The Tryptophan Paradox

Anti-Inflammatory Effects From Fish Oils.mp4

Black Currant Berries: Vitamin C and Polyphenols

The black Currant plant (Ribes nigrum) is a deciduous shrub with toothed and pointed leaves. Flowers form in loose pendulous racemes in the same axis as the leaves and are greenish-white in colour (figure 1). The black Currant plant is native to Asia and Europe but is now found throughout the World where it is widely cultivated for its berries. In Britain, the black currant shrub can be found growing wild in hedgerows and woods, and the berries from such plants are frequently harvested for their nutritional properties. In this regard, traditionally, black currants have been used to create jams and preserves. However, the black currant shrub is far less common in the British Isles than other berry producing shrubs such as the blackberry plant (Rubus Sp.). Historic records show that the medicinal properties of the black currant plant date back to at least the 16 century, but the plant is now largely grown for use in the food industry for its colour and flavour enhancing properties.

Figure 1. The black currant plant. Picture taken from: Stodola, J., Volak, J. and Severa, F. 1984. Illustrated Book of Medicinal Herbs. Octopus Books, London. First edition.

Black currant berries are a rich source of vitamin C and also contain polyphenols. The polyphenolic fraction of black currant berries is made up mainly (~75 %) anthocyanins from the flavonoid group of polyphenols. However in addition, black currant berries also contain other flavonoids, most notably flavonols including quercetin. Hydroxycinnamic acids and their derivatives such as chlorogenic acid also make up a substantial amount of the polyphenols in black currant berries. The polyphenols in black currant berries have been shown to inhibit the intestinal enzyme α-glucosidase, and in this way may have beneficial effects of blood sugar. The berries also contain pectin, a soluble form of fibre that may further stabilise blood sugar levels. The leaves of black currant shrubs are rich in vitamin C, organic acids, tannins and essential oils and have been studies for their diuretic and diaphoretic properties. Decoctions of the leaves are thought useful in the treatment of diarrhea, rheumatism and urinary infections.

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The Role of Dopamine in Mood

Dopamine is a neurotransmitter in the brain that is synthesised in a chemical pathway originating from the amino acid L-phenylalanine. The enzyme phenylalanine hydroxylase converts L-phenylalanine to L-tyrosine, and then the enzyme tyrosine hydroxylase converts L-tyrosine to L-DOPA. Finally, L-DOPA decarboxylase removes a carbon dioxide from L-DOPA to form dopamine. Dopamine synthesis is concentrated mainly in the part of the brain called the nucleus accumbens, which is a primitive part of the brain that is involved in stimulating feelings of euphoria, motivation and pleasure. Increasing dopamine synthesis in the nucleus accumbens is associated with increased motivational behaviour, assertiveness, and an increase in labido. Dopamine may also be involved in the regulation of appetite through affecting secretion of prolactin and may be required for short term memory and other cognitive functions. Dopamine deficiency may also be related in some way to the onset of depressive symptoms.

Other symptoms of dopamine deficiency in the brain can include apathy, long sleep duration, irritability and the addiction to recreational drugs such as alcohol, caffeine, or illegal street drugs. The addiction to drugs is worthy of note because it is the seeking of such drugs to boost dopamine levels that may be the first indication that brain levels of dopamine are insufficient. While many drugs do increase the release of dopamine from dopamine containing neurones, they do not address the underlying cause of the low dopamine levels, and in this way often have deleterious effects in the long term. One of the best ways to ensure that the brain can produce adequate dopamine is through good nutrition. For example, the rate limiting step in the synthesis of dopamine requires a molecule of iron, and so iron deficiencies can inhibit flux through the pathway. In addition, supplying the amino acid L-tyrosine in amounts greater than normally found in the diet can also increase the synthesis of dopamine naturally.

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Serotonin Deficiency?

Serotonin is an important neurotransmitter in the central nervous systems on mammals. In man, research has uncovered many functions for serotonin. Originally discovered in both Italy and American, the name serotonin derives from the word ‘sero’ for blood and ‘tonin’ for muscle tone, this being on account of the discovery that the substance was able to affect muscle contraction. Chemically serotonin is known as 5-hydroxytryptamine, and although it plays an important role in the brain and central nervous system, serotonin has effects on most physiological systems in the body, particularly the digestive system. Serotonin is synthesised primarily in the raphe nuclei in a pathways that required the essential amino acid L-tryptophan and therefore serotonin systems are reliant of dietary sources of protein to function. The amino acid L-tryptophan is converted to 5-hydroxytryptophan, and then to serotonin with tryptophan hydroxylase, an iron requiring enzyme, controlling the rate limiting step.

A number of symptoms of serotonin deficiency have been identified including low self-esteem, anxiety, eating disorders, cravings for sweet foods, impatience and impulsiveness, fatigue and a loss of libido. Although protein foods are the source of the precursor amino acid for serotonin synthesis, it is carbohydrate foods that might be most useful in increasing brain levels of serotonin. This is because carbohydrate foods stimulate insulin release and this drives branched chain amino acids into muscle tissue. Removing branched chain amino acids from circulation removes competition for the large neutral amino acid transporter to the brain, which L-tryptophan uses. As a result more L-tryptophan makes it into the brain and more serotonin is produced. A number of foods including bananas and pineapples are good sources of serotonin, but it is unclear how well they raise brain levels of serotonin. Taking dietary supplements of 5-hydroxytryptophan from Griffonia simplicifolia also increase brain levels of serotonin.

