"Supplements Target Ketogenesis and Metabolic Flexibility for Sports and Health."¹ (June 2016) Last month there was a review of the state of caloric restriction / fasting and ketogenic diets today. However, many readers have little interest in either caloric restriction or ketogenic diets as lifestyle choices. Both of these approaches are difficult to follow even if being utilized for specific health purposes. Nevertheless, their basic principles have application to general health and to athletics. The foremost impediment to taking advantage of these approaches was laid out in the 2016 article.

A major problem in achieving keto-adaptation by diet alone is that most individuals who have been raised on Western-style diets can take six months or more to make the shift and this shift becomes ever more difficult as we age. Studies examining the role of carbohydrates in the metabolism with roughly 30 year old males in good physical condition have revealed, for instance, that even transitioning from a high glycemic index diet to a low glycemic index diet while maintaining the same ratio of carbohydrate, fat and protein can take more than four weeks. Shifting to fatty acid metabolism for energy can be difficult.

For most of us, the issue is whether a moderate change in diet accompanied by a judicious utilization of special foods and dietary supplements can achieve the goals usually associated with caloric restriction, fasting and ketogenic diets. Fortunately, the answer for the preponderance of readers is "yes." Both for anti-aging purposes and for athletics, metabolic flexibility likely can be achieved through approaches within the reach of almost everyone. The goal is not to be ketogenic all the time, but to be able to metabolize ketones and free fatty acids routinely and easily. For a nice introduction to the distinction, readers might visit the blog entitled "Ketogenesis, Measuring Ketones, and Burning Fat vs Being in Ketosis."²

The Diet

Previously in these pages, it was noted that consuming too little protein presents issues, but, likewise, too much protein in the diet, meaning above roughly 30 percent of calories, defeats a major goal of caloric restriction, which is to not just reduce circulating insulin, but also to avoid elevating insulin-like growth factor-1 (IGF-1). Although those not trained in nutrition seldom realize this, protein sources can be used for gluconeogenesis, which is to say, to produce glucose from, non-carbohydrate sources. It is not just consuming too little fat and too much carbohydrate or too much of these two together with too little protein that defeat the aims of an anti-aging diet.

The recent Prospective Urban Rural Epidemiology (PURE) study followed 135,335 adults in eighteen countries for over seven years with respect to morbidity and mortality in terms of cardiovascular disease, strokes and non-cardiovascular disease mortality as correlated with the effects of nutrients.³ In an interview, Dr. Mashid Dehghan, the lead author, reported that Participants were categorized into quintiles of nutrient intake (carbohydrate, fats, and protein) based on percentage of energy provided by nutrients. We assessed the associations between consumption of carbohydrate, total fat, and each type of fat with cardiovascular disease and total mortality.

As noted by the researchers, their results flatly contradict decades of nutritional advice: High carbohydrate intake was associated with higher risk of total mortality, whereas total fat and individual types of fat were related to lower total mortality. Total fat and types of fat were not associated with cardiovascular disease, myocardial infarction, or cardiovascular disease mortality, whereas saturated fat had an inverse association with stroke. Global dietary guidelines should be reconsidered in light of these findings.

In the PURE study, those who consumed at least 35 percent of their calories from fat were 23 percent less likely to die than those who consumed only 10 percent or less as fat. According to PURE findings, the higher the fat intake, the less the chance of stroke. Those who consumed 77 percent of their calories as carbohydrates were 28 percent more likely to die than those who consumed less than 46 percent as carbohydrates. The conclusion of the study? "In a nutshell, a healthy diet based on the PURE results would be rich in fruits, beans, seeds, vegetables, and fats, include dollops of whole grains, and be low in refined carbohydrates and sugars."

The observant reader who takes the time to look at the PURE study's findings will quickly realize that the traditional reliance on "markers" such as blood LDL-cholesterol levels—markers long used to argue against the inclusion saturated fats any large amount of fats in general in the diet as well to promote carbohydrate consumption— does not correspond well with the actual endpoints of morbidity and mortality. This does not mean that the PURE diet needs to be ketogenic. To quote from the TotalHealth 2016 article, As admitted by Ben Greenfield, a serious triathlete who was tested with regard to the ergogenic benefits of a ketogenic diet, "after the study at University of Connecticut, I personally quit messing around with ketosis and returned to what I considered to be a more sane macronutrient intake of 50-60% fat, 20- 30% protein, 10-30% carbohydrate."⁴

As a practical matter, a more normal diet with supplements might look like this:
The diet should not be high in simple sugars, fructose or refined carbohydrates. For non-athletes and those looking primarily to increase metabolic flexibility, the diet should resemble a modified Sears Diet, meaning approximately 20 - 30 percent protein, 30 - 40 percent carbohydrate and 30 - 40 percent fat. For athletes and individuals who seriously want to initiate and maintain a fat-adapted diet, Ben Greenfield's suggestion is more in order: "50-60% fat, 20-30% protein, 10-30% carbohydrate."

Those who want to achieve most of the benefits of a ketogenic diet without undergoing the grueling restrictions normally involved (limitations not just on carbohydrate intake, which are extreme, but also on protein intake) should consider the fact that ketone bodies supply 2–6 percent of the body's energy requirements after an overnight fast (no eating at bedtime) with the higher figure reflecting a longer period without eating. After three days of fasting, 30–40 percent of energy needs are met by endogenously produced ketones. Such facts, again, lead to at least two possibilities aside from caloric restricted and ketogenic diets. First, will consuming exogenous ketones as esters or salts provide the same benefits as special diets? Second, is there a role for dietary supplements in delivering these benefits?

Ketones (Acetoacetate and β-hydroxybutyrate) Esters and Salts?

The new kid on the block in anti-aging and sports supplements is oral ketones, including a ketone ester (D-beta-hydroxybutyrate and D 1,3-butanediol) sports drink and ketone salts, typically beta-hydroxybutyrate bound to calcium, magnesium, potassium or sodium. A limited body of research indicates that such supplements may improve very long-duration endurance performance, but relatively little is known about their impact on short-duration and high-intensity workouts. Likewise, it is unclear that supplementation with ketones delivers the same benefits as adaptation to a ketogenic diet.

