Thursday, November 8, 2012

Mitochondria: Fuel, Fluxxx and Heat (NSFW)

Buddha Bar (Sex Lounge)
Credit: Youtube.com



Fuel and Fluxxx...

Why do we store fat? Why do we eat?  A scientist who wrote about reproduction, fuel, photoperiods and fecundity wrote the below abstract...[1]

"While there is a relatively direct connection between
circulating levels of metabolic fuels and the GnRH [gonadotropin releasing hormone] pulse generator [in SCN behind the retina], this might not be the only energy-related pathway influencing the secretion of this neuropeptide. The overall control of energy balance is an immensely complex process and a number of pathways involved in it might secondarily influence the activity of GnRH neurons. Peripheral signals influencing energy balance and thus possibly GnRH secretion could come from the liver, pancreas, stomach, duodenum or adipose tissue, and these signals could be sent to the brain via the vagus nerves or by hormones such as leptin, insulin, insulin-like growth factor 1 or ghrelin. These hormones could act directly on the neural circuits controlling the GnRH neurons or they could act by modulating the availability of metabolic fuel. Likewise, the neuropeptides regulating GnRH secretion in the forebrain could also include galanin, orexin, the urocortins and endogenous opioids. Recent interest has focused on kisspeptin, the product of the KISS1 gene. The presence of kisspeptin is necessary for normal reproductive development and it can override the reproductively detrimental effect of mild food restriction."

Obviously how we expend fuel is highly complex and humans are ruled by a big, big, big, hungry, hot brains... Grow or growl? Feast or fast? F-ck or forage? Repair or repast?





HEAT: Cellular Bioenergetics Creates Wildly Explosive, Exothermic Reaction Generating Water



CALORIES IN  ≠  CALORIES OUT

...we are not neat bomb-calorimeters, but open, conserved, networked metabolic and energy systems...

Photos credit: [2].













The Evolution of Body Heat?

When oxidized, the great majority of our food and stored energy goes to the production of HEAT.      What governs this? It is multifactorial but adrenaline, thyroid, cortisol and mitochondria quality are just a few [2]. Active tissues contain more mitochondria. Heat makes us mammals and birds. We have hot bodies, precisely 37C for the great majority.


In the 'Hot Brain:  Survival, Temperature, and the Human Body' the authors theorized that temperature gave us advantages over eukaryotic infections (yeast, fungal origins -- we are eukaryotic) which plagued bird/reptile species which were not armed with high 37C temperatures or fever-inducing capabilities [3].  It is a very interesting theory. Control of thermoregulation (heat loss v. heat gain) is believed to have evolved in the brain of therapsids. Our sinuses are larger. Mammalian brains have a Circle of Willis where 4 arteries (internal carotids and vertebral arteries) provide a complete internal brain circulation with collaterals, such that despite blockage of one or more of the 4 major arteries circulation in the brain and to the body remains intact.  Unfortunately only 25-33% of us have a 'perfect' classic circle of Willis; others have degrees of narrowing or asymetry in certain areas or another. Photos courtesy: Hot Brain, pp. 44, 142.

Recently a microbiologist, Casadevall, from Albert Einstein had the same theory that the rise of mammals can be attributed to 'endothermy and homeothermy [which] are thought to contribute to mammalian resistance to mycosis by creating a thermal exclusionary zone that inhibits most fungal species. The remarkable resistance of mammals to mycotic diseases is probably a combination of a vertebrate immune system, with both innate and adaptive arms, and elevated body temperatures... The currently favored hypothesis for the demise of dinosaurs and end of the age of reptiles is a bolide impact approximately 65 million year ago with the possibility that other events, such as increased volcanism, contributed to disrupting the cretaceous ecosystem. That ecological calamity was accompanied by massive deforestation, an event followed by a fungal bloom, as the earth became a massive compost. Although one cannot know which spores were present at the time, the likelihood that pathogenic fungi existed at the K-T boundary is enhanced by the finding that the potential for pathogenicity probably arose independently several times in evolution...'[3]