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Quest Vitamin E: Supplement Recommendation

The Three Easiest Ways To Increase Antioxidant Levels

Antioxidants are important to humans because they protect our cells and tissues from the free radicals. The free radical theory of disease suggests that excessive accumulation of free radicals such as peroxide, the superoxide anion and the hydroxyl radical are able to cause oxidative stress, and that this leads to the degeneration of cells, ultimately causing chronic disease. To counteract this problem, the body has an array of antioxidants that it can use to quench the free radical chain reactions before they cause tissue damage. While some of these antioxidants are produced in the cells, many are plant chemicals that are derived from our diet. Here are three easy to implement steps that will significantly boost antioxidant levels and help prevent disease.

1. Drink Green Tea
Green tea is a rich source of a group of plant chemicals called the flavan-3-ols. Flavan-3-ols are sometimes referred to as catechins, and belong to the flavonoid group of polyphenols. Green tea is the best source of flavan-3-ols, although they can be found in smaller concentrations in black tea, particularly darjeeling, and apples. Green tea has been shown to possess anti-cancer and cardioprotective effects and it is thought that the flavan-3-ols it contains may be the reason for this effect. Three to five cups a day significantly increases antioxidant defences.

2. Add Spices To Your Food
Of all the plant foods spices contain the highest antioxidant capacity. This is partly because the spices are dried and therefore have a low water content, but also because the plants that spices are made from are excellent sources of antioxidants. Of the spices cloves are particularly high in antioxidants, but most spices have strong antioxidant potential. Spices such as rosemary, basil, black pepper, ginger, cinnamon, thyme and marjoram are easy to add to foods and will increase the antioxidant capacity of those foods significantly.

3. Take A Vitamin C Supplement
The maximum amount of vitamin C that even a high quality diet can provide is around 600 mg per day. However, a single vitamin C capsule can provide 1000 mg. As the plasma is not saturated with vitamin C until an intake of around 2500 mg is achieved, supplements are the only way to obtain optimal plasma levels. Vitamin C supplements have been shown to increase cellular levels of glutathione, the primary endogenous antioxidants in cells. As glutathione levels rise the risk of disease falls significantly.

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Carbohydrate Cravings? Try L Glutamine

Alfalfa: Nutrient Dense Herb

Alfalfa (Medicago sativa) is perennial herb that belongs to the Fabaceae or legume family of plants. Alfalfa grows to around one metre in height and possesses leaves that look similar to trilobed clover leaves. Alfalfa produced purple flowers which mature into spiral-shaped seed pods. Alfalfa was found mainly in the Mediterranean and Middle East and was extensively cultivated by the Romans and Greek civilisations. However, since this time alfalfa has spread throughout the world where it is used extensively as a livestock feed crop. The medicinal properties of alfalfa are one of a general tonic. This relates to the very high nutrient content that the plant possesses. In particular alfalfa contains high concentrations of a number of vitamins including vitamin A, thiamine, pyridoxine, cobalamin, vitamin C, vitamin E and vitamin K. As well as containing high concentrations of vitamins, alfalfa may be a good sources of minerals. However, this is dependent on the mineral content upon which the alfalfa plant is grown.

As with soybeans, alfalfa also contains the isoflavones daidzein and genistein, although the levels are lower in alfalfa compared to soybeans. Many other legumes also contain isoflavones, but the soybean is the richest source. The flavonoid fomentation is also present. The isoflavones and flavonoids in alfalfa may confer antioxidant protection to the consumer, explaining some of the health benefits of the herb. Alfalfa possesses cholesterol lowering properties and this may relate to the presence of saponins. Researchers have suggested that plant saponins can decrease the absorption of cholesterol in the gut, although as dietary cholesterol is not able to alter plasma cholesterol levels, it is unclear how this mechanisms is able to function. It is perhaps more likely that the saponins are absorbed and then regulate metabolism of cholesterol in some way. The coumarins coumestans and medicagol are also present in alfalfa and along with the isoflavones and flavonoids may contribute to the antioxidant effects of alfalfa.

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Metabolic ‘Ash’: Acid-Base Balance

The acid-base balance of human plasma and other tissues is of vital importance. Acidosis and alkalosis are medically accepted terms, and can be found in any textbook of medical physiology. Acidosis refers to an excess of acid in the body or a low pH, while alkalosis refers to an excess alkalinity in the body or too high a pH. Acidosis is far more common than alkalosis and can result from diabetes, uncontrolled respiratory disorders, heavy loss of fluids from diarrhea for example, or through renal insufficiency. These relatively short term, serious and easily diagnosable conditions of acid-base imbalance are well characterised and understood. However a chronic, subtle and more insidious deviation from normal homeostatic acid-base balance is thought to occur through regular consumption of low quality foods containing too many acid forming foods. Such a nutritional disorder is now recognised as a likely cause of Western lifestyle diseases, particularly osteoporosis.