As one can learn from a variety of sources, "ketone bodies are three water-soluble molecules that are produced by the liver from fatty acids during periods of low food intake (fasting), carbohydrate restrictive diets, starvation and prolonged intense exercise… These ketone bodies are readily picked up by the extra-hepatic [outside the liver] tissues, and converted into acetyl-CoA which then enters the citric acid cycle and is oxidized in the mitochondria for energy. In the brain, ketone bodies are also used to make acetyl-CoA into long-chain fatty acids."⁵

In the liver, metabolism of fatty acids for energy, as opposed to ketone bodies, works in conjunction with a normal pattern of activity in the mitochondria, including the citric acid cycle. Ketone bodies are formed when there is not enough glucose from either carbohydrates, including glycogen, or the breakdown of protein to fuel the cycle. Technically, the supply of oxaloacetate is exhausted, at which point the liver produces and exports ketone bodies to tissues that can metabolize ketones fully. In starvation and under very low carbohydrate intake accompanied by restrained protein intake, ketone bodies supply up to 50 percent of the energy requirements for most body tissues and up to 70 percent of the energy required by the brain. The blog mentioned above provides a nice diagram of the cellular steps involved in ketone formation. The author also helpfully points out:

As I have written about eight hundred times in other posts, you do not need to be generating high levels of ketones to be metabolizing fat. The body does not operate in a binary system where the two choices are:

(1) Maintain deep ketosis …or…
(2) Become obese

Just because you're not in ketosis doesn't mean you're somehow not metabolizing fat so that the only other possible destination for it is to be stored.⁶

Ketone esters and salts can be ingested in an attempt to mimic a ketogenic state and work by elevating blood ketone levels to force the burning fat as fuel while interfering with certain other glycogen-related metabolic pathways. Whether supplements are the equivalent of a ketogenic diet in terms of benefits has been tested in humans only to a limited extent. In animal trials, they are not entirely equivalent and this appears also to be the case in humans. Let's start first with the animal experiments. The positive finding is that a 28-day administration of five ketone supplements on blood glucose, ketones, and lipids in male Sprague– Dawley rats caused a rapid and sustained elevation of beta-hydroxybutyrate and a reduction of blood glucose.⁷ No doubt, this represented a shift in the energy source to make use of the ingested ketones.

However, in a comparative trial of a ketogenic diet, ketone supplementation and control diet examining both control and chronic stress conditions, results differed with the intervention. Chronic experiments showed that under control conditions, only the ketogenic diet resulted in pronounced metabolic alterations and improved performance in the novel object recognition test and only the ketogenic diet prevented stress-induced deficits at the end of the trial and improved certain other aspects of performance. The advantage was to the ketogenic diet rather than supplementation in the areas of blood glucose, insulin and overall fat metabolism.⁸ Ketone supplements in animal models do indeed provide benefits, but not at the level of diet-induced endogenous production.

Thanks to recently published clinical trials, in the area of human athletic performance there now is evidence as to the limitations of ketone supplements. In one study, ten healthy adult males with similar athletic abilities and body mass indices fasted and then consumed either beta-hydroxybutyrate ketone salts or a matched placebo in a randomized order followed by a cycling time trial. Power output on the day participants consumed ketone salts was seven percent lower than on the day they consumed the placebo. As observed by study co-author Jonathan Little, assistant professor in University of British Columbia's (UBC) Okanagan's School of Health and Exercise Sciences, "Elevated blood ketones seem to inhibit the body's use of glycogen, the stored form of glucose, and favours burning fat instead."^9,10 A previous study utilizing ketone esters (573 mg/kg athlete body weight) in conjunction with carbohydrate consumption had positive findings of better performance in cycling to exhaustion trials.¹¹

The authors of both studies seem to agree that the ingestion of ketones leads to nutritional ketosis that alters the hierarchy of fuel substrate usage during exercise and it is clear that as the intensity of exercise increases, the demand for carbohydrate as an energy source increases. The ketone salt trial tested shorter and higher intensity training versus the longer period tested in the ketone ester trial, hence these were not entirely apple-to-apple trials. In addition, the ketone ester trial tested roughly 30 grams of ketone ester taken in conjunction with carbohydrate leading to significant benefit versus carbohydrate alone. However, bicycle ergometer time trial performance was only approximately two percent greater using the ketone ester plus carbohydrate versus carbohydrate alone "representing a modest increase in physical capacity in these highly trained athletes, despite significant changes in muscular metabolism." This finding, once again, indicates the difficulty of fully substituting ketones for glycogen-dependent aspects of muscle performance.

The latest studies continue the trend from above. Ingested ketones, for instance, as esters, impaired performance in elite cyclists in ˜31 kilometer laboratory-based time trials on a cycling ergometer programmed to simulate the 2017 World Road Cycling Championships course.¹² Achieving overall fat / keto adaptation via dietary means is more successful. Nevertheless, aside from the difficulty in following such diets, keto adaptation to a low carbohydrate, high fat diet requires time. Three weeks clearly is not sufficient even in highly trained athletes such as elite endurance walkers.¹³ Ten weeks in trained athletes appears to be on the margin, improving feelings of wellbeing, but not performance.¹⁴ At least insofar as attested in published trials, a full 12 weeks or more of adaptation is required even in the relatively young (20 subjects, 33 ± 11 years) and vigorous to achieve superior endurance results in comparison to a high carbohydrate diet.¹⁵

The above findings lead this author to the observation that although ketone ester-induced ketosis may increase metabolic flexibility during exercise by reducing glycolysis and increasing muscle fat oxidation, the benefits during shorter time periods and/or higher VO2/max demands are either not great or actually negative. Metabolic flexibility in the ester trial, such as it was, required the coingestion of carbohydrate. Without the co-ingestion of carbohydrate, as demonstrated in the other ketone trials (both salt and ester), there was a significant inhibition of the ability to access glycogen stores for energy upon demand.

