Category: Natural chemicals
Introduction and description
Thiamine or thiamin or vitamin B1 is a water-soluble vitamin of the B complex. All living organisms use thiamine, but it is synthesized only in bacteria, fungi, and plants. Animals must obtain it from their diet, and thus, for them, it is an essential nutrient. It is on the World Health Organization's List of Essential Medicines, a list of the most important medication needed in a basic health system.
Human storage of thiamine is about 25 to 30 mg, with the greatest concentrations in skeletal muscle, heart, brain, liver, and kidneys. Thiamine is mainly the transport form of the vitamin, while the active forms are phosphorylated thiamine derivatives. ThMP (thiamine monophosphate) and free (unphosphorylated) thiamine is present in plasma, milk, cerebrospinal fluid, and, it is presumed, all extracellular fluids. Thiamine is excreted principally in the urine.
Uses in the body
Thiamine’s phosphate derivatives are involved in numerous cellular processes. The best-characterized form is thiamine pyrophosphate (TPP), a coenzyme in the catabolism of sugars and amino acids. Thiamine is used in the biosynthesis of the neurotransmitter acetylcholine and gamma-aminobutyric acid (GABA). Thiamine derivatives are key to carbohydrate metabolism. Thiamine is also key in the creation of adenosine triphosphate (ATP), which is a major form of energy for the cell and is also involved in myelin synthesis. Adenosine thiamine diphosphate (AThDP) or thiaminylated adenosine diphosphate exists in small amounts in vertebrate liver, but its role remains unknown.
Thiamine derivatives and thiamine-dependent enzymes are present in all cells of the body, thus a thiamine deficiency adversely affects all of the organ systems. However, the nervous system is particularly sensitive to thiamine deficiency.
Insufficient intake in all mammals results in Wernicke-Korsakoff's syndrome, optic neuropathy, and a disease called beriberi that affects the peripheral nervous system (polyneuritis) and/or the cardiovascular system.
Thiamine deficiency has a potentially fatal outcome if it remains untreated. In less severe cases, nonspecific signs include malaise, weight loss, irritability and confusion. Other symptoms include impairment of sensory, motor, and reflex functions, causing calf muscle tenderness; peripheral neuropathy (tingling or numbness in the extremities), partial paralysis or sensory loss; mental confusion, muscular atrophy, oedema, tachycardia, cardiomegaly, and congestive heart failure.
The brain requires a much greater amount of thiamine than in other cells of the body. Much of ingested thiamine never reaches the brain because of passive diffusion and the blood brain barrier. In effect, a thiamine deficiency can cause brain damage of all sorts from Alzheimer’s to autism.
Given thiamine’s key role in carbohydrate metabolism, there may be a link between thiamine deficiency and obesity.
Furthermore deficiency may be linked to diseases associated with inadequate myelin regeneration or repair, such as multiple sclerosis.
A positive diagnosis test for thiamine deficiency can be ascertained by blood tests. The normal thiamine concentration in EDTA-blood is about 20-100 µg/l.
Rather alarmingly, there have been no studies on what an overdose of thiamine can do to you. Given the extensive supplementation of food stuffs with this vitamin, this is not a very good position to be in. According to Wikipedia “There are no reports available of adverse effects from consumption of excess thiamine by ingestion of food and supplements”. This is because no reports are collected or as they say “the data is inadequate for a quantitative risk assessment”.
Causes of imbalance
Poor farming practise
Food additives - Thiamine in foods can be degraded in a variety of ways. Sulfites, which are added to foods usually as a preservative, attacks thiamine at the methylene bridge in the structure, cleaving the pyrimidine ring from the thiazole ring. The rate of this reaction is increased under acidic conditions.
Consumption of an excess of Plant thiamine antagonists - These compounds interact with the thiamine to oxidize the thiazole ring, thus rendering it unable to be absorbed. Examples include
- Two flavonoids, quercetin and rutin, have been implicated as thiamine antagonists.
- Caffeic acid – which is found in coffee. It is one of the main natural phenols in argan oil. It is also found in barley grain. Overdose on any of these and it could have an effect
- Chlorogenic acid - Chlorogenic acid can be found in peaches, prunes, although it would be very hard to overdose on these. But it is also one of the phenols found in green coffee bean extract often sold as a supplement. And one of the main means by which an excess may be delivered is via food additives. Chlorogenic acid is marketed under the tradename Svetol, a food additive used in coffee products, chewing gum, and mints, and also as a stand-alone product.
- Tannic acid – Tannic acid is not the same as tannin. It is a chemical used in beer clarification, and in soft drinks and juices as a flavouring agent. It is also used in the wine industry as a natural clarifying agent, colour stabilizer and taste enhancer. In the United States, tannic acid is recognized as safe by the Food and Drug Administration, but according to EU directive 89/107/EEC tannic acid cannot be considered as a food additive and consequently does not hold an E number.