'Although we do not know the timeline for the recovery of the planet climate, it is estimated that photosynthesis was shut down for 6 months and climate cooling persisted for at least 9 years, and the occurrence of a fungal bloom sufficient to have left fossil evidence implies that surviving animals were exposed to massive numbers of fungal spores. The darkened skies and cooler temperatures that accompanied the K-T cataclysm would have shielded the sun and reduced the ability of ectothermic creatures such as reptiles to induce fevers by insolation, a necessary activity for protection against fungal diseases. Hence, it is reasonable to posit that ectothermic creatures unable to induce behavioral fevers and in weakened states from environmental stress would have been at a severe disadvantage relative to small mammals with their innate thermal exclusionary zones for fungal growth. Further complicating the situation for reptiles is that eggs can be vulnerable to fungal attack, whereas mammalian progeny would be protected in placentae.'[3]

I think it has merit. We generate a lot of HEAT and it comprises a cr*pload of our total energy losses (as many in NY know without electricity due to Storm Sandy and no heat to fight night time drops to freezing temperatures). As Casadevall reported  'the mammalian lifestyle is energetically costly.'






Mitochondria: Water (H2O) = 286 kJ of P-O-W-E-R

Many obesity researchers appear to forget these multiple evolutionary and hormetic factors in their Big Pharma funded, tenure-track equations. One did not (though partly Joslin funded which is Big Pharma).


In a Nature article, Tseng et al discuss mechanisms to find a drug target to increase cellular bioenergetics and energy expenditure as an anti-obesity strategy [2]. (But... Drug targets are always silly, no?) They discuss PPAR-delta, AMPK and several other pathways with potential promise.  A succinct explanation of how mitochondria produce energy on demand by harnessing the energy from the formation of water in the cellular bioenergetics of mitochondrial metabolism of fuel is provided. They define bioenergetics as the 'Studies the flow of chemical bond energy within organisms. In a living cell, the principal reactions of fuel metabolism take place in the mitochondria, where food energy is released,oxygen is consumed, and water and carbon dioxide are produced.'

All life on earth utilizes the energy formed from water formation to power pathways and metabolism. Remember the Calvin Cycle/Photosynthesis where carbs (glucose) are formed from air (CO2), and energy of the sun? In the mitochondria, the opposite reaction occurs. Energy from the exothermic reaction of water forming from air (O2) and the enzymatic burning of fuel (oxidizable food, glucogen, glucose, fat) result in HEAT and ATP. When one mole of H2O is created from one H2 (hydrogen) and half O2 (oxygen), 286 kJ of power are released (in other words, 68 kcal, which is about one small potato).... FROM FORMATION OF ONLY ONE MOLE OF WATER.

CO2 1/2 O2  =   one mole H2O (~18 grams water = 3.5 teaspoons)  =  286 kJ






Fuel Efficiency of Our Mitochondrial Cellular Respiration

With cellular respiration, instead of an enormous, exothermic explosion (like a hydrogen bomb), the electrons and protons are added step-wise on a gradient known as the electron transport chain (ECT) in plants and animals.  A biological mitochondrial 'battery' is created with the 'anode' on the inner mitochondrial membrane side and the 'cathode' on the other.  Heat is energy released when oxygen is the final proton acceptor and coupled to the enzyme (F1F0-ATPase) that forms ATP, the universal currency of cellular energy in the body. When the protons fall across the proton channel, ATP is formed.  We use ATP as fuel every minute every day for all cellular work, then recycled back to ADP.  In one day, it is estimated that our mitochondria may produce our own weight in ATP [5].

Efficiency of the theoretical transfer of energy from oxidizable fuel to ATP and heat is pretty darn good: 39% ATP and 61% heat [5]. Mitochondria are energy rockstars. Obviously many biolgical factors determine true efficiency: iron status (cytochromes are composed of heme), ubiquinol, oxidative and inflammatory state, thyroid, HPA axis function, hormones, etc.