Metabolic Fitness Supplements

to understand that nutrients that aid metabolic fitness generally fulfill a number of requirements, among them the following:

• It is helpful to support fat metabolism directly such as through improved transport of fatty acids into the mitochondria for oxidation.
• Insulin sensitivity must be improved and maintained and insulin levels kept low.
• The release of fatty acids from fat cells likely is less important than is dis-inhibiting fatty acid metabolism. The first is accomplished with caffeine, yet often with a downside such as increased cortisol levels, hence alternatives to caffeine and other similar stimulants are needed.
• Inclusion of substances that actively promote fatty acid oxidation is important to help kick-start the body's ability to metabolize fats.
• Excessive gluconeogenesis by the liver (creation of glucose from glycogen in response to the release of glucagon) should be inhibited to promote fatty acid oxidation as the alternative.
• With diets that are heavy in alcohol and fat, potential "reverse" effects must be prevented.

The sources of useful supplements are not generic and this should be kept in mind because different production methods lead to different products with different results. The following discussion reviews key nutrients that fulfill one or more of the above requirements.

Potassium-Magnesium Hydroxycitrate
Very few athletes are aware of the benefits of (–)-hydroxycitric acid (HCA) for sports despite some impressive findings in terms of greater endurance and faster recovery plus reduced inflammation. This is because early trials—there were several large ones—failed to produce benefits for reasons that, in retrospect, are obvious. First, calcium HCA and calcium-containing HCA salts exhibit very poor uptake and poor results in comparative trials.^16,17,18 To this should be added the "food effect," meaning the finding that consuming food within 30 minutes of ingesting HCA typically reduces uptake by approximately 60 percent. HCA salts under normal delivery never exhibit more than lackluster bioavailability, hence any reduction of that already modest uptake into the system leads to extremely poor results. A third factor is that even seemingly nearly identical HCA salts (as tested by standard high performance liquid chromatography / HPLC) produced by slightly differing production techniques can exhibit up to 10-fold differences in bioavailability.¹⁹ Notably lacking in the research literature is any attempt to determine cellular uptake, an issue separate from bioavailability. Published research simply assumes that all uptake issues can be reduced to bioavailability, meaning blood levels, an assumption proven to be invalid with a number of nutritional substances, such as coenzyme Q10.

One way around these uptake problems with HCA is by means of a special liquid delivery. HCA salts normally are not stable in ready-to-drink formats and break apart to yield what is known as a lactone. The HCA lactone leads to good uptake—bioavailability—but little or no benefits because the molecule exhibits the wrong shape.²⁰ A recently issued US patent describes a method that not only stabilizes HCA salts in liquid, but also dramatically improves their bioavailability and physiologic efficacy.²¹

Properly produced and delivered HCA can lead to striking improvements in early fat utilization for energy, glycogen sparing and increases in endurance. This is in part because HCA helps to control the muscle's selection of fuels, an experimental finding from twenty years ago.²² More recently, using mice as the model, HCA ingestion for 13 days was found to increase fat oxidation and improve endurance exercise time to fatigue by 43 percent compared to a placebo.²³ Chronic HCA ingestion alters fuel selection rather than the simple release of fat from stores as is true of lipolysis per se, i.e., the mechanism for HCA is not the same as with caffeine, capsaicin, etc. Second, the combination of HCA plus L-carnitine improves glycogen status in liver and various muscle tissues versus placebo in exercised-trained rodents. Readers will recall that glycogen-related issues bulk large in the performance failings of ketogenic diets and ketone supplements.

What about HCA ingestion in humans? Similar positive endurance results were found by the same laboratory both with untrained men and women and with trained athletes as found in the animal tests. The following trial was conducted in trained athletes leading to significant improvements in endurance:

Subjects [n = 6] were administered … HCA or placebo as a control (CON) for 5 d, after each time performing cycle ergometer exercise at 60% VO2max for 60min followed by 80% VO2max until exhaustion.²⁴

Under the conditions of the trial, time to exhaustion at 80 percent VO2max went from approximately six minutes to approximately 8.5 minutes, which is a remarkable level of improvement. Lactate levels were lower. In evaluating the results, it must be observed that the earlier animal trials indicated that there is a greater shift in metabolism if the ingestion period lasts longer. But note clearly: the HCA salt used in these trials was a pure synthesized trisodium hydroxycitrate, not the usual HCA available as a dietary supplement.²⁵

Another benefit from HCA is as much as a 100 percent improvement in glycogen repletion in muscle after exercise when a post-workout snack is consumed.²⁶

Mango Leaf Extract and Caffeic Acid Enhance HCA's Ability to Improve Fat Metabolism

An issue that almost always is ignored with HCA is that under conditions of accelerated use of fat for energy, such as during fasting or ketogenic diets, there is a cycle that can undermine the compoundfs effects on fat metabolism by activating inside cells the substance acetyl-CoA carboxylase.²⁷ Two compounds that help to prevent this and actually improve fatty acid oxidation are caffeic acid and mangiferin (a constituent of mango leaf).

Caffeic acid is interesting for a number of reasons. For current purposes, it has been shown to improve the ability to metabolize fats for energy and also to promote the ability of glucose to enter cells, i.e., it is insulin sensitizing. In terms of HCA, caffeic acid helps block the actions of acetyl-CoA carboxylase.²⁸ This means that it helps to block the impact of high alcohol intake and high fat intake or fasting on HCA, thus allowing HCA to perform the function of disinhibiting fatty acid metabolism via β-oxidation as mentioned above.

