Ketosis, Ketones, And How It All Works
Ketosis is a process that the body does on an everyday basis, regardless of the number of carbs you eat. Your body adapts to what is put in it, processing different types of nutrients into the fuels that it needs. Proteins, fats, and carbs can all be processed for use. Eating a low carb, high fat diet just ramps up this process, which is a normal and safe chemical reaction. When you eat carbohydrate based foods or excess amounts of protein, your body will break this down into sugar – known as glucose. Why? Glucose is needed in the creation of ATP (an energy molecule), which is a fuel that is needed for the daily activities and maintenance inside our bodies. If you’ve ever used our keto calculator to determine your caloric needs, you will see that your body uses up quite a lot of calories. It’s true, our bodies use up much of the nutrients we intake just to maintain itself on a daily basis. If you eat enough food, there will likely be an excess of glucose that your body doesn’t need. There are two main things that happen to excess glucose if your body doesn’t need it: Glycogenesis. Excess glucose will be converted to glycogen and stored in your liver and muscles. Estimates show that only about half of your daily energy can be stored as glycogen. Lipogenesis. If there’s already enough glycogen in your muscles and liver, any extra glucose will be converted into fats and stored. So, what happens to you once your body has no more glucose or glycogen? Ketosis happens. When your body has no access to food, like when you are sleeping or when you are on a ketogenic diet, the body will burn fat and create molecules called ketones. We can thank our body’s ability to switch metabolic pathways for that. These ketones are created when the body breaks down fats, creating Continue reading >>
On This Site Tests: Urine Ketones (see Urinalysis - The Chemical Exam); Blood Gases; Glucose Tests Elsewhere On The Web Ask a Laboratory Scientist Your questions will be answered by a laboratory scientist as part of a voluntary service provided by one of our partners, the American Society for Clinical Laboratory Science (ASCLS). Click on the Contact a Scientist button below to be re-directed to the ASCLS site to complete a request form. If your question relates to this web site and not to a specific lab test, please submit it via our Contact Us page instead. Thank you. Continue reading >>
Ketone Bodies: A Review Of Physiology, Pathophysiology And Application Of Monitoring To Diabetes.
Abstract Ketone bodies are produced by the liver and used peripherally as an energy source when glucose is not readily available. The two main ketone bodies are acetoacetate (AcAc) and 3-beta-hydroxybutyrate (3HB), while acetone is the third, and least abundant, ketone body. Ketones are always present in the blood and their levels increase during fasting and prolonged exercise. They are also found in the blood of neonates and pregnant women. Diabetes is the most common pathological cause of elevated blood ketones. In diabetic ketoacidosis (DKA), high levels of ketones are produced in response to low insulin levels and high levels of counterregulatory hormones. In acute DKA, the ketone body ratio (3HB:AcAc) rises from normal (1:1) to as high as 10:1. In response to insulin therapy, 3HB levels commonly decrease long before AcAc levels. The frequently employed nitroprusside test only detects AcAc in blood and urine. This test is inconvenient, does not assess the best indicator of ketone body levels (3HB), provides only a semiquantitative assessment of ketone levels and is associated with false-positive results. Recently, inexpensive quantitative tests of 3HB levels have become available for use with small blood samples (5-25 microl). These tests offer new options for monitoring and treating diabetes and other states characterized by the abnormal metabolism of ketone bodies. Continue reading >>
Ketone Bodies Formed In The Liver Are Exported To Other Organs
Ketone Bodies In human beings and most other mammals, acetyl-CoA formed in the liver during oxidation of fatty acids may enter the citric acid cycle (stage 2 of Fig. 16-7) or it may be converted to the "ketone bodies" acetoacetate, D-β-hydroxybutyrate, and acetone for export to other tissues. (The term "bodies" is a historical artifact; these compounds are soluble in blood and urine.) Acetone, produced in smaller quantities than the other ketone bodies, is exhaled. Acetoacetate and D-β-hydroxybutyrate are transported by the blood to the extrahepatic tissues, where they are oxidized via the citric acid cycle to provide much of the energy required by tissues such as skeletal and heart muscle and the renal cortex. The brain, which normally prefers