Ketosis: tissue unsaturation

This morning I came across this thread on ketosis and tissue unsaturation. I still watch the the Ray Peat forum because there are some curious people who ask interesting questions and they get smacked with wooden spoons. What is unfortunate is that those holding the spoon(s) are grossly mistaken.

This thread reminded me of a recent email exchange with Dr. Peat, in which he wrote the following in response to a brief summary I wrote on polyunsaturated fats, that summary is the basis for my recent post(s) on polyunsaturated fats:

That’s my interpretation too, it seems that we are perfectly adapted to a very warm planet with a lot of CO2 and with fats unsaturated according to the effects on structure and electronic behavior needed for special functions. I think our body temperature keeps our enzymes from evolving into the cold-blooded pattern, keeping us ready to handle the n-9 based fats when things improve.

Which brings me to the misunderstanding/misinterpretation some people have regarding PUFA. It is exogenous (dietary) polyunsaturated fats that are problematic born from the essential fatty acid doctrine. The body indeed produces it’s own unsaturated fatty acids such as those found in the brain for structure and special functions to the degree that they are needed when the body is fed appropriately.

Neonatal ketosis is crucial for proper neonate development.

Lactate and the brain: the neonate

Lactate-Balls-JPEG-1024x948Lactate seems to be able to produce C02 efficiently, at least in the context of the early postnatal period. What is interesting is that blood lactate doesn’t seem to be elevated. Yet it is being oxidized preferentially over glucose. Glucose seems to be being spared for specialized precursors. It is also interesting that lactate doesn’t seem to be going through the Cori cycle but straight to the Krebs (Medina, 1985), which is interesting because it might mean these early adaptive responses are not in the same stressful context such as working muscles? Much like producing ketones from ketogenic fatty acids is not stressful.

Dombrowski, G. J., Swiatek, K. R., & Chao, K. L. (1989). Lactate, 3-hydroxybutyrate, and glucose as substrates for the early postnatal rat brain. Neurochemical research, 14(7), 667–75. Retrieved from

The dependence of cerebral energy metabolism upon glucose, 3-hydroxybutyrate, and lactate as fuel sources during the postnatal period was investigated. The brain of 6 day old suckling pups used very little glucose, but by the 15th postnatal day glucose was the major catabolite. Hydroxybutyrate was not a major brain fuel at either 6 or 15 days of age. Its utilization accounted for only 19% of the brain’s total energy needs at 15 days of age, even through blood ketone concentrations are near maximal at this time. Seventy percent of the cerebral metabolic requirements were met by lactate in animals aged 6 days. The major role played by lactate as a substrate for brain metabolism in young pups was not a result of abnormally elevated blood lactate concentrations. The slow catabolism of glucose in young brain can not be explained by low rates of influx or inadequate enzymatic capacity.

Fernández, E., & Medina, J. M. (1986). Lactate utilization by the neonatal rat brain in vitro. Competition with glucose and 3-hydroxybutyrate. The Biochemical journal, 234(2), 489–92. Retrieved from

The maximum rates of lactate oxidation and lipogenesis from lactate by early-neonatal brain slices were considerably greater than those for utilization of glucose and 3-hydroxybutyrate at physiological concentrations. Lactate inhibited glucose utilization, but enhanced 3-hydroxybutyrate utilization. 3-Hydroxybutyrate inhibited lactate and glucose utilization. Glucose slightly inhibited oxidation of lactate and 3-hydroxybutyrate, but scarcely enhanced lipogenesis from these substrates.

Holmgren, C. D., Mukhtarov, M., Malkov, A. E., Popova, I. Y., Bregestovski, P., & Zilberter, Y. (2010). Energy substrate availability as a determinant of neuronal resting potential, GABA signaling and spontaneous network activity in the neonatal cortex in vitro. Journal of neurochemistry, 112(4), 900–12. doi:10.1111/j.1471-4159.2009.06506.x

While the ultimate dependence of brain function on its energy supply is evident, how basic neuronal parameters and network activity respond to energy metabolism deviations is unresolved. The resting membrane potential (E(m)) and reversal potential of GABA-induced anionic currents (E(GABA)) are among the most fundamental parameters controlling neuronal excitability. However, alterations of E(m) and E(GABA) under conditions of metabolic stress are not sufficiently documented, although it is well known that metabolic crisis may lead to neuronal hyper-excitability and aberrant neuronal network activities. In this work, we show that in slices, availability of energy substrates determines whether GABA signaling displays an inhibitory or excitatory mode, both in neonatal neocortex and hippocampus. We demonstrate that in the neonatal brain, E(m) and E(GABA) strongly depend on composition of the energy substrate pool. Complementing glucose with ketone bodies, pyruvate or lactate resulted in a significant hyperpolarization of both E(m) and E(GABA), and induced a radical shift in the mode of GABAergic synaptic transmission towards network inhibition. Generation of giant depolarizing potentials, currently regarded as the hallmark of spontaneous neonatal network activity in vitro, was strongly inhibited both in neocortex and hippocampus in the energy substrate enriched solution. Based on these results we suggest the composition of the artificial cerebrospinal fluid, which bears a closer resemblance to the in vivo energy substrate pool. Our results suggest that energy deficits induce unfavorable changes in E(m) and E(GABA), leading to neuronal hyperactivity that may initiate a cascade of pathological events.