Mangiferin, the primary active component in mango leaf extract, is even more significant than is caffeic acid. With regard to HCA, mangiferin, like caffeic acid, inhibits acetyl- CoA carboxylase. However, matters do not stop there. In various in vitro and animal trials, mangiferin increased fatty acid oxidation. A major finding is that the compound does the same, and safely, in human beings. Overweight patients with hyperlipidemia (serum triglyceride ≥ 1.70 mmol/L, and total cholesterol ≥ 5.2 mmol/L) were included in a double-blind randomized controlled trial. Participants were randomly allocated to groups, either receiving mangiferin (150 mg/day) or an identical placebo for 12 weeks. As reported in the published study,²⁹

A total of 97 participants completed the trial. Compared with the placebo control, mangiferin supplementation significantly decreased the serum levels of triglycerides and FFAs, and insulin resistance index. Mangiferin supplementation also significantly increased the serum levels of mangiferin, high-density lipoprotein cholesterol, L-carnitine, β-hydroxybutyrate, and acetoacetate, and increased lipoprotein lipase activity.

The increase in β-hydroxybutyrate and acetoacetate as well as lipoprotein lipase activity is a clear indication that mangiferin improves the availability of stored fats and promotes the oxidation of these fats for the production of energy as they became available.

Asparagine, Malate and Aspartates for Energy and Endurance

Some of the best supplements for health and sports have, as it were, slipped under the radar over the years. We tend to be attracted to whatever is "new" to the point of overlooking that these new items often are not actually novel, just older concepts dressed up in new terminology. A good example of this is the great fanfare given to the recent "discoveries" involving nicotinamide riboside. (Caloric Restriction, Fasting and Nicotinamide Riboside TotalHealth Feb 2015)³⁰ Proffered benefits include anti-aging effects, better energy metabolism and endurance.³¹ Strikingly, both the mechanisms involved and the benefits, upon closer examination, look remarkably similar to the benefits associated with what is known as the malate-aspartate shuttle. The anti-aging benefits, for instance, are similar to those associated with the Chinese herb rock lotus, which activates the enzyme (malate dehydrogenase) linked with this shuttle. (Uncovering the Longevity Secrets of the ROCK LOTUS TotalHealth April 2010)³²

For the hard science minded, the malate/aspartate shuttle is a principal mechanism for the movement of reducing equivalents from the cytoplasm to the mitochondria. In other words, this mechanism keeps energy as electrons flowing from the cytoplasm of the cell into the mitochondria and supports the production of adenosine triphosphate (ATP), the basic energy unit of the body. Ketones can play a similar role. As expressed in a recent paper, "cellular energy production depends on the metabolic coenzyme nicotinamide adenine dinucleotide (NAD), a marker for mitochondrial and cellular health. Furthermore, NAD activates downstream signaling pathways (such as the sirtuin enzymes) associated with major benefits such as longevity and reduced inflammation... [a ketogenic diet] will increase the NAD+/NADH ratio."³³ (NAD exists in oxidized and reduced forms, NAD+ and NADH.) This process is exactly what the recent discoveries regarding nicotinamide riboside are about. The shuttle also is involved in replenishing oxaloacetate, which was mentioned above with regard to ketogenesis and the Krebs/Citric Acid Cycle. Part of the role of oxaloacetate is shown in the diagram.

Now it just so happens that malic and aspartic acid (the "salts" are termed malate and aspartate) are components of this movement of energy. Malate, aspartate and the compound asparagine are known as oxaloacetate precursors. Many athletes use citrulline malate to help promote performance and reduce fatigue thinking that it is the citrulline that is active although, in fact, it is the malate. For instance, in an animal trial a month of supplementation with L-malate increased swimming time endurance by between 26.1 and 28.5 percent.³⁴ The researchers observed the activities of cytosolic and mitochondrial malate dehydrogenase were significantly elevated in the L-malate-treated group compared with the control group.

As pointed out in the TotalHealth article on the rock lotus, the malate dehydrogenase enzyme takes a period of time to be increased in the cell. A number of acute trials of, for instance, aspartates in athletes, compounds that affect the same shuttle mechanism, failed, but this should have been expected due to basic physiology and one wonders why those researchers even bothered. Under conditions of moderate exertion, supplementation with asparagine and aspartate plus L-carnitine increased time to exhaustion by approximately 40 percent.³⁵ In another animal trial, this time with intense exercise and only the two amino acids, the supplemented group showed higher exercise time, lower blood lactate concentration and a decreased the rate of glycogen degradation compared to control leading to the conclusion that "supplementation may increase the contribution of oxidative metabolism in energy production and delay fatigue during exercise performed above the AT [anaerobic threshold]."³⁶

To be sure, there are skeptics regarding magnesium—potassium aspartates for use as ergogenic aids.³⁷ However, the proposed mechanisms of action until recently have been wrong, the time frame for supplementation (acute rather than chronic), the amounts supplemented, etc., typically have been quite wide of the mark. The key mechanism of action involves the shuttle and oxaloacetate. Interestingly, this mechanism also promotes the proper metabolism of that great enemy of athletes, lactic acid. Lactic acid actually can be converted back into an energy source during exercise. As Ben Greenfield explains things in a wonderful post,³⁸ A significant rate limiting step of converting lactic acid into glucose is the conversion of the molecule Nicotinamide Adenine Dinucleotide (NAD) into Nicotinamide Adenine Dinucleotide Hydrogenase (NADH). So what does this have to do with oxaloacetate? In studies, acute oxaloacetate exposure enhances resistance to fatigue by increasing NAD to NADH conversion and allowing lactic acid to get recycled and converted to glucose at a much higher rate.³⁹

Oxaloacetate is notoriously unstable and difficult to supplement orally. A mixture of its precursors (aspartate salts, asparagine and a malate source) plus an activator of the malate dehydrogenase enzyme (rock lotus) supplemented over a period of time (three to four weeks) is a better way to achieve desired benefits. Finally, another benefit of a mixture of malate and aspartate is that the malate-aspartate shuttle plays a role in the regeneration of L-arginine and the production of nitric oxide.⁴⁰

