carrots, and for good reason: the common orange veggie has high amounts of beta-carotene, which is actually a vitamin A precursor and also the reason carrots got their name. But vitamin A is actually a group of chemicals that are similar in structure, and include retinol (the most biologically active form of vitamin A), retinal, and retinoic acid.

β-carotene is slightly different in that it is cleaved in the intestinal mucosa by an enzyme to form retinol. Other carotenoids include lycopene and lutein but, although similar to vitamin A, they are not actually vitamin A in the truest sense. One distinction is that excessive amounts of vitamin A from over-supplementation, can cause toxicity (although deficiency is much more common). On the other hand, β-carotene does not cause vitamin A toxicity because there exists a regulatory mechanism that limits vitamin A production from beta carotene when high levels are ingested.

A large number of physiological systems may be affected by vitamin A deficiency which is most often associated with strict dietary restrictions and excess alcohol intake. Patients with Celiac disease, Crohn’s disease and pancreatic disorders are particularly susceptible due to malabsorption.  Vitamin A is also essential for the developing skeletal system and deficiency can result in growth retardation or abnormal bone formation. 

The functions of vitamin A are very diverse:

  • Eyesight: Vitamin A forms retinal, which combines with a protein (rhodopsin) to create the light-absorbing cells in the eye. This explains why a common clinical manifestation of deficiency is night blindness and poor vision.
  • Skin: In addition to promoting healthy skin function and integrity, vitamin A regulates the growth of epithelial surfaces in the eyes and respiratory, intestinal, and urinary tracts. Deficiency impairs epithelial regeneration, which can manifest as skin hyperkeratization, infertility, or increased susceptibility to respiratory infections.
  • Anemia: Vitamin A helps transfer iron to red blood cells for incorporation into hemoglobin; thus, a vitamin A deficiency will exacerbate an iron deficiency.
  • Weight management: Vitamin A reduces the size of fat cells, regulates the genetic expression of leptin (a hormone that suppresses appetite), and enhances the expression of genes that reduce a person’s tendency to store food as fat.
  • Cancer prevention: Vitamin A deficiency impairs the body’s ability to launch cell-mediated immune responses to cancer cells. Vitamin A inhibits squamous metaplasia (a type of skin cancer) and inhibits breast cancer cell growth.
  • Fertility: Vitamin A plays a key role in the synthesis of sperm.
  • Autism: Vitamin A is part of the retinoid receptor protein (G-alpha protein), which is critical for language processing, attention, and sensory perception. Some autistics have a defect in this protein that vitamin A supplementation can modulate.
  • Sleep: Vitamin A deficiency alters brains waves in non-REM sleep, causing sleep to be less restorative.

Vitamin A also interacts with other micronutrients. For example, zinc is required to transport vitamin A into tissues, so a zinc deficiency will limit retinal binding protein (RBP) synthesis and thus limits the body’s ability to use vitamin A stores in the liver. Oleic acid, a fatty acid found in olive oil, facilitates the absorption of vitamin A in the gut.

Find out if you have a vitamin A deficiency, and take steps to correct it, by ordering a micronutrient test today. 

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Topics: micronutrients, Vitamin A, Vitamins, Fertility, Cancer Prevention, Celiac Disease, Supernutrients, Weight Management, Vitamin A Deficiency, Chron's Disease, Anemia, Nutrients, β-carotene

Minerals and Metabolism – What Is the Association?

Posted by SpectraCell Laboratories, Inc. on Thu, Feb 09, 2017 @ 12:52 PM

woman running1.jpgMinerals are substances required within cells to catalyze metabolic reactions. These chemical reactions largely determine the ability of the body to carry out metabolism and ultimately, health status. When it comes to weight management, mineral deficiencies can compromise metabolism. Below are some examples, among many, of familiar minerals with a role in this process:

  1. Zinc: A zinc deficiency can reduce the hormone leptin (this hormone regulates appetite and promotes satiety), therefore signaling you to stop eating for the short-term following a meal. Leptin is released in a dose-dependent manner in response to insulin. Any alteration in the efficiency of either hormone (insulin or leptin) can potentially affect the other.
  1. Calcium: This bones health mineral inhibits the formation of fat cells and burns fat cells by oxidizing fatty acids for energy.
  1. Chromium: This mineral makes cells more sensitive to insulin, thus helping reduce body fat and increase lean muscle.
  1. Magnesium: Low magnesium in cells impairs a person’s ability to use glucose for fuel, instead storing it as fat.  Correcting a magnesium deficiency stimulates metabolism by increasing insulin sensitivity, and may also inhibit fat absorption.
  1. Copper: A copper deficiency can lead to the inability to metabolize fructose efficiently, which can lead to decreased energy levels and high blood triglycerides. Copper also has a role fatty acid metabolism; repletion can help optimize metabolism.
  1. Selenium: In some, a selenium deficiency can reduce thyroid hormone levels since it is a cofactor for the conversion of precursor thyroid hormone (T4) to active thyroid hormone (T3). Reduced thyroid function resulting from selenium deficiency will lower metabolism throughout the body.
  1. Manganese: This mineral is a cofactor to the powerful antioxidant, superoxide dismutase, which works to quell inflammation, one of the key contributors to obesity and weight gain.

Since they work synergistically, mineral balance is key. The “if-some-is-good, more-is-better” approach can be dangerous when it comes to micronutrients because too much of one can induce a deficiency in another. This is why a comprehensive analysis of micronutrient status is essential. SpectraCell’s Micronutrient Test measures not only these minerals, but several other micronutrients including vitamins, antioxidants, amino and fatty acids, and metabolites. 

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Topics: micronutrients, Vitamins, Minerals and Metabolism, Weight Management, Metabolism-Boosting Vitamins