Plants (chloroplasts) get 3-6% efficiency from transfer of solar energy to the energy bonds of plant starches and fatty acids. Particular C4 plants can get 7-8% (sugarcane) and one super cyanobacteria strain Chlorobaculum tepidum achieves 10%. Various modern fuel efficiencies are approximately -- for coal (~20-30s%) and solar (20%). Photo credit: [5].



References

1. Climate change and seasonal reproduction in mammals. Bronson FH.Philos Trans R Soc Lond B Biol Sci. 2009 Nov 27;364(1534):3331-40.

2. Cellular bioenergetics as a target for obesity therapy.Tseng YH, Cypess AM, Kahn CR. Nat Rev Drug Discov. 2010 Jun;9(6):465-82. [Free PDF here]

3. The Hot Brain: Survival, Temperature, and the Human BodyCarl V Gisolfi, Francisco Mora Teruel. MIT Press (Bradford Book), 2000. [Free SCRIBD text here]

4. Fungi and the rise of mammals.Casadevall A. PLoS Pathog. 2012 Aug;8(8):e1002808.  [PDF]

5. http://highered.mcgraw-hill.com/sites/dl/free/0073525502/930160/mad25502_ch08.pdf

Monday, November 5, 2012

Phat Fat Mitochondrial Energetics: Mobilization v. Accumulation


Adipose is Alive

In ancestral times, adipose stores may have determined longevity and survival past harsh cold winters. My ancestors moved from northern China 8-10+ generations ago to the mountainous areas of Taiwan (according to my dad several hundred years ago). I suppose those who didn't live past the impoverished seasons where food resources were scarce would not have made it, nor would their genes. I can thank them for my persistent fat stores *haa*. Adipose tissue is an endocrine gland which is know to secrete hormones such as leptin and adiponectin to control hunger, body energy balance and energy expenditure. These hormones are involved directly with mitochondrial biogenesis as well, in other words the production and destruction of the mini powerhouses found in all cells (except perhaps glycolytic-dependent cancer cells, which I think are all of them).

Whole body energy balance are determined by many factors, including most importantly:
1) demand
2) diet
3) d*ng hormones (or lack of)



All Organs Sync For Survival

Our brain coordinates many of the hormones that either mobilize or store adipose, e.g. fat. The brain includes the hypothalamus, pituitary, pineal, forebrain, hindbrain, midbrain and our senses for perception (ears, eyes, nose, taste, temperature, barometric pressure, etc). For example, insulin is triggered cephalically (via the brain): by tasting sweetness whether artificial or real, by smelling food, seeing food or even imagining food. Hearing? Hearing the neighborhood ice cream truck as a kid?




Humans Killed for Fat

Fat may have been the biggest boon for man during evolution (see prior animal pharm: humans as marine-based carnivores). Fat contained omega-3s concentrated up the food chain from green chlorophyll sources (grass, algae, etc) and into the muscle fat, organ meats, brains and fat stores of animals and seafood. The encephalization of ancient man is believed to be highly associated with the intake of dietary omega-3s. Perhaps the current de-encephalization over the last 100 yrs is related to the relative deficiency of dietary omega-3s? Or growing overabundance of omega-6s? THANK YOU VERY MUCH corn-fed cows and Keys.




Fat Yields the Most Energy in Human/Mammalian Energy Systems

Hormones for MOBILIZING fat stores far out number the hormones that ACCUMULATE fat. See diagram, modified from Gary Taubes GCBC from a 1965 table of hormonal regulation. Forgive me I use the term 'hormone' loosely because food is hormonal. Fatty acids bind PPAR receptors. We have ~ 3-4 routes to produce energy (some cells utilize glutamine, but I don't know which... neurons only?). Burning fatty acids yields the highest net energy unit (ATP). Why I've wondered? So many hormones promote the escape of fatty acids from temporary storage -- intramuscular, liver, visceral fat, brown fat and subcutaneous fat. Why do we readily release fatty acid energy? Sex, power, survival/suicide? Heat for 37C?