Conclusions
Move over, NO (nitric oxide) supplements! Altering muscle fuel selection and increasing the anaerobic threshold are the hallmarks of metabolic flexibility in sports. Greater utilization of stored fatty acids for fuel, reduced lactate accumulation and better recycling, enhanced glycogen stores and an elevation of VO2max before the body's limited stores are called upon without an impairment of carbohydrate utilization is an ideal situation. It is not clear that fulfilling this goal demands artificially elevating blood ketone bodies, either through diet or supplements. Instead, maximizing the efficiency of energy pathways that make use of stored fatty acids and the malate-aspartate shuttle would seem to be not just sufficient, but preferred. Chronic HCA ingestion alters muscle fuel selection and improves glycogen stores, especially in conjunction with L-carnitine. Caffeic acid enhances these actions, as does mangiferin from mango leaf in ways that have been demonstrated in humans to augment the metabolism of both fatty acids and carbohydrates leading to elevated energy production. The malate-aspartate shuttle and the enzyme malate dehydrogenase support oxaloacetate recycling and the efficient operation of the citric acid cycle to sustain fatty acid oxidation and the reconversion of lactic acid to glucose for use as fuel by the muscles. Surely a clincher for this approach is that it promises health and anti-aging benefits, not just improvements in athletic performance.

Endnotes

1. Supplements Target Ketogenisis and Metabolic Flexibility TotalHealth Magazine
2. Measuring Ketones
3. Dehghan M, Mente A, Zhang X, Swaminathan S, Li W, Mohan V, Iqbal R, Kumar R, Wentzel-Viljoen E, Rosengren A, Amma LI, Avezum A, Chifamba J, Diaz R, Khatib R, Lear S, Lopez-Jaramillo P, Liu X, Gupta R, Mohammadifard N, Gao N, Oguz A, Ramli AS, Seron P, Sun Y, Szuba A, Tsolekile L, Wielgosz A, Yusuf R, Hussein Yusufali A, Teo KK, Rangarajan S, Dagenais G, Bangdiwala SI, Islam S, Anand SS, Yusuf S; Prospective Urban Rural Epidemiology (PURE) study investigators. Associations of fats and carbohydrate intake with cardiovascular disease and mortality in 18 countries from five continents (PURE): a prospective cohort study. Lancet. 2017 Nov 4;390(10107):2050–62.
4. How To Get Into Ketosis
5. Ketone_Bodies
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8. Brownlow ML, Jung SH, Moore RJ, Bechmann N, Jankord R. Nutritional Ketosis Affects Metabolism and Behavior in Sprague-Dawley Rats in Both Control and Chronic Stress Environments. Front Mol Neurosci. 2017 May 15;10:129.
9. Ketone sports supplements: Good for athletic performance or not?
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38. Underground Training Tactics For Enhancing Endurance – Part 2
39. Nogueira, L., Hogan, D., & Hogan, M. (n.d.). Acute oxaloacetate exposure enhances resistance to fatigue iin vitro mouse soleus muscle. (2011). The FASEB Journal, (25), 1104.5.
40. Hou E, Sun N, Zhang F, Zhao C, Usa K, Liang M, Tian Z. Malate and Aspartate Increase L-Arginine and Nitric Oxide and Attenuate Hypertension. Cell Rep. 2017 May 23;19(8):1631–39.

For Sports and Health

Most readers who have heard of ketosis and ketogenesis likely associate the concepts with dieting and the works of Dr. Robert C. Atkins (Dr. Atkins’ Health Revolution, 1989; Dr. Atkins’ New Diet Revolution, 1992) that launched a bit of a movement in the 1990s. Much less well known is the role of ketosis in sports and the importance of being able to enter ketosis as an aspect of metabolic flexibility, meaning the ability to rapidly and easily shift between carbohydrates and fats as fuel substrates to match, on the one hand, dietary sources of calories and, on the other hand, particular physical demands for energy. In fact, the health implications of metabolic flexibility are significant and are related to the body’s degree of insulin sensitivity and thereby to the components of the metabolic syndrome. The latter condition often is defined as being based on insulin resistance and associated with abdominal (central) obesity, elevated blood pressure, elevated fasting plasma glucose, high serum triglycerides and low high-density lipoprotein (HDL) levels. This way of looking at matters makes ketogenesis and metabolic flexibility major determinants of health. One does not need to be diabetic or even pre-diabetic for these issues to be important, a point that Harry Preuss, MD and various coauthors, including myself, make in a recent article intended for practicing physicians, “Importance of Fasting Blood Glucose in Screening/Tracking Overall Health.”^1,2

Not only athletes for reasons having to do with competition, but also non-athletes for reasons of health likely would benefit from some form of supplement protocol or other approach that can achieve ketogenesis and maintain metabolic flexibility without depending entirely on the diet. Indeed, achieving ketosis via diet alone is hard to maintain over the long haul for a variety of reasons. Eating mostly protein and fat may sound like a treat at the beginning, but highly restricting all sources of carbohydrates quickly leads to a boring diet and even limited social interaction because few social events are built around ketogenic snacks! It also means avoiding many or most sources of phytonutrients, not eating adequate fiber for gut health and bowel regularity, probably inadequately eliminating toxins via the bile route in the stool, and even ramping up production of the hormone cortisol.³ Extreme ketosis leads to unpleasant breath (acetone breath) although this is not an issue with moderate and healthy ketogenesis.

Background on Ketosis and Ketogenic Diets
There are only two primary sources of energy, carbohydrates and fats. If needed for energy, protein can be broken down to yield a carbohydrate component, not a fatty acid component. Ketosis refers to the state in which the body meets its energy requirements largely through the oxidation of ketone bodies. These build up in the blood when glucose is not being used for energy and even the brain can run on ketone bodies. Glycolysis is the opposite number to ketosis in that it refers to the oxidation of glucose, for which all carbohydrates ultimately are a source, for energy. People sometimes associate ketosis with diabetes, but ketosis is a nutritional process whereas in diabetes the body either lacks sufficient insulin or cannot respond properly to insulin and therefore builds up ketone bodies due to a failure of metabolism while at the same time not properly harnessing fats for fuel. There is plenty of evidence to the effect that ketogenic diets can be healthful. Traditional Eskimo diets consisted almost entirely of raw meat and blubber (fat) and yet the Eskimos did not exhibit diabetes. Similarly, for certain neurologic conditions children are raised from early life into their thirties or later with completely normal physiologic and mental development without eating any carbohydrates at all.