glucose as a fuel, can adapt to the use of acetoacetate or D-β-hydroxybutyrate under starvation conditions, when glucose is unavailable. A major determinant of the pathway taken by acetyl-CoA in liver mitochondria is the availability of oxaloacetate to initiate entry of acetyl-CoA into the citric acid cycle. Under some circumstances (such as starvation) oxaloacetate is drawn out of the citric acid cycle for use in synthesizing glucose. When the oxaloacetate concentration is very low, little acetyl-CoA enters the cycle, and ketone body formation is favored. The production and export of ketone bodies from the liver to extrahepatic tissues allows continued oxidation of fatty acids in the liver when acetyl-CoA is not being oxidized via the citric acid cycle. Overproduction of ketone bodies can occur in conditions of severe starvation and in uncontrolled diabetes. The first step in formation of acetoacetate in the liver (Fig. 16-16) is the enzymatic condensation of two molecules of acetyl-CoA, catalyzed by thiolase; this is simply Continue reading >>
Ketones are a beneficial product of fat metabolism in the body. When carbohydrate intake is restricted, it lowers blood sugar and insulin levels. As insulin levels fall and energy is needed, fatty acids flow from the fat cells into the bloodstream and are taken up by various cells and metabolized in a process called beta-oxidation. The end result of beta-oxidation is a molecule called acetyl-coA, and as more fatty acids are released and metabolized, acetyl-coA levels in the cells rise. This causes a sort of metabolic “feedback loop” which triggers liver cells to shunt excess acetyl-Coa into ketogenesis, or the making of ketone bodies. Once created, the liver dumps the ketone bodies into the blood stream and they are taken up by skeletal and heart muscle cells at rates of availability. In addition, the brain begins to use ketones as an alternate fuel when blood levels are high enough to cross the blood brain barrier. Testing Laboratory Microbiology - Air Quality - Mold Asbestos - Environmental - Lead emsl.com There are three major types of ketone bodies present in the human blood stream when the metabolic process of ketosis is dominant: Acetoacetate (AcAc) is created first β-hydroxybutyrate (BHB) is created from acetoacetate Acetone is a spontaneously created side product of acetoacetate In times of starvation, or a low carbohydrate intake resulting in low insulin levels, ketone bodies supply up to 50% of the energy requirements for most body tissues, and up to 70% of the energy required by the brain. Glucose is the main source of fuel for neurons when the diet is high in carbohydrates. But when carbs are restricted, ketogenesis becomes the primary fuel process for most cells. During fasting or low carbohydrate intake, levels of ketone bodies in the blood stream can Continue reading >>
Ketone Body Metabolism
Ketone body metabolism includes ketone body synthesis (ketogenesis) and breakdown (ketolysis). When the body goes from the fed to the fasted state the liver switches from an organ of carbohydrate utilization and fatty acid synthesis to one of fatty acid oxidation and ketone body production. This metabolic switch is amplified in uncontrolled diabetes. In these states the fat-derived energy (ketone bodies) generated in the liver enter the blood stream and are used by other organs, such as the brain, heart, kidney cortex and skeletal muscle. Ketone bodies are particularly important for the brain which has no other substantial non-glucose-derived energy source. The two main ketone bodies are acetoacetate (AcAc) and 3-hydroxybutyrate (3HB) also referred to as β-hydroxybutyrate, with acetone the third, and least abundant. Ketone bodies are always present in the blood and their levels increase during fasting and prolonged exercise. After an over-night fast, ketone bodies supply 2–6% of the body's energy requirements, while they supply 30–40% of the energy needs after a 3-day fast. When they build up in the blood they spill over into the urine. The presence of elevated ketone bodies in the blood is termed ketosis and the presence of ketone bodies in the urine is called ketonuria. The body can also rid itself of acetone through the lungs which gives the breath a fruity odour. Diabetes is the most common pathological cause of elevated blood ketones. In diabetic ketoacidosis, high levels of ketone bodies are produced in response to low insulin levels and high levels of counter-regulatory hormones. Ketone bodies The term ‘ketone bodies’ refers to three molecules, acetoacetate (AcAc), 3-hydroxybutyrate (3HB) and acetone (Figure 1). 3HB is formed from the reduction of AcAc i Continue reading >>
Ketone Bodies Metabolism