Medina, J. M. (1985). The role of lactate as an energy substrate for the brain during the early neonatal period. Biology of the neonate, 48(4), 237–44. Retrieved from

The role played by lactate as an energy substrate for the newborn rat during the early neonatal period was studied. Plasma lactate is mostly removed within the first 2 h after delivery, i.e. during the presuckling period. Lactate removal was enhanced by hyperoxia but strongly inhibited by hypoxia, showing a direct correlation with blood oxygen concentrations. Lactate was not converted into glucose during the presuckling period, gluconeogenesis being insignificant in these circumstances; instead it was rapidly oxidized through the tricarboxylic acid cycle. Likewise, lactate was significantly oxidized by brain slices from newborns at birth. At physiological concentrations, lactate oxidation by brain slices was 10- and 3-fold higher than that of glucose and 3-hydroxybutyrate, respectively. In the same circumstances, lipogenesis de novo from lactate was 2- and 5-fold higher than from glucose and 3-hydroxybutyrate, respectively. The results suggest that lactate is the main metabolic fuel for the brain during the early neonatal period.

Vicario, C., Arizmendi, C., Malloch, G., Clark, J. B., & Medina, J. M. (1991). Lactate utilization by isolated cells from early neonatal rat brain. Journal of neurochemistry, 57(5), 1700–7. Retrieved from

The utilization of lactate, glucose, 3-hydroxybutyrate, and glutamine has been studied in isolated brain cells from early newborn rats. Isolated brain cells actively utilized these substrates, showing saturation at concentrations near physiological levels during the perinatal period. The rate of lactate utilization was 2.5-fold greater than that observed for glucose, 3-hydroxybutyrate, or glutamine, suggesting that lactate is the main metabolic substrate for the brain immediately after birth. The apparent Km for glucose utilization suggested that this process is limited by the activity of hexokinase. However, lactate, 3-hydroxybutyrate, and glutamine utilization seems to be limited by their transport through the plasma membrane. The presence of fatty acid-free bovine serum albumin (BSA) in the incubation medium significantly increased the rate of lipogenesis from lactate or 3-hydroxybutyrate, although this was balanced by the decrease in their rates of oxidation in the same circumstances. BSA did not affect the rate of glucose utilization. The effect of BSA was due not to the removal of free fatty acid, but possibly to the binding of long-chain acyl-CoA, resulting in the disinhibition of acetyl-CoA carboxylase and citrate carrier.

Vicario, C., & Medina, J. M. (1992). Metabolism of lactate in the rat brain during the early neonatal period. Journal of neurochemistry, 59(1), 32–40. Retrieved from

The metabolism of lactate in isolated cells from early neonatal rat brain has been studied. In these circumstances, lactate was mainly oxidized to CO2, although a significant portion was incorporated into lipids (78% sterols, 4% phosphatidylcholine, 2% phosphatidylethanolamine, and 1% phosphatidylserine). The rate of lactate incorporation into CO2 and lipids was higher than those found for glucose and 3-hydroxybutyrate. Lactate strongly inhibited glucose oxidation through the pyruvate dehydrogenase-catalyzed reaction and the tricarboxylic acid cycle while scarcely affecting glucose utilization by the pentose phosphate pathway. Lipogenesis from glucose was strongly inhibited by lactate without relevant changes in the rate of glycerol phosphate synthesis. These results suggest that lactate inhibits glucose utilization at the level of the pyruvate dehydrogenase-catalyzed reaction, which may be a mechanism to spare glucose for glycerol and NADPH synthesis. The effect of 3-hydroxybutyrate inhibiting lactate utilization only at high concentrations of 3-hydroxybutyrate suggests that before ketogenesis becomes active, lactate may be the major fuel for the neonatal brain. (-)-Hydroxycitrate and aminooxyacetate markedly inhibited lipogenesis from lactate, suggesting that the transfer of lactate carbons through the mitochondrial membrane is accomplished by the translocation of both citrate and N-acetylaspartate.

Adam, P. A., Räihä, N., Rahiala, E. L., & Kekomäki, M. (1975). Oxidation of glucose and D-B-OH-butyrate by the early human fetal brain. Acta paediatrica Scandinavica, 64(1), 17–24. Retrieved from

The isolated brains of 12 previable human fetuses obtained at 12 to 21 weeks’ gestation, were perfused through the interval carotid artery with glucose (3 mM) and/or DL-B-OH-butyrate (DL-BOHB), 4.5 MM, plus tracer quantities of either glucose-6-14C (G6-14C) or beta-OH-butyrate-3-14C (BOHB3-14C). Oxidative metabolism was demonstrated by serial collection of gaseous 14CO2 from the closed perfusion system, and from the recirculating medium. Glucose and BOHB were utilized at physiological rates as indicated (mean plus or minus SEM): G6-14C at 0.10 plus or minus 0.01 mumoles/min g brain (n equal 7) or 17.5 plus or minus 1.9 mumoles/min kg fetus; and BOHB3-14C at 0.16 plus or minus 0.05 mumoles/min g (n equal to 5) or 27.3 plus or minus 7.4 mumoles/min kg. Based on fetal weight, glucose metabolism by brain apparently accounted for about 1/3 of basal glucose utilization in the fetus. On a molar basis BOHB3-14C was taken up at 1.47 times the rate of G6-14C. Both BOHB3-14C and G6 14C were converted to 14CO2. The rate of BOHB3-14C conversion to 14CO2 was equal to its rate of consumption, and exceeded the conversion of glucose to CO2 because 45% of the G6-14C was incorporated into lactate-14C. Accordingly, both substrates support oxidative metabolism by brain; and BOHB is a major potential alternate fuel which can replace glucose early in human development.