Athletes and some "paleodieters" speak of keto-adaptation, which means simply moving the metabolism to preferentially accessing stored fats as fuel sources rather than depending on glucose. The body has quite limited stores of glycogen or "animal starch" stored primarily in the liver in contrast to virtually unlimited calories stored as fats. A quite standard assessment is that there may be 400 grams of glycogen in the liver and another 100 grams in the muscles. Glycogen is associated with water on a 1:3 to 1:4 ratio. A major problem in achieving keto-adaptation by diet alone is that most individuals who have been raised on Western-style diets can take six months or more to make the shift and this shift becomes ever more difficult as we age. Studies examining the role of carbohydrates in the metabolism with roughly 30 year old males in good physical condition have revealed, for instance, that even transitioning from a high glycemic index diet to a low glycemic index diet while maintaining the same ratio of carbohydrate, fat and protein can take more than four weeks. Shifting to fatty acid metabolism for energy can be difficult.

High fat diets were employed at the turn of the century to treat Type I diabetes, the form that begins in childhood with the destruction of the insulin-producing cells of the pancreas. Since the body can and will produce its own blood sugar from protein in order to feed the brain, there is always some role for insulin in the body regardless of the diet followed. Needless to say, those with juvenile diabetes almost invariably died young until the discovery of insulin.

In adult-onset or Type II diabetes, which typically begins fairly late in life and with those already overweight, diet and exercise often can completely control the problem. This and other clues have led a number of researchers to suspect that excess weight gain is related to insulin production either directly or indirectly, as discussed briefly above. Dr. Robert C. Atkins was one of the first to popularize the notion of dieting by bypassing the insulin mechanism through eliminating most carbohydrates from the diet while continuing to consume both proteins and fats. Atkins' Diet is both high in protein and high in fat.

High protein, low fat/very low carbohydrate diets have been common for some time, but not with the particular justification that they bypass the insulin mechanism. Generally the justifications have had to do with energy production, or rather the lack of it on these diets. In the Stillman Diet, for instance, it was argued that protein molecules are so large that they use up extra energy as a food for the body. This diet calls for the drinking of at least eight glasses of water a day, which truly is necessary to remove the waste products of excess protein consumption and from the oxidation of the body's own fats.

Very similar is the famous Scarsdale Diet, designed for use for only two weeks at a time. Both strictly limit carbohydrates and, somewhat less strictly, fats. Both do reduce weight in the short term, but such large amounts of protein are hard on the body. In contrast to these, the Dr. Atkins' Diet allows for unlimited amounts of both proteins and fats, but for restricted amounts of carbohydrates according to the theory that a faulty insulin mechanism is the cause of excess weight. A more limited form of this ketone-based diet popularized at about the same time as the Atkins Diet is presented by Dr. Calvin Ezrin in The Endocrine Control Diet (1990).

Athletes long have experimented with ketogenic diets. For instance, during the 1990s a number of top bodybuilders in the World Bodybuilding Federation adopted a diet similar to the one Atkins uses (roughly 40 percent of calories from protein and 60 percent from fat) in order to cut body fat and build muscle. These individuals were all undertaking extremely hard physical labor, so the diet itself cannot be a source of fatigue, but must in fact supply considerable energy.⁴ Nevertheless, even major competition class athletes ultimately generally give up on strict ketogenic diets. As admitted by Ben Greenfield, a serious triathlete who was tested with regard to the ergogenic benefits of a ketogenic diet, "after the study at University of Connecticut, I personally quit messing around with ketosis and returned to what I considered to be a more sane macronutrient intake of 50-60% fat, 20-30% protein, 10-30% carbohydrate."⁵

Ketogenesis with Supplements
Can ketogenesis be achieved using a more normal diet with the help of supplements? The answer appears to be "yes." Nevertheless, there are important considerations, among which are the following:

• The diet should not be high in simple sugars, fructose or refined carbohydrates. For non-athletes and those looking primarily to increase metabolic flexibility, the diet should resemble a modified Sears Diet, meaning approximately 20¨C 30 percent protein, 30¨C40 percent carbohydrate and 30¨C40 percent fat. For athletes and individuals who seriously want to initiate and maintain a fat-adapted diet, Ben Greenfield's suggestion is more in order: "50-60% fat, 20-30% protein, 10- 30% carbohydrate."
• It is helpful to support fat metabolism directly such as through improved transport of fatty acids into the mitochondria for oxidation.
• Insulin sensitivity must be improved and maintained and insulin levels kept low.
• The release of fatty acids from fat cells likely is less important than is disinhibiting fatty acid metabolism. The first is accomplished with caffeine, yet often with a downside such as increased cortisol levels, hence alternatives to caffeine and other similar stimulants are needed.
• Inclusion of substances that actively promote fatty acid oxidation is important to help kick-start the body's ability to metabolize fats.
• Excessive gluconeogenesis by the liver (creation of glucose from glycogen in response to the release of glucagon) should be inhibited to promote fatty acid oxidation as the alternative.
• With diets that are heavy in alcohol and fat, potential "reverse" effects must be prevented.

A small number of supplements, especially if taken together, may fulfill the above requirements and actually have been tested successfully in a pilot case. The subject in question was able to consume a normal diet, indeed one that included quite a bit of alcohol, by relying on only four supplements to remain in moderate ketosis during much of the day: hydroxycitric acid, wild bitter melon extract, sesame lignan extract and green coffee bean extract. The sources of these supplements were not generic and this should be kept in mind because different production methods lead to different products with different results. Published comparative trials, for example, with hydroxycitric acid have shown this definitively.

