“It’s not that chocolates are a substitute for love. Love is a substitute for chocolate. Chocolate is, let’s face it, far more reliable than a man …”
— Miranda Ingram
Substances in chocolate that have been discussed in the scientific literature as pharmacologically significant, include: anandamide, arginine, epicatechins, histamine, magnesium, phenylethylamine (PEA), polyphenols, salsolinol, serotonin, theobromine, tryptophan, tyramine and vitamin C. Of course some of these exist in higher concentrations in other foods, but other foods have much less appeal than chocolate!
The Cacao Bean’s Natural Chemical Constituents and Their Concentrations (when available):
3-ALPHA-L-ARABINOSIDYL-CYANIDIN
3-BETA-D-GALACTOSIDYL-CYANIDIN
4-HYDROXY-3-METHOXY-BENZOIC-ACID
3-METHYLOXYTYRAMINE
ACETIC-ACID 1,520 – 7,100 ppm
ALANINE 10,400 ppm
ALKALOIDS 33,900 ppm
ALPHA-THEOSTEROL
AMYL-ACETATE
AMYL-ALCOHOL
AMYL-BUTYRATE
AMYLASE
ANANDAMIDE
ARABINOSE
A cacao god
ARGININE 800+ ppm
ASCORBIC-ACID 31 ppm
ASCORBIC-ACID-OXIDASE
ASPARIGINASE
BETA-THEOSTEROL
CAFFEIC-ACID
CAFFEINE Petiole 51 – 525 ppm or 500 – 12,900 ppm, Skin 130 – 723 ppm
CALCIUM 800 – 1,100 ppm
CAMPOSTEROL
CARBOHYDRATES 347,000 – 445,000 ppm
CATALASE
CHLORIDE 120 ppm
CHROMIUM (10 times more than whole wheat, highest of any major food)
CITRIC-ACID 4,500 – 7,500 ppm
COPPER 24 ppm
COUMARIN
CYANIDIN-3-BETA-L-ARABINOSIDE
CYANIDIN-3-GALACTOSIDE
CYANIDIN-GLYCOSIDE 4,000 – 5,000 ppm
DOPAMINE
EPIGALLOCATECHIN
ERGOSTEROL
ESCULETIN
FAT 371,000 – 582,300 ppm
FERULIC-ACID
FIBER 59,000 – 89,000 ppm
FORMIC-ACID
FURFUROL
GLUCOSE 3,000 ppm
GLUTAMIC-ACID 10,200 ppm
GLYCINE 900 ppm
HISTAMINE
HISTIDINE 800 ppm
INVERTASE
IRON 36 – 37 ppm
IRON-OXIDE 40 ppm
ISOBUTYL-ACETATE
ISOLEUCINE 5,600 ppm
L-EPICATECHIN 27,000 ppm
LACTIC-ACID
LEUCINE
LEUCOCYANIDINS 14,000 – 35,000 ppm
LINALOL 5 ppm
LINOLEIC-ACID
A cacao god
LINOLENIC-ACID
LYSINE 800 ppm
LYSOPHOSPHATIDYLCHOLINE
MAGNESIUM
MANNAN
MANNINOTRIOSE
MANNOSE
MELIBIOSE
MESO-INOSITOL
METHYLTETRAHYDROISOQUINOLINE
METHYL-HEPTENONE
N-BUTYLACETATE
N-LINOLEOYLETHANOLAMINE — Anandamide reuptake inhibitor
N-NONACOSANE
N-OLEOLETHANOLAMINE — Anandamide reuptake inhibitor
NIACIN 17 – 18 ppm
NICOTINAMIDE 21 ppm
NITROGEN 22,800 ppm
NONANOIC-ACID
O-HYDROXYPHENYLACETIC-ACID
OCTOIC-ACID
OLEIC-ACID 190,000 – 217,000 ppm
OLEO-DIPALMATIN 76,500 – 92,800 ppm
OLEOPALMITOSTEARIN
OXALIC-ACID 1,520 – 5,000 ppm
P-ANISIC-ACID
P-COUMARIC-ACID
P-HYDROXY-BENZOIC-ACID
P-HYDROXYPHENYLACETIC-ACID
P-TYRAMINE
PALMITIC-ACID
PALMITODIOLEN
PANTOTHENIC-ACID (Vitamin B5) 13 ppm
PECTIN
PENTOSE
PEROXIDASE
A cacao god
PHENYLALANINE 5,600 ppm
PHENYLETHYLAMINE
PHOSPHATIDYL-CHOLINE 92 – 1,328 ppm
PHOSPHOLIPIDS
PHOSPHORUS 3,600 – 5,571 ppm
POLYPHENOLS 78,000 – 100,000 ppm
PROLINE 7,200 ppm
PROPIONIC-ACID
PROTEIN 120,000 – 180,000 ppm
PROTEINASE
PROTOCATECHUIC-ACID
PURINE 30,000 – 40,000 ppm
PYRIDOXINE (Vitamin B6) 1 ppm
RIBOFLAVIN (Vitamin B2) 1 – 4 ppm
SALSOLINOL
SERINE 8,800 ppm
SEROTONIN
SITOSTEROL
SPERMIDINE
SPERMINE
STACHYOSE
STARCH 60,000 ppm
STEARIC-ACID
STEARODIOLEIN
STIGMASTEROL
SYRINGIC-ACID
TANNINS 75,400 ppm
TARTARIC-ACID
TELEMETHYLHISTAMINE
THEOBROMINE 10,000 – 33,500 ppm
THEOPHYLLINE 3,254 – 4,739 ppm — Theophylline is a methyl-xanthine with diuretic and bronchial smooth muscle relaxant properties.
THIAMINE (vitamin B1) 1 – 3 ppm
THREONINE 1,400 ppm
TOCOPHEROL (BETA, GAMMA) (vitamin E forms)
TRIGONELLINE
TRYPTOPHAN
TYRAMINE
TYROSINE 5,700 ppm
VALERIANIC-ACID
VALERIC-ACID
VALINE 5,700 ppm
VANILLIC-ACID
VERBASCOSE
VERBASCOTETROSE
WATER 36,000 ppm
XYLOSE
NOTE: The ppm (parts per million) values listed above will not add up to 1,000,000 as some constituents contain the other (e.g,. protein contains glycine), the information is derived from many different studies, and the natural variation of nutrients.