Freinkel, N., Cockroft, D. L., Lewis, N. J., Gorman, L., Akazawa, S., Phillips, L. S., & Shambaugh, G. E. (1986). The 1986 McCollum award lecture. Fuel-mediated teratogenesis during early organogenesis: the effects of increased concentrations of glucose, ketones, or somatomedin inhibitor during rat embryo culture. The American journal of clinical nutrition, 44(6), 986–95. Retrieved from

Whole rat embryos were explanted at head-fold, late pre-somite stage (day 9.5 of gestation) and cultured in rat sera varyingly supplemented with glucose (3, 6, 9, or 12 mg/mL), D,L sodium beta-hydroxybutyrate (2, 4, 8, or 16 mM), or both (6 mg/mL D-glucose plus 8 mM beta-hydroxybutyrate). During 48 h culture, increasing glucose alone or beta-hydroxybutyrate alone effected growth retardation and faulty neural and extraneural organogenesis in dose-dependent fashion. Synergistic dysmorphogenic effects occurred when minimally teratogenic concentrations of glucose and beta-hydroxybutyrate were combined. Sera from diabetic animals containing somatomedin inhibitor bioactivity were also able to produce growth retardation and major developmental lesions in presence of amounts of glucose and ketones which of themselves were not teratogenic. Thus, aberrant fuels and fuel-related products can impair growth and organogenesis in early post-implantation embryo. Such fuel-mediated teratogenesis may be multifactorial and include possibilities for synergistic and additive interactions.

n-Butyrate enhances induction of thyroid hormone-responsive nuclear protein

Nishii, Y., Ichikawa, K., Miyamoto, T., Takeda, T., Kobayashi, M., Suzuki, S., … Hashizume, K. (1993). n-Butyrate enhances induction of thyroid hormone-responsive nuclear protein. Endocrine journal, 40(5), 515–21. Retrieved from

Effects of n-butyrate on nuclear thyroid hormone receptors and on thyroid hormone-responsive nuclear protein were investigated by means of a perfusion system in rat liver. Treatment with 5 mM n-butyrate resulted in an increase (150%) in the maximal binding capacity of 3,5,3’-L-triiodothyronine (T3) nuclear receptors without altering the affinity of receptor for T3. However, further perfusion for 4 h decreased the number of the receptors to the control level. n-Butyrate increased the amount of acetylated histone H4. The ability of nuclear T3 receptors to bind to core histones was diminished by acetylation of the core histones. Thyroid hormone-responsive nuclear protein (n protein) was increased by T3. The induction of the n protein by T3 was augmented by n-butyrate. These results suggested that n-butyrate modulates thyroid hormone-responsive gene expression in rat liver via the increased number of nuclear receptors or changes in the chromatin constitution.

Polyunsaturated fats: why are they harmful? Part I

Some people in nutritional science are aware that the polyunsaturated fats such as those found in industrial vegetable oils can be harmful. But few people that I’ve read seem to illustrate why PUFA are harmful in a way that gives a logical understanding. When someone says something is harmful they are merely stating something. It does not mean they actually understand the “why”. A person might read a study and the study might be correct and that person may regurgitate what was in the study. Though the person may be informed they lack the visual pictures painted in the mind that helps to form a basis from which other conclusions can be drawn. In other words, they have no real understanding. That phenomenon is rampant in nutritional science. From a practical standpoint that approach may work, but for a person who is in a complicated situation or trying to understand more than that, the approach is limited, and taking shots in the dark could have negative consequences.

In order to understand the world around us, we cannot just memorize facts and connect dots. It leads to superficial understanding.

Many people have said that polyunsaturated fats are harmful and have provided evidence for why by putting together pieces of their effects in different contexts. But that does nothing in the end to help us to predict upstream and downstream effects, in that approach we are without prediction power for making rational choices.

In your body you have different lipid-like hormones and nutrients. A lot of these hormones and nutrients are unsaturated. In other words, they resemble the polyunsaturated fatty acids. In a body that doesn’t have bottles of corn oil floating around, these unsaturated hormones and nutrients bind to the cells as they should, like putting a key into a keyhole. Though that is a rather mechanical way of thinking about it, the analogy is useful. When you consume polyunsaturated fats they in effect bind to the same places your hormones would normally bind. As long as the body remains fairly unstressed this poses minimal problems in the short term.