Taubes quoted Hans Krebs who received the Nobel in Medicine in 1953 'All three major constituents of food supply carbon atoms.. for combustion." GNG= gluconeogenesis (glucose/glycogen from any source -- protein, fat, carbs); ATP lesson (click HERE and UCD Lecture and med biochem):



Low Yield but Mandatory Without Oxygen
--anaerobic glycolytic (glucose/GNG) [Yield: 2 ATP]


High Yield in the Presence of Oxygen
--aerobic glycolytic (glucose/GNG) [Yield: 38 ATP] 
--aerobic beta-oxidation of fatty acids like palmitate [Yield: 129 ATP]
--aerobic beta-oxidation of fatty acids like stearate [Yield: 146 ATP]
--aerobic beta-oxidation of fatty acids like ketones [Yield: 51 ATP]
--aerobic oxidation of alcohol [Yield: 16 ATP]


Carbon lengths:
Glucose: 6-carbon carb
Palmitate: 16-carbon saturated fatty acid
Stearate: 18-carbon saturated fatty acid
Ketones (b-oh-butyrate, Ac-Acetate): 4 carbon fatty acid
Alcohol: 2-carbon 'the fourth food group' *haa* tequila is paleo, no?

Prior animal pharm: Palmitate Utilized Between Meals




Mitochondrial Medicine

Where does all this high energy production occur? Of course. Your mitochondria (the lower-net-energy anaerobic pathway is independent of mitochondria, occurs in the cytoplasma).

So. Don't scr*w up your mitochondria. That's like jacking your ride. Blowing out your carburetor.

...FLUNKING your human SMOG TEST.

Mitochondrial medicine is a new field but old premises still apply. The paleo evolutionary paradigm for which your mitochondria and DNA were perfected and honed over 2.5M years of natural and sexual selection are what we believe optimize health and maximize vitality.

Saturday, November 3, 2012

Phytanic Acid (Red Meat, Dairy, Seafood): Binds PPAR-α and RXR


'...Like all things come from the sun'
referencing all the food at the table,
daughter Natalie
ATB Sunset Girl
Courtesy: Youtube.com



Food, Sunlight and Nuclear Receptors

I've discussed RXR/RAR (carotenoids/ vitamin A receptor), VDR (vitamin D receptor) and PPAR-α (saturated fat/omega-3 receptor). These are a constellation of receptors found in the nucleus of all cells which control growth, maturation, reproduction, proliferation, apoptosis (cell suicide), autophagy (cell re-cycling) and inflammation.  Bioactive components of our food and hormone vitamin D from sunlight exposure (or organ meat consumption) bind and control nuclear receptors.

See prior posts:
PPAR -- Dagger in the Heart of CAD and all Chronic Conditions
Benefits of Grassfed Butter





Phytanic Acid Generates Carnitine

A recent study looked at the level of phytanic acid (PA), a
fatty acid found in red meat, dairy fat, and seafood which has activity on receptors known to control and regulate cancer, inflammation, triglycerides/cholesterol and even energy status in skeletal muscles. It may have several mechanisms for health regulation. One mechanism found is that phytanic acid is an agonist for several nuclear receptors including RXR and PPAR-α. I would not be surprised if it has affinity and binds other receptors as well.

We don't synthesize phytanic acid on our own; we can only source from food (animal based). Phytanic acid and its metabolite pristanic acid contribute to the activation of carnitine in peroxisomes which are later transported to mitochondria for fatty acid oxidation (burning and synthesis of energy, ATP). A lack of carnitine has been shown to lower mitochondrial processes and is significant factor in disease. Like phytanic acid, carnitine can mainly be sourced only from MEAT and seafood, not vegetables. We produce it but not very well. Many factors affect carnitine levels (kidney function, ACTH/cortisol, thyroid and diet. French authors write 'L-carnitine ensures regeneration of coenzyme A and is thus involved in energy metabolism. L-carnitine also ensures elimination of xenobiotic substances. Carnitine deficiencies are common.'  Photo credit: [1].