1. Metabolism of ketone bodies Gandham.Rajeev Email:[email protected] 2. • Carbohydrates are essential for the metabolism of fat or FAT is burned under the fire of carbohydrates. • Acetyl CoA formed from fatty acids can enter & get oxidized in TCA cycle only when carbohydrates are available. • During starvation & diabetes mellitus, acetyl CoA takes the alternate route of formation of ketone bodies. 3. • Acetone, acetoacetate & β-hydroxybutyrate (or 3-hydroxybutyrate) are known as ketone bodies • β-hydroxybutyrate does not possess a keto (C=O) group. • Acetone & acetoacetate are true ketone bodies. • Ketone bodies are water-soluble & energy yielding. • Acetone, it cannot be metabolized 4. CH3 – C – CH3 O Acetone CH3 – C – CH2 – COO- O Acetoacetate CH3 – CH – CH2 – COO- OH I β-Hydroxybutyrate 5. • Acetoacetate is the primary ketone body. • β-hydroxybutyrate & acetone are secondary ketone bodies. • Site: • Synthesized exclusively by the liver mitochondria. • The enzymes are located in mitochondrial matrix. • Precursor: • Acetyl CoA, formed by oxidation of fatty acids, pyruvate or some amino acids 6. • Ketone body biosynthesis occurs in 5 steps as follows. 1. Condensation: • Two molecules of acetyl CoA are condensed to form acetoacetyl CoA. • This reaction is catalyzed by thiolase, an enzyme involved in the final step of β- oxidation. 7. • Acetoacetate synthesis is appropriately regarded as the reversal of thiolase reaction of fatty acid oxidation. 2. Production of HMG CoA: • Acetoacetyl CoA combines with another molecule of acetyl CoA to produce β-hydroxy β-methyl glutaryl CoA (HMC CoA). • This reaction is catalyzed by the enzyme HMG CoA synthase. 8. • Mitochondrial HMG CoA is used for ketogenesis. Continue reading >>
What Are Ketones?
With the gradual resurgence of low-carb diets in recent years, the word “ketones” is thrown around a lot. But many people aren’t really aware of the details. What are ketones, really? And what do they do in the body? There can be a lot of misinformation regarding the answers to these questions, so read on for a full overview of ketones and their role in a ketogenic diet. Ketones, also known as “ketone bodies,” are byproducts of the body breaking down fat for energy that occurs when carbohydrate intake is low. Here’s how it works: When there isn’t a sufficient level of available glucose — which is what the body uses for its main source of fuel — and glycogen levels are depleted, blood sugar and insulin are lowered and the body looks for an alternative source of fuel: in this case, fat. This process can happen when a person fasting, after prolonged exercise, during starvation, or when eating a low-carb, ketogenic diet. And when the body begins breaking down fats for energy like this, a process known as beta-oxidation, ketones are formed for use as fuel for the body and brain. This is known as ketosis. People following a ketogenic diet specifically reduce their carbohydrate intake for this reason: to create ketones for energy. Many people use the benefits of ketosis — less reliance on carbs and more burning of fat — to possibly help lower blood pressure, reduce cravings, improve cholesterol, increase weight loss, improve energy, and more. TYPES OF KETONE BODIES So, what else about ketones do we need to know? To start, there are technically three types of ketone bodies: Acetoacetate (AcAc) Beta-hydroxybutyric acid (BHB) Acetone Both acetoacetate and beta-hydroxybutyrate are responsible for transporting energy from the liver to other tissues in the body Continue reading >>
6 Health Benefits Of Ketogenesis And Ketone Bodies
With heavy coverage in the media, ketogenic diets are all the rage right now. And for a good reason; for some people, they truly work. But what do all these different terms like ketogenesis and ketone bodies actually mean? Firstly, this article takes a look at what the ketogenesis pathway is and what ketone bodies do. Following this, it will examine six potential health benefits of ketones and nutritional ketosis. What is Ketogenesis? Ketogenesis is a biochemical process through which the body breaks down fatty acids into ketone bodies (we’ll come to those in a minute). Synthesis of ketone bodies through ketogenesis kicks in during times of carbohydrate restriction or periods of fasting. When carbohydrate is in short supply, ketones become the default energy source for our body. As a result, a diet to induce ketogenesis should ideally restrict carb intake to a maximum of around 50 grams per day (1, 2). Ketogenesis may also occur at slightly higher levels of carbohydrate intake, but for the full benefits, it is better to aim lower. When ketogenesis takes place, the body produces ketone bodies as an alternative fuel to glucose. This physiological state is known as ‘nutritional ketosis’ – the primary objective of ketogenic diets. There are various methods you can use to test if you are “in ketosis”. Key Point: Ketogenesis is a biological pathway that breaks fats down into a form of energy called ketone bodies. What Are Ketone Bodies? Ketone bodies are water-soluble compounds that act as a form of energy in the body. There are three major types of ketone body; Acetoacetate Beta-hydroxybutyrate Acetone (a compound created through the breakdown of acetoacetate) The first thing to remember is that these ketones satisfy our body’s energy requirements in the same w Continue reading >>