Under stress, however, the body releases the protective hormones. If the body is saturated with the polyunsaturated fats, the unsaturated hormones can no longer bind. Over time, the body can no longer respond to stress efficiently because the protective hormones can no longer function, in effect, the polyunsaturated fats are mimicking the binding of unsaturated hormones blocking the protective hormones from functioning.

Over time, as we age, we gradually lose the ability to respond to stress because of this process. In other words, resistance to stress is the ability to respond to stress efficiently. As we lose the efficiency to respond to stress, we age because we are unable to repair the damage caused by stress. In other words, aging is a feature of the body not being able to respond to stress efficiently and completely. Stasis must shift to maintain balance. It is the shifting process that can be problematic.

In the cell there is an organelle called the peroxisome. The peroxisomes break down lipid like substances or xenobiotic compounds. In other words, they protect the cell from foreign compounds. That seems to be one of their primary functions.

What is interesting here is that the mitochondria work in a similar parallel when they metabolize oxygen.

I had known from prior research that the polyunsaturated fats cause problems with cellular respiration by reducing the efficiency of the mitochondria, thus overall efficiency of the cell, in a sense turning the mitochondria into “mush”. Different fuel substrates have differing efficiency, so I needed something more, something that pointed to a problem with the nature of polyunsaturated fats themselves.

When a cell is exposed to PUFA the peroxisomes proliferate or increase in number rapidly. Peroxisomes are especially sensitive to the unsaturated fatty acids. In the laboratory, fish oil is commonly used in their study. Interestingly, the saturated fats do not cause proliferation in most cases. It is also interesting that cholesterol lowering drugs also cause peroxisome proliferation. Remember: peroxisomes proliferate when exposed to harmful substances.

So the cells can, to some extent, protect themselves from PUFA by breaking them down. Given that, why can’t we consume PUFA with a clear conscious? And why do some people seem to be able to eat more than others?

Part 2 shortly.

Conjugated linoleic acid protects against gliadin-induced depletion of intestinal defenses

Bergamo, P., Gogliettino, M., Palmieri, G., Cocca, E., Maurano, F., Stefanile, R., … Rossi, M. (2011). Conjugated linoleic acid protects against gliadin-induced depletion of intestinal defenses. Molecular nutrition & food research, 55 Suppl 2, S248–56. doi:10.1002/mnfr.201100295

SCOPE: The involvement of oxidative stress in gluten-induced toxicity has been evidenced in vitro and in clinical studies but has never been examined in vivo. We recently demonstrated the protective activity of conjugated linoleic acid (CLA), which functions by the activation of nuclear factor erythroid 2-related factor2 (Nrf2), a key transcription factor for the synthesis of antioxidant and detoxifying enzymes (phase 2). Here, we evaluate the involvement of nuclear factor erythroid 2-related factor2 in gliadin-mediated toxicity in human Caco-2 intestinal cells and in gliadin-sensitive human leukocyte antigen-DQ8 transgenic mice (DQ8) and the protective activity of CLA.

METHODS AND RESULTS: Gliadin effects in differentiated Caco-2 cells and in DQ8 mice, fed with a gliadin-containing diet with or without CLA supplementation, were evaluated by combining enzymatic, immunochemical, immunohistochemical, and quantitative real-time PCR (qRT-PCR) assays. Gliadin toxicity was accompanied by downregulation of phase 2 and elevates proteasome-acylpeptide hydrolase activities in vitro and in vivo. Notably, gliadin was unable to generate severe oxidative stress extent or pathological consequences in DQ8 mice intestine comparable to those found in celiac patients and the alterations produced were hampered by CLA.

CONCLUSION: The beneficial effects of CLA against the depletion of crucial intestinal cytoprotective defenses indicates a novel nutritional approach for the treatment of intestinal disease associated with altered redox homeostasis.

Update: moving the blog to a different address

Effective now all future posts will be at this address:

As of now there is no system to what I’ve been posting, I prefer to write on a whim and post whatever I happen to be thinking about (it keeps my stress hormones down) but I expect things to become more organized and hopefully more useful as time progresses because there does seem to be people who are reading my opinions. There will also be another author writing posts as well giving a female perspective on different topics.

Ultimately my goal is to get people thinking about how the body works in different contexts and learn how to adapt to the adaptations the body makes throughout our lifespans. I don’t know all the answers. But I always welcome questions and comments.

Once I solve hosting issues the site will then have a seamless move to

Lactate and the brain

The lactate shuttle theory has been around for a couple of decades. Essentially, it is associated with the idea that the brain prefers lactate as an energy substrate, but lactate shuttle theory is actually describing a (proposed) mechanism, not the implications. I had been aware of the idea, but was not sure of the context of functionality. From some prior research I had found that the brain stores glycogen.

Peter has a brief post on this.

You always find a high concentration of GLUTx transporters in high energy organs. Having a high concentration of GLUTx transporters points to earlier times and to some interesting ideas.

The fact that ROS (reactive oxygen species) from glucose causes problems in the brain has always seemed strange to me given the common idea that the brain prefers glucose. Bypassing glucose metabolism with either fructose 1,6-bisphosphate or ketones has anticonvulsant activity. Given the composition of the fatty acids in the brain ROS seems like a really really bad idea, and it is probably the reason that if ROS is reduced things start working better.

