Beta Hydroxybutyrate: Benefits and How to Optimize Levels - Dr. Axe

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Beta Hydroxybutyrate: The Ketone that Supports Weight Loss & Brain Health


Beta hydroxybutyrate - Dr. Axe

The human body is capable of using two primary types of fuel: glucose (provided by carbohydrate foods) and ketone bodies (made from fat). When you follow a very-low carb, very-high fat diet — also known as the ketogenic diet — your body starts producing organic ketone compounds, including the type called beta hydroxybutyrate (BHB or beta-hydroxybutyrate), which serve as an alternative fuel source to carbohydrates.

What is beta hydroxybutyrate used for in the body? Some of the most noteworthy beta hydroxybutyrate benefits and uses include supporting weight loss, preventing or treating diabetes and insulin resistance, helping to treat epilepsy, fighting cancer, protecting the brain, improving cognitive function, and potentially increasing life span/longevity.

Not only can your body make ketone bodies including BHB, but you can also acquire BHB from ketone supplements. Exogenous ketones, or simply consuming foods like MCT oil, can be beneficial for boosting the many positive effects of the keto diet and intermittent fasting.

What Is Beta Hydroxybutyrate?

The definition of beta hydroxybutyrate is a ketone body (or simply a ketone) that is an intermediate product of the breakdown of fats in the body. Ketogenesis is considered the metabolism of fatty acids by β-oxidation. BHB is one of three main ketone body compounds that are produced when someone is in the metabolic state of ketosis (the other two are acetoacetic acid and acetone).

Normally, when someone eats a standard diet that includes various sources of carbohydrates, the main function of carbs is to provide fuel or energy for the body. In the absence of carbohydrates and when a depletion of glycogen (the storage form of carbohydrate) occurs — which is exactly what happens when someone follows the keto diet — the liver makes ketones from fatty acids.


While carbohydrates are the body’s “preferred fuel source” and the first type of energy used to fuel physical and cellular activities, fat is also a fuel source. Usually we only need small amounts of dietary fat/essential fatty acids to maintain steady energy, but when following the keto diet the need for fat drastically increases.

Other situations in which beta hydroxybutyrate is produced is when someone fasts (abstains from eating food) for around 16 hours or more. Since the body interprets fasting as a sign that energy intake is low, it increases ketone production in order to have another fuel source. The production of ketone bodies helps save any available glucose for the brain, which uses glucose quickly. When glucose is not available, fatty acids as well as ketone bodies can also be metabolized by the brain.

Types of BHB

Is beta hydroxybutyrate natural? Yes, it’s a naturally occurring compound that is produced by the body in response to very low-carb dieting, fasting or starvation. There are two types of beta hydroxybutyrate that the human body is capable of making: D-BHB (the type used for efficient energy, which also has anti-aging effects) and L-BHB (used to a lesser extent for energy and also for synthesis of fatty acids).

When your body produces ketones from fatty acids, it does so in roughly these amounts:

  • Beta-hydroxybutyrate (BHB) — 78 percent of total ketones in the blood
  • Acetoacetate (AcAc) — approximately 20 percent of ketones in the blood
  • Acetone — only about 2 percent of ketones in the blood

Exogenous ketones (ketones supplements that come from outside the body) are also used to mimic or amplify the positive effects of calorie restriction or very low carbohydrate ketogenic diets. While there are three types of ketone bodies, the ketone found in exogenous ketone supplements is usually only beta hydroxybutyrate.


1. Supports Weight Loss

When carbs are drastically restricted while fasting or following the keto diet, insulin levels are lowered, allowing for fat to be released from fat (adipose) tissue and steady weight loss to occur.

Ketones can also help improve energy output, physical performance and recovery (once keto flu symptoms subside). And exercise, especially vigorous and endurance types, increases the update of ketone bodies, which further supports fat burning.