456 calories
3.6 g H2O
12.0 g protein
46.3 g fat (typically 40 to 50 grams, but sometimes as low as 12 grams)
34.7 g total carbohydrate (starch ranges from 1.3 to 7.5 grams according to Ridenour, Amer. Jour. Pharm., 1895, p. 209)
8.6 g fiber (albuminous matter ranges from 6 to 18 grams)
3.4 g ash
106 mg calcium
537 mg phosphorus
3.6 mg Fe (iron)
0.17-0.24 mg thiamine
0.14-0.41 mg riboflavin
1.7 mg niacin
2.1 mg nicotinamide
1.35 mg pantothenic acid
0.09 mg pyridoxine
3.0 mg ascorbic acid
The Individual Amino Acids In The Water-Soluble Fractions of Unfermented and Fermented Beans are (in grams per 100 grams):
| Compound | Unfermented | Fermented |
|---|---|---|
| lysine | 0.08 | 0.56 |
| histidine | 0.08 | 0.04 |
| arginine | 0.08 | 0.03 |
| threonine | 0.14 | 0.84 |
| serine | 0.88 | 1.99 |
| glutamic acid | 1.02 | 1.77 |
| proline | 0.72 | 1.97 |
| glycine | 0.09 | 0.35 |
| alanine | 1.04 | 3.61 |
| valine | 0.57 | 2.60 |
| isoleucine | 0.56 | 1.68 |
| leucine | 0.45 | 4.75 |
| tyrosine | 0.57 | 1.27 |
| phenylalanine | 0.56 | 3.36 |
Unfermented and Fermented Beans Contain
p-hydroxybenzoic acid
vanillic acid
p-coumaric acid
ferulic acid
syringic acid
The Fermented Beans Also Contain
protocatechuic
phenylacetic
phloretic acid
esculetin (a lactone)
o- and p-hydroxyphenyl acids
The Unfermented Beans Also Contain
Caffeic acid
According to the Wealth of India, the Edible Pulp of the Fruit Contains
79.7 to 88.5% water
0.5 to 0.7% albuminoids, astringents, etc.
8.3 to 13.1% glucose
0.4 to 0.9% sucrose
A trace of starch
0.2 to 0.4% non-volatile acids (as tartaric)
0.03% Fe2O3
0.4% mineral salts (K, Na, Ca, Mg)
| Class | Compound | Percent by Weight |
|---|---|---|
| Neurotransmitters | Serotonin | 0.62 – 5.82 |
| Histamine | 0.04 – 0.13 | |
| Methylxanthines | Theobromine | < 1.3 |
| Caffeine | not detected | |
| Tetrahydroisoquinolines | Salsolinol | High |
| Methyltetrahydroisoquinoline | < 0.01 | |
| Amines | Phenylethylamine | 0.02 – 2.20 |
| Tele-methylhistamine | 0.01 – 1.54 | |
| Spermidine | 0.05 – 1.15 | |
| p-tyramine | 0.02 – 0.35 | |
| 3-methyloxytyramine | 0.02 – 0.33 | |
| Tryptamine | 0.03 – 0.18 | |
| Spermine | 0.00 – 0.13 |
Source: Biochemist, Apr/May 1993, p. 15.
20-30% palmitic and lower acids (16:0)
30-35% stearic and higher acids (18:0)
30-35% oleic acid (18:1)
2-4% linoleic (18:2) (omega 6 fatty acid)
0-0.3% linolenic (18:3) (omega 3 fatty acid)
Cocoa butter contains mainly beta- and gamma-tocopherols (vitamin E forms) in the range of 150-250 mg/gram.
Polar lipids make up 1-2% of the cacao bean. Of these polar lipids two-thirds are glycolipids and one-third are phospholipids and phytosterols. Phytosterols are found in concentrations of 1.8 to 2 mg/gram and are composed of sitosterol (50-70%), stigmasterol (20-30%) and camposterol (5-9%).
For more information on understanding fats and oils in food, please reference Udo Erasmus’ book Fats That Heal, Fats That Kill.
Cocoa Powder Contains Over 300 Volatile Compounds, Including
Esters
Hydrocarbons
Lactones
Monocarbonyls
Pyrazines
Pyrroles
The Important Flavour Components Include
Aliphatic esters
Polyphenols (antioxidants)
Unsaturated aromatic carbonyls
Pyrazines
Diketopiperazines
Theobromine
Cocoa Powder Also Contains
18% Proteins (8% digestible)
Fats (cocoa butter)
Amines and Alkaloids, including:
Theobromine (0.5 to 2.7%)
Caffeine (0.25% in cocoa; 0.7 to 1.70 in fat-free beans, with forasteros containing less than 0.1% and criollos containing 1.43 to 1.70%)
Tyramine
Dopamine
Salsolinol
Trigonelline
Free amino acids
Tannins
Phospholipids
According to Jonathan Ott in his book The Cacahuatl Eater: Ruminations Of An Unabashed Chocolate Addict, 100 grams of Cocoa Contains:
550 mg magnesium
3.6 mg copper
7.6 mg zinc
3.8 mg manganese
0.17 mg pyridoxine
0.33 mg pantothenic acid
0.2 mg vitamin E
The Average Cacao Shell Contains
11.0% moisture
3.0% fat
13.5% protein
16.5% crude fiber
9.0% tannins
6.0% pentosans
6.5% ash
0.75% theobromine
The remaining percentages were unspecified in this report.
Cacao Shells/Skins Were Found by T. S. Clarkson To Contain
0.9% alkaloids (theobromine, caffeine)
10.9% nitrogenous matter
5.32% fat
5.6% mucilage
9.07% ash containing aluminum
A resin soluble in ether and alcohol, and having the odour of cacao.
In addition to alkaloids (mainly theobromine), tannins and other constituents, cocoa shells/skins contain a pigment that is a polyflavone glucoside with a molecular weight of over 1500; this pigment is claimed to be heat and light resistant, highly stable at pH 3 to 11, and useful as a food colourant; it was isolated at a 7.9% yield (Leung, 1980).
As students of nutrition, we are convinced that the primary components of foods that influence feelings of health, well-being, nourishment and satisfaction are minerals. We believe that any conversation about nutrition can first begin with a study of minerals because the primary mineral or minerals contained in a food reveal much about its magic.
Magnesium is the most deficient major mineral in the diet of civilisation and yet is one of the most important of all minerals. Over 80% of the United States’ population is deficient in magnesium.