Do butter and bison do a body good?

YESSSSSS.




Chlorophyll Is Biotransformed into Phytanic Acid by Fish and Mammals

Apparently the chlorophyll content of the meat, seafood or dairy is what determines the amount of this important fatty acid, phytanic acid. 'PA (3,7,11,15-tetramethylhexadecanoic acid) is a branched-chain fatty acid generated by the oxidation of the phytol side chain of chlorophyll in mammals. Because humans cannot release phytol from chlorophyll, PA in the human body comes from dairy products and ruminant fats in the diet' [2]. Shore-based food such as fish, salmon, molluscs, snails and krill have significant levels too since these consume smaller fish which consume chlorophyll from algae and green phytoplankton. Phytanic acid is also found in menhaden oils. There is a vague association with prostate cancer and levels of phytanic acid however the below authors discuss "the available data do not support a general causal link between circulating phytanic acid and prostate cancer risk." Phytanic acid is metabolized in peroxisomes -- little fatty storage droplets where enzymes breakdown and metabolize fatty acids. Many of the metabolic breakdown products then go to the mitochondria to provide energy, intermediaries for the respiratory and energy producing complexes, and/or to absorb and quench ROS (reactive oxygen species, aka POLLUTION generated from energy production). If mitochondria are working awry, I suspect phytanic acid accumulation occurs because it is not being appropriately metabolized which could be genomic or post-genomic (Refsum syndrome).



Evolutionary Medicine: Mitochondrial Dysfunction

Many of our chronic diseases are a result of mitochondrial dysfunction -- our tiny nuclear power plants are on the 'blink'...often preferring glycolytic combustion over superior fatty-acid burning.  Mitochondria provide awesome power but can wreak untold destruction as well.

--compromised controls, directions and regulation for proper nuclear plant functioning (AMPK, cAMP)
--lacking power grid efficiency (leptin, insulin, cortisol, SIRT1, adiponectin, secretin, fertuin-A)
--malfunctioning or missing power plant cogs and parts (minerals, carnitine, AcCoA/pantothenic acid, omega-3)
--deficiency of buffering, recycling and containment of nuclear waste (coenzyme Q10/ ubiquinol)
--lacking managers and communicators (cell membrane stability and communication: omega-3 vitamins A B D E K2 thyroid cortisol estrogen progesterone DHEA pregnenolone testosterone saturated fat etc)
--excessive disruptions (high carb diets, endocrine disruptors, PCBs, heavy metals)





From Bacteria 4.5+ bya To Mitochondria

Other strategies to keep mitochondria free of breakdowns -- lifestyles and diet aligned with our evolutionary past from 4.5+ Billion Years Ago:

--lowish carbish (~150 grams or less net effective carbs I like...varying on goals, gut, adrenals, etc)
--saturated fat (~20% or more -- dietary or butt-sourced)
--low fructose
--low omega-6
--high omega-3
--high phytanic acid *wink*
--organic shore-based and grassfed/pasture-based fat and protein
--organic mineral rich plants, berries, nuts, meat/fish/fowl
--intermittent feast v. fast (seasonality)
--optimal hormesis status
--low pollution (air, water, mind)
--enjoyment of culture, music, arts, spiritual enlightenment
--engaging in community and social networks
--movement: rapid intense and languid continuous (yeah S*X counts)


Prior animal pharm:
You are only as strong as your weakest mitochondria...





Health and Food Connection

When I consume ghee (clarified butter), egg yolks, veggies, adequate starches and adequate grassfed beef, pork and lamb, I notice more and easy weight maintenance and improved muscle composition. Mental and physical performance are pretty excellent too. How do you break down food and its effects on mitochondria? Researchers are trying and it's a good thing....
Phytanic acid--an overlooked bioactive fatty acid in dairy fat?

Hellgren LI.
Ann N Y Acad Sci. 2010 Mar;1190(1):42-9.