When I started researching neonatal ketosis, I saw that besides the elevated ketones in neonates, lactate was also elevated. Ketones and lactate seem to be essential for a developing brain. Here are some papers on lactate below that can be tied in with the neonatal ketosis post.

So given this, the question is why? Why in neonates are ketones and lactate elevated? Does the status of a neonate represent an optimal status that we as adults should mimic, or is the status of the neonate a contextual adaptation? I have my own ideas as to why. What are some of your thoughts?

Gladden, L. B. (2008). A lactatic perspective on metabolism. Medicine and science in sports and exercise, 40(3), 477–85. doi:10.1249/MSS.0b013e31815fa580

Hashimoto, T., & Brooks, G. A. (2008). Mitochondrial lactate oxidation complex and an adaptive role for lactate production. Medicine and science in sports and exercise, 40(3), 486–94. doi:10.1249/MSS.0b013e31815fcb04

Holmgren, C. D., Mukhtarov, M., Malkov, A. E., Popova, I. Y., Bregestovski, P., & Zilberter, Y. (2010). Energy substrate availability as a determinant of neuronal resting potential, GABA signaling and spontaneous network activity in the neonatal cortex in vitro. Journal of neurochemistry, 112(4), 900–12. doi:10.1111/j.1471-4159.2009.06506.x

Kasischke, K. (2011). Lactate fuels the neonatal brain. Frontiers in neuroenergetics, 3(June), 4. doi:10.3389/fnene.2011.00004

Philp, A., Macdonald, A. L., & Watt, P. W. (2005). Lactate–a signal coordinating cell and systemic function. The Journal of experimental biology, 208(Pt 24), 4561–75. doi:10.1242/jeb.01961

Tyzio, R., Allene, C., Nardou, R., Picardo, M. A., Yamamoto, S., Sivakumaran, S., … Ben-Ari, Y. (2011). Depolarizing actions of GABA in immature neurons depend neither on ketone bodies nor on pyruvate. The Journal of neuroscience : the official journal of the Society for Neuroscience, 31(1), 34–45. doi:10.1523/JNEUROSCI.3314-10.2011

Wyss, M. T., Jolivet, R., Buck, A., Magistretti, P. J., & Weber, B. (2011). In vivo evidence for lactate as a neuronal energy source. The Journal of neuroscience : the official journal of the Society for Neuroscience, 31(20), 7477–85. doi:10.1523/JNEUROSCI.0415-11.2011

Zilberter, Y., Zilberter, T., & Bregestovski, P. (2010). Neuronal activity in vitro and the in vivo reality: the role of energy homeostasis. Trends in pharmacological sciences, 31(9), 394–401. doi:10.1016/

Wistar rats allowed to self-select macronutrients from weaning to maturity choose a high-protein, high-lipid diet

Jean, C., Fromentin, G., Tomé, D., & Larue-Achagiotis, C. (2002). Wistar rats allowed to self-select macronutrients from weaning to maturity choose a high-protein, high-lipid diet. Physiology & behavior, 76(1), 65–73. Retrieved from

The aim of this work was to study the evolution of rat food choice in relation to their age and metabolic parameters. Eighty Wistar rats were studied from birth to 13 weeks of age. At weaning, six litters were fed on a macronutrient self-selecting diet and four on a standard diet. In self-selecting males, protein intake was maximal at Week 7 of age and then plateaued (Week 13), whereas in females, protein consumption peaked at Week 7 and then steadily decreased. Females showed a strong and early preference for fat, which increased continuously with age. Males and females ingested their total energy intake during the dark period (respectively, 79% and 70%). Simple meals (composed of one item) were mainly ingested during the light phase, while mixed meals (at least two items) were ingested during the night. In males, most mixed meals began with carbohydrate bouts and finished with proteins, while in females no particular choice was observed at the beginning of meals, but most of them ended with protein bouts. Body weights of either male and female self-selecting or control fed rats were not significantly different at the end of the experiment. Differences between dietary groups in body fat mass were not observed with the exception of higher subcutaneous fat found in self-selecting rats. Moreover, insulinemia was lower in both male and female self-selecting rats. The high-protein, high-fat diet chosen by the self-selecting rats could be linked to a prevention of the age-related insulin resistance.

Omnivorous wolves, spiders that play tether ball, worms instead of oranges, and yogurt and honey improve sleep

Features of a successful therapeutic fast of 382 days’ duration

Stewart, W. K., & Fleming, L. W. (1973). Features of a successful therapeutic fast of 382 days’ duration. Postgraduate medical journal, 49(569), 203–9. Retrieved from

A 27-year-old male patient fasted under supervision for 382 days and has subsequently maintained his normal weight. Blood glucose concentrations around 30 mg/100 ml were recorded consistently during the last 8 months, although the patient was ambulant and attending as an out-patient. Responses to glucose and tolbutamide tolerance tests remained normal. The hyperglycaemic response to glucagon was reduced and latterly absent, but promptly returned to normal during carbohydrate refeeding. After an initial decrease was corrected, plasma potassium levels remained normal without supplementation. A temporary period of hypercalcaemia occurred towards the end of the fast. Decreased plasma magnesium concentrations were a consistent feature from the first month onwards. After 100 days of fasting there was a marked and persistent increase in the excretion of urinary cations and inorganic phosphate, which until then had been minimal. These increases may be due to dissolution of excessive soft tissue and skeletal mass. Prolonged fasting in this patient had no ill-effects.