An ancient pyramid at Teotihuacan, Mexico
In nature, the primary source of magnesium is cacao (raw chocolate beans)! Other sources of magnesium include seaweeds such as kelp and dulse, unprocessed wheat seeds, sunflower seeds, almonds, cashews, chlorophyll-rich green vegetables, micro-algae (chlorella, spirulina, AFA blue-green algae, marine phytoplankton), cleansing fruits such as cassia (senna), and/or sea salts. Notably, magnesium is found at the centre of the chlorophyll molecule.
Due to its unusually high content of alkaline magnesium, cacao is the most alkaline of all nuts. Cacao contains more magnesium than almonds do calcium.
Magnesium supports the heart, increases brainpower, causes strong peristalsis (bowel movements), relaxes menstrual cramping, relaxes muscles, increases flexibility, helps build strong bones and increases alkalinity. Magnesium, as a primary alkaline mineral, opens up over 300 different detoxification and elimination pathways.
Dr. Bernard Jensen’s research on the heart indicates that this organ requires two minerals more than any other, magnesium and potassium. Cacao, of course, is a fantastic food source of heart-supporting magnesium.
Magnesium is concentrated eighteen times greater in the heart muscle than in the bloodstream. Magnesium is the primary mineral missing when heart problems occur. Magnesium increases the overall vigour of the heart muscle. This mineral also decreases blood coagulation thus lowering blood pressure and helping the heart pump more effectively. An abundance of magnesium is effective in decreasing angina pain and in lowering some types of high blood pressure.
Chocolate to the Mayans and Aztecs was referred to as yollotl eztli (heart blood). Chocolate, as we know it, is known for its sensual love vibration. Chocolates are always given as love offerings. Interestingly, the magnesium levels and antioxidants in cacao support the heart directly. We have often heard that “chocolate opens the heart” — which is actually true.
Our personal experience of this has been profound. We feel that chocolate is helping usher in the “Cardiozoic Age” — the Age of Heart. Cacao seems to help correct the imbalance between mind and heart, allowing the mind to serve the heart. Increasing the heart energy brings forth compassion, wonder, healing and, most importantly, unconditional love.
Magnesium activates almost all the key enzymes needed for our neurons to produce energy from glucose, in the form of ATP (adenosine triphosphate) molecules. Magnesium is also necessary for the stable storage of ATP, so it will not spontaneously break down and waste its energy as heat. Proper brain function depends on a constant supply of ATP. When magnesium is in abundance then the brain works with clarity and focus. When magnesium is chronically deficient or depleted, then brain metabolism and brainpower are sharply reduced. Now we see why cacao is such an extraordinary brain food.
In the cerebrospinal fluid that bathes the brain and spinal cord, magnesium is present in higher concentrations than in the blood plasma. Of the 300+ different enzymes in the human body that require magnesium to function, a great many are crucial to cerebral metabolism and cognitive function. For example, magnesium activates glutamine synthetase, an enzyme responsible for converting waste ammonia — an extremely toxic byproduct of normal protein metabolism — into urea for proper disposal. The ability to focus and pay attention can be compromised by even small increases in brain ammonia.
Magnesium is also needed to activate the enzyme (D6D) that converts medium-chain omega 3 fatty acids (such as hemp seed and flaxseed oil) into DHA, the most abundant fatty acid in brain cell membranes. Deficiencies in DHA have been associated with numerous neurological disorders from attention-deficit disorder (ADD and ADHD), poor memory, post-partum depression and Alzheimer’s disease.
Our brain needs magnesium to build the protective myelin sheaths that insulate the nerve fibers that network our nervous system.
Biochemist James South, an expert on brain nutrition, sees a remarkable similarity between the symptoms of attention-deficit disorder (ADD) and the symptoms of chronic magnesium deficiency. These include difficulty concentrating and remembering, confusion and disorientation, irritability and apathy, as well as muscular restlessness.
Magnesium and vitamin B deficiencies cause a reduction in the production of dopamine. Studies in animals have shown that a magnesium deficiency causes a depletion of brain dopamine without affecting brain serotonin and norepinephrine (noradrenalin). Active vitamin B6, by the way, increases the cellular absorption of magnesium and therefore works in concert to increase the production of dopamine. Natural active vitamin B6 (found in high concentrations in spirulina, goji berries and bee pollen) increases the cellular absorption of magnesium and therefore works in concert to increase the production of dopamine. We will revisit the incredible synergy between spirulina, goji berries and bee pollen with cacao in the Chocolate Alchemy section of this book.
Charles Plumier, Cacao, from a manuscript on plants and civilizations in the Antilles, c. 1686
Magnesium is essential to the pituitary gland. This gland takes information from the hypothalamus in the brain and transmits it through the body as chemical messengers or hormones. These hormones directly influence the production of many other vital hormones in the body. Cacao’s high magnesium levels thus have a marvellous effect in supporting balanced hormone levels.
When the pituitary lacks magnesium, it causes the adrenal glands to overproduce, thus increasing the heart rate, causing excitability and an inability to cope comfortably with daily challenges. This lack of magnesium leads inevitably to psychological, social, physical, emotional, mental and spiritual stress.
Magnesium is also the primary reason why cacao works great as a laxative. Think about it, the major problem with Western civilisation is not war, the economy or crime; these are symptoms of a bigger problem — constipation! And cacao ends constipation! Imagine if everyone in Washington DC ate cacao! Can you see what this means for the future of the planet?
Accounts of chocolate causing PMS are unfounded and scientifically unproven. In fact, chocolate seems to soothe PMS symptoms as most women know intuitively. Woman have a chocolate center in their brain which informs them of the truth, while men tend to remain clueless. Low magnesium levels are likely the primary reason women crave chocolate before, during and/or after the menstrual period. Magnesium requirements may increase before, during and/or after the menstrual cycle. Other secondary reasons why chocolate cravings increase may be due to cacao’s hormone balancing effects and its natural endorphins (anandamide).
To relax, muscles need magnesium. Magnesium increases flexibility and strength. A chronic magnesium deficiency leads to excessive muscle tension, including spasms, twitches and restlessness. This can be especially true of the hands and feet and facial muscles.
According to Professor L. Kervran in his book, Biological Transmutations, magnesium can be biologically transmutated into calcium. However, the reverse has not been observed. This accounts for the observation that increased magnesium intake has been shown to strengthen bones. It also accounts for the strange alkaline properties of high magnesium foods.
