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 >>
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 >>
Ketones: Your Brain’s Preferred Fuel Source
Ketones have long been touted as a superior fuel source for the brain that possesses a wide array of cognitive benefits. Our brains are made up of two types of cells, neurons, and glial cells, and both are imperative for our brains to function properly (1). Under normal physiological conditions, the principle energy source utilized by the brain cells is glucose (2). Glucose transporters saturate brain capillaries to allow glucose to cross the blood-brain barrier. Once in the brain, glucose is metabolized to pyruvate which enters the mitochondria of the brain cells to ultimately generate energy through aerobic metabolism (3). However, ketone bodies may also provide energy to the brain through different mechanisms. Brain Fuel In addition to glucose, brain cells can derive energy from monocarboxylates which include lactate and the ketone bodies beta-hydroxybutyrate (β-HB) and acetoacetate (AcAc) (2). It is controversial whether or not lactate can be used as a fuel source in the brain; however, many laboratories have reported that BHB is a major fuel supplier for the brain, especially under specific physiological conditions (3,4). BHB and glucose do not nourish the brain uniformly but rather have specific areas of localization. BHB accumulates primarily in the pituitary and pineal glands, as well as in portions of the hypothalamus, and the lower cortical layers (4). Physiological conditions that elevate BHB and consequently provide increased energy to the aforementioned areas of the brain include starvation, fasting, pregnancy, prolonged exercise, uremia, during the prenatal period, infancy, during the chronic consumption of a high fat/low carbohydrate ketogenic diet, and possibly even ketone supplementation (4). Ketones: Brain’s Utilization Capacity Low circulating gluc Continue reading >>
Ketosis: Metabolic Flexibility In Action
Ketosis is an energy state that your body uses to provide an alternative fuel when glucose availability is low. It happens to all humans when fasting or when carbohydrate intake is lowered. The process of creating ketones is a normal metabolic alternative designed to keep us alive if we go without food for long periods of time. Eating a diet low in carb and higher in fat enhances this process without the gnawing hunger of fasting. Let’s talk about why ketones are better than glucose for most cellular fuel needs. Legionella Testing Lab - High Quality Lab Results CDC ELITE & NYSDOH ELAP Certified - Fast Results North America Lab Locations legionellatesting.com Body Fuel Basics Normal body cells metabolize food nutrients and oxygen during cellular “respiration”, a set of metabolic pathways in which ATP (adenosine triphosphate), our main cellular energy source is created. Most of this energy production happens in the mitochondria, tiny cell parts which act as powerhouses or fueling stations. There are two primary types of food-based fuel that our cells can use to produce energy: The first cellular fuel is glucose, which is commonly known as blood sugar. Glucose is a product of the starches and sugars (carbohydrates) and protein in our diet. This fuel system is necessary, but it has a limitation. The human body can only store about 1000-1600 calories of glucose in the form of glycogen in our muscles and liver. The amounts stored depend on how much muscle mass is available. Men will be able to store more because they have a greater muscle mass. Since most people use up about 2000 calories a day just being and doing normal stuff, you can see that if the human body depended on only sugar to fuel itself, and food weren’t available for more than a day, the body would run Continue reading >>
on on Fats (or triglycerides) within the body are ingested as food or synthesized by adipocytes or hepatocytes from carbohydrate precursors ([link]). Lipid metabolism entails the oxidation of fatty acids to either generate energy or synthesize new lipids from smaller constituent molecules. Lipid metabolism is associated with carbohydrate metabolism, as products of glucose (such as acetyl CoA) can be converted into lipids. Lipid metabolism begins in the intestine where ingested triglycerides are broken down into smaller chain fatty acids and subsequently into monoglyceride molecules (see [link]b) by pancreatic lipases, enzymes that break down fats after they are emulsified by bile salts. When food reaches the small intestine in the form of chyme, a digestive hormone called cholecystokinin (CCK) is released by intestinal cells in the intestinal mucosa. CCK stimulates the release of pancreatic lipase from the pancreas and stimulates the contraction of the gallbladder to release stored bile salts into the intestine. CCK also travels to the brain, where it can act as a hunger suppressant. Together, the pancreatic lipases and bile salts break down triglycerides into free fatty acids. These fatty acids can be transported across the intestinal membrane. However, once they cross the membrane, they are recombined to again form triglyceride molecules. Within the intestinal cells, these triglycerides are packaged along with cholesterol molecules in phospholipid vesicles called chylomicrons ([link]). The chylomicrons enable fats and cholesterol to move within the aqueous environment of your lymphatic and circulatory systems. Chylomicrons leave the enterocytes by exocytosis and enter the lymphatic system via lacteals in the villi of the intestine. From the lymphatic system, the chylo Continue reading >>
- Effect of Probiotics on Glucose and Lipid Metabolism in Type 2 Diabetes Mellitus: A Meta-Analysis of 12 Randomized Controlled Trials
- Impact of menopause and diabetes on atherogenic lipid profile: is it worth to analyse lipoprotein subfractions to assess cardiovascular risk in women?