Abstract
Phytanic acid is a multibranched fatty acid with reported retinoid X receptor (RXR) and peroxisome proliferator-activated receptor-alpha (PPAR-alpha) agonist activity, which have been suggested to have preventive effects on metabolic dysfunctions. Serum level in man is strongly correlated to the intake of red meat and dairy products and the concentration in these products is strongly correlated to the chlorophyll content in the feed of the cattle. Available data suggest that phytanic acid is a natural agonist for RXR at physiological concentrations, while it is more likely that it is the metabolite pristanic acid, rather than phytanic acid itself, that acts as PPAR-alpha agonist. Animal studies show increased expression of genes involved in fatty acid oxidation, after intake of phytol, the metabolic precursor of phytanic acid, but it is at present not possible to deduce whether phytanic acid is useful in the prevention of ectopic lipid deposition. Phytanic acid is an efficient inducer of the expression of uncoupler protein 1 (UCP1). UCP1 is expressed in human skeletal muscles, were it might be important for the total energy balance. Therefore, phytanic acid may be able to stimulate energy dissipation in skeletal muscles. Phytanic acid levels in serum are associated with an increased risk of developing prostate cancer, but the available data do not support a general causal link between circulating phytanic acid and prostate cancer risk. However, certain individuals, with specific single-nucleotide polymorphisms in the gene for the enzyme alpha-methylacyl-CoA racemase, might be susceptible to raised phytanic acid levels. PMID: 20388135




Phytanic Acid (Cheese, Butter) Human RCT

How does phytanic acid perform as a drug? In a tiny Denmark RCT, this was tested.  The control group however also received phytanic acid therefore the results were substantially diluted out IMHO. Methods: In a double-blind, randomized, 4 wk, parallel intervention study 14 healthy young subjects were given 45 g milk fat/d from test butter and cheese with 0.24 wt% phytanic acid or a control diet with 0.13 wt% phytanic acid. The outcomes were positive and associate with metrics that indicate improved mitochondrial functioning (better insulin sensitivity, more fat oxidation, decreased glycolysis).   The lipoprotein changes were impressive but unfortunately the study was too small for meaningful stats. HDL-cholesterol increased by 10% in only one month.  No drug achieves this... or without killing patients or raising BG and diabetes (particularly Crestor).  Is it all phytanic acid?  I dunno...  The researchers enriched the test dairy products by feeding the cows more green material. Subsequently the omega-3 to omega-6 profile in test butter and cheese also improved. They discussed, 'The test butter with the highest content of phytanic acid, also had the highest content of α-linolenic acid [omega-3] and a lower n-6:n-3 ratio of about 1.8. This is in agreement with the higher proportion of clover and grass in the green feeding regime.'   Notwithstanding the beneficial numbers, butter and cheese have other proven bioactive food components which improve heart health, inflammation, insulin resistance and cancer risks, principally, cholesterol, vitamin A/retinol, saturated fatty acids including butyrate, omega-3, taurine (if raw), stigmasterol (if raw; Wulzen factor), folate (5-MTHF) and vitamin K2 (menaquinones).

Results:
(a) HDL increase 10% 
(b) Insulin reduction 15%
(c) TG reduction 22% 




References

1.Verhoeven NM et al. Phytanic acid and pristanic acid are oxidized by sequential peroxisomal and mitochondrial reactions in cultured fibroblasts. The Journal of Lipid Research, Vol. 39, 66-74, January 1998. [Free PDF here]

2. Cell proliferation inhibition and alterations in retinol esterification induced by phytanic acid and docosahexaenoic acid.
Tang XH, Suh MJ, Li R, Gudas LJ.
J Lipid Res. 2007 Jan;48(1):165-76.

3. Novel branched-chain fatty acids in certain fish oils.
Ratnayake WM, Olsson B, Ackman RG.
Lipids. 1989 Jul;24(7):630-7.

4. Oxidative stress and mitochondrial dysfunction in Fibromyalgia. MINIREVIEW.
Cordero MD, Miguel MD, Carmona-López I, Bonal P, Campa F, Moreno-Fernández AM.
Neuro Endocrinol Lett. 2010 Apr 29;31(2):169-173.

