When we say ketones, we are referring to the primary circulating fatty acid metabolites beta-hydroxybutyrate (OHB) and acetoacetate (AcAc). Much more on ketone basics here. Exogenous ketones (also called ketone supplements) and well-formulated ketogenic diets share one or more thing in common. Both of them bring about increased circulating concentrations of beta-hydroxybutyrate (BOHB), but ultimately are related to totally different patterns of ketosis, as well as differing metabolic and physiologic outcomes. In a nutshell, they must not be assumed to have equivalent effects simply because they achieve similar BOHB blood levels. With that said, there are many reasons we need to continue to study the many forms and potential applications of keto magnesium supplements.
For the past few million years, the only method for humans to utilize ketones for fuel would be to restrict carbohydrates low enough and long enough to induce the liver to make them. This is admittedly hard for most people to accomplish in a world that still believes that dietary carbs are excellent and fats are bad. An emerging alternative would be to consume ketones as a nutritional supplement. The study into how these function within the body and what benefits they could confer remains early stage, but there are already a number of such products on the market. In this section, we will discuss how exogenous ketones affect blood ketone levels, and how they may influence health insurance and disease when compared with ketones produced in the human body.
The 2 predominant ketones made by the liver are beta-hydroxybutyrate (BOHB) and acetoacetate (AcAc). Here’s a brief breakdown of basic info about these ketones:
It is estimated which a keto-adapted adult can make 150 or even more grams of ketones daily after adjusting to a total fast (Fery 1985), and possibly 50-100 grams daily on the well-formulated ketogenic diet.
Some AcAc naturally stops working to make acetone, which will come out with the lungs and kidneys, giving a chemical odor to the breath when ketones are high.
A lot of the AcAc made in the liver is acquired by muscle and transformed into BOHB.
Included in the keto-adaptation process, how muscles and kidneys cope with BOHB and AcAc changes over the first weeks and months, and so the ratio of AcAc to BOHB inside the blood changes considerably within the first week or two.
As the ultimate fate of the majority of ketones inside the blood will be burned for fuel, BOHB and AcAc appear to have differing roles in regulating genes and cellular functions.
Particularly with gene regulation, BOHB seems to play a far more significant regulatory role than AcAc, but AcAc may have a particular role in signaling muscle regeneration .
Sources and Formulations of Exogenous Ketones – The two compounds commonly referred to as ‘ketone bodies’ (BOHB and AcAc) are produced and utilized for multiple purposes across nature from algae to mammals, but seldom in concentrations ideal for extraction as human food. Because of this, the cause of many exogenous ketones is chemical synthesis. Furthermore, most current research and make use of of ketone supplements targets BOHB. This is because AcAc is chemically unstable – it slowly fails to form acetone by releasing loejbp one molecule of CO2.
In a keto-adapted individual where ketone metabolism is brisk with up to 100 grams or more being oxidized (i.e., ‘burned for energy’) daily, the tiny amount lost in breath and urine as acetone is minor. But as this breakdown occurs spontaneously without having the aid of enzymes, additionally, it transpires with AcAc in a stored beverage or food (even in an air-tight container), making the shelf-life of AcAc-containing products problematic. Thus all current ketone supplements consist of BOHB in a few form instead of the naturally sourced combination of BOHB and AcAc created by the liver.
Another essential difference between endogenous and exogenous BOHB is the fact that most synthetic BOHB found in nutritional supplements is a mixture of the 2 ‘D’ and ‘L’ isomers, whereas endogenously produced BOHB includes merely the D-isomer. Metabolically, both isomers are extremely different, and current published information suggests that the majority of the energy and signaling advantages of BOHB derive through the D-form. This can be potentially problematic because the L-isomers usually are not metabolized through the same chemical pathways since the D-forms (Lincoln 1987, Stubbs 2017), and it remains unclear whether humans can convert the L-form towards the D-form.
Thus, whilst the L-isomers do not seem to be toxic, they are not prone to impart the same benefits since the D-forms. Furthermore, the present assays for blood ketones are specific towards the D-isomer, so it will be challenging to track blood levels and clearance of the L-isomer taken in a supplement.