30 November 2008

Give Thanks to Your Mitochondria This Holiday Season

Once you've finished gorging yourself on turkey and pie and have decided to burn off that extra "fuel" by shopping non-stop (as an aerobic workout) on Black Friday morning, remember that you have your cells' mitochondria to thank [1].

The mitochondria house the enzymes and conditions necessary for aerobic respiration via the citric acid cycle [1p761-2]. Just a couple of turns of the cycle and the food you eat can give you double the energy than what the cell can produce under anaerobic conditions of glycolysis and the pyruvate dehydrogenase complex [1p761-2].

But the citric acid cycle also does so much more. In the same oxygen-requiring breath of turns, the citric acid cycle makes up molecular precursors or "building blocks" needed by the body [2]. Like glycolysis this role gives the citric acid cycle amphibolic status that includues both catabolism of food and anabolism, or biosynthesis [1p770].

In fact, we owe the citric acid cycle thanks for biosynthesizing non-essential amino acids [1p770]. When the body runs low on one of these, the cell uses the carbon skeletons of citric acid cycle intermediates to produce them again [1p770]. Two intermediates used are:

- Oxaloacetate, in conjunction with glutamate, for the production of aspartate via a transamination reaction—where an enzyme catalyzes the transfer of an alpha-amino group to an alpha-ketoic acid [1p770].

- Alpha-ketoglutarate, in conjunction with ammonium and reduced by NADPH, produces glutamate, which is used to produce glutamine, proline and arginine [1p770].

These amino acids are then used for production of various essential proteins including enzymes and for building body tissues [1p596-7]. Other anabolic building blocks of the citric acid cycle include citrate for creating fatty acids and cholesterol, succinyl-CoA for heme, malate for producing pyruvate, and oxaloacetate for producing glucose [2].

Although the citric acid cycle is also found in bacteria [2], the mitochondria's efficient amphibolic role made its inclusion as part of eukaryotic cells an essential step in the evolution of multi-celled organisms [1p746]. Because mitochondria have their own mtDNA and grow and multiply like bacteria, they are thought to have descended of bacteria captured in eukaryotic cells millions of years ago [1p746].

Genetic research reveals the capture happened only once because all mitochondria can be traced back to one alpha-proteobacterial ancestor [3] and humans one Mitochondrial Eve [4]. As more is learned about that day of capture of our Mitochondrial Eve, we might also find it to be a true day for celebration and to express gratitude.


1. Denniston KJ, Topping JJ, Caret RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007.

2. Wiley. The citric acid cycle [animation]. Available at http://www.wiley.com/college/pratt/0471393878/student/animations/citric_acid_cycle/index.html. Accessed November 28, 2008.

3. Gray MW, Burger G, Lang BF. The origin and early evolution of mitochondria. Genome Biol. 2001; 2(6): reviews1018.1–reviews1018.5. Available at: http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=138944. Accessed on November 28, 2008.

4. Cann RL, Stoneking M, Wilson AC. Nature. 1987 January;325:31-36. Available at http://www.nature.com/nature/ancestor/pdf/325031.pdf. Accessed on November 28, 2008.

26 November 2008

Incredible, edible egg but so high in cholesterol

If it wasn't for its high content of cholesterol, egg yolks would be regarded more strongly as one of nature's health powerhouses [1]. And, if regularly eaten, the egg would go a long way of ensuring against different nutritional deficiencies [1].

Hope has come for a more incredible, edible egg...

If soluble fiber and red yeast rice works on humans to lower cholesterol, why not chickens? They do. Soluble fiber has been shown to significantly impact the amount of total cholesterol in eggs [2]. And a study in China revealed that chickens fed red yeast rice produced egg yolks with significantly less triglycerides and LDL cholesterol [3].

In addition, eggs fortified with omega-3 oils are now a popular marketplace novelty and a welcome approach. Although omega-3 fortification won't change egg cholesterol content, it may help improve its profile for heart health [4].

Contrary to popular opinion, switching to quail eggs would not be beneficial since their cholesterol content is similar to that of chicken eggs [5].

1. Nutrition Data. Available at: http://www.nutritiondata.com/facts/dairy-and-egg-products/113/2. Accessed on November 26, 2008.

2. McNaughton JL. Effect of Dietary Fiber on Egg Yolk, Liver, and Plasma Cholesterol Concentrations of the Laying Hen. J Nutr. Available at: http://jn.nutrition.org/cgi/content/abstract/108/11/1842. Accessed on November 26, 2008.

3. Wang J, Pan T. Effect of red mold rice supplements on serum and egg yolk cholesterol levels of laying hens. Available at: http://cat.inist.fr/?aModele=afficheN&cpsidt=150059352. Accessed on November 26, 2008.