2. Helps Prevent or Treat Diabetes/Insulin Resistance

Ketones decrease circulating glucose and insulin, leading to decreased insulin‐like growth factor receptor signaling. In studies involving rats, the use of exogenous has been shown to decrease blood glucose and insulin levels even when the rats are eating highly processed diets high in cornstarch. As such, BHB can help on an insulin resistance diet.

3. Fights Cancer

In animal studies, giving mice that are affected by late-stage cancer exogenous ketones has been shown to help increase survival rates significantly. In a 2014 study published in the International Journal of Cancer, ketone supplementation was shown to “decrease tumor cell viability and prolong survival of mice with metastatic cancer.”

One reason that very low-carb diets may help fight cancer is because cancer cells express an abnormal metabolism characterized by increased glucose consumption, which facilitates genetic mutations and mitochondrial dysfunction. Studies suggest that cancer cells are unable to effectively use ketone bodies for energy, while healthy tissues can. Ketones have also been shown to inhibit the proliferation and viability of cultured tumor cells.

In this particular study, mice were fed a standard diet supplemented with either 1,3‐butanediol (BD) or a ketone ester that was metabolized to the ketone bodies BHB and acetoacetate. Tumor growth was monitored. Survival time, tumor growth rate, blood glucose, blood βHB and body weight were measured throughout the survival study. Ketone supplementation was shown to decrease proliferation and viability of cancerous cells, even in the presence of high glucose. Dietary ketone supplementation with BD and ketone ester prolonged survival in the mice with systemic metastatic cancer by 51 percent and 69 percent, respectively.

4. Protects the Brain

Studies suggest that BHB benefits when it pertains to cognitive/mental health include improving memory, focus, attention, physical performance and learning; lowering free radical damage; reducing inflammation and risk for cognitive decline in older adults; protecting against and treating epilepsy and neurodegnerative diseases; and reducing risk for mood-related disorders, such as depression.

Ketones can help reduce the risk of neurodegenerative diseases — such as Alzheimer’s disease, dementia and Parkinson’s — by reducing oxidative stress in the brain and protecting brain cells (especially the mitochondria), neurons and synapses. Ketones also seem to help reduce accumulation of the molecule called amyloid-β, which has been associated with development of diseases, including Alzheimer’s. When glucose is not available, the brain becomes very receptive and responsive to ketone bodies, especially BHB, which it absorbs readily (roughly at the pace of 0.032 mmol/kg per minute).

5. Has Anti-Inflammatory Effects

BHB can help prevent the release of inflammatory molecules that contribute to various diseases affecting the heart, brain, bones, skin and so on. Research suggests that BHB interferes with an inflammatory response called NLRP3 inflammasome, plus reduces the release of pro-inflammatory cytokines, including interleukin IL-1β and IL-18.

6. Potentially Increases Life Span

While this hasn’t yet been proven in human studies, studies involving yeast, mice and primates have found that ketones can help extend life span and promote longevity. For years, it’s been known that calorie restriction is one intervention that extends life span by reducing excess fat mass, causing less oxidative stress and inflammation, causing positive changes to the gut microbiome, lowering and insulin growth hormone, and causing less iron accumulation. According to one study published in the IUBMB Journal, ketone bodies have been found to “mimic the life span extending properties of caloric restriction.”


According to the author’s conclusion, “We hypothesize that increasing the levels of ketone bodies will also extend the life span of humans and that calorie restriction extends life span at least in part through increasing the levels of ketone bodies.”

Researchers believe that ketones may be able to extend life span due to decreased activity of insulin/IIS. Ketone bodies also seem to help combat free radical damage and power cells’ mitochondria, including in older individuals who have limited ability to oxidize glucose metabolites. This has a positive effect on gene expression and increases protection against oxidative stress, such as by improving antioxidant enzyme activities, including superoxide dismutase 2, catalase, glutathione peroxidase and others.

