When we say ketones, our company is referring to the main circulating fatty acid metabolites beta-hydroxybutyrate (OHB) and acetoacetate (AcAc). More on ketone basics here. Exogenous ketones (also known as 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 associated with totally different patterns of ketosis, in addition to differing metabolic and physiologic outcomes. In short, they must not be assumed to have equivalent effects since they achieve similar BOHB blood levels. Having said that, there are many reasons we should continue to study the various forms and potential applications of best keto supplements.
For the past few million years, the only method for humans to make use of ketones for fuel would be to restrict carbohydrates low enough and for enough time to induce the liver to ensure they are. This is admittedly hard for many individuals to do in a world that also believes that dietary carbs are excellent and fats are bad. An emerging alternative is to consume ketones being a health supplement. The study into how these function in the body and what benefits they are able to confer remains early stage, but we already have a number of such products on the market. In this section, we will discuss how exogenous ketones affect blood ketone levels, and just how they could influence health and disease in comparison to ketones produced in the human body.
The 2 predominant ketones made by the liver are beta-hydroxybutyrate (BOHB) and acetoacetate (AcAc). Here’s a quick breakdown of basic info about these ketones:
It is actually estimated which a keto-adapted adult can make 150 or more grams of ketones daily after adjusting to an overall total fast (Fery 1985), and possibly 50-100 grams daily over a well-formulated ketogenic diet.
Some AcAc naturally fails to make acetone, which will come out through the lungs and kidneys, giving a chemical odor to the breath when ketones are high.
Most of the AcAc made in the liver is found by muscle and changed into BOHB.
Included in the keto-adaptation process, how muscles and kidneys deal with BOHB and AcAc changes over the first few weeks and months, and so the ratio of AcAc to BOHB in the blood changes considerably within the first couple of weeks.
Whilst the ultimate fate of the majority of ketones inside the blood will be burned for fuel, BOHB and AcAc seem to have differing roles in regulating genes and cellular functions.
Particularly with gene regulation, BOHB seems to play a more significant regulatory role than AcAc, but AcAc could have a particular role in signaling muscle regeneration .
Sources and Formulations of Exogenous Ketones – The 2 compounds commonly referred to as ‘ketone bodies’ (BOHB and AcAc) are produced and employed for multiple purposes across nature from algae to mammals, but seldom in concentrations useful for extraction as human food. For that reason, the origin of most exogenous ketones is chemical synthesis. Furthermore, most current research and make use of of ketone supplements focuses on BOHB. That is because AcAc is chemically unstable – it slowly fails to make acetone by releasing loejbp one molecule of CO2.
In a keto-adapted individual where ketone metabolism is brisk with as much as 100 grams or even 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 assistance of enzymes, in addition, 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 some form instead of the natural mix of BOHB and AcAc made by the liver.
Another significant distinction between endogenous and exogenous BOHB is that most synthetic BOHB utilized in dietary supplements is a combination of the two ‘D’ and ‘L’ isomers, whereas endogenously produced BOHB contains only the D-isomer. Metabolically, the 2 isomers are very different, and current published information suggests that the majority of the energy and signaling benefits of BOHB derive from the D-form. This can be potentially problematic as the L-isomers are certainly not metabolized using the same chemical pathways because the D-forms (Lincoln 1987, Stubbs 2017), plus it remains unclear whether humans can convert the L-form towards the D-form.
Thus, whilst the L-isomers do not look like toxic, they are not likely to impart exactly the same benefits since the D-forms. In addition, the present assays for blood ketones are specific towards the D-isomer, so it will be challenging to track blood levels and clearance for any L-isomer taken in a supplement.