- Exercise and Glucose Metabolism in Persons with Diabetes Mellitus: Perspectives on the Role for Continuous Glucose Monitoring
Best Exogenous Ketone Supplements
Exogenous ketones are a very new and exciting health food supplement that offers numerous health benefits to those who use them regularly. They’ve only been on the market since 2014, but ketones themselves have been studied extensively throughout the last several decades. Ketones are made in the liver from stored fat cells, providing us with energy in times when the body doesn’t have available glucose or “glycogen” to burn. Examples include when you’re pushing the body hard physically and burn off all your stored sugar energy (glycogen/blood glucose), or during times of famine when food is scarce. Exogenous ketones are exactly the same as ketones as far as the body is concerned. “Exogenous” simply means that the ketones are derived from sources outside the body, whereas ketones manufactured by the liver from fat stores are referred to as “endogenous” ketones. The Human Body Isn’t Meant to Run on Sugar All the Time Ketones are now recognized by science as the preferred energy source for both the brain and heart, while our biological power-source inside the body, the mitochondria, also thrive when fueled by ketone bodies instead of glucose. Mitochondria are the sole driving force behind aging in the body, as they help kill aged and/or malformed cells (eg., cancer), form new healthy cells, and in general help keep the body vital and full of energy. Several studies where exogenous ketones have been administered show boundless improvements in athletic performance, cancer treatment, Alzheimer’s, dementia, inflammatory diseases, and genetic disorders of all kinds. Exogenous ketones aren’t to be compared with the hyped-up raspberry ketones that are so popular for weight loss these days. Raspberry ketones are somewhat similar on a molecular level, but are Continue reading >>
Dynamic Adaptation Of Nutrient Utilization In Humans
Most cells use glucose for ATP synthesis, but there are other fuel molecules equally important for maintaining the body's equilibrium or homeostasis. Indeed, although the oxidation pathways of fatty acids, amino acids, and glucose begin differently, these mechanisms ultimately converge onto a common pathway, the TCA cycle, occurring within the mitochondria (Figure 1). As mentioned earlier, the ATP yield obtained from lipid oxidation is over twice the amount obtained from carbohydrates and amino acids. So why don't all cells simply use lipids as fuel? In fact, many different cells do oxidize fatty acids for ATP production (Figure 2). Between meals, cardiac muscle cells meet 90% of their ATP demands by oxidizing fatty acids. Although these proportions may fall to about 60% depending on the nutritional status and the intensity of contractions, fatty acids may be considered the major fuel consumed by cardiac muscle. Skeletal muscle cells also oxidize lipids. Indeed, fatty acids are the main source of energy in skeletal muscle during rest and mild-intensity exercise. As exercise intensity increases, glucose oxidation surpasses fatty acid oxidation. Other secondary factors that influence the substrate of choice for muscle include exercise duration, gender, and training status. Another tissue that utilizes fatty acids in high amount is adipose tissue. Since adipose tissue is the storehouse of body fat, one might conclude that, during fasting, the source of fatty acids for adipose tissue cells is their own stock. Skeletal muscle and adipose tissue cells also utilize glucose in significant proportions, but only at the absorptive stage - that is, right after a regular meal. Other organs that use primarily fatty acid oxidation are the kidney and the liver. The cortex cells of the Continue reading >>
What is ketosis? Ketosis is the physiological state where the concentration of ketone bodies in the blood is higher than normal. This is generally agreed to be at beta-hydroxybutyrate (BHB) concentrations greater than 0.5 mM. How to achieve ketosis? Ketosis occurs either as a result of increased fat oxidation, whilst fasting or following a strict ketosis diet plan (ENDOGENOUS ketosis), or after consuming a ketone supplement (EXOGENOUS ketosis). When in a state of ketosis the body can use ketones to provide a fuel for cellular respiration instead of its usual substrates: carbohydrate, fat or protein. Why does ketosis exist? Normally, the body breaks down carbohydrates, fat, and (sometimes) proteins to provide energy. When carbohydrate is consumed in the diet, some is used immediately to maintain blood glucose levels, and the rest is stored. The hormone that signals to cells to store carbohydrate is insulin. The liver stores carbohydrate as glycogen, this is broken down and released between meals to keep blood glucose levels constant. Muscles also store glycogen, when broken down this provides fuel for exercise. Most cells in the body can switch readily between using carbohydrates and fat as fuel. Fuel used depends on substrate availability, on the energy demands of the cell and other neural and hormonal signals. The brain is different as it is dependent on carbohydrates as a fuel source. This is because fats cannot easily cross the blood-brain barrier. The inability to make use of energy within fat poses a problem during periods where there is limited carbohydrate in the diet. If blood glucose levels fall to low, brain function declines. Relatively little energy is stored as carbohydrate (2,000 kCal) compared to fat (150,000 kCal). The body's store of carbohydrates runs Continue reading >>
Brain: Ketone Metabolism
Definition The three ketone bodies are acetone, acetoacetic acid, and beta-hydroxybutyric acid. Ketone bodies are derived from the incomplete oxidation of fatty acids in the liver and are used for energy (ATP generation) in the heart and brain. Ketone bodies are transported from the liver to other tissues, where acetoacetate and beta-hydroxybutyrate can be reconverted to acetyl-CoA to produce energy, via the Krebs cycle. The brain gets its energy from ketone bodies when insufficient glucose is available, such as during fasting and starvation. In the event of low blood glucose, most other tissues have additional energy sources besides ketone bodies (such as fatty acids), but the brain does not. After the diet has been changed to lower blood glucose for 3 days, the brain gets 30% of its energy from ketone bodies. After about 40 days, this goes up to 70% (during the initial stages the brain does not burn ketones, since they are an important substrate for lipid synthesis in the brain). By using alternative fuels, the demand for glucose is reduced and muscle proteins are spared further degradation. Subspecialty Keyword history See Also: Sources PubMed Continue reading >>
The Fat-fueled Brain: Unnatural Or Advantageous?
Disclaimer: First things first. Please note that I am in no way endorsing nutritional ketosis as a supplement to, or a replacement for medication. As you’ll see below, data exploring the potential neuroprotective effects of ketosis are still scarce, and we don’t yet know the side effects of a long-term ketogenic diet. This post talks about the SCIENCE behind ketosis, and is not meant in any way as medical advice. The ketogenic diet is a nutritionist’s nightmare. High in saturated fat and VERY low in carbohydrates, “keto” is adopted by a growing population to paradoxically promote weight loss and mental well-being. Drinking coffee with butter? Eating a block of cream cheese? Little to no fruit? To the uninitiated, keto defies all common sense, inviting skeptics to wave it off as an unnatural “bacon-and-steak” fad diet. Yet versions of the ketogenic diet have been used to successfully treat drug-resistant epilepsy in children since the 1920s – potentially even back in the biblical ages. Emerging evidence from animal models and clinical trials suggest keto may be therapeutically used in many other neurological disorders, including head ache, neurodegenerative diseases, sleep disorders, bipolar disorder, autism and brain cancer. With no apparent side effects. Sound too good to be true? I feel ya! Where are these neuroprotective effects coming from? What’s going on in the brain on a ketogenic diet? Ketosis in a nutshell In essence, a ketogenic diet mimics starvation, allowing the body to go into a metabolic state called ketosis (key-tow-sis). Normally, human bodies are sugar-driven machines: ingested carbohydrates are broken down into glucose, which is mainly transported and used as energy or stored as glycogen in liver and muscle tissue. When deprived of d Continue reading >>
How Are Ketones Used For Energy?