4. Manitoba Agriculture and Rural Initiatives. Increasing Omega-3 Fatty Acids in Eggs from Small Chicken Flocks. Avaialable at: http://www.gov.mb.ca/agriculture/livestock/poultry/bba01s04.html. Accessed on November 26, 2008.

5. Bragagnolo N, Rodriguez-Amaya DB. Comparison of the cholesterol content of Brazilian chicken and quail eggs. J Food Comp Anal. Available at: http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WJH-48B5K4K-1&_user=10&_rdoc=1&_fmt=&_orig=search&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=beb35c37292ad81fe9a7e2e94bc9b859. Accessed on November 25, 2008.

When cholesterol starts creeping up past 200

When total cholesterol begins to creep up past 200 mg/dL, it's time to change diet [1]. If it reaches 240 mg/dL or higher, then the body is at high risk of coronary artery disease and cardiac death [1]. The risk is only accentuated if LDL cholesterol is higher than 160 mg/dL and HDL cholesterol is lower than 40 mg/dL (50 for women) [1].

So, what can be done? Takng cholestyramine and colestipol will help promote excretion of bile [2]. The "statins" atorvastatin, lovastatin and simvastatin can block key enzymes that synthesize cholesterol [2]. Even niacin in the form of nicotinic acid can help through its effects on widening blood vessels [3]. But the benefits of these drugs and the vitamin are extremely limited, because if treatment is stopped, cholesterol can and probably will go back up again unless there is a change of diet [4]. The drugs can also have possible side effects such as liver damage, muscle pain and break down, and kidney problems [4].

A change in diet and lifestyle is most important. Regular exercise, particularly aerobic exercise, increases HDL cholesterol, which in turn helps to lower total cholesterol and LDL cholesterol [5]. In addition, according to Mayo Clinic, the top five foods for lowering cholesterol are oat bran (soluble fiber), nuts, fish oil, olive oil, and plant sterols [6]. Soluble fiber included with meals may reduce absorption of cholesterol, nuts like walntus and almonds can replace high-saturated fat and high-cholesterol foods because their lipid profile includes PUFAs, fish helps to lower TGs through its content of omega-3 oils, olive oil PUFAs and antioxidants help (avoid lite olive oil), and plant sterols block absorption of cholesterol [6].


1. Mayo Clinic. Cholesterol levels: What numbers should you aim for? Available at: http://www.mayoclinic.com/health/cholesterol-levels/CL00001. Accessed on November 25, 2008.

2. Tortora GJ, Derrickson B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons.

3. Grundy SM, Mok HY, Zech L, Berman M. Influence of nicotinic acid on metabolism of cholesterol and triglycerides. Available at: http://www.jlr.org/cgi/content/abstract/22/1/24. Accessed on November 25, 2008.

4. Mayo Clinic.Statins: Are these cholesterol-lowering drugs right for you? Available at: http://www.mayoclinic.com/health/statins/CL00010. Accessed on November 25, 2008.

5. Stein RA, Michielli DW, Glantz MD, Sardy H, Cohen A, Goldberg N, Brown CD. Effects of different exercise training intensities on lipoprotein cholesterol fractions in healthy middle-aged men. Am Heart J.1990 Feb; 119(2 Pt 1): 277-83. Available at: http://grande.nal.usda.gov/ibids/index.php?mode2=detail&origin=ibids_references&therow=282138. Accessed on November 25, 2008.

6. Mayo Clinic. Cholesterol: The top 5 foods to lower your numbers. Available at: http://www.mayoclinic.com/health/cholesterol/CL00002. Accessed on November 25, 2008.

22 November 2008

When you're full of dirty, hot air.

You could be a politician or you could have emphysema. The disorder usually is due to years of irritation from cigarette smoke, but anyone could get emphysema if exposed to years of air pollution or exposure to industrial dust [1p887].

The long-term irritation and resulting inflammation damages or destroys the walls of air sacs in the lungs [2]. The loss of elasticity causes bronchioles to collapse and air becomes trapped in the air sacs, over-stretching them and not allowing full ability to exhale [2]. The air sacs can rupture and the lung is left with abnormally large air spaces that stay filled with air [2].

Oxygen diffusion across the respiratory membrane is also reduced due to less surface area for gas exchange [1p887]. This limits the amount of oxygen in the blood and can result in leaving a person breathless even during mild exercise [1p887]. Symptoms are coughing, loss of appetite as well as fatigue [2].

Excessive mucus and inactivity of cilia–eventually allow irritants to damage the alveolar tissue, which can end up allowing squamous cancer cells to spread into the lower respiratory tract [3].

It's worth noting that oxygen therapy is one of the few therapies actually proven to keep those with emphysema living longer and with a better quality of life [4]. If you know anyone with emphysema, let them know. Oxygen therapy at night can be especially beneficial [4]. And if the patient doesn't exercise, all the more reason.

Three out of four adults with alpha-1 antitrypsin deficiency (AAT), a genetic disorder, will also get emphysema. Since the liver makes the protein and releases it into the blood stream it only takes a blood test to find out if you have AAT deficiency.