Caffeine as an antioxidant: inhibition of lipid peroxidation induced by reactive oxygen species

Devasagayam, T. P., Kamat, J. P., Mohan, H., & Kesavan, P. C. (1996). Caffeine as an antioxidant: inhibition of lipid peroxidation induced by reactive oxygen species. Biochimica et biophysica acta, 1282(1), 63–70. Retrieved from

Caffeine (1,3,7-trimethyl xanthine), an ingredient of coffee, has been investigated for its potential antioxidant activity against oxidative damage to rat liver microsomes. Such damage was induced by three reactive oxygen species of cardinal importance in causing membrane damage in vivo namely hydroxyl radical (.OH), peroxyl radical (ROO.) and singlet oxygen (1O2). The results obtained showed that caffeine was an effective inhibitor of lipid peroxidation, at millimolar concentrations, against all the three reactive species. The extent of inhibition was high against peroxidation induced by .OH, medium against 1O2 and low against ROO. In general, the antioxidant ability of caffeine was similar to that of the established biological antioxidant glutathione and significantly higher than ascorbic acid. Investigations into the possible mechanisms involved in the observed antioxidant effect reveal that the quenching of these reactive species by caffeine may be one of the possible factor responsible. The rate constant of caffeine with .OH was 7.3 x 10(9) M-1 s-1 and with 1O2 it was 2.9 x 10(7) M-1 s-1. Considering their potential for damage, half-life estimates and generation in biological systems, the ability of caffeine to inhibit oxidative damage induced by these reactive species in membranes suggest one more positive attribute of caffeine, whose daily intake as coffee may be considerable in most populations.

Increased sugar uptake promotes oncogenesis via EPAC/RAP1 and O-GlcNAc pathways

Onodera, Y., Nam, J.-M., & Bissell, M. J. (2013). Increased sugar uptake promotes oncogenesis via EPAC/RAP1 and O-GlcNAc pathways. The Journal of clinical investigation, 124(1). doi:10.1172/JCI63146

There is a considerable resurgence of interest in the role of aerobic glycolysis in cancer; however, increased glycolysis is frequently viewed as a consequence of oncogenic events that drive malignant cell growth and survival. Here we provide evidence that increased glycolytic activation itself can be an oncogenic event in a physiologically relevant 3D culture model. Overexpression of glucose transporter type 3 (GLUT3) in nonmalignant human breast cells activated known oncogenic signaling pathways, including EGFR, β1 integrin, MEK, and AKT, leading to loss of tissue polarity and increased growth. Conversely, reduction of glucose uptake in malignant cells promoted the formation of organized and growth-arrested structures with basal polarity, and suppressed oncogenic pathways. Unexpectedly and importantly, we found that unlike reported literature, in 3D the differences between “normal” and malignant phenotypes could not be explained by HIF-1α/2α, AMPK, or mTOR pathways. Loss of epithelial integrity involved activation of RAP1 via exchange protein directly activated by cAMP (EPAC), involving also O-linked N-acetylglucosamine modification downstream of the hexosamine biosynthetic pathway. The former, in turn, was mediated by pyruvate kinase M2 (PKM2) interaction with soluble adenylyl cyclase. Our findings show that increased glucose uptake activates known oncogenic pathways to induce malignant phenotype, and provide possible targets for diagnosis and therapeutics.

No effect of 600 grams fruit and vegetables per day on oxidative DNA damage and repair in healthy nonsmokers

Møller, P., Vogel, U., Pedersen, A., Dragsted, L. O., Sandström, B., & Loft, S. (2003). No effect of 600 grams fruit and vegetables per day on oxidative DNA damage and repair in healthy nonsmokers. Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology, 12(10), 1016–22. Retrieved from

In several epidemiological studies, high intakes of fruits and vegetables have been associated with a lower incidence of cancer. Theoretically, intake of antioxidants by consumption of fruits and vegetables should protect against reactive oxygen species and decrease the formation of oxidative DNA damage. We set up a parallel 24-day dietary placebo-controlled intervention study in which 43 subjects were randomized into three groups receiving an antioxidant-free basal diet and 600 g of fruits and vegetables, or a supplement containing the corresponding amounts of vitamins and minerals, or placebo. Blood and urine samples were collected before, once a week, and 4 weeks after the intervention period. The level of strand breaks, endonuclease III sites, formamidopyrimidine sites, and sensitivity to hydrogen peroxide was assessed in mononuclear blood cells by the comet assay. Excretion of 7-hydro-8-oxo-2’-deoxyguanine was measured in urine. The expressions of oxoguanine glycosylase 1 and excision repair cross complementing 1 DNA repair genes, determined by real-time reverse transcription-PCR of mRNAs, were investigated in leukocytes. Consumption of fruits and vegetables or vitamins and minerals had no effect on oxidative DNA damage measured in mononuclear cell DNA or urine. Hydrogen peroxide sensitivity, detected by the comet assay, did not differ between the groups. Expression of excision repair cross complementing 1 and oxoguanine glycosylase 1 in leukocytes was not related to the diet consumed. Our results show that after 24 days of complete depletion of fruits and vegetables, or daily ingestion of 600 g of fruit and vegetables, or the corresponding amount of vitamins and minerals, the level of oxidative DNA damage was unchanged. This suggests that the inherent antioxidant defense mechanisms are sufficient to protect circulating mononuclear blood cells from reactive oxygen species.

