Ketones serve as an alternative energy source for the human body, specifically our mitochondria – the ‘powerhouse’ of cells.
While it can be argued that glucose (sugar) is the primary source of energy in humans, it is not essential for our survival.
Ketones, on the contrary, are byproducts of fat metabolism in humans when carbohydrates are restricted, and are thus necessary substrates for living.
Biochemically speaking, ketones are simple, organic compounds that contain a central carbon atom bound to an oxygen atom and two carbon-containing substituents, designated by an “R” symbol (see chemical structure below).
Ketones are ‘simple’ molecules because they don’t contain any chemical groups that readily react.
In humans, three different ketones (also referred to as ketone bodies) are made in the mitochondria of the liver, including acetone, acetoacetic acid (AcAc), and beta-hydroxybutyric acid (BHB).
The image below shows the chemical structures of these three ketone bodies:
Note that BHB is not technically a ketone since it contains a reactive hydroxyl group where a double-bonded oxygen would usually be.
Nevertheless, BHB still functions like a ketone in humans and is converted to energy (via acetyl-CoA), just like acetoacetate and acetone can be; however, the conversion of acetone to acetyl-CoA is rather inefficient.
Entering Ketosis – When and Why Does the Body Produce These Ketone Bodies?
Ketone bodies, particularly acetoacetate, is made from the breakdown of fatty acids. Fatty acids become a primary energy source in humans when carbohydrate intake is low.
When carbs are kept in low enough quantities long enough, the body enters a state called “ketosis”.
When ketosis takes place, acetoacetate is present in large amounts throughout the body, which can then go on to form BHB and acetone. Our body may then use these molecules for energy purposes.
Remember, when carbohydrates are low, the body needs an ‘alternative’ fuel source for survival. Ketone bodies are that fuel source that steps in and powers the body.
Naturally, during periods when food is limited (such as intermittent fasting), ketone body production also increases for energetic purposes. This is why dietary protocols like intermittent fasting might heighten the ketosis effects of low-carbohydrate diets.
Raspberry ketone seems to be a popular ingredient in many fat-loss and general health supplements nowadays. However, despite its designation, raspberry ketone is not in the same category as ketone bodies.
Many consumers believe that exogenous ketone supplements are the same as raspberry ketone supplements, which is not the case.
Raspberry ketone is a polyphenol found in red raspberries that gives them their pleasant aroma and ruby red color.
Chemically speaking, raspberry ketone is similar to the compound synephrine and might have fat-loss benefits. However, it is not yet understood if raspberry ketone serves as an efficacious supplement for body composition purposes.
7-Keto-DHEA is a unique derivative of DHEA (dehydroepiandrosterone), a steroid produced abundantly in humans.
While DHEA is typically converted to either testosterone or estrogen, 7-keto-DHEA has a slightly different chemical structure; in turn, 7-keto-DHEA imparts different effects in the body.
Some supplement companies claim 7-keto-DHEA is useful for weight loss, muscle building, and delays in the aging process.
In short, raspberry ketone and 7-keto DHEA are neither ketone bodies nor are they related to ketogenic diets. They may have separate benefits, but research is still out on their efficacy as dietary supplements.
All in all, ketones are physiologically essential for our health and well-being. Better yet, they provide a superb fuel source when carbohydrates aren’t available and can help with the fat loss process.
Remember, when testing for ketone bodies, you are generally best going with blood sampling. Urinalysis through products like Ketostix can help in the short-term and for ketogenic diet newbies, but that isn’t a reliable test method in the long-term.
The good thing is that once you confirm you’re producing adequate amounts of ketones, you don’t need to recheck very frequently.