1. Tortora, GJ, Derrickson, B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons.
2. Mayo Foundation for Medical Education and Research. Emphysema and Smoking. Available at http://emphysema.org/.
3. http://www.pul.unimaas.nl/respir.htm
4. http://www.nslij.com/body.cfm?id=5987
5. http://www.nlm.nih.gov/medlineplus/alpha1antitrypsindeficiency.html

Bad case of heartburn

After a large meal and red wine some of the stomach acid produced can flow back into the esophagus due to a relaxed or weakened sphincter [1]. Lying down on the couch is a bad idea since it probably would make the acid backup worse [2].

The resulting heartburn causes the primary symptoms, which is a burning pain in the chest under the breastbone [2]. Heartburn can happen occasionally to almost anyone, but if the symptoms become frequent, then the heartburn may be related to gastroesophageal reflux disease [2].

You can drink some baking soda mixed with cream of tartar and water as a temporary measure, then think about changing your diet to smaller meals and losing some fat [2].

Home remedies might help. Digestive enzymes help to get the digestive process moving more quickly. Increasing fiber absorbs acid and gas. Tea soothes the stomach and gets things going. You can also try ginger.

1. Tortora, GJ, Derrickson, B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons.
2. Mayo Clinic. Heartburn. Available at: http://www.mayoclinic.com/health/heartburn-gerd/DS00095. Accessed on November 22, 2008.

I'll have a tall glass of fresh-squeezed fructose

Orange juice delivers a potent dose of what is roughly half glucose and half fructose [1].

Glucose, we know, is the simple sugar that serves as the primary source of fuel to the blood, brain and muscle [2p735]. Its intake stimulates the release of insulin, goes through glycolysis to create energy, and is used to synthesize of glycogen for storage [2p735].

Fructose does not stimulate the release of insulin, nor does it enter glycolysis in the same way as glucose [3]. In fact it enters glycolysis a few steps later after going through its own metabolism. After being transported to the liver, fructose is phosphorylated by fructokinase to form fructose 1-phosphate, then by aldolase B to dihydroxyacetone phosphate and glyceraldehyde [3p58]. Glyceraldehyde is phosphorylated to glyceraldehydde 3-phosphate, and this molecule along with dihydroxyacetone enter glycolysis [3p58]. In the muscle, fructose is phosphorylated by hexokinase to fructose 6-phosphate, which is then used for glycogenesis or glycolysis [3p358].

Apart from being famous for being sweeter than glucose and the disaccharide sucrose (of which fructose is half part of), would the low-glycemic "fruit sugar" be better for the body since it create less of an insulin response? Science says "probably not."

In fact, high consumption of fructose is now being blamed for type 2 diabetes. The influx of fructose to the liver from soda with high-fructose corn syrup is found to interfere with glucose metabolism through metabolic dyslipidemia, a disturbance that may induce insulin resistance [4]. You get extra lipogenesis from fructose. Fructose by-passes the conversion of glucose 6-phosphate to fructose 1,6-phosphate. This is glycolysis's main regulatory step. Fructose, then, is "unregulated" and able to "uncontrollably" over-produce triglycerides. Evidence is now showing that the diabetes and obesity, which have become modern-day epidemics, could be prevented through significant reduction of fructose in the diet [4].

Research is also showing fructose may be more detrimental than glucose in high amounts. A study at the University of California on overweight or obese adults who were given beverages sweetened with fructose or glucose showed that those drinking the beverage with fructose gained pounds and had higher triglycerides and higher serum LDL cholesterol levels [5].


1. Ghanim H, Mohanty P, Pathak R, Chaudhuri A, Sia CL, Dandona P. Orange juice or fructose intake does not induce oxidative and inflammatory response. Available at:
http://care.diabetesjournals.org/cgi/content/abstract/30/6/1406. Accessed on November 20, 2008.
2. Denniston KJ, Topping JJ, Caret RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007.
3. Salway JG. Medical biochemistry at a glance, 2nd ed. 2006; Malden, Mass: Blackwell Publishing. (excellent book!!)
4. Basciano H, Federico L, Khosrow A. Fructose, insulin resistance and metabolic dyslipidemia. Nutrition & Metabolism. Available at: http://www.nutritionandmetabolism.com/content/2/1/5. Accessed on November 22, 2008.
5. DeNoon DJ. Study: Fructose increases heart risk factors and weight. WebMD Health News. Available at: http://www.medicinenet.com/script/main/art.asp?articlekey=82117. Accessed on November 20, 2008.

21 November 2008

When you can't degrade glycogen

Your brain, blood and muscles depend almost entirely on dietary glucose as a fuel source so your body must store the sugar for continual supply [1p733]. If you go without eating for a while or jog a mile or two you’ll find yourself relying on glycogen for energy [1p733]. The long-branched glucose polymer acts as a store of glucose molecules, ready for the moment’s need [1p733]. But imagine having inherited a defective gene that resulted in not allowing your body to degrade glycogen stores.