When food in metabolised it produced an ‘ash’ residue that is a reflection of the mineral content of the foods. Plant foods contain high amounts of potassium and this produces potassium salts that can alkalinise the blood. In contrast the sulphur containing amino acids present in animal protein for example leave an acid residue that can acidify the blood. Alkaline foods include most fruits and vegetables, nut and some cereal grains such as millet. Acid foods include fish, meat, eggs, wheat, peanuts and lentils. Neutral foods that do not affect the acid-base balance include milk, butter and vegetable oils. It is recommended that between 20 and 50 % of foods are acid forming, whilst 50 to 80 % are alkaline forming foods. The ability to alkalinise the blood may be ones of the reasons for the beneficial effects of fruits and vegetables. Traditional diets tend to provide more alkalinising that acidifying foods, which may be one of their key benefits. Drinking mineral rich water may also be able to lower the acidity of the tissues and thus restore health.

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Weight Loss By Controlling Insulin

Coleus forskohlii: cAMP Activator

The Coleus forskohlii plant is a member of the mint family that is found naturally growing in sunny regions in Asian countries such as India, Nepal, Thailand and Sri Lanka. Traditionally the roots have been used as a medicine, and this relates to their content of a chemical called forskolin. However, although the active chemical in the Coleus forskohlii plant is forskolin, other compounds within the root are thought to increase the absorption and metabolic effect of the isolated forskolin. Biochemically forskolin is able to activate the enzyme adenylate cyclase, which in turn is responsible for increasing cellular concentrations of the second messenger cyclic AMP (cAMP). Cyclic AMP in turn is responsible for activating protein kinase A, which causes a number of cellular changes. Adrenaline and glucagon activate receptors in tissues, and these in turn activate adenylate cyclase. As forskolin increases cAMP levels by activating adenylate cyclase, it could be expected that forskolin has health effects relating to these hormonal systems.

And this is exactly what is found (figure 1). In particular increased cellular levels of cAMP cause a decrease in platelet activation, relaxation of arteries, increase cardiac output force, relaxation of smooth muscle, increased insulin secretion, increased thyroid production and increased lipolysis. Forskolin may also bind and inhibit certain membrane transporters and inhibit platelet-activating factor (PAF) binding to its receptors, thus decreasing the allergic and inflammatory effects of PAF. The biochemistry of forskolin make it useful in the treatment of allergic conditions such as eczema and psoriasis. The smooth muscle relaxing effects of the herb make it particularly useful at increasing the diameter of the airway in asthmatics. The cardiac stimulating, smooth muscle relaxing and platelet inhibiting effects of forskolin make it useful in the treatment of high blood pressure. The ability of forskolin to increase thyroid function and increase lipolysis may make is useful in the treatment of obesity, although it can never be a substitute for a high quality diet.

Figure 1. The metabolic effects of forskolin in humans.

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Why Is Vitamin E Cardioprotective?

Vitamin E is a group of plant derived phenolic isomers. These isomers include alpha, beta, delta and gamma-tocopherol and alpha, beta, delta and gamma tocotrienol. All vitamin E isomers share the same biological activity as alpha tocopherol, the most biologically active of form of vitamin E. Vitamin E is interesting nutritionally because it shows cardioprotective properties in humans. High intakes of alpha-tocopherol for example, may reduce the risk of myocardial infarction significantly, particularly in those who have already suffered a heart attack. It has been speculated that the antioxidant properties of vitamin E are responsible for its ability to reduce heart attack risk. One early theory suggests that vitamin E may reduce lipid peroxidation levels in the low density lipoprotein (LDL) particles, a phenomenon that may be a prerequisite to the formation of atherosclerotic plaques. However, more recently it has been shown that a more simple mechanism may be responsible for the cardioprotective effects of vitamin E.

Vitamin E may protect prostacyclin synthase from damage by free radicals, thus increasing levels of prostacyclin I₂ (which is cardioprotective).

The reason that vitamin E may protect from myocardial infarction does relate to its antioxidant effects. However, it might have nothing to do with LDL and the formation of atherosclerosis. Clotting generally occurs in damaged arteries, possibly through scorbutic bleeding as described by Linus Pauling. In healthy arteries arteries however clotting should not occur, and this is prevented by an eicosanoid called prostacyclin I2 (PGI2). Prostacyclin I2 is formed by the enzyme prostacyclin synthase, which is susceptible to free radical damage. Antioxidants like vitamin E may protect prostacyclin synthetase and thus maintain adequate levels of prostacyclin I2. Interestingly antioxidants have also been shown to protect the enzyme nitric oxide synthase from destruction by free radicals. Nitric oxide synthase is responsible for producing nitric oxide, a second messenger that signals the relaxation of blood vessels. Antioxidants such as vitamin E may therefore protect enzymes which are vital to the prevention of myocardial infarctions.

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