The Menier chocolate factory near Paris, France circa 1900
• aggressive behaviour
• alcoholism
• amyotrophic lateral sclerosis
• anorexia
• apathy
• arrhythmia
• asthma
• attention deficit disorder (ADD and ADHD)
• blood vessel clots
• calcification of organs, tissue, and small arteries
• cancer
• cerebral palsy
• chronic fatigue syndrome
• cluster headaches
• confusion
• constipation
• convulsions
• cramps
• depression
• diabetes
• disorientation
• failure to grow
• fibromyalgia
• fluoride toxicity
• head injuries
• heart-related conditions
• headaches
• HIV
• hyperacidity
• hypertension
• insomnia
• irritability
• kidney stones
• migraines
• multiple sclerosis (MS)
• muscular weakness
• muscle tremors
• muscle tics
• myocardial infarction
• nervousness
• neuromuscular problems
• osteoporosis
• premenstrual syndrome (PMS)
• psychiatric disorders
• rheumatoid arthritis
• sickle cell anaemia
• stress
• toxic shock syndrome
• vertigo
• Alcohol
• Alcohol-withdrawal-stress
• Cocaine
• Beta-adrenergic agonists (for asthma)
• Corticosteroids (CS) (for asthma)
• Theophylline (isolated for asthma)
• Diuretics
• Thiazide
• Caffeine (coffee)
• Phosphates (found in soda drinks)
• Nicotine
• Physical or mental stress
• Excessive dietary fat – especially meats, nuts, and seeds
• High quantities of dietary fiber
• High quantities of dietary calcium
• Deficiencies of copper, boron, or vitamin B6
Research indicates that cacao contains therapeutic levels of magnesium. Therapeutic levels indicate an ability to reverse a deficiency as the following study indicates:
“Ability of a Cocoa Product to Correct Chronic Magnesium (Mg) Deficiency In Rats” by Planells E., Rivero M., Mataix J., Llopis J., Department of Physiology, School of Pharmacy, Institute of Nutrition and Food Technology, University of Granada, Spain. Int J Vitam Nutr Res 1999 Jan; 69(1):52-60
Epidemiological studies have reported that Western diets are often deficient in magnesium (Mg). We investigated the ability of a cocoa-derived product, used in some European countries as a dietary complement added to milk, to aid recovery from chronic Mg deficiency in rats. The animals were divided into three groups, each of which received a different amount of dietary Mg. Rats in the Mg-deficient (D) group received an Mg-deficient diet (0.225 g Mg/kg food) during 8 weeks. In the cocoa-supplement group (D + CC), the rats consumed the Mg-deficient diet for 5 weeks, and were then switched for 3 further weeks to the same diet supplemented with 3% (wt/wt) cocoa product, so that the Mg content of the diet was 0.27 g/kg food. Rats in the control group (C) were given the same diet as in group D, except that the amount of Mg was 0.56 g Mg/kg food. We measured the concentration of Mg, Ca and P from ten rats in plasma, whole blood, skeletal muscle, heart, kidney and femur in rats that were fed the diets for 35, 42, 49 or 56 days. In animals fed the cocoa-supplemented diet (D + CC) significant improvements were found between days 35 and 56 in the alterations in Mg, Ca and P caused by Mg deficiency in all tissues studied. On day 56, kidney and bone concentrations of Mg and Ca had returned to normal. Our findings show that the habitual use of the cocoa product as a dietary supplement favours correction of the negative effects of long-term feeding with a diet moderately deficient in Mg.
According to research cited in The New York Times, fresh cacao beans are super-rich in antioxidant flavonols. Cacao beans contain 10,000 milligrams (10 grams) per 100 grams of flavonol antioxidants. This is a whopping 10% antioxidant concentration level! This makes cacao one of the richest sources of antioxidants of any food. Compare the cacao bean to processed cocoa powder and chocolates which range in flavonol content from the more common concentration of 500 milligrams per 100 grams in normal chocolate bars to 5,000 milligrams in Mars Corporation’s special Cocoapro cocoa powder.
Research has demonstrated that the antioxidants in cacao are highly stable and easily available to human metabolism.
Cornell University food scientists found that cocoa powder has nearly twice the antioxidants of red wine and up to three times what is found in green tea.
Their findings were published in an article entitled “Cocoa Has More Phenolic Phytochemicals and a Higher Antioxidant Capacity than Teas and Red Wine” found in the American Chemical Society’s Journal of Agriculture and Food Chemistry, a peer-reviewed publication.
Scientists have known that cocoa contains significant antioxidants, but no one knew just how rich they were compared with those in red wine and green tea.
The Cornell researchers, led by Chang Y. Lee, chairman of the Department of Food Science and Technology at Cornell University’s New York State Agricultural Experiment Station in Geneva, N.Y., say the reason that cocoa leads the other drinks is its high content of antioxidant compounds called phenolic phytochemicals, or flavonoids. They discovered 611 milligrams of the phenolic compound gallic acid equivalents (GAE) and 564 milligrams of the flavonoid epicatechin equivalents (ECE) in a single serving of cocoa. Examining a glass of red wine, the researchers found 340 milligrams of GAE and 163 milligrams of ECE. In a cup of green tea, they found 165 milligrams of GAE and 47 milligrams of ECE.
Lee and his colleagues used two chemical tests that measured how well the cocoa antioxidant compounds scavenge and clean up free radicals. Free radicals are renegade oxygen molecules that have been associated with DNA damage, premature aging, heart disease and cancer.
“If I had made a prediction before conducting the tests, I would have picked green tea as having the most antioxidant activity,” said Lee. “When we compared one serving of each beverage, the cocoa turned out to be the highest in antioxidant activity, and that was surprising to me.” Phenolic compounds protect plants against insects and pathogens, and they remain active even after food processing. A decade ago “food scientists did not know that phenolics had an important role in human health,” says Lee.
University of California at Davis research demonstrated that antioxidant levels in the blood rose exponentially for six hours after the subjects consumed semisweet chocolate. Antioxidants can reach target cells in as quickly as 30 minutes when cocoa is consumed as a beverage according to studies done by Holt R.R., Lazarus S.A., Sullards M.C., et al.
A growing body of research has suggested that chocolate has beneficial effects on the cardiovascular system. The Journal of Clinical Nutrition and many other peer-reviewed publications have reported that the antioxidant polyphenols in chocolate are protective of the heart and circulatory system.