Beta hydroxybutyrate - Dr. Axe

How to Optimize Levels

The best way to naturally increase/optimize beta hydroxybutyrate levels is by eating a very-low carb, very high-fat diet (the ketogenic diet). This can also be combined with intermittent fasting or other types of fasting to further boost ketone production. And to really increase BHB production and fat burning, you can combine a ketogenic diet, intermittent fasting and exogenous ketones like BHB salts.

Even when correctly following the keto diet, many people can also benefit from using ketone supplements (exogenous ketones) — although for the most payoff it’s best to alter your diet, leading to natural ketone production. Keep in mind that most low-carb diets will not lead to increased ketone levels — only the ketogenic diet can effectively do this.

How do you follow the ketogenic diet and stay in “nutritional ketosis”? In simplest terms, you need to get 70 percent to 80 percent of your daily calories from fat, no more than 20 percent to 25 percent of calories from protein and no more than 5 percent to 10 percent carbs of daily calories from carbohydrates.

What are the best beta hydroxybutyrate food sources for boosting levels?

The top foods for increasing ketone production are healthy fats like MCT oil, butter and coconut oil. MCT oil is a very popular food/supplement among people following the keto diet because it has positive effects, including boosting ketone production, increasing energy, and reducing appetite and cravings, plus it’s less expensive than many exogenous ketone supplements. How can you use MCT oil? Try adding a tablespoon or more to your coffee in the morning.

Below are the best low-carb foods to eat regularly when following the ketogenic diet:

  • Healthy fats — coconut oil, MCT oil, avocado, avocado oil, walnut oil, olive oil
  • Pastured/cage-free eggs
  • Grass-fed meats — beef, organs, game meat, lamb, bison, pastured chicken, turkey, duck
  • Full-fat dairy— choose organic types like cream cheese, cheeses, sour cream, butter, ghee
  • Wild-caught fish and seafood — some of the best choices are mackerel, sardines, salmon
  • Nuts and seeds — nut butter, almonds, macadamia nuts, cashews,  walnuts, chia seeds, flaxseeds
  • Non-starchy veggies — all types of leafy greens, zucchini, asparagus, artichoke, cruciferous veggies like broccoli, etc.
  • Herbs, spices, vinegars, mustards, cocoa powder and stevia extract

What’s the best BHB supplement/ketone supplement?

Benefits of adding a beta hydroxybutyrate supplement to your routine include helping with the transition into a state of ketosis, supporting energy levels when in a fasted state, preventing keto flu symptoms, and improving athletic/exercise performance and recovery. Ketone supplements can be used in between meals or before a workout to provide a quick source of ketones. You can also use ketone supplements to help you get back into ketosis more easily and quickly if you’ve abandoned the diet for a period of time.

There are three main types of ketone supplements:

  • Ketone salts (sometimes called BHB salts), which are ketones bound to minerals.
  • Ketone esters, which are basically “raw ketones” and metabolize quickly into BHB. This type is not widely available for most consumers but is typically used in research/studies.
  • Ketone oils, including MCT oil. MCT (medium chain triglyceride) oils are used by the body to boost ketones and burn fat easily. Coconut oil also contains medium chained triglycerides, but MCT oil is a more concentrated source. MCTs must be broken down first before they can be used for energy, making this type of supplement slightly less efficient.

The amount of ketones in your blood, urine and breath can be tested to provide a reading of your body’s ketone levels and to indicate that you are (or are not) in ketosis. Depending on the quality of ketone supplements, different brands and types will affect blood BHB (ketone) levels in different ways. The higher quality a product is, the better it will be at helping you enter and stay in ketosis.