5. Oxidative stress: emerging mitochondrial and cellular themes and variations in neuronal injury.
Higgins GC, Beart PM, Shin YS, Chen MJ, Cheung NS, Nagley P.
J Alzheimers Dis. 2010;20 Suppl 2:453-73.

6. Mitochondrial dysfunction and mitophagy activation in blood mononuclear cells of fibromyalgia patients: implications in the pathogenesis of the disease.
Cordero MD, De Miguel M, Moreno Fernández AM, Carmona López IM, Garrido Maraver J, Cotán D, Gómez Izquierdo L, Bonal P, Campa F, Bullon P, Navas P, Sánchez Alcázar JA.
Arthritis Res Ther. 2010;12(1):R17. Free PMC ArticleFree text

7. Connecting the Dots: Molecular and Epigenetic Mechanisms in Type 2 Diabetes.
Goh KP, Sum CF.
Curr Diabetes Rev. 2010 Jun 9.

8. Fetal programming of atherosclerosis: possible role of the mitochondria.
Leduc L, Levy E, Bouity-Voubou M, Delvin E.
Eur J Obstet Gynecol Reprod Biol. 2010 Apr;149(2):127-30.

9. Spinal cord repair in MS: does mitochondrial metabolism play a role?
Ciccarelli O, Altmann DR, McLean MA, Wheeler-Kingshott CA, Wimpey K, Miller DH, Thompson AJ.
Neurology. 2010 Mar 2;74(9):721-7.

10. Antibacterial free fatty acids: activities, mechanisms of action and biotechnological potential.
Desbois AP, Smith VJ.
Appl Microbiol Biotechnol. 2010 Feb;85(6):1629-42.

11. Eating, exercise, and "thrifty" genotypes: connecting the dots toward an evolutionary understanding of modern chronic diseases.
Chakravarthy MV, Booth FW.
J Appl Physiol. 2004 Jan;96(1):3-10. [Free PDF here]

12. Glycolysis: a bioenergetic or a survival pathway?
Bolaños JP, Almeida A, Moncada S.
Trends Biochem Sci. 2010 Mar;35(3):145-9.

13. Type 2 diabetes, cardiovascular disease, and the evolutionary paradox of the polycystic ovary syndrome: a fertility first hypothesis.
Corbett SJ, McMichael AJ, Prentice AM.
Am J Hum Biol. 2009 Sep-Oct;21(5):587-98.

14. Liver fattening during feast and famine: an evolutionary paradox.
van Ginneken VJ.
Med Hypotheses. 2008;70(5):924-8.

15. Biochem pages http://themedicalbiochemistrypage.org/fatty-acid-oxidation.html

16. Carnitine: an overview of its role in preventive medicine.
Kendler BS.
Prev Med. 1986 Jul;15(4):373-90. Review.

17. [L-carnitine: metabolism, functions and value in pathology]
Jacob C, Belleville F.
Pathol Biol (Paris). 1992 Nov;40(9):910-9. Review. French.

18. The metabolism of phytanic acid and pristanic acid in man: a review.
Verhoeven NM, Wanders RJ, Poll-The BT, Saudubray JM, Jakobs C.
J Inherit Metab Dis. 1998 Oct;21(7):697-728. Review.

19. Phytanic acid--an overlooked bioactive fatty acid in dairy fat?
Hellgren LI.
Ann N Y Acad Sci. 2010 Mar;1190:42-9.

20. Effect of dairy fat on plasma phytanic acid in healthy volunteers - a randomized controlled study.  [Free PDF here.]
Werner LB, Hellgren LI, Raff M, Jensen SK, Petersen RA, Drachmann T, Tholstrup T.
Lipids Health Dis. 2011 Jun 10;10:95.

21. Bioactive food components, inflammatory targets, and cancer prevention.
Kim YS, Young MR, Bobe G, Colburn NH, Milner JA.
Cancer Prev Res (Phila). 2009 Mar;2(3):200-8.