Research published in the Journal of the American College of Nutrition and the journal Circulation demonstrates that eating a few squares of dark chocolate daily increases the ability of the blood vessels to dilate. This study focused on flavonoids, another term for the antioxidants found in chocolate.
A group of eleven volunteers were given 46 grams (1.6 ounces) of dark chocolate rich in flavonoids daily for two weeks and compared with a control group of ten volunteers who were given dark chocolate low in flavonoids.
At the end of the trial, the researchers used ultrasound to measure how well blood vessels were able to relax if blood flow increased, a process called flow-mediated dilation. They examined the brachial artery in the arm; how well this artery dilates reflects the ability of the coronary arteries to dilate.
At the end of the two weeks, the arteries of the group that had eaten the flavonoid-rich chocolate had a greater capacity to expand, up from 10.2 percent to 11.5 percent, compared with a reduction in the control group. The senior researcher, Mary Engler, Professor of Physiological Nursing at the University of California, said: “Improvements in endothelial function — the ability of the artery to dilate — are indicative of improved vascular health and a lower risk for heart disease.”
The researchers also found that concentrations of the cocoa flavonoid epicatechin, thought to be beneficial for blood vessel function, was higher in the high-flavonoid group. About this Engler added: “It is likely that the elevated blood levels of epicatechin triggered the release of active substances that vasodilate, or increase, blood flow in the artery.”
The Associated Press reported, in August 2004, the findings of a study conducted by cardiologists at Athens Medical School in Greece indicating dark chocolate improves the functioning of the cells lining blood vessels. The study involved 17 healthy young volunteers who were given 3.5 ounces of either dark chocolate or fake chocolate. The study found that chocolate made the blood vessels more flexible thus decreasing the potential of hardening of the arteries and reducing the possibility of heart disease. Flavonoid antioxidants contained in chocolate were suspected of creating the noticeable improvement in cardiovascular health.
In other research, chocolate antioxidants have been shown to reduce the oxidation of low-density lipoproteins (LDL) or “bad cholesterol.” Cocoa powder in an infusion concentration of 1.5% to 3.3% inhibits LDL oxidation as much or better than green tea. The oxidation of LDL is considered a major factor in the development of heart disease and strokes.
Additionally, stearic acid, the predominant saturated fat in chocolate, is a unique fatty acid which has a neutral effect on blood cholesterol levels.
Research recently carried out at King’s College, London, suggests that chocolate antioxidants inhibit platelet aggregation (the clumping of red blood cells) which decreases the likelihood of atherosclerosis (degradation of the arteries).
Further research by the Department of Nutrition at the University of California at Davis found that not only does chocolate prevent platelet aggregation, it beneficially thins the blood as well. Thinner blood lowers blood pressure and decreases the possibility of blood clots or strokes. What was interesting was that their research demonstrated that the protective factors were specifically in the unadulterated cacao bean.
Studies done on the Kuna tribe of the San Blas Islands off of Panama by Dr. Norman K. Hollenberg, Professor of Medicine at Brigham and Women’s Hospital and Harvard Medical School, found a connection between eating cacao and circulatory system health. Dr. Hollenberg found that the Kuna tribespeople had a high-salt diet, yet normal blood pressure and they consume locally-grown cacao at every meal. His study followed some of the Kuna people as they migrated into the city, where they started consuming commercially ground cocoa which caused their blood pressure to rise.
A study financed by National Institute of Health grants and Mars Corporation involved 27 healthy people ranging in age from 18 to 72. Each consumed a cocoa powder beverage containing 900 milligrams of flavonol antioxidants daily for five days. Using a finger cuff, blood flow was measured on day one and day five of the study. Researchers found a “significant improvement” in blood flow and in the function of the endothelial cells that line the blood vessels.
Research has recently been conducted on the effects of chocolate antioxidants on cancer. Cocoa powder has shown an inhibitory effect on human colonic adenocarcinoma in vitro.
In vitro studies have demonstrated the inhibitory effect of epicatechin antioxidants on human 5-lipoxygenase which may contribute to the reported anti-inflammatory effects of chocolate.
On top of, and in addition to all of this, a study of 8,000 male Harvard graduates showed that chocolate-lovers lived longer than abstainers. Their longevity may be explained by the high polyphenol levels in chocolate.
What all this is saying is that cacao is miraculous. Premium chocolate is good for you. Cocoa is at least as good and actually much better for you than red wine or green tea, and chocolate can actually save the planet.
| dark chocolate | 13,120 |
| milk chocolate | 6,740 |
| prunes | 5,770 |
| raisins | 2,830 |
| blueberries | 2,400 |
| blackberries | 2,036 |
| kale | 1,770 |
| strawberries | 1,540 |
| spinach | 1,260 |
| raspberries | 1,220 |
| brussel sprouts | 980 |
| plums | 949 |
| alfalfa sprouts | 930 |
| broccoli | 890 |
Source: US Department of Agriculture / Journal of the American Chemical Society
Cacao and dark chocolate boost antioxidants; however, the addition of dairy milk cancels out the effects of antioxidants. Studies indicate that dairy products specifically block the absorption of all the great antioxidants in chocolate! Consider the following studies:
“Plasma Antioxidants From Chocolate” Mauro Serafini*, Rossana Bugianesi*, Giuseppe Maiani*, Silvia Valtuena*, Simone De Santis* & Alan Crozier†
There is some speculation that dietary flavonoids from chocolate, in particular epicatechin, may promote cardiovascular health as a result of direct antioxidant effects or through antithrombotic mechanisms. Here we show that consumption of plain, dark chocolate results in an increase in both the total antioxidant capacity and the epicatechin content of blood plasma, but that these effects are markedly reduced when the chocolate is consumed with milk or if milk is incorporated as milk chocolate. Our findings indicate that milk may interfere with the absorption of antioxidants from chocolate in vivo and may therefore negate the potential health benefits that can be derived from eating moderate amounts of dark chocolate.
“Nutrition: Milk and Absorption of Dietary Flavanols”
December 18, 2003
Nature 426, 788 (18 December 2003); doi:10.1038/426788a
Mauro Serafini* and Alan Crozier†
Serafini et al. reply — Our results indicate that there is an increase in total antioxidant capacity (TAC) and epicatechin content of plasma in people who have consumed dark chocolate, and that these effects are reduced by the presence of milk.