Ketone bodies Acetone Acetoacetic acid (R)-beta-Hydroxybutyric acid Ketone bodies are three water-soluble molecules (acetoacetate, beta-hydroxybutyrate, and their spontaneous breakdown product, acetone) that are produced by the liver from fatty acids during periods of low food intake (fasting), carbohydrate restrictive diets, starvation, prolonged intense exercise,, alcoholism or in untreated (or inadequately treated) type 1 diabetes mellitus. These ketone bodies are readily picked up by the extra-hepatic tissues, and converted into acetyl-CoA which then enters the citric acid cycle and is oxidized in the mitochondria for energy. In the brain, ketone bodies are also used to make acetyl-CoA into long-chain fatty acids. Ketone bodies are produced by the liver under the circumstances listed above (i.e. fasting, starving, low carbohydrate diets, prolonged exercise and untreated type 1 diabetes mellitus) as a result of intense gluconeogenesis, which is the production of glucose from non-carbohydrate sources (not including fatty acids). They are therefore always released into the blood by the liver together with newly produced glucose, after the liver glycogen stores have been depleted (these glycogen stores are depleted after only 24 hours of fasting). When two acetyl-CoA molecules lose their -CoAs, (or Co-enzyme A groups) they can form a (covalent) dimer called acetoacetate. Beta-hydroxybutyrate is a reduced form of acetoacetate, in which the ketone group is converted into an alcohol (or hydroxyl) group (see illustration on the right). Both are 4-carbon molecules, that can readily be converted back into acetyl-CoA by most tissues of the body, with the notable exception of the liver. Acetone is the decarboxylated form of acetoacetate which cannot be converted Continue reading >>
ketone body any of three related compounds, including acetone, found in the blood and urine when there is excessive oxidation of fatty acids by the liver, as during starvation or pregnancy, or in diabetes ketone body Any of three compounds, acetoacetic acid, acetone, and beta-hydroxybutyric acid, that are ketones or derivatives of ketones and are intermediate products of fatty acid metabolism. Ketone bodies accumulate in the blood and urine when fats are being used for energy instead of carbohydrates, as in individuals affected by starvation or uncontrolled diabetes mellitus. Also called acetone body . THE AMERICAN HERITAGE® DICTIONARY OF THE ENGLISH LANGUAGE, FIFTH EDITION by the Editors of the American Heritage Dictionaries. Copyright © 2016, 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved. ketone-body Continue reading >>
ketone body n. Any of three compounds, acetoacetic acid, acetone, and beta-hydroxybutyric acid, that are ketones or derivatives of ketones and are intermediate products of fatty acid metabolism. Ketone bodies accumulate in the blood and urine when fats are being used for energy instead of carbohydrates, as in individuals affected by starvation or uncontrolled diabetes mellitus. Also called acetone body. American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved. ketone body n (Biochemistry) biochem any of three compounds (acetoacetic acid, 3-hydroxybutanoic acid, and acetone) produced when fatty acids are broken down in the liver to provide a source of energy. Excess ketone bodies are present in the blood and urine of people unable to use glucose as an energy source, as in diabetes and starvation. Also called: acetone body Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014 ke′tone bod′y n. any of several compounds, as acetoacetic acid, acetone, and hydroxybutyric acid, that are intermediate in the metabolism of fatty acids and are produced in excessive amounts under certain abnormal conditions, as in diabetes mellitus. Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved. Noun 1. ketone body - a ketone that is an intermediate product of the breakdown of fats in the body; any of three compounds (acetoacetic acid, acetone, and/or beta-hydroxybutyric acid) found in excess in blood and urine of persons with meta Continue reading >>
What Are Ketones And Are They Healthy?