If it wasn’t for Mendelian genetics, von Gierke’s disease may never have been completely understood [2]. Also called type 1 glycogen storage disease, the inherited disorder was found in 1952 using Mendel’s principles to result from a defective gene that causes the lack of glucose-6-phosphate [2 & 1p740]. The enzyme is necessary for catalyzing the final step in gluconeogenesis and glycogenolysis, which is needed for synthesis of glucose from noncarbohydrates precursors and removal of glucose from glycogen when blood glucose levels are low [1p740].

Without an ability to degrade glycogen, those with the disease suffer from low blood sugar between meals that can reach dangerous levels, and excessive accumulation of glycogen in the liver, muscle and in the tubules of the kidneys that can create further health complications [1p740 & 3]. Symptoms include an enlarged liver; puffy cheeks and limbs; a swollen belly; constant hunger; stunted growth; delayed or underdeveloped puberty, gout, easy bruising and nosebleeds, fatigue, and irritability [3].

Living with von Gierke’s disease requires avoiding low blood sugar through frequent meals that include carbohydrates and feeding tubes used at night [3]. Because lactose and fructose can’t be broken down properly, milk and fruits are usually avoided [3].


1. Denniston KJ, Topping JJ, Caret RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007.
2. Lorentz CP, Wieben ED, Tefferi A, Whiteman D, Dewald G. Primer on medical genomics part I: History of genetics and sequencing of the human genome. Mayo Clin Proc. 2002;77:773-782. Available at: http://www.mayoclinicproceedings.com/inside.asp?AID=165&UID=. Accessed on November 19, 2008.
2. MedlinePlus. Von Gierke disease. Medical Encyclopedia. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000338.htm. November 19, 2008.

16 November 2008

A little history on breast cancer

It was good to learn a bit about breast cancer, especially considering that I walked for breast cancer just recently and was among many breast cancer survivors. Now I know a little more about what their lives are like.

A little history lesson summarized (see source below):

Breast cancer dates back to 1600 BC (as far as we know) in ancient Egypt. The Egyptians used to cauterize the tumors. The first surgeries removing lymph nodes didn't occur until the early 1800s. In 1882 the first mastectomies occurred, particularly the radical mastectomy. The procedure was popular up until the 1970s and is still common. One in 12-13 women will suffer from breast cancer. Research continues to find a cure.

Source: http://www.syl.com/articles/thehistoryofbreastcancerfightingthemostcommoncancerinwomen.html


Preventing spread of breast cancer

We may soon see drugs that can help prevent the spread of breast cancer. Last year in April it was found that breast cancers produce an overabundance of the protein Akt, which plays a key role in metastasis.(1)

Akt's role was tested by researchers who bred mice with a missing gene for Akt.(1) Mice with no copies of the gene for Akt rarely developed tumors, those with only one copy of the gene for Akt developed some tumors, while mice with two copies of the gene developed cancer rapidly.1

The research could potentially lead to drugs that target this protein in humans.(1)


1. Thomas Jefferson University (2007, April 11). Scientists Identify Protein Key To Breast Cancer Spread, Potential New Drug Target. ScienceDaily. Retrieved November 16, 2008, from http://www.sciencedaily.com­ /releases/2007/04/070409181641.htm

Radical Mastectomy and Arm Swelling

Due to the presence of breast cancer, Mrs. Franco had a right radical mastectomy in which her right breast and underlying muscle, right axillary lymph nodes and vessels were removed. Now she is experiencing swelling in her right arm Why did the surgeon remove lymph tissue as well as the breast? Why is Mrs. Franco's right arm swollen?

Radical mastectomy is now rarely performed and only used in cases of extensive tumors or cancer cells that have invaded the chest wall (1). In this case, the cancer may have moved into lymph nodes under the arm and in the chest muscle.(2) The spread of the cancer would have occurred via metastasis, cells traveling through the lymph or blood and establishing new tumors wherever they lodge (3p811).

The right arm is swollen due to lymphedema, which is an accumulation of lymph in lymphatic vessels (3p841). If the swelling comes with tenderness and redness and she is feeling a fever come on, it is possible that infection may have occurred.(4) She should seek treatment immediately to not see symptoms worsen.


1. http://www.oncologychannel.com/mastectomy/index.shtml
2. Tortora, GJ, Derrickson, B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons.
3. http://som.medselfed.com/asp/prodDisplay.asp?prodId=407&partnerId=som&id=&cachedate=
4. http://www.breastcancer.org/tips/lymphedema/avoid.jsp

Scuba Diving Hypoxia

Just reading and writing about blood loss has made me feel a little lightheaded, and then I realized where I'd seen the term hypoxia.

Hypoxia can occur at high altitudes, especially if scuba diving at high altitudes, because the air has less pressure than at sea level and you inhale less oxygen.(1)

To prevent hypoxia while scuba diving at high altitudes (which could kill you), you should take a few days to acclimatize yourself to thinner air, make sure you don't over-exert yourself underwater, catch your breath regularly, and rise to the survace slowly.(1)


1. http://www.ehow.com/how_2238064_prevent-hypoxia-scuba-diving.html

Gunshot hypovolemic shock

A gunshot wound and bleeding is sure to cause hypovolemic shock due to blood loss, external and internal (1p756). The body is generating the response as part of a negative feedback system that is attempting to correct the problem (1p756):

- Low systolic blood pressure is due to reduced amount of blood.

- Rapid heart rate is caused by sympathetic increase of blood levels of epinephrine and norepinephrine.

- Weak, rapid pulse is due to reduced amount of blood and cardiac output.

- Reduced blood flow to kidneys causes secretion of antidiuretic hormone that increases water reabsorption and causes blood vessel constriction by secreting renin.

- The thirst is due to loss of extracellular liquid.

- Cool, pale, and clammy skin is due to the sympathetic constriction of blood vessels and stimulation of sweating.

- The confused and disoriented mental state is because of reduced oxygen supply to the brian.

An emergency room will need to stop the bleeding right away and replace loss of blood and fluids.(2) This is in addition to helping whatever other situation the bullet might have caused.


1. Tortora GJ, Derrickson B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons, p756-758.
2. MedlinePlus. Hypovolemic shock. Medical Encyclopedia. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000167.htm.

Why Vitamin B is My Co-pilot

B vitamins play a major role in producing energy in the cells, but they certainly aren't top gun. They are converted in the body to act as coenzymes.

As coenzymes they have almost no independent catalytic power because they must rely on being temporarily bound as organic prosthetic groups to an apoenzyme, then called a holoenzyme (1p643).

In a very complex reaction of three enzymes and five coenzymes, four B vitamin-derivative coenzymes act in synergy with yet another coenzyme (lipoamide) to produce pyruvate dehydrogenase complex (1p750).

Thus, any deficiency of the four B vitamins—thiamine, riboflavin, niacin, and pantothenic acid—could severely impact cellular respiration.(1p750)

You could think of pyruvate dehydrogenase complex as a fighter jet equipped with B vitamin wingmen. The pilot is its substrate pyruvate, which later develops into that maverick of a central charcter in the citric acid cycle, acetyl CoA (1p751).


1. Denniston KJ, Topping JJ, Caret RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007.

15 November 2008

Power-Saving Tips From Biochemistry

Need to lower the electric bill? You could learn a thing or two about conservation from your body's own cells.

Each one possesses a highly evolved system of energy efficiency that consists of regulatory enzymes (1). These catalysts can be activated and deactivated depending on conditions in the cell (1p649-651).

When strategically located as a first step or near-first step of a metabolic pathway, a regulatory enzyme acts as biochemical light switch.(2) The enzyme switches "on" and "off" effectively speeding up or slowing down pathway production and preventing any drain of effort.(2)

An example of three regulatory enzymes in action can be found in glycolysis, the 10-reaction pathway used to produce energy from carbohydrates(1p726):

1. Hexokinase catalyzes the first reaction of the pathway and is inhibited by high concentration of its own product.

2. Phosphofructokinase, the key regulatory enzyme, catalyzes the third reaction and is allosterically inhibited by glycolysis product, ATP, and intermediate, citric acid. This is an example of feedback inhibition.

3. Pyruvate kinase catalyzes the last reaction. Because it is activated by activation of phosphofructokinase through feedforward activation, it is allosterically inhibited by inhibition of phosphofructokinase.

In other words, the last enzyme in the pathway is saying, "First and third one out, don't forget to turn off the lights."


1. Denniston, KJ, Topping, JJ & Caret, RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007

2. Stavrianeas, S. Teaching glycolysis regulation to undergraduates using an electrical power generation analogy. Adv Physiol Educ. 2005;29:128-130. Available at: http://advan.physiology.org/cgi/content/full/29/2/128-a. Accessed on Nov. 15, 2008.

14 November 2008

Deeply Flawed

Our bodies are not perfect. Far from it. In fact, they have serious flaws. Most importantly, its greatest flaw is that one day it will die. Over time evolution decided it preferred that humans die so those younger, stronger kids can take over eating, mating, etc.

You and I may not be OK with dying. If we pour effort or money into anything, it should be in trying to keep ourselves living longer. Live long and forever, if at all possible. Gosh, I think I'll have to dedicate my life to learning about longevity.

Most of all, longevity of the brain. The way I se it, if my brain goes, I pretty much am done too. Gotta study longevity, brain health, etc.

08 November 2008

Choline for adrenaline

Ciara is driving home from school, listening to her favorite music, when a dog darts into the street in front of her car. She manages to swerve to avoid hitting the dog. As she continues on her way she notices her heart is racing, she has "goose-bumps" and her hands are sweaty.

When the dog darted in front of Clara's car, her body went through a sympathetic "fight-or-flight" response, which is an inborn, automatic effect that can occur under conditions of acute stress.(1&2) The effects may have also included pupils dilating, airways to her lungs dilating, blood vessels to her kidneys and gastrointestinal tract constricting, blood vessels involved in exercise to fight off danger dilating, release of glucose by the liver, liver cells performing glycogenolysis.(1p537)

The effect is triggered by acetylcholine released from sympathetic nerves, which can activate many tissues simultaneously.(1p537 & 2) A release of adrenaline and norepinephrin from the medulla of the adrenals facilitate the intense physical effects.(2) We share this response with many other animals.(2)

Gives you a new reason to make sure you get the choline you need daily for synthesis of acetylcholine.


1. Tortora, GJ & Derrickson, B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons.
2. Psychologist World. Stress: The fight or flight response. Available at: http://www.psychologistworld.com/stress/ fightflight.php. Accessed on Oct. 25, 2008.

I am 99% bacteria, 1% human

Sounds really creepy, but it's true. And we count on all our little friends to keep us healthy, keeping our gastrointestinal tract functioning and absorbing minerals well, and producing the critical vitamin K that is so important to our lives. Vitamin K, made by the large intestine flora, is vital for synthesis of clotting factors that make up normal blood clotting. It also helps inhibit osteoporosis by keeping calcium out of your arteries and in your bones.

So next time you need to get rid of an infection and are on antibiotics, be sure to repopulate and grow your gut flora with probiotics and prebiotics to keep yourself healthy long-term.

07 November 2008

A Tale of Two Bacterial Strains

It was the hottest of times, it was the coldest of times, and it was billions of years before the French revolution when one bacterial strain became two and possibly a few more.1p630 One of these strains would thrive in what we now know to be the Arctic Cold.1p627 Another would survive in the vents of a volcano.1p627 Not so coincidentally, both strains depend on vital functions of hexokinase.1p627 Normally hexokinase would become denatured while exposed to hot, molten rock.1p627

How does the volcano strain survive? The answer lies in significantly more R group interactions of amino acids found in holding its tertiary structure together.1p630 These noncovalent interactions play their role of stability via hydrogen bonding, ionic bonding and van der Waals forces.1p614 The extra support keeps hexokinase's globular protein alpha-helix and beta-pleated sheets from unfolding.1p609

Although perhaps not nearly complex as R group interactions, the bacterial strains would require another variation: maintaining membrane fluidity.1p582 The two bacterial strain's membrane lipids differ in their ratios of saturated and unsatured fats.1p582 While North Pole bacteria require a greater percentage of unsaturated fat double-bond "kinks" for their membranes to stay fluid, the membranes of bacteria in a firy environment are usually made up of a higher percentage of saturated fats.1p582

What does this information mean for humankind? The mystery of the beginning of life may partially lie in how both bacterial strains developed. Animals and plants both contain hexokinase, which plays roles in glycolysis and possibly sugar signal transduction pathways.1p726 & 2 Additionally all cells contain membrane lipids.1p557 Thus, the more we learn about these bacteria, the more we may learn about ourselves and our own humble origins.


1. Denniston, KJ, Topping, JJ, Caret, RL. General, Organic, and Biochemistry, 5th ed. New York: McGraw Hill; 2007.

2. Sheen, J, Jang, J. The role of hexokinase in plant sugar signal transduction and growth and development. Plant Molec Biol. 2000;44:451–461. Available at: http://genetics.mgh.harvard.edu/sheenweb/reprints/sugarPMB00.pdf. Accessed on November 5, 2008.

02 November 2008

Lecithin - good for your brain and liver

Lecithin provides choline, which is a precursor for the neurotransmitter acetylcholine in the brain.(1) Choline is also necessary to remove fat from the liver.(2) Thus, supplementation could be extremely beneficial for alcoholics to prevent against cirrhosis.(2)


1. http://www.jacn.org/cgi/content/abstract/11/5/473
2. http://www.medschool.northwestern.edu/newsworthy/past-years/2002/2002H-May/choline.htm

Ampipathic lecithin

Lecithin's talent comes from its amphipathic nature.(1) The compound's hydrophilic polar head dissolves in water while its hydrophobic polar tail dissolves in the triglycerides, thus, acting in a way of suspending triglycerides in water.(1p568)

As an emulsifier in ice cream, lecithin keeps ice cream smooth with fat globules evenly distributed throughout the solution.(2) It serves to bring fat and ice crystals together, which normally don't mix. Before commercial lecithin was available, egg yolks were used.(2)

Another useful application:

Want to know how to make your own salt air foam to a homemade margarita? The secret is soy lecithin. You can buy it at any health food store and mix about a teaspoon with water, salt and lime juice.


1. Denniston, KJ, Topping, JJ & Caret, RL. General, Organic, And Biochemistry, 5th ed. New York: McGraw Hill; 2007, p568.

2. Halford, B. Ice cream: The finer points of physical chemistry and flavor release make this favorite treat so sweet. Science & Technology. 2004;82(45):51. Available at: http://pubs.acs.org/cen/whatstuff/stuff/8245icecream.html. Accessed on November 1, 2008.

Why does low cholesterol cause aggression?

There might be a Darwinian explanation. According to Meninger clinic researchers, lower blood LDL cholesterol may be a signal for famine, which led to an adaptation of a response of more aggressive behavior.(1) Of course I think this is a pretty far-reaching hypothesis, but it's interesting.


Erickson, MT. Lowered serum cholesterol, famine and aggression : a Darwinian hypothesis. Available at: http://cat.inist.fr/?aModele=afficheN&cpsidt=2872688. Accessed on November 2, 2008.

What's the new rage? Omega-3 Index

Blood omega-3 oils could be just as or more important than blood LDL cholesterol levels.

Last week I attended a conference in Las Vegas where I heard a cardiologist say bluntly that doctors need to be retrained to stop limiting their focus to blood LDL cholesterol for preventing heart disease and start using the novel Omega-3 Index.

What's that?

According to a 2004 article in Preventative Medicine, the index serves as a "novel, physiologically relevant, easily modified, independent, and graded risk factor for death from CHD that could have significant clinical utility."(1)

The Omega-3 Index is used as a biomarker to measure the percentage of EPA and DHA omega-3 fatty acids in the blood cell membranes.(2) The omega-3 oils replace other fatty acids.(2)

A high value of omega-3 oils is linked to reduced risk of cardiovascular disease as well as other benefits.(2) A value of 8 percent or above in omega-3 oils can mean a 90 percent reduced risk of sudden cardiac death.(2)


1. Harris, WS, Von Schacky, C. The Omega-3 Index: a new risk factor for death from coronary heart disease. Available at: http://www.ncbi.nlm.nih.gov/pubmed/15208005. Accessed on November 1, 2008.

2. Daniells, S. Omega-3 index could be goalpoasts for max heart health. Available at: http://www.nutraingredients.com/Research/Omega-3-index-could-be-goalposts-for-max-heart-health. Accessed on November 1, 2008.

01 November 2008

Promoters say cholesterol is a nutrient - not true

I am a bit stunned by argument for consuming cholesterol by cholesterol-promoterscholesterol-and-health.com because the body makes all the cholesterol it needs (about a gram a day)and a dietary amount is unnecessary.(1) For this reason, I'm not sure I can bring myself to call the lipid a nutrient.

While it is true that cholesterol-rich foods such as eggs may be considered good for the body and could even reduce risk heart disease, these benefits are not attributed to their cholesterol amounts, but to other nutrients that come with the cholesterol.(2)

From what I can gather, the only real reason for seeking out dietary cholesterol is if a person has a genetic disorder that would interfere with the body's own cholesterol production.(3)


1. American Heart Association. Cholesterol. Available at: http://www.americanheart.org/presenter.jhtml?identifier=4488. Accessed on November 1, 2008.

2. Harvard's School of Public Health. Nutrition Source: Eggs and heart disease. Available at: http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/eggs/index.html. Accessed on November 1, 2008.

3. University of Utah Genetic Science Learning Center. Smith-Lemli-Opitz Syndrome. Available at: http://learn.genetics.utah.edu/content/disorders/whataregd/slos/. Accessed on November 1, 2008.

3 reasons to still avoid cholesterol (even though it's not bad for you)

More than 50 years have gone by since it was first discovered that too much LDL cholesterol in the blood is linked to heart disease, and, in response, healthcare professionals of all kinds have provided a simple message: "cholesterol is bad".(1)

More recent research, however, tells a different story -- that eggs, liver, shrimp and lobster are not the demons they were once thought to be.(1) Most people who eat these cholesterol-rich foods will find they have little or no impact on blood cholesterol levels.(1) This is good news for the average man who eats 337 milligrams and average woman who eats 217 milligrams daily.(2)

Why then do the American Heart Association and many informed healthcare professionals still recommend intake of cholesterol be no more than 300 milligrams?(2)

Reason 1: Dietary cholesterol comes from animal foods usually along with saturated fat.(2) Both saturated fat and trans fat have a significant impact on higher amounts of LDL cholesterol in the blood.(2)

Reason 2: The body produces about a gram of cholesterol a day, all it needs.(2) Extra cholesterol from the diet is unnecessary and must be removed from the body via the liver.(2)

Reason 3: Cholesterol intake can have an impact on blood LDL cholesterol levels in certain individuals.(2) Thus, those with high blood cholesterol should be conscious of this fact.(2)

1. Harvard School of Public Health. The bottom line: Choose healthy fats, limit saturated fat, and avoid trans fat. Nutrition Source: Fats and Cholesterol [online]. Available at: http://www.hsph.harvard.edu/nutritionsource/what-should-you-eat/fats-full-story/index.html. Accessed on Nov. 1, 2008.
2. American Heart Association. Cholesterol. Available at: http://www.americanheart.org/presenter.jhtml?identifier=4488. Accessed on Nov. 1, 2008.

Don't drive long-distances with grandpa if he has diabetes

The ultra-frequent pit stops will drive you nuts (even if he's your beloved grandpa). Buy grandpa a plane ticket!

Excessive thirst and urination signals uncontrolled diabetes mellitus, diabetic ketoacidosis or diabetes insipidus.(1) Urinalysis and blood testing are meant to detect the first two conditions.(2&3) When blood testing shows normal glucose levels and there is no presence of ketones in the urine, then diabetes insipidus is diagnosed.(1&2)

Diabetes insipidus is a condition that occurs when the kidneys cannot conserve water properly.(3) The cause is a defect in antidiuretec hormone receptors or an inability to secrete antidiuretic hormone.(4p659) The hormone, produced by the hypothalamus and stored and released by the pituitary gland, cause the kidneys to return more water to the blood.(4p631-3) Without the hormone working properly, urination increases substantially.(4p633)


1. MedlinePlus. Urination - excessive volume. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/003146.htm. Accessed on Nov. 1, 2008.
2. MedlinePlus. Ketones - urine. Available at: http://www.nlm.nih.gov/MEDLINEPLUS/ency/article/003585.htm. Accessed on Nov. 1, 2008.
3. MedlinePlus. Diabetes insipidus. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000377.htm. Accessed on Nov. 1, 2008.
4. Tortora, GJ & Derrickson, B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons, p.659.

Get an opthalmoscopic exam

A non-invasive, five- to 10-minute opthalmoscopic examination can reveal:

Hypertension - Detected by swelling of the optic nerve and visual center of the retina can, hypertension is caused from narrowing arteries and amount of blood pumped by the heart.(2&3) If hypertension is not controlled it can lead to permanent damage to the optic nerve or macula. Decreasing salt intake, eating healthy, physical activity and even supplementation with omega-3 oils or coenzyme Q10 can improve conditions.(3)

Diabetes mellitus and diabetic retinopathy - Diabetes is a condition whereby the body is resistant to insulin or cannot produce sufficient insulin.(4) It can lead to spots floating in vision, blurred vision, dark streaks or a red film blocking vision, poor night vision and diabetic retinopathy. The latter is detected using a dye to spot bleeding from blood vessels in the center of they eye.(5)

Cataracts - Detected by examining abnormalities in the cornea, iris, lens, and the space between the iris and cornea, cataracts cause clouding of the lens of the eye.(6) The impaired vision can develop slowly and reach a point when surgery may be needed.(6) Cataracts can be prevented through early detection, not smoking, eating well, protection from the son, and treating other problems such as diabetes.(6)

Age-related macular disease - Detected when abnormal blood vessels behind the retina start to grow and leak fluid damaging the macula rapidly, age-related macular disease (degeneration) gradually destroys sharp, central vision.(7) The disease causes no pain so its onset can be a surprise.(7) The disease appears to affect white women more than other populations.(7) Prevention involves not smoking, eating healthy, maintaining normal blood pressure, maintaining a healthy weight and exercising regularly.(7)


1. Tortora, GJ & Derrickson, B. Principles of Anatomy and Physiology, 11th ed; 2006. New York: John Wiley & Sons.
2. MedlinePlus. Hypertensive retinopathy. Medical Encyclopedia [online]. Available at: http://www.nlm.nih.gov/medlineplus/ency/article/000999.htm. Accessed on Nov. 1, 2008.
3. Mayo Clinic. High blood pressure (hypertension). Available at: http://www.mayoclinic.com/health/high-blood-pressure/DS00100. Accessed on Nov. 1, 2008.
4. Mayo Clinic. Type 2 diabetes. Available at: http://www.mayoclinic.com/health/type-2-diabetes/DS00585. Accessed on Nov. 1, 2008.
5. Mayo Clinic. Diabetic retinopathy. Available at: http://www.mayoclinic.com/health/diabetic-retinopathy/DS00447. Accessed on Nov. 1, 2008.
6. Mayo Clinic. Cataracts. Available at: http://www.mayoclinic.com/health/cataracts/DS00050. Accessed on Nov. 1, 2008.
7. National Eye Institute. Age-related macular degeneration. Available at: http://www.nei.nih.gov/health/maculardegen/armd_facts.asp. Accessed on Nov. 1, 2008.