A recent study showed that only one out of 500 people who thought they were allergic to chocolate actually tested positive. The idea that chocolate is a common allergen has been around for a long time, but recent evidence suggests an allergy to chocolate is quite rare. It is more often the case that the person is in fact allergic to pasteurized milk and dairy products. Pasteurized milk is the number one food that causes allergies.
Research by US Naval Academy concluded that there is no evidence that chocolate causes or exacerbates acne.
Acne is likely triggered by the refined sugars added to chocolates. Refined sugar can cause hypoglycemia, hormone fluctuations, moodiness and skin outbreaks.
We have actually seen individuals who do react and get acne even after they eat high-quality, organic, dairy-free, 70%+ cacao, cooked chocolate bars. However, these same individuals have no reaction to eating raw cacao, even in large amounts (20-40 cacao beans in a day).
Our perspective based on experience is that cooking cacao changes the chemical structure of cacao causing it to be more allergenic, although the allergens even in processed chocolate are very low.
“When one has drunk this beverage, one can travel all day without fatigue and without taking any nourishment.” — Bernal Diaz del Castillo, a soldier in Cortes’ army whose memoir, published many years after his journey, remains one of the most famous accounts of the conquest.
Cacao can increase one’s energy substantially. Cacao does contain the stimulating methylxanthines: theobromine and caffeine. Although the quantities of these substances range from 1 to 2 percent of the whole cacao bean, the effects are felt.
In 18 commercial specimens of cacao, A. Eminger (Forschungsberichte ber Lebensmittel, 1896, p. 275; see also Amer. Jour. Pharm., 1897, p. 113) found theobromine to vary from 0.88 to 2.34 percent, caffeine from 0.05 to 0.36 percent.
We are just beginning to understand that there is a difference between raw theobromine and caffeine and cooked theobromine and caffeine. Certainly, more research needs to be done. Our experience indicates that the theobromine and caffeine compounds in their raw, uncooked form have milder effects.
Consider the research done in homeopathy, a branch of medical science. Experimental provings of chocolate by homeopaths indicate its stimulating effect when cooked, but not when eaten raw. One experiment conducted with a decoction of roasted ground cacao beans in boiling water produced an excitement of the nervous system similar to that caused by black coffee and an excited state of circulation, demonstrated by an accelerated pulse. Notably, when the same decoction was made with raw, unroasted beans neither effect was noticeable, leading the provers to conclude that the physiological changes were caused by aromatic substances released during roasting.
The base chemical theobromine (C7H8N4O2) is sparsely distributed in the plant world, occurring in 19 species, most of them in the Sterculiaceae and Rubiaceae families. Theobromine was discovered in cacao seeds by Woskresensky in 1841. Some other popular theobromine containing substances include: coffee, tea (Camellia sinensis), the world-famous yerba maté drink (which has a dynamic interaction with cacao) and the kola nut, a close relative of cacao, which is famous as a constituent of soda drinks.
Yerba maté (Ilex paraguariensis) tea and cacao together create a stimulating beverage of varying strength depending on the quality of the yerba maté. Together, of course, the two substances increase the levels of xanthine alkaloids, including: theobromine, theophylline, matteine and caffeine as well.
Theobromine can form as a metabolite of caffeine. This means that if one ingests caffeine, then, after some time, theobromine will show up in the blood and in the urine. Though still habituating, theobromine is milder and has about a quarter of the stimulating power of its sister molecule caffeine. Theobromine gently stimulates the central nervous system, relaxes smooth muscles and dilates blood vessels.
Theobromine is a more effective cough medicine than traditional remedies. Peter Barnes, Professor of Thoracic Medicine at Imperial College London and colleagues, gave ten healthy volunteers tablets containing either: theobromine (the equivalent of about two cups of cocoa), codeine (a common cough suppressant) or a placebo.
As part of a standard test for cough medicines, the volunteers each inhaled a gas containing a derivative of chili peppers that induces coughing.
Those given theobromine needed about one-third more of the gas to produce coughing than those who took codeine; and they experienced no side effects. Codeine was only slightly more effective than the placebo at preventing coughing and has side effects such as drowsiness and constipation.
Theobromine is also a mild diuretic (increases urination) and had been used as a medical drug in cases where a heart attack had resulted in an accumulation of body fluid.
Theobromine is a cardiac stimulant. This is a reason why it had been used to treat high blood pressure. One of the reasons why dogs should not eat cacao or chocolate is because this food can cause a cardiac arrest since dogs lack the enzymes necessary to metabolise quantities of theobromine in excess of 100-150 mg per kilogram of the dog’s body weight.
In humans, theobromine has quite long-lasting effects. Liver enzymes decrease theobromine levels by only 50% between six to ten hours after consumption.
It seems that theobromine is formed in the cacao seed and in its papery skin when it begins to sprout as a protective mechanism against bacteria. Theobromine has demonstrated cariostatic effects (it destroys the bacteria that cause tooth decay). According to Park, C.E. et al. (1979), cacao powder has proven effective to inhibit the growth of 102 types of bacteria. At least one antibiotic chemical responsible for this activity is theobromine.
According to E. Knebel (1892), the presence of a red hue in some fermented cacao beans is due to the decomposition of a sugar-compound in cacao under the influence of fermentation which results in dextrose and cacao-red theobromine.
Based on the evidence, we are lead to the conclusion that fresh (unsprouted) cacao seeds taken directly from the fruit contain low or no theobromine and therefore have less stimulating and habituating properties.
Estimates of how much caffeine is present in cacao differ, depending on the source. Consider the following estimates we came across in our research:
• A 1.4 ounce serving of chocolate contains the same amount of caffeine as one cup of decaffeinated coffee.
• A cup of hot chocolate usually contains about four or five milligrams of caffeine, which is about one-twentieth that of a cup of regular coffee.
• According to the Chocolate Information Centre, a 50-gram piece of dark chocolate — about the size of your average chocolate bar — will yield between 10 and 60 milligrams of caffeine, while an average five-ounce cup of coffee can yield up to 175 milligrams.
• 800 grams of milk chocolate contains the equivalent amount of caffeine present in a cup of coffee.
• One ounce of Hershey’s Baking Chocolate, Special Dark and Milk Chocolate contain 26, 22 and 5 milligrams of caffeine respectively.
• A cup of coffee may contain 50 to 175 milligrams of caffeine, a cup of tea contains 25 to 100 milligrams, and a cup of cocoa beverage contains 25 milligrams to none.