When it comes to what does and doesn’t work in terms of effective weight management and lifestyle changes, ketogenic living has definitely made a mark in the industry of health and wellness. If you join the keto-community, you can hear real testimonials from people just like yourself who have seen incredible results by switching to a ketogenic lifestyle. We know ketosis works by the visible results people see in the mirror and by the success stories we hear time and time again. The other reason we bank on ketosis helping people like yourself, is that it comes down to being a science. Based on the way the body works and natural reactions to dietary changes, ketogenic eating effects overall fat burning and has been proven. Ketosis is a process our bodies go through on a daily basis regardless of what macronutrients you are eating. Switching your diet to low carb choices, focusing on healthy fats and proteins while avoiding sugars, will just increase your ketogenic state and speed up your natural fat burning ability. Our natural calorie burning ability is quite high and many of the calories we consume are just to keep our body going day by day, but too many excess calories or glucose spikes could sabotage your weight loss goals. WHEN OUR BODY HAS TOO MUCH GLUCOSE When we consume too many carbohydrates or excessive protein, our bodies begin to break this down as sugar, otherwise known as glucose. Too much glucose is the contributing factor to unwanted weight gain and inability to shed those last few pounds. Note that glucose is needed for the creation of ATP (an energy molecule), which our bodies need for daily energy expenditure and body functions. There are two main processes that happen with too much glucose present in the body. Glycogenisis occurs when excess glucose Continue reading >>
Ketones The Preferable Energy To Brain
Ketones Ketones are organic water soluble compounds, chemically characterised by the presence of carbonyl group in which a carbon atom forms a double bond with an oxygen atom and joins with two other carbons. Increased ketone level (B-hydroxybutyrate) in the blood called ketosis which is nutritional as long as ketone level in the blood is within the normal average which is 0.3-5mmol/l. Ketone bodies They are the three ketones released in the liver as by-products during the process of fat metabolism. It includes beta- hydroxyl butyrate, acetoacetate and acetone. The last one is excreted in the urine while the other two are used for energy. The body usually depends on glucose for energy .In cases of fasting, and starvation there is a decrease in blood glucose levels. That pushes the body to utilize the stored fat and release fatty acids and ketones as an alternative source of energy. This ketone production is mainly for the brain. “Ketone supply the brain with the energy not only to survive but to thrive " Dr.Bruce fife All the body organs can either use glucose or fatty acid as a source of energy except the brain. The brain can only use glucose or ketones to produce the energy it needs .Ketones are the preferable source of energy for the brain as the fatty acids are the preferable source of energy for the heart. Due to the myths of our time, we are encouraged to follow a low- fat diet to keep our heart and brain healthy, but in truth our heart and brain prefer fat sources to function better and become healthier. Ketones are a high-energy fuel that nourishes the brain. Dr.theodore vanltallie MD, Home > Ketones 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 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 >>
Do We Burn Ketones For Energy?
Many low carb dieters believe that ketones fuel the entire body. They don't. So, what are Ketones Really Used For? “I am in ketosis,” What does that mean? Do your muscles use ketones to move? Does your metabolism use ketones to keep your unconscious systems, such as physical digestion or your need to breath, running smoothly? Are you burning ketones to fuel your everyday physical activities, such as getting out of bed, making breakfast, and going to work? Most low-carb dieters would say: “Yes. We burn ketones for energy.” However, that statement is misleading. And here's why: The Truth About Ketone Oxidation Ketones are only used to fuel your everyday activities in the very beginning of your low-carb diet. Initially, when you drop your carbohydrate intake to 20 net carbs per day, or less, the body has no way to know how long that deprivation is going to last. In a glycogen-depleted condition, ketones are used to support the activities of almost every organ, system, and body function. This adaptive response saves the available glycogen (the storage form of carbohydrates) for the central nervous system and a few other cells that don't have mitochondria. And that is where the confusion comes in. Most of the articles you'll read about the state of ketosis only talk about what happens during the first week or two. I noticed that in some of the biochemistry texts available online. They explained what initially happens to the metabolism during starvation, or at the very beginning of a low-carb diet, but they didn't go into what the liver does if the situation continues past a few days. In this blog post, we're going to take a closer look at what ketones are actually used for and what happens when the carbohydrate stress doesn't let up. What Does the Latest Scientific R Continue reading >>