By Dr. Mercola
For many years, carb-loading has been the go-to solution for building energy storage capacity in athletes. This is built on the premise that since glucose is a quick-burning form of energy, bolstering your capacity to store glucose will help boost athletic performance.
However, nutritional science suggests this is far from an ideal strategy. Ketones are emerging as a far better fuel.
For optimal health, I recommend eating a diet high in healthy fats and low in net carbs (total carbohydrates minus fiber), and this type of diet may be particularly beneficial for endurance athletes.
Despite running counter to conventional sports nutrition advice, research has shown that high-fat, low-carb ketogenic diet may provide superior benefits.
We all have to eat; we need fuel and other nutrients to live. The question is how to get what we need without generating excessive reactive oxygen species (ROS), which can damage your health by attacking cell membranes, proteins, DNA and even your mitochondria — all of which can contribute to disease.
Optimal health is all about keeping your mitochondria healthy, and low-carb, high healthy-fat diets tend to do that far more effectively than high-carb, low-fat diets.
The sad fact is that most people eat foods that drive their metabolism in the wrong direction — away from health. The Westernized diet constantly biases you toward using high net carbs for fuel in the form of glucose.
But when you're burning glucose as your primary fuel, you actually inhibit your body's ability to access and burn body fat for energy. This, I believe, is a major contributor to obesity and diabetes, two of our most significant health problems.
Ketones — A Healthy Fuel
When you keep net carbs low, your body switches to burning fat for fuel and your liver begins to convert some of that fat into energy molecules called ketone bodies.
Ketones made by the body are called endogenous. But you can also supply your body with exogenous ketones from supplements, such as medium-chain triglyceride (MCT) oil, which is readily converted to ketones. Coconut oil contains some MCTs, but straight MCT oil is a more concentrated source.
Most commercial brands of MCT oil contain just two of the fatty acids found in coconut oil: 8-carbon (C8) and 10-carbon (C10) fats.
They usually contain close to a 50/50 combination of both chain lengths. I prefer taking straight C8 (also known as caprylic acid), as it converts to ketones far more rapidly than do C10 fats, and may be easier on your digestion.
Coconut oil provides a mixture of all the medium-chain fats, including C6, C8, C10 and C12 fats, the latter of which is also known as lauric acid, which makes up over half of the fat in coconut oil. There are benefits to all of these fatty acids. However, MCT oil is more efficient at increasing ketone levels.
MCTs are processed differently from the long-chain fats in your diet. Normally, a fat taken into your body must be mixed with bile released from your gallbladder and acted on by pancreatic enzymes to break it down in your digestive system.
MCTs don't need bile or pancreatic enzymes. Once they reach your intestine, they diffuse through your intestinal membrane into your bloodstream and are transported directly to your liver, which naturally converts the oil into ketones.
Your liver then releases the ketones back into your bloodstream, where they are transported throughout your body. They can even pass the blood-brain barrier to supply your brain with energy.
Exogenous Ketones Alter Your Metabolism
Scientists have also created synthetic ketones, which may or may not be beneficial depending on the kind you choose (more on this later). A recent study1 evaluating the effectiveness of ketones on sports performance used a ketone ester drink consisting of (R)-3-hydroxybutyrate and (R)-1,3-butanediol.
I know this may sound very unusual to you, given my stand on keeping to natural foods and products, but stay with me here and let me explain the potential benefits. As reported by Reuters:2
"Usually, energy for muscle cells comes from carbohydrates or fat, but when those fuels aren't available and the body is in 'starvation mode' the liver will break down fat stores into ketones to use as fuel …
In the new study, researchers found that when ketones are provided in a drink, the body will use them for muscle fuel. Ketone-powered workouts resulted in less lactate, a byproduct of breaking down sugar that causes muscle cramps and soreness.
The researchers studied 39 high-level athletes, including former Olympic cyclists, to see how their metabolism changed after consuming the ketone drink and exercising."
Ketone Drink Boosts Athletic Performance
When given the ketone ester drink, the competitive cyclists were able to cycle an average of 411 meters (m) further during the 30-minute workout trial, compared to when they were given a drink high in carbohydrates or fat.
This amounts to a 2 percent increase in speed, and while that may not sound like much, it can make a big difference in professional competitions where just fractions of a second often separate winners from the rest of the pack.
According to the authors, by supplying your body with ketones, you can give your metabolism a temporary — and totally legal — boost.
As reported in Science Daily,3 the ketone drink "works by temporarily switching the primary source of cellular energy from glucose or fat to ketones — molecules derived from fat that are known to be elevated in people consuming a low-carb … diet." Commenting on the findings, Timothy Noakes, Ph.D., a professor of exercise science and sports medicine at the University of Cape Town, South Africa, and a long-time low-carb advocate, told Reuters:
"Hopefully this finding will help many athletes realize that optimum fueling for sport is not simply to ingest as much carbohydrate as possible — before, during and after exercise. Most athletes will perform better by simply training more and eating fewer carbohydrates."
As the exercise became more intense, ketone uptake in the athletes' muscles increased, and during long-distance (endurance) workouts, their muscles relied heavily on ketones as the primary fuel. Only during high-intensity interval training, such as sprints, did their muscles prefer glucose. That's because during short, intense bursts of activity your muscles work anaerobically, meaning without oxygen, and since ketone cannot be broken down without oxygen, your muscles are prevented from using ketones for fuel.
The ketone drink used in this study — originally developed as an energy supplement for soldiers — is currently under commercial development and may become available later this year.
Ketone Esters — The Latest 'Biohack' Favorite
In a recent podcast, Ben Greenfield interviewed Dr. Richard Veech (above),4 a leading expert on ketosis and a senior researcher and laboratory chief at the National Institutes of Health (NIH). Veech is also the inventor of the ketone esters used in this study.
Veech, who comes on around the nine-minute mark in this interview, discusses the benefits of and uses for synthetic (exogenous5) ketones, which mimic or replicate your body's natural ketones (endogenous). Here are some key points made during this interview:
• Nutritional ketosis is a survival adaptation, as your brain has only two options for fuel: glucose and ketones. Ketones can also be used by most every organ and cell in your body with the exception of your liver, which lacks the enzyme needed to utilize them as fuel, and your red blood cells, which don't have mitochondria, which is where ketones are metabolized.
• An easier, although not necessarily better alternative to nutritional ketosis can be achieved by ingesting synthetic or exogenous ketones, such as MCT oil, coconut oil and other commercial ketone supplements. Ten percent of C8 or C10 MCT oil is converted into ketones. The remainder is beta-oxidized in your mitochondria along with other fatty acids. Since only 14 percent of most coconut oils are C8 or C10 MCTs, the conversion rate is even lower.
• There are two types of ketone bodies your body can use for energy: beta-hydroxybutyrate (BHB) and acetoacetate (AcAc). (A third ketone body, acetone, is excreted as waste, primarily through your breath). The ketone ester created by Veech is synthesized from an organic chemical called 1, 3-butanediol and a monoester, which your body then converts into BHB.
Exogenous ketone supplements are usually some combination of BHB salts, MCT powder and ketogenic amino acids, such as leucine or lysine. If you use these as ketone supplements, follow the package directions for dosage.
Also understand that more is not better — the salt load can add up quickly and you also want to be sure that you keep your ketone levels close to what your body would make on its own, so as not to exceed your ability to buffer the pH in your blood. (You can monitor this with a blood ketone meter and strips, such as Abbott's Precision Xtra.)
Could Ketones Be the Answer to Alzheimer's?
Veech also touches on the benefits of ketones for Alzheimer's patients. Six years ago, I wrote about Dr. Mary Newport's efforts to treat her husband's Alzheimer's using coconut oil. She was successful for several years but sadly it was not a cure. Veech believes his ketone formula would have a better success rate, and once commercially available might be a viable treatment alternative.
Personally, I feel it's best that you stick to MCT oil or coconut oil until the current crop of supplements have been researched more thoroughly.
Ketones actually appear to be the preferred source of energy for the brain in people affected by diabetes, Alzheimer's, Parkinson's and maybe even ALS, because in these diseases, certain neurons have become insulin resistant or have lost the ability to efficiently utilize glucose. As a result, neurons slowly die off. If ketones are present, these neurons may still be able to survive and thrive.
Unlike carbohydrates, ketones don't stimulate an insulin surge. Another benefit: they don't need insulin to help them cross cell membranes, including neuronal membranes. Instead, they use simple diffusion so they can even enter cells that have become insulin resistant.
How to Increase Ketones Naturally
Besides taking exogenous ketone supplements, in which case you must be very careful about your selections, you can increase your body's natural production of ketones by:
• Water-only fasting or other types of intermittent fasts, such as Peak Fasting.
• Exercise in a fasted state (for example, if you're Peak Fasting, you could exercise in the morning, while still in a fasted state, before eating your first meal).
• Adopting a ketogenic diet, which means eating foods high in healthy fats, with moderate protein and low net carbs (think non-fiber carbs). Sources of healthy fats include seeds, nuts, butter, olives, avocado, MCT oil and coconut oil. Another good food is raw cacao or cacao butter — it's a phenomenal source of healthy saturated fats and beneficial polyphenols.
Maintaining net carb intake at or below 50 grams allows you to enter into nutritional ketosis (the metabolic state associated with an increased production of ketones in your liver, which is the biological reflection of being able to burn fat). However, we are all different in how we respond to foods, so expect this amount to vary from person to person.
Some people can be in a full fat-burning state with full ketosis at a level of nonfiber carbs that's higher than 50 grams, sometimes even as high as 70 or 80 grams. However, if you're insulin resistant or have type 2 diabetes, you may need to limit your net carbs to 20 or 30 grams per day.
To find your personal carb target, it's important to measure not just your blood glucose but also your ketones, which can be done either through urine, breath or blood. This will give you an objective measure of whether or not you're truly in ketosis, rather than just relying on counting the grams of carbohydrates you consume.
Using a nutrient tracker will radically improve your ability to understand your ketogenic diet nutrient targets and assess the nutrient value of your food choices. There are a number of trackers available, but my first choice is Cronometer.com/Mercola. That's my revision of the basic Cronometer tracker, and it's already set to default to macronutrient levels that will support nutritional ketosis.
Ketogenic Diet Also Promotes Increased Muscle Mass and Longevity
Recent research has found about a dozen genes associated with longevity. One of these genes effectively interferes with the degradation of branched-chain amino acids, such as leucine, which is important in building muscle mass. Interestingly, ketones share a close structural similarity to these branched-chain amino acids, and seem to be preferentially metabolized.
In other words, ketones spare those branched-chain amino acids, leaving higher levels of them available, which may promote longevity and maintain muscle mass. So not only do the ketones produced help feed your brain and keep your mind sharp, ketosis also spares muscle protein, allowing your body to keep muscle mass intact rather than degrade it to meet energy needs. This is how ketosis allows humans to survive so long without food (approximately 70 days or so).
In multiple studies, including those of Veech, ketones have been shown to be both neurotherapeutic and neuroprotective. They also appear to lower markers of systemic inflammation, such as IL-6 and others.
In the final analysis, I believe there's a future for supplemental ketones. Just be careful with most of those currently available — use, but don't abuse! At present, it seems MCT oil is your best and perhaps safest bet as it is virtually impossible to overdose. (Your body will rid itself of the excess by causing diarrhea — don't test your limits!) I prefer C8 MCT oil over those containing both C8 and C10.
One final note: Veech and his team are working hard to make his ketone esters commercially available but it may be a while yet before you can easily purchase them.