- Betel nuts – appear to act as antagonists
Pharmaceuticals - Tannic acid [described above] is still used in pharmaceutical applications to produce albumin tannate which is used as an anti-diarrhea agent. Tannic acid is also used to produce tannate salts of certain anti-histamines and anti-tussives to impart increased stability or slow release properties to the API (active pharmaceutical ingredient). But aside from this specific cause, pharmaceuticals in general are implicated in Thiamine deficiency, this LINK takes you to the eHealthme web site where the list of pharmaceuticals is shown.
Intestinal damage/disease - Thiamine is released by the action of phosphatase and pyrophosphatase in the upper small intestine. At low concentrations, the process is carrier-mediated, and, at higher concentrations, absorption occurs via passive diffusion. Active transport is greatest in the jejunum and ileum. If the intestine is damaged or diseased this process can be inhibited. It is also inhibited by folic deficiency. Gastric sleeves clearly have a very detrimental effect here.
HIV/AIDs – Thiamine deficiency may also occur in patients with impaired nutrition from other causes, such as HIV-AIDS.
Mineral deficiency – Magnesium is required for the binding of thiamine to thiamine-using enzymes within the cell, thus mineral deficiency can cause thiamine under utilisation.
Alcoholism - Alcoholics may have thiamine deficiency because of the following:
- Inadequate nutritional intake: Alcoholics tend to intake less than the recommended amount of thiamine.
- Decreased uptake of thiamine from the GI tract: Active transport of thiamine into enterocytes is disturbed during acute alcohol exposure.
- Liver thiamine stores are reduced due to hepatic steatosis or fibrosis Impaired thiamine utilization:
- Ethanol per se inhibits thiamine transport in the gastrointestinal system and blocks phosphorylation of thiamine to its cofactor form (ThDP).
Genetic diseases - Genetic diseases of thiamine transport are rare but serious. Thiamine responsive megaloblastic anemia (TRMA) with diabetes mellitus and sensorineural deafness is an autosomal recessive disorder caused by mutations in the gene SLC19A2. Leigh disease (subacute necrotising encephalomyelopathy) is an inherited disorder that affects mostly infants in the first years of life and is invariably fatal.
According to the USDA Nutrients database the principle sources of Vitamin B1 are as follows:
- Marmite and vegemite – yeast extract spread
- Leavening agents - baker’s yeast
- Ovaltine and Horlicks
- Rice bran and rice bran oil/wholegrain rice
- Seaweed – spirulina
- Seeds – flaxseeds, sunflower seeds, sesame seeds, safflower seeds, poppy seeds, mustard seeds
- Cocoa powder and chocolate
- Hibiscus tea
- Red peppers - and green peppers
- Nuts – Macadamia nuts, pistachio, hickory
- Porridge and wholegrains – wholegrain oats, wheat germ, oatmeal, whole grain rye, and other whole grains contain more thiamine than refined grains, as thiamine is found mostly in the outer layers of the grain and in the germ (which are removed during the refining process). For example, 100 g of whole-wheat flour contains 0.55 mg of thiamine, while 100 g of white flour contains only 0.06 mg of thiamine
- Red meat – Pork, ham, salami, pork sausages, bacon
- Beans – black beans, black turtle beans, soy beans, black-eyed beans, white beans, pinto beans, yellow beans; lentils and split peas
- Water chestnuts
- Brassicas – such as kale and cauliflower
- Adzuki beans Nutrient content from USDA 006997
- B-Vitamin Intake from Diet and Supplements and Breast Cancer Risk in Middle-Aged Women: Results from the Prospective NutriNet-Santé Cohort 027373
- Broad bean Nutrients from USDA 006996
- Broccoli Nutrients from USDA database 007164
- Brussel sprouts Nutrients 007162
- Cabbage nutrients from USDA database 007160
- Cancer prevention by natural compounds 017699
- Cauliflower Nutrients from USDA database 007161
- Chickpea Nutrient content from USDA 006992
- Dairy products vitamins and mineral 005906
- Dietary Strategies for the Treatment of Cadmium and Lead Toxicity - 03 Vitamins 016837
- Dr Duke's list of chemicals and activity for the Shallot 017969
- Dr Duke's List of Chemicals and their Biological Activities in: Cola acuminata (P. BEAUV.) SCHOTT & ENDL. (Sterculiaceae) -- Abata Cola 027647
- Dr Duke’s list of Chemicals and their Biological Activities in: Cucurbita pepo L. (Cucurbitaceae) -- Zucchini 027494
- Kohlrabi Nutrients from USDA database 007163
- Lentils Nutrient content from USDA 006995
- Nutrition for brain recovery after ischemic stroke: an added value to rehabilitation 020757
- Ovaltine original nutrient content 007180
- Peas Nutrients according to USDA 006994
- USDA Nutrients - Fish, anchovy, european, raw 012452
- USDA Nutrients - Fish, Cod 012455
- USDA Nutrients - Fish, Herring 012459
- USDA Nutrients - Fish, Mackerel 012472
- USDA Nutrients - Fish, Oysters 012458
- USDA Nutrients - Fish, Salmon 012487
- USDA Nutrients - Fish, Sardines 012453
- USDA Nutrients - Fish, Scallops 012457
- White beans Nutrients from USDA 006998