Effects of Coffee Consumption, Smoking, and Hormones on Risk for Primary Sclerosing Cholangitis

Andersen, I. M., Tengesdal, G., Lie, B. A., Boberg, K. M., Karlsen, T. H., & Hov, J. R. (2013). Effects of Coffee Consumption, Smoking, and Hormones on Risk for Primary Sclerosing Cholangitis. Clinical gastroenterology and hepatology : the official clinical practice journal of the American Gastroenterological Association. doi:10.1016/j.cgh.2013.09.024

BACKGROUND & AIMS: Little is known about nongenetic risk factors for primary sclerosing cholangitis (PSC), except a possible protective effect of smoking. We investigated the relationship between environmental risk factors and susceptibility to PSC. METHODS: A questionnaire was distributed to patients with PSC, recruited from Oslo University Hospital Rikshospitalet in Norway through 2011, and randomly chosen individuals from the Norwegian Bone Marrow Donor Registry (control subjects). Data were analyzed from 240 patients with PSC and 245 control subjects, matched for gender and age. RESULTS: A lower proportion of patients with PSC were daily coffee drinkers than control subjects, both currently (76% vs 86%; odds ratio [OR], 0.52; 95% confidence interval [CI], 0.32-0.82; P = .006) and at the age of 18 years (35% vs 49%; OR, 0.58; 95% CI, 0.40-0.83; P = .003). The associations were mainly attributed to differences observed in men. Twenty percent of the patients were ever (current or former) daily smokers compared with 43% of control subjects (OR, 0.33; 95% CI, 0.22-0.50; P < .001). Ever daily smoking before PSC diagnosis was associated with older age at diagnosis (42 years vs 32 years; P < .001). Ever daily smoking (P < .001) and being a coffee drinker at the age of 18 years (P = .048) were independently and negatively associated with PSC. Fewer female patients with PSC than control subjects reported ever use of hormonal contraception (51% vs 85%; P < .001). Among female patients, there was a strong correlation between increasing number of children before the diagnosis of PSC and increasing age at diagnosis (r = 0.63; P < .001). CONCLUSIONS: Coffee consumption and smoking might protect against development of PSC. In women, the disease might be influenced by hormonal factors.

Ketones inhibit mitochondrial production of reactive oxygen species production following glutamate excitotoxicity by increasing NADH oxidation

Maalouf, M., Sullivan, P. G. G., Davis, L., Kim, D. Y. Y., & Rho, J. M. M. (2007). Ketones inhibit mitochondrial production of reactive oxygen species production following glutamate excitotoxicity by increasing NADH oxidation. Neuroscience, 145(1), 256–64. doi:10.1016/j.neuroscience.2006.11.065

Dietary protocols that increase serum levels of ketones, such as calorie restriction and the ketogenic diet, offer robust protection against a multitude of acute and chronic neurological diseases. The underlying mechanisms, however, remain unclear. Previous studies have suggested that the ketogenic diet may reduce free radical levels in the brain. Thus, one possibility is that ketones may mediate neuroprotection through antioxidant activity. In the present study, we examined the effects of the ketones beta-hydroxybutyrate and acetoacetate on acutely dissociated rat neocortical neurons subjected to glutamate excitotoxicity using cellular electrophysiological and single-cell fluorescence imaging techniques. Further, we explored the effects of ketones on acutely isolated mitochondria exposed to high levels of calcium. A combination of beta-hydroxybutyrate and acetoacetate (1 mM each) decreased neuronal death and prevented changes in neuronal membrane properties induced by 10 microM glutamate. Ketones also significantly decreased mitochondrial production of reactive oxygen species and the associated excitotoxic changes by increasing NADH oxidation in the mitochondrial respiratory chain, but did not affect levels of the endogenous antioxidant glutathione. In conclusion, we demonstrate that ketones reduce glutamate-induced free radical formation by increasing the NAD+/NADH ratio and enhancing mitochondrial respiration in neocortical neurons. This mechanism may, in part, contribute to the neuroprotective activity of ketones by restoring normal bioenergetic function in the face of oxidative stress.