  • Quality ketone products can help increase blood ketone levels to as high as 1.5 mmol/L. Following a keto diet correctly can increase levels even more. Most people on the keto diet will have ketone levels between 2–3 mmol/L.
  • The optimal range of beta hydroxybutyrate is between 0.6–6.0 mmol/L, depending on your goals and the condition you’re treating. When you’re not purposefully limiting carb take, levels will stay below 0.5 mmol/L.
  • For general weight loss, aim to get your levels above 0.6 mmol/L. Doctors may aim for higher levels of ketones in patients who are being treated for therapeutic purposes, up tp 3–6 mmol/L.
  • Fasting can increase BHB levels to above 0.6 mmol/L within 12–16 hours. If you fast for two days, your level will likely climb to 1–2 mmol/L.
  • Intense exercise for 90 minutes can also boost BHB to 1–2 mmol/L.
  • When you’re in ketosis, you have a higher than usual level of ketones in your blood or urine, but this is not the same as ketoacidosis, which affects diabetics. Ketone levels at or above 3 mmol/L in diabetics can be indicative of ketoacidosis and can be dangerous. In very severe diabetic ketoacidosis, the beta-hydroxybutyrate serum concentration may exceed 25 mmol/L. Diabetics should always work with a doctor and be monitored when following the keto diet in order to reduce the risk for any complications.
Beta hydroxybutyrate - Dr. Axe

Side Effects

You won’t be able to remain in ketosis or produce ketones (including BHB) if you’re not correctly following the ketogenic diet. For example, a common keto myth is that the diet is high in protein. Eating too much protein and/or carbohydrates is actually a problem on the ketogenic diet, as is eating too little fat.

This will either prevent you from entering ketosis or pull you out of it, ceasing ketone production and increasing symptoms like fatigue, cravings, muscle weakness and brain fog.

Remember that when you first enter ketosis some unusual symptoms are expected, and this is actually a sign that you’re adhering to the keto diet correctly. Your mouth may be dry, and you will probably have increased thirst, so drink more water and consider adding salt to your meals since you’re losing more in your urine. You’ll probably experience a lack of appetite and start losing weight. You may feel tired temporarily and also have bad breath. Things should start improving after a week or so, in which you should experience more energy, focus and appetite control.

If your symptoms persist for more than two weeks, chances are you need to make changes because you’re not actually in ketosis. Try upping your fats, further decreasing carbs, drinking more water and keeping a food journal to track your progress. You can also test your urine or saliva to see if your ketone levels are in the optimal range.

Is beta hydroxybutyrate safe? BHB is something that your body produces to ensure survival in times of food scarcity or starvation. The production of ketones is actually a survival mechanism and totally natural and safe. However, taking exogenous ketones is a bit different, since these are not made by the body. Ketosis itself can also result in side effects, especially when you initially transition into this metabolic state.

Beta hydroxybutyrate side effects (or side effects of ketosis) may include unpleasant taste in your mouth, fatigue, weakness, indigestion, dizziness, low blood sugar, sleep-related issues, mood changes, frequent urination, constipation, cramps, and trouble exercising or recovering.

With time your body gets used to ketosis and producing more ketone bodies, so symptoms should only be temporary and last for about one to two weeks.

Final Thoughts

  • Beta hydroxybutyrate (BHB) is a type of ketone body that is produced when you’re following the ketogenic diet, fasting or if someone is starving. BHB is one of the three ketones and is the most abundant type, helping provide energy in the absence of carbohydrates.
  • There are two types of BHB that the human body is capable of making: D-BHB (the type used for efficient energy, which also has anti-aging effects) and L-BHB (used to a lesser extent for energy and also for synthesis of fatty acids).
  • Benefits of BHB and ketones include supporting weight loss, preventing or treating diabetes and insulin resistance, helping treat epilepsy, fighting cancer, protecting the brain, improving cognitive function, and potentially increasing life span/longevity.
  • Foods/habits that increase beta hydroxybutyrate production include eating a very-low carb, high-fat diet, fasting, taking exogenous ketone supplements and intense exercise.
  • Some of the best foods for boosting BHB include MCT oil, coconut oil, butter, ghee and other healthy fats.
  • Optimal ketone levels when following the ketogenic diet are between 0.6 and 3 mmol/L, although sometimes doctors will monitor patients as their levels increase up to 6 mmol/L for therapeutic purposes.

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