Potassium-Magnesium Hydroxycitrate
The key component in supplement-support ketogenesis is (-)¨Chydroxycitric acid (HCA). That some forms of properly manufactured HCA can be used to encourage ketogenesis has been known at least since 2000. In that year, Ishihara published that HCA ingestion for 13 days increased fat oxidation and improved endurance exercise time to fatigue by 43 percent compared to a placebo in mice.⁶ Over the following few years, three studies by Lim and others in trained athletes demonstrated that ingestion of HCA enhances endurance performance via increasing fat oxidation and sparing glycogen utilization during moderate intensity exercise. In fact, in trained athletes HCA ingestion for five days shifted fuel selection to fat oxidation at both 60 percent and 80 percent VO2max during exercise.⁷ Lim further demonstrated a number of significant findings. First, using mice as his model, he showed that chronic HCA ingestion alters fuel selection rather than the simple release of fat from stores as is true of lipolysis, i.e., mechanism for HCA is not the same as with caffeine, capsaicin, etc. Second, Lim's review data that showed that the combination of HCA plus L-carnitine improves glycogen status in liver and various muscle tissues versus placebo in exercised-trained rodents. Since the publication of Lim's papers, this finding has been repeated more than once with human athletes. Although L-carnitine improves the effect, it is not necessary.⁸ Third, Lim in his studies employed a pure synthesized trisodium hydroxycitrate salt rather than commercial calcium or calcium-potassium HCA salts, which did not yield his results. As is true of many herbal products, the benefits of HCA are highly dependent upon how the item is prepared. The acid must be stabilized by the addition of high pH ions (basic or alkali), such as those of potassium, magnesium or calcium. Using the wrong stabilizing counter-ions results in little or no activity. In the case of the acid derived from Garcinia cambogia and related sources, adding any calcium at all reduces some desired benefits and blocks other benefits entirely.⁹ This fact has been verified by more than one comparative trial.

Another benefit of HCA that supports ketogenesis is its impact on insulin sensitivity. At the 2005 Annual Meeting of the American College of Nutrition for the first time it was reported that the potassium-magnesium HCA salt in an animal model gave the same blood glucose regulation as found in the control arm of the test while almost literally cutting insulin levels in half.¹⁰ The same study demonstrated that this salt dramatically improved glucose clearance from the blood, lowered systolic blood pressure and also lowered several key indicators of inflammation, including C-reactive protein and tumor necrosis factor-alpha (TNF-alpha). In contrast, the potassium-calcium salt exerted no effect upon insulin and blood sugar regulation and only very poorly influenced blood pressure.¹¹ In the areas of insulin metabolism, glucose regulation and blood pressure, the proprietary potassium-magnesium salt was between five and seven times as active as the potassium-calcium salt of the fruit acid. A paper just published this year also indicates that HCA may help to regulate thyroid hormones and promote muscle protein synthesis.¹²

Wild Bitter Melon Extract and Sesame Lignan Extract
As indicated above, HCA appears to be extremely useful in freeing the body's metabolism regulators to allow a shift towards preferentially oxidizing fatty acids for energy. Increasing insulin sensitivity and reducing insulin levels removes one of the primary brakes on fatty acid metabolism. A complement to these actions is direct activation of fatty acid oxidation. Both wild bitter melon and sesame seed lignans help to do just this. Bitter melon previously has been discussed in these pages under the title, "Going WILD with Bitter Melon for Blood Sugar Support."¹³ As noted in that article, it has been found that extracts of bitter gourd activate cellular machinery to regulate energy production (technically, AMP-activated protein kinase or AMPK) and the way that fats are handled by the liver. These components can account for as much as 7.1 g/ kg of the dried wild material.

The sesamolin lignan found in sesame seeds (but not in most extracts) likewise increases fat metabolism. As pointed out in an important study, the "[e]ffects of sesamin and sesamolin (sesame lignans) on hepatic fatty acid metabolism were compared in rats. Sesamolin rather than sesamin can account for the potent physiological effect of sesame seeds in increasing hepatic fatty acid oxidation observed previously. Differences in bioavailability may contribute to the divergent effects of sesamin and sesamolin on hepatic fatty acid oxidation. Sesamin compared to sesamolin was more effective in reducing serum and liver lipid levels [with]sesamolin more strongly increasing hepatic fatty acid oxidation." "Sesamolin rather than sesamin can account for the potent physiological effect of sesame seeds in increasing hepatic fatty acid oxidation observed previously."¹⁴ "...gene expression of hepatic enzymes involved in fatty acid oxidation [was] much stronger with episesamin and sesamolin than with sesamin¡­[serum] half lives of 4.7±0.2, 6.1±0.3 and 7.1±0.4 h for sesamin, espisesamin and sesamolin, respectively...¹⁵

Green Coffee Bean Extract
After meals, up to 70 percent of the glucose from food is stored in muscle and other lean tissues. However, moment-to-moment regulation of blood glucose typically is handled by the liver. It does this via two processes, both of which are highly regulated. Gluconeogenesis generates glucose from certain noncarbohydrate carbon substrates, including certain amino acids and lipid components, such as triglycerides. Glycogenolysis is the freeing of glucose from glycogen stores. In the liver, but not the muscles, the hormone glucagon is involved. The liver also uses the enzyme glucose-6-phosphatase. With aging and as the metabolic syndrome develops, regulation of these two processes becomes impaired. Dysregulation is a particularly significant issue in diabetes.

Coffee, especially green coffee extracts, supply chlorogenic acid, which inhibits the glucose-6-phosphatase enzyme.^16,17 Chlorogenic acid also inhibits glucose absorption from the intestinal tract and thus reduces after meal blood glucose spikes.

Ketogenesis requires that the body preferentially use fatty acids for fuel. This cannot happen if either gluconeogenesis or glycogenolysis is not under proper control.