Fatty liver induced by injection of l-tryptophan

Yukiko, H., Takashi, K., & Takashi, S. (1967). Fatty liver induced by injection of l-tryptophan. Biochimica et Biophysica Acta (BBA) – Lipids and Lipid Metabolism, 144(2), 233–241. Retrieved from

l-Tryptophan caused the accumulation of neutral lipids in liver within 2.5 h after its intraperitoneal injection into rats. This accumulation of neutral lipids continued for about 24 h. Peripheral fatty liver was diagnosed histologically by Sudan III staining. The minimal effective dose was 0.5 mg/g of body weight. The level of cholesterol and phospholipids in liver did not alter. 3-Hydroxyanthranilic acid and l-kynurenine were as effective as l-tryptophan in inducing the accumulation of neutral lipids, but other metabolites of tryptophan, kynurenic acid, anthranilic acid, quinolinic acid, nicotinic acid and nicotinamide did not produce the lipid accumulation. The administration of other amino acids, such as l-leucine, l-lysine, l-tyrosine, l-threonine and l-methionine, did not increase the amount of total lipids in liver. Simultaneous administration of ATP, ADP, AMP, adenosine or folic acid with l-tryptophan prevented the fatty liver. A marked decrease in the concentration of ATP in the liver was shown by the administration of l-tryptophan or l-kynurenine. These observations support the concept that l-tryptophan-induced fatty liver is due to the decreased level of ATP. A possible mechanism of ATP depression by administered l-tryptophan is discussed.

Free, long-chain, polyunsaturated fatty acids reduce membrane electrical excitability in neonatal rat cardiac myocytes

Kang, J. X., Xiao, Y. F., & Leaf, A. (1995). Free, long-chain, polyunsaturated fatty acids reduce membrane electrical excitability in neonatal rat cardiac myocytes. Proceedings of the National Academy of Sciences, 92(9), 3997–4001. doi:10.1073/pnas.92.9.3997

Because previous studies showed that polyunsaturated fatty acids can reduce the contraction rate of spontaneously beating heart cells and have antiarrhythmic effects, we examined the effects of the fatty acids on the electrophysiology of the cardiac cycle in isolated neonatal rat cardiac myocytes. Exposure of cardiomyocytes to 10 microM eicosapentaenoic acid for 2-5 min markedly increased the strength of the depolarizing current required to elicit an action potential (from 18.0 +/- 2.4 pA to 26.8 +/- 2.7 pA, P < 0.01) and the cycle length of excitability (from 525 ms to 1225 ms, delta = 700 +/- 212, P < 0.05). These changes were due to an increase in the threshold for action potential (from -52 mV to -43 mV, delta = 9 +/- 3, P < 0.05) and a more negative resting membrane potential (from -52 mV to -57 mV, delta = 5 +/- 1, P < 0.05). There was a progressive prolongation of intervals between spontaneous action potentials and a slowed rate of phase 4 depolarization. Other polyunsaturated fatty acids–including docosahexaenoic acid, linolenic acid, linoleic acid, arachidonic acid, and its nonmetabolizable analog eicosatetraynoic acid, but neither the monounsaturated oleic acid nor the saturated stearic acid–had similar effects. The effects of the fatty acids could be reversed by washing with fatty acid-free bovine serum albumin. These results show that free polyunsaturated fatty acids can reduce membrane electrical excitability of heart cells and provide an electrophysiological basis for the antiarrhythmic effects of these fatty acids.

Saturated free fatty acids, polyunsaturated free fatty acids

It’s something I don’t really understand. It’s like saying, you have a diet of higher fat that is not conducive to high metabolic rate, but you add in a few hormones and it’s fixed. But if the fat diet provided enough energy, why do these hormones naturally decline in the first place? How can hormones compensate for an energy problem?

I think Edward must have a good explanation for this, because his posts have hinted about good thyroid not being incompatible with higher fat ratio.

The underlying explanation is that there is a difference between saturated free fatty acids and polyunsaturated free fatty acids. Essentially you self-induce mitochondrial diseases with polyunsaturated free fatty acids; you can’t do that with saturated free fatty acids. There is a longer post here but sadly no time. Sometime after the 16th.

Targeting SOD1 reduces experimental non-small-cell lung cancer

Glasauer, A., Sena, L. A., Diebold, L. P., Mazar, A. P., & Chandel, N. S. (2013). Targeting SOD1 reduces experimental non-small-cell lung cancer. The Journal of clinical investigation, 124(1). doi:10.1172/JCI71714

Approximately 85% of lung cancers are non-small-cell lung cancers (NSCLCs), which are often diagnosed at an advanced stage and associated with poor prognosis. Currently, there are very few therapies available for NSCLCs due to the recalcitrant nature of this cancer. Mutations that activate the small GTPase KRAS are found in 20% to 30% of NSCLCs. Here, we report that inhibition of superoxide dismutase 1 (SOD1) by the small molecule ATN-224 induced cell death in various NSCLC cells, including those harboring KRAS mutations. ATN-224-dependent SOD1 inhibition increased superoxide, which diminished enzyme activity of the antioxidant glutathione peroxidase, leading to an increase in intracellular hydrogen peroxide (H2O2) levels. We found that ATN-224-induced cell death was mediated through H2O2-dependent activation of P38 MAPK and that P38 activation led to a decrease in the antiapoptotic factor MCL1, which is often upregulated in NSCLC. Treatment with both ATN-224 and ABT-263, an inhibitor of the apoptosis regulators BCL2/BCLXL, augmented cell death. Furthermore, we demonstrate that ATN-224 reduced tumor burden in a mouse model of NSCLC. Our results indicate that antioxidant inhibition by ATN-224 has potential clinical applications as a single agent, or in combination with other drugs, for the treatment of patients with various forms of NSCLC, including KRAS-driven cancers.