Some believe that cacao generally contains no caffeine at all. This idea is based on the confusion between the sister alkaloids: caffeine and theobromine. The two stimulants are related and have similar structures, but are nonetheless different chemicals with different effects and properties.
The Biochemist, (Apr/May 1993, p. 15) did chemical composition tests where they specifically distinguished between caffeine and theobromine. They typically found up to 1.3%, by weight, theobromine in chocolate. They also found other pharmacologically active compounds including up to 2.20% phenylethylamine, up to 1.54% telemethylhistamine, and occasionally up to 5.82% serotonin. They could not detect any caffeine at all. The Merck Index, 12th Edition, says that a very small amount of caffeine is found in the shell/skin of the cacao bean, but then the shell/skin are typically discarded before eating or processing.
We have seen that those who are caffeine-sensitive (have caffeine allergies) may react to processed chocolate with a strong headache or other symptoms and to cacao with a slight headache or other symptoms. This reaction could be caused by caffeine or theobromine. If this happens, we recommend immediately drinking a glass of water containing two tablespoons of MSM (methyl-sulphonyl-methane) powdered crystals, which typically alleviates minor symptoms of food-based allergies. Also, consider that dehydration is a causative agent in headaches.
In a study by Moffett A.M., et al., involving 25 subjects selected because they believed that eating chocolate caused their headaches, only two subjects consistently developed migraine headaches after exposure to chocolate (the subjects were given identical-looking bars which may or may not have contained chocolate). In a total of 80 exposures to chocolate, only 13 headaches were reported. Moffett, et al. summarized their experiment with the conclusion: “chocolate on its own is rarely a precipitant of migraine.”
Research indicates that overdoses of chocolate in a range sufficient to deliver 300 mg of caffeine and 300 mg of theobromine can irritate the stomach and central nervous system.
Our experience indicates that eating raw cacao, over time, can actually desensitize one to the cooked xanthine components of processed chocolate. We have noted that individuals who would feel headaches or irritations in their breasts from processed chocolate, will feel improvements in these sensations by eating raw cacao over time.
Phenylethylamine (PEA) has been dubbed the “love chemical.” Based on the hard, scientific evidence this is probably not true, but it sounds great! PEA seems to help create feelings of attraction, excitement and euphoria. When we fall in love our PEA levels increase and we become peppy and full of optimism. PEA is noticeably abundant in the brains of happy people.
The brain releases PEA when we are sexually aroused. PEA levels can peak during orgasm.
If we believe that things have gone wrong in our life however, especially our love life, our PEA levels drop. Those suffering from depression have noticeably lower PEA levels. According to the research, orally administered PEA has been noted to reverse depression symptoms in 60% of the patients tested with no side effects, chemical dependancy or tolerance limits over time (e.g. doses stay the same over time).
In 1982, chocolate was found to contain up to 2.2% phenylethylamine (PEA). Anecdotal evidence indicates that PEA is somehow related to chocolate’s explicit effects as the pharmaceutical drug selegiline (l-deprenyl), which delays the breakdown of PEA, can accentuate chocolate’s effects.
Chocolate seems to keep our PEA levels high, no matter what is happening in our love life. This is one of the leading theories as to why chocolate has the reputation of replacing lost love.
From a grounded, scientific perspective, PEA is the structural molecule behind catecholamine neurotransmitters such as dopamine, epinephrine (adrenaline) and norepinephrine (noradrenaline).
PEA increases the activity of neurotransmitters (brain chemicals) in parts of the brain that control our ability to pay attention and stay alert. Elevated PEA levels occur when we are captivated by an attractive person, good book, movie or project; this happens specifically during those moments when we are so focused that we lose all track of time, food and the outside world.
When the brain is flooded with PEA, the presynaptic vesicles will pull in PEA in preference to the neurotransmitter dopamine. Dopamine is then blocked from being deactivated and dopamine levels rise. Elevated dopamine levels are associated with increasing mental concentration and a positive attitude.
PEA also increases the effectiveness of another neurotransmitter, norepinephrine (noradrenalin). Norepinephrine increases feelings of joy.
PEA is found pre-made and in great natural abundance in two wonderful raw foods: cacao and blue-green algae (especially the blue pigments of algae). These two foods can elevate the presence of PEA in our brain.
Blue-green algae works with cacao in creating a strong ability to focus, stay in the moment and pay attention even if we suffer from Attention Deficit Disorder (ADD). Also, these foods help us to be more absorbed in whatever person or project is before us and we suspect this is part of what makes these two foods fantastic natural appetite suppressants.
A neurotransmitter called anandamide (n-arachidonoylethanolamine) was isolated in chocolate by neuroscientist Daniele Piomelli in 1996. Anandamide is an endogenous cannabinoid naturally found in the human brain. Anandamide is a type of lipid (oil) known as “the bliss chemical” because it is released while we are feeling great. In fact, anandamide is derived from the Sanskrit word “ananda” meaning bliss.
It has long been known that the brain contains a receptor site that can be filled by the tetrahydrocannabinol (THC) found in cannabis. A receptor site is a structure on the surface of a cell that can lock onto certain molecules, making it possible to carry a signal through the cell wall — a “lock-and-key” system. This is how cannabis makes us high.
The chemical our body produces that normally fills this THC receptor site is anandamide. This means that eating chocolate can get you high, not to the level of cannabis, but to a noticeable degree nonetheless.
The pharmacological effects of anandamide indicate that it may play an important part in the regulation of mood, memory, appetite and pain perception. It may act as the chief component in the control of cognition and emotion. Physiological experiments demonstrate that anandamide may be as important as the more well-known neurotransmitters, dopamine and serotonin.
High levels of anandamide were found in young men who ran or cycled at a moderate rate for about an hour, according to a study published in the journal NeuroReport by the Georgia Institute of Technology and the University of California, Irvine. Anandamide may be responsible for the euphoric feeling some people experience when they exercise that we sometimes call “runner’s high.” Arne Dietrich, the study’s principal investigator believes the body releases cannabinoids to help cope with the prolonged stress and pain of moderate or intense exercise.
The findings of this study indicate that sufferers of glaucoma and cancer have alternatives to using cannabis for pain control and those are: exercise and … chocolate!
Anandamide
Not only does cacao contain anandamide, it also contains anandamide inhibitors. N-oleolethanolamine and N-linoleoylethanolamine, two structural cousins of anandamide present in chocolate, both inhibit the metabolism of anandamide. Essentially, these inhibitors decrease our bodies’ ability to breakdown anandamide. This means that natural anandamide and/or cacao anandamide may stick around longer, making us feel good longer, when we eat cacao.