What Are Ketones and Are They Healthy? If you are up on your health news or follow anyone in the health field, you have likely heard the term ketogenic diet. The goal of the ketogenic diet is to adapt the body to utilize fat as its primary fuel source instead of sugar. The body does this by first converting fat into what are called ketones that the cells can then burn as fuel. It is at this point that I typically get asked, what are ketones? In this article, I am going to clear up any gaps, explain exactly how ketogenisis works, and why it can be so beneficial for the human body. Biological Role of Ketones For our ancestors, eating three meals a day just wasn’t a thing. Instead they would hunt and forage for the foods they could find. When there wasn’t food, they wouldn’t eat. What this means is that sometimes they would go for days at a time with no food. To sustain life during times of scarcity, the body is thought to have developed the ability to utilize fat as an alternative fuel source. In a traditional nutrition course, you would learn that sugar is the body’s primary fuel source while fat is a secondary fuel source. When sugar stores are burned up, the cells then convert to burning fat as an energy source. What we are finding out now is that fat can actually be a healthier and more sustainable source of energy. Our Society Is Full of Sugar Burners Modern day, we have an abundance of food that is available to us at all times. Most of us regularly eat three meals a day with intermittent snacking in between. This kind of frequent eating, along with an overemphasis on carb-rich and sugary foods, causes a reduced ability to burn fat. As these foods damage our bodies on a metabolic level, we actually lose the ability to produce ketones. This type of reliance on Continue reading >>
Fenofibrate Induces Ketone Body Production In Melanoma And Glioblastoma Cells
1Department of Food Biotechnology, Faculty of Food Technology, University of Agriculture, Krakow, Poland 2Molecular and Metabolic Oncology Program, Department of Oncologic Sciences, Mitchell Cancer Institute, University of South Alabama, Mobile, AL, USA 3Department of Human Nutrition, Faculty of Food Technology, University of Agriculture, Krakow, Poland 4Neurological Cancer Research, Stanley S Scott Cancer Center, Louisiana State University Health Sciences Center, New Orleans, LA, USA Ketone bodies [beta-hydroxybutyrate (bHB) and acetoacetate] are mainly produced in the liver during prolonged fasting or starvation. bHB is a very efficient energy substrate for sustaining ATP production in peripheral tissues; importantly, its consumption is preferred over glucose. However, the majority of malignant cells, particularly cancer cells of neuroectodermal origin such as glioblastoma, are not able to use ketone bodies as a source of energy. Here, we report a novel observation that fenofibrate, a synthetic peroxisome proliferator-activated receptor alpha (PPARa) agonist, induces bHB production in melanoma and glioblastoma cells, as well as in neurospheres composed of non-transformed cells. Unexpectedly, this effect is not dependent on PPARa activity or its expression level. The fenofibrate-induced ketogenesis is accompanied by growth arrest and downregulation of transketolase, but the NADP/NADPH and GSH/GSSG ratios remain unaffected. Our results reveal a new, intriguing aspect of cancer cell biology and highlight the benefits of fenofibrate as a supplement to both canonical and dietary (ketogenic) therapeutic approaches against glioblastoma. Continue reading >>
What Are Ketone Bodies And Why Are They In The Body?
If you eat a calorie-restricted diet for several days, you will increase the breakdown of your fat stores. However, many of your tissues cannot convert these fatty acid products directly into ATP, or cellular energy. In addition, glucose is in limited supply and must be reserved for red blood cells -- which can only use glucose for energy -- and brain tissues, which prefer to use glucose. Therefore, your liver converts many of these fatty acids into ketone bodies, which circulate in the blood and provide a fuel source for your muscles, kidneys and brain. Video of the Day Low fuel levels in your body, such as during an overnight fast or while you are dieting, cause hormones to increase the breakdown of fatty acids from your stored fat tissue. These fatty acids travel to the liver, where enzymes break the fatty acids into ketone bodies. The ketone bodies are released into the bloodstream, where they travel to tissues that have the enzymes to metabolize ketone bodies, such as your muscle, brain, kidney and intestinal cells. The breakdown product of ketone bodies goes through a series of steps to form ATP. Conditions of Ketone Body Utilization Your liver will synthesize more ketone bodies for fuel whenever your blood fatty acid levels are elevated. This will happen in response to situations that promote low blood glucose, such as an overnight fast, prolonged calorie deficit, a high-fat and low-carbohydrate diet, or during prolonged low-intensity exercise. If you eat regular meals and do not typically engage in extremely long exercise sessions, the level of ketone bodies in your blood will be highest after an overnight fast. This level will drop when you eat breakfast and will remain low as long as you eat regular meals with moderate to high carbohydrate content. Ketone Bodi Continue reading >>