L-Carnitine and Astaxanthin
L-carnitine is a nutrient that, among other things, helps to shuttle fatty acids into the mitochondria for oxidation. In the discussion of HCA above it was noted that the combination of HCA and L-carnitine greatly improves the replenishment of glycogen stores after exercise. Unfortunately, tissue levels of L-carnitine are highly regulated and difficult to elevate to the extent necessary for ergogenic benefits in athletes. HCA improves L-carnitine metabolism by increasing uptake.HCA is an insulin memetic as well as an insulin sensitizer. HCA also shifts the body towards metabolizing fats, which makes L-carnitine's job easier. Another approach is to supplement with astaxanthin. Astaxanthin (≥4 mg/d) has been shown to reduce lactic acid accumulation during exercise, improve fatty acid oxidation and maintain better blood glucose levels while improving endurance. The mechanism may involve carnitine palmitoyltransferase I.^18,19

Conclusion
Studies have demonstrated the importance of metabolic flexibility for maintaining cardiovascular health and reducing the risk of developing metabolic syndrome components. Likewise, studies have shown that the related ability to enter ketosis as needed for athletic purposes can render rich ergogenic rewards. Nevertheless, enabling ketogenesis or keto-adaptation, however desirable this might be, through dietary measures alone under modern circumstances in Western countries is not only inconvenient, but downright difficult. Fortunately, it is possible to enable keto-adaptation through the use of appropriate supplements. These include properly manufacture HCA salts, wild bitter melon extract, sesame lignans and green coffee bean extracts. L-carnitine and astaxanthin are two more supplements that fit into this schema.

1. Preuss HG, Mrvichin N, Clouatre D, et al. Importance of Fasting Blood Glucose in Screening/Tracking Overall Health. The Original Internist. 2016, March:13-15,17.18.
2. Bjornholt JV, Erikssen G, Aaser E, et al. Fasting blood glucose: an underestimated risk factor for cardiovascular death. Results from a 22-year follow-up of healthy nondiabetic men. Diabetes Care. 1999 Jan;22(1):45.9.
3. Sears B. Anti-inflammatory Diets. J Am Coll Nutr. 2015;34 Suppl 1:14.21.
4. Mauro DiPasquale, M.D., "Let the Fat be with You: The Ultimate High-Fat Diet," Muscle Magazine International (July and September 1992); "High Fat, High Protein, Low Carbohydrate Diet: Part I," Drugs in Sports 1, 4 (December 1992) 8.9.
5. https://bengreenfieldfitness.com/2015/12/how-to-get-into-ketosis/
6. Ishihara K, Oyaizu S, Onuki K, Lim K, Fushiki T. Chronic (-)-hydroxycitrate administration spares carbohydrate utilization and promotes lipid oxidation during exercise in mice. J Nutr. 2000 Dec;130(12):2990.5.
7. Lim K, Ryu S, Suh H, Ishihara K, Fushiki T. (-)-Hydroxycitrate ingestion and endurance exercise performance. J Nutr Sci Vitaminol (Tokyo). 2005 Feb;51(1):1.7.
8. Cheng IS, Huang SW, Lu HC, Wu CL, Chu YC, Lee SD, Huang CY, Kuo CH. Oral hydroxycitrate supplementation enhances glycogen synthesis in exercised human skeletal muscle. Br J Nutr. 2012 Apr;107(7):1048.55.
9. Louter-van de Haar J, Wielinga PY, Scheurink AJ, Nieuwenhuizen AG. Comparison of the effects of three different (.)-hydroxycitric acid preparations on food intake in rats. Nutr Metab (Lond). 2005 Sep 13;2(1):23. See also notes 18 and 19.
10. Clouatre, D., Talpur, N., Talpur, F., Echard, B., Preuss, H. Comparing metabolic and inflammatory parameters among rats consuming different forms of hydroxycitrate. Journal of the American College of Nutrition 2005;24:429 Abstract.
11. Clouatre D, Preuss HG. Potassium Magnesium Hydroxycitrate at Physiologic Levels Influences Various Metabolic Parameters and Inflammation in Rats. Current Topics in Nutraceutical Research 2008;6(4): 201.10.
12. Han N, Li L, Peng M, Ma H. (-)-Hydroxycitric Acid Nourishes Protein Synthesis via Altering Metabolic Directions of Amino Acids in Male Rats. Phytother Res.2016 May 4. doi: 10.1002/ptr.5630.
13. http://www.totalhealthmagazine.com/Vitamins-and-Supplements/Going-WILD-with-Bitter-Melon-for-Blood-Sugar-Support.html
14. Lim JS, Adachi Y, Takahashi Y, Ide T. Comparative analysis of sesame lignans (sesamin and sesamolin) in affecting hepatic fatty acid metabolism in rats. Br J Nutr. 2007 Jan;97(1):85.95.
15. Ide T, Lim JS, Odbayar TO, Nakashima Y. Comparative study of sesame lignans (sesamin, episesamin and sesamolin) affecting gene expression profile and fatty acid oxidation in rat liver. J Nutr Sci Vitaminol (Tokyo). 2009 Feb;55(1):31.43.
16. Henry-Vitrac C, Ibarra A, Roller M, Merillon JM, Vitrac X. Contribution of chlorogenic acids to the inhibition of human hepatic glucose-6-phosphatase activity in vitro by Svetol, a standardized decaffeinated green coffee extract. J Agric Food Chem. 2010 Apr 14;58(7):4141.4.
17. Bassoli BK, Cassolla P, Borba-Murad GR, et al. Chlorogenic acid reduces the plasma glucose peak in the oral glucose tolerance test: effects on hepatic glucose release and glycaemia. Cell Biochem Funct. 2008 Apr;26(3):320.8.
18. Malmsten C, Lignell A. Dietary Supplementation with Astaxanthin-Rich Algal Meal Improves Strength Endurance; A Double Blind Placebo Controlled Study on Male Students. Carotenoid Science. 2008;13:20.22.
19. Aoi W, Naito Y, Takanami Y, Ishii T, Kawai Y, Akagiri S, Kato Y, Osawa T, Yoshikawa T. Astaxanthin improves muscle lipid metabolism in exercise via inhibitory effect of oxidative CPT I modification. Biochem Biophys Res Commun. 2008 Feb 22;366(4):892.7.