N-oleoylethanolamine and N-linoleoylethanolamine specifically target the endogenous cannabinoid system of the brain, mimicking the psychotropic effects caused by plant-derived cannabinoids either directly (by activating cannabinoid receptors) or indirectly (by increasing anandamide levels in the brain). To put it simply, these inhibitors promote and prolong the feeling of well-being that anandamide can induce or can amplify the effects of THC.
Because of cacao’s large size we should call it a nut (like a cashew, which like cacao, is also the seed of a fruit). Normally nuts and seeds contain enzyme inhibitors that attempt to inhibit our digestion so that we do not eat the tree or plant into extinction. That is the main reason why eating too many raw nuts and seeds in a meal causes us to feel uncomfortably full, and also may cause constipation. With cacao, the situation seems to be a little bit different as cacao is a laxative and possesses other types of enzyme inhibitors.
From our knowledge of pharmacology, we believe that cacao contains no (or an insignificant amount of) digestive enzyme inhibitors, and instead possesses neurotransmitter modulating enzyme inhibitors such as monoamine oxidase enzyme inhibitors or related compounds (we already know, for example, that cacao has two anandamide uptake inhibitors, so it is reasonable to assume there are others).
Monoamine oxidase (MAO) refers to two classes of enzymes (MAO A and MAO B) that, in the human body, eat up or recycle neurotransmitters such as serotonin, dopamine, adrenalin, noradrenalin, etc. When we are young we produce lots of neurotransmitters and therefore experience more joy, curiosity and excitement. As we age, monoamine oxidase enzymes become more aggressive and recycle our neurotransmitters too early, therefore lowering the level of our neurotransmitters. A low level of neurotransmitters has been linked to depression, grumpy behavior, unpleasant moodiness and the process of aging itself.
Scientists, basing their work on ancient traditions of plant shamanism, have pursued the idea of using monoamine oxidase inhibitors (MAOIs) to inhibit monoamine oxidase enzymes (MAOs) thus allowing the level of neurotransmitters to increase.
Based on the study of certain plants an array of synthetic monoamine oxidase inhibiting (MAOI) drugs have been created by the pharmaceutical industry as antidepressants and youthening agents. However, according to the work of Dr. Gabriel Cousens and others, these synthetics have proven more erratic and dangerous than their natural counterparts. For example, synthetic MAOI drugs have proven dangerous when taken with processed chocolate (due to the presence of the tyramine formed in fermented cacao beans) and they should not be taken together. There is one major exception to the danger of synthetic MAOIs, a synthetic MAOI developed by accident by Dr. Ana Aslan of the National Geriatric Institute in Bucharest, Romania, has proven to possess youthening properties. This product is now widely available as an oral tablet called Gerovital or GH3.
Natural monoamine oxidase inhibitors called beta-carbolines (which inhibit MAO A) are found in the seeds of the Syrian rue plant (Peganum harmala), in the Ayahuasca vine (Banisteriopsis caapi), in Passion flowers (Passiflora incarnata) and in other plants. Natural MAOI’s that inhibit MAO type B include nicotine. (The presence of nicotine as an MAO B may account for the unique phenomenon of certain organic tobacco smokers living long lives).
The effects of cacao as an antidepressant, as a youthening agent, an enhancer of intuition, an appetite suppressant and its ability to enhance entheogenic plants seem to place it in the same category as the other MAOI plants. We previously suspected, and now know, that cacao contains MAO inhibitors known as tetrahydro-beta-carbolines. Rumours that cacao is an MAOI—that once abounded in the world of chocolate alchemists—have now been confirmed.
Perhaps it is true that there is an energy surrounding cacao (immortalized forever in Roald Dahl’s book Charlie and the Chocolate Factory) that creates beings who are inevitably transformed into zany, creative Oompa Loompas. Cacao does seem to make one younger. Remember the study of 8,000 male Harvard graduates who ate chocolate and outlived their peers.
Our experience from eating raw cacao regularly is that some pharmacological system is present in this food that heightens intuitive and psychic abilities. MAOI’s are known to activate dormant parts of our brain and neurochemistry. This allows us to access some of the 90% of our brains we do not normally use.
Anyone who eats chocolate knows that it diminishes appetite. There is evidence indicating MAOIs also diminish appetite.
There is actually no scientific evidence to implicate chocolate consumption with obesity. In fact, the reverse seems to be the case. Eating cacao helps one to lose weight. This is why nearly every weight-loss product on the market contains cocoa powder — which decreases appetite. Diet companies hint they are doing you a favor by providing chocolate weight-loss products, when in fact they use chocolate because it works!
Essentially, cacao makes one look, feel and behave younger, allows one to increase their psychic powers, as well as eat less and lose weight! No wonder the ancients called it “the food of the gods.”
Cacao contains significant quantities of the essential amino acid tryptophan which is yet another powerful mood-enhancing nutrient. From research obtained by cross referencing data on the internet, cocoa powder consists of somewhere between 0.2%-0.5% tryptophan.
The presence of tryptophan in the diet is critical for the production of serotonin, our primary neurotransmitter. Once in our bodies tryptophan reacts with vitamin B6 and vitamin B3 in the presence of magnesium to produce serotonin. Enhanced serotonin function typically diminishes anxiety and increases our ability to fend off stress. According to Dr. Gabriel Cousens, serotonin is literally our “stress-defence shield.”
Tryptophan also helps produce other tryptamine neurotransmitters including melatonin and dimethyltryptamine, both associated with sleep. This may be a reason why the chocolate drink, even though high in stimulating theobromine with perhaps some caffeine is nevertheless more of an evening beverage than a morning beverage, as it typically does not cause insomnia.
Tryptophan is heat-volatile and susceptible to damage or destruction by cooking. As a result, tryptophan is usually deficient in many cooked-food diets, even if animal protein intake is high. (This may be a large reason why depression is on the rise). Eating cacao beans raw would thus be an excellent way to obtain dietary tryptophan.
* Antioxidant Research Laboratory, Unit of Human Nutrition, National Institute for Food and Nutrition Research, Via Ardeatina 546, 00178 Rome, Italy
† Plant Products and Human Nutrition Group, Graham Kerr Building, Division of Biochemistry and Molecular Biology Institute of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ
