What is Inositol?
Inositol, which also known as Phytic Acid, is a carbohydrate of cyclic structure and almost ubiquitous within the human organism, since it is present in the vast majority of its cells. But if any organic element can be selected in terms of its richness in this substance, this must be breast milk, which constitutes the irrefutable proof of the inborn need of the newborn to receive a regular contribution of this substance.
Within the cataloguing of the different nutrients that make up the so-called immediate principles, Inositol shares its condition, already alluded to, of carbohydrate with a Group B Vitamin, to be exact, Vitamin B8.
It is considered a substance with nutritional activity, since it carries out different biological effects after entering the bloodstream once absorbed in the intestinal tract; but, in contrast to the rest of the vitamins, in adults it is not considered essential due to the ability of the organism to synthesize it from the glucose molecule.
Many chemical compounds appear in nature in forms that differ very slightly in the structure of their molecule: they are called isomers.
Inositol is no different, having nine possible presentations, which only differ in the arrangement of some of its atoms (to be more precise, in the orderings of the hydrogen and OH groups around the carbon atoms that make up its ring structure).
Of all of them, the most common is Myo-Inositol, as it is the one that is closely related with the nervous system of mammals (of course, including humans), as well as with some other locations.
Of all the other isometric isomers (their technical name), only four of them appear spontaneously in nature, the rest of them being produced through laboratory synthesis, these are: D-Inositol, L-Inositol, Myo-Inositol and Scyloinositol or Esciclitol.
Natural Sources of Inositol
We can begin by stating that food products tend to contain the Myo-Inositol isomer to some degree and, grosso modo, the ones that contain most amount of this this semi-essential vitamin are whole grain cereals and citrus fruits (among which lemon is an exception), which would occupy the top of the list, while dairy products and meat are at the back of the pack. But let's take a more exhaustive look at this subject.
Regarding animal sources, Myo-Inositol is mainly found in most of the viscera, with particular concentration in the liver and encephalon.
On the other hand, Inositol from vegetables usually comes from a chemical precursor called Phytic Acid, which initially is a nutritionally inert substance that becomes a food for certain bacteria of the digestive tract, which then transform it into biologically active Inositol.
Many fruits, vegetables, seeds, legumes, cereals (particularly oats and wheat bran) and nuts contain high levels of this compound. For example, among the latter, in almonds it represents 9.4% of its weight, and in nuts, almost 7%.
Among the fruits that are rich in Inositol, melon and grapefruit stand above the rest. As a reference, 100 grams of this citrus juice contains 380 milligrams of Inositol.
It may be useful to present a more detailed ranking of foods in terms of Inositol concentration (cited in a decreasing order and in milligrams per gram):
- Raisin (4,70)
- Cantaloupe (3,55)
- Orange (3,07)
- Mandarin (1,49)
- Kiwi (1,36)
- Cherry (1,27)
- Nectarine (1,18)
- Mango (1)
- Pear (0,73)
- Peach (0,53)
- Apricot (0,52)
- Watermelon (0,46)
- Avocado (0,46)
- Pineapple (0,33)
- Apple (0,24)
- Rutabaga swede (2,52)
- Aubergine (0,84)
- Brussel sprouts (0,81)
- Cabbage (0,70)
- Asparagus (0,68)
- Spinach (0,66)
- Artichoke (0,6), mainly in the heart.
- Pepper (0,57)
- Tomato (0,54)
- Onion (0,27)
- Lettuce (0,16)
- Cucumber (0,15)
- Carrot (0,12)
- Mushrooms (0,09)
- Wheat bran (2,74)
- Whole Wheat (1,42) and Wholegrain Wheat (0,47)
- Oat flour (0,40)
- Pasta (0,31)
- Brown Rice (0,30) and White Rice (0,17)
- White Bread (0,25)
Meat and derivatives:
- Beef liver (0,64)
- Mince meat (0,37)
- Egg yolk (0,34)
- Sirloin (0,30)
- Chicken breast (0,30)
- Pork chops (0,42)
Fish and seafood:
- Oysters (0,25)
- Tuna (0,15)
- Sardines (0,12)
- Clams (0,03)
- Whole milk(0,04)
- Yogurt (0,1)
- White beans (2,83), Red beans (2,49) and Green beans (1,93).
Properties and Benefits of Inositol
In a pure state, its visual aspect is that of a whitish crystalline powder, which dissolves very easily in water and whose melting point is 226 ° C, in other words, below that temperature it is in a solid state.
A characteristic that is quite relevant regarding metabolism related with Inositol is that the human organism is programmed to carry out its synthesis. The main tissues where this synthesis takes place are the intestinal mucosa, the central nervous system, the liver and the kidney.
It is found in almost all the cells of the organism, since it is a substance that integrates the molecular structure of phospholipids, fatty compounds of capital importance in the architecture of the cell membrane, with special emphasis on neurons or nerve cells. Due to its high level of participation in tissue organisation, we can conclude that:
- Its existence is fundamental for nervous impulse transmission and for synthesizing neurotransmitters (indispensable substances for this task). This property gives way to a large list of pathological processes linked to the nervous system can be prevented with an adequate ingestion and internal synthesis of Inositol, such as depression, since it has been demonstrated that Inositol levels in the cerebrospinal fluid (the one that internally bathes the central nervous system) of depressed people are appreciably low. It seems that, the link between Inositol and the Serotonin synthesis is what triggers depression. A similar situation can explain other neurological conditions such as bipolar disorder, obsessive-compulsive disorder, anorexia, bulimia, agoraphobia or fear of open spaces, claustrophobia (the inverse phenomenon) and even attention deficit associated to hyperactivity. It also has an influence on the sleep quality, state of mind, anxiety and stress.
- Combined with Choline (as will be seen below, regarding to supplements), it is a substance to be taken into account to reduce the blood cholesterol level.
- In the liver, it has a lipotropic function, assuming an important role in fat mobilisation. In order to develop this function, its synergy with Choline is also important, they prevent lipid build up in the the liver, taking them to the cells where needed.
- It can combat constipation as a result of stimulating the smooth muscles of the gastrointestinal tract, which helps to regulate intestinal peristalsis or motility.
- On a whole it is a necessary collaborator, as a vitamin, of the enzymatic activity of many biochemical reactions of metabolism. This has a unique impact on:
- Healthy sight, skin and hair.
- Correct food digestion and the good state of the digestive system.
- Normal bone marrow cell formation, which are fundamental for blood flow and the immune system.
There is a wide variety of physiological effects produced by this substance that are separate to those related to cell membranes, which allow it to intervene decisively in the modulation of the cellular response to stimuli and the role of enzymes.
Inositol has a molecular structure that allows it to travel easily between the exterior and the interior of cells, a characteristic that is crucial to understand its relevance in vital functions. Based on this, it adopts a mechanism called "the second messenger", whose essence is the intracellular response of the Inositol molecule to the presence of a specific hormone and, as a consequence of it, the start of a cascade of biochemical reactions that materialize a precise physiological effect.
These reactions include many types; cell line differentiation, proliferation of others or even those that lead to cell death.
For cell organization and specialization in tissues and organs, an extremely subtle communications network is essential, under whose control are the phenomena of cellular multiplication and coordination of all the activities carried out by them.
In the work scheme of any of the multiple communication systems that sustain to the organism, everything starts with a first signal, called the first messenger that can be a hormone, a releasing factor of the hypothalamus (vital gland of the encephalon), a growth factor, etc. This first messenger is released into the extracellular medium and moved by the specific stimuli, until it comes into chemical contact in the plasma membrane of the cell, by a highly specific membrane receptor that identifies it as a lock its key. And from this point onwards, the biochemical phenomenas responsible for the vital function in each case begin, both at the level of the membrane and the organelles contained in the cell´s cytoplasm.
Among these receptors, there is one of great relevance that uses the so-called G proteins, which are linked to nitrogenous bases called Guanines (a component of DNA). They control the release of two new intracellular messengers, the second messengers, which are Myo-Inositol and Diacylglycerol and occupy the last link in the chain of communication immediately prior to the manifestation of the physiological effect.
Perhaps the most decisive factor in the success of the therapeutic effects of Inositol is its ability to support neurotransmitters derived from its ability to intervene indirectly in the central nervous system, without being involved in any interaction with the cerebral receptors.
How can it perform such a subtle task? One of its methods consists in the regulating calcium contained within cells, when Inositol Triphosphate is projected onto an organelle of the cytoplasm of the cell called endoplasmic reticulum, within which it facilitates the release of calcium reserves, which, through a chain reaction, activate the neurotransmitters. On the other hand, Inositol acts as an osmosis regulator (an innate permeability of the cell coating), facilitating the movement of water and the elements in solution through the membrane.
Another good example of the significant changes that Inositol promotes in the body is the response to the insulin release from the islets of Langerhans of the pancreas, a physiological channel in which it behaves as a sensitising agent of the hormone in question.
In fact, people who suffer from type 2 diabetes experience changes in the amount of Inositol that is expelled through urine.
Closely linked to changes in insulin resistance, is the metabolic syndrome, where Inositol also plays a leading role by preventing some of the alterations, such as obesity or hyperlipidemia (high blood fat levels).
In particular, a reduction of 20% in LDL has been determined, which is already indicative of a good control of the predisposition towards metabolic syndrome, due to its condition as a risk factor for cardiovascular diseases.
The abundance of Inositol in the central nervous system has been proven in several studies aimed at identifying in detail, the role of Inositol in a number of syndromes. These have concluded that a prolonged deficit of cellular Inositol can degenerate in the appearance of neurological disorders of considerable severity. Two if them will be examined in detail below.
Summarizing, it is a neuronal failure caused by a degeneration of neuronal tissue.
This disorder entails irregular neuronal signalling, on which scientific proves that Inositol can help correct, even in cases where the degenerative process has diminished the physiological capacity of its cells.
The Scyloinositol isomer and its contribution towards fighting the Amyliod pathology
Scyloinositol stands out for its potential to be able to stabilise the deposits of small groups of molecules, of a glycoprotein substance called β-Amyloide, which is closely related to the different degeneration processes throughout the body.
In particular, we will focus on the action that takes place in the hippocampus, a prominence that is located inside the brain directly linked to memory and spatial orientation and whose deterioration seems to be determinant in the symptoms of Alzheimer's disease, as revealed a clinical research work that lasted for a year and a half with patients suffering from Alzheimer's in mild and moderate degrees.
It should also be noted that the cyclohexanehexol-Inositol isomer also seems to contribute to the reducing the accumulation of these deposits of the β-Amyloid substance.
This is a disorder whose denomination perfectly reflects its clinical picture: compulsive attitudes and obsessive thoughts.
In the pathophysiological basis of its development, the decrease in serotonin concentration in the brain stands out, the neurotransmitter that has most affects mental well-being.
Its role in reproduction
The relation between Inositol and the polycystic ovary syndrome, deserves special mention.
It is known that the majority of the women that suffer this, experience a high grade of insulin inefficiency while playing its role in the tissues, which in the past, encouraged research trials to established the existence or not of a cause-effect relationship between both parameters, Inositol and insulin resistance.
These studies showed significant recovery of insulin sensitivity after the intake of Myo-Inositol during periods of three months, which collaterally results in a lower incidence of polycystic ovary syndrome in the supplemented women.
At ovule level, Myo-Inositol seems to have a role in its maturation, being an effective marker to identify those that are ready to be fertilised. In fact, in women affected with polycystic ovary syndrome, the increase in the number of high-quality oocytes has been proven by the use of Myo-Inositol.
Other benefits and properties of Inositol
Inositol is so versatile that, regarding the organism, as well as its main benefits, there is another large list of minor properties, including probiotic capacity, circulatory system protection, lowers blood pressure, it is anti-carcinogenic and stimulates immune response.
Inositol is also known for its ability to neutralize certain metals, such as cadmium or aluminium, which can be very positive when detoxifying the body, which is achieved by preventing them from entering the bloodstream and to be eliminated by faeces.
Inositol is also used for beauty treatments seeking basically to stop the appearance of wrinkles and expression lines, at the same time it is considered a bulwark in the prevention of diseases of external tissues, sharing with almost all the vitamins of group B a direct effect on the vitality of skin, nails and scalp. It can be noted its ability to prevent dermatitis and eczema, on the one hand, and hair loss, on the other.
Some effects of Inositol deficiency
- Male sterility, because in the testicles it contributes to sperm production.
- Eye diseases, since the eyes are one of the anatomical regions with the highest concentration of Inositol. The absence of this element could be responsible for night blindness and photophobia, which is a symptom of extreme difficulty in supporting direct light.
- Other nervous problems not mentioned: as a vitamin, one of its functions is to act on the enzymatic mechanisms that regulate the balance between copper and zinc in neurons. Its absence or deficit leads to the rupture of that balance with predominance of copper, which could be responsible for numerous problems of the nervous system: anxiety, insomnia, phobias, etc.
- It seems their deficiency aggravates neurological problems in diabetic patients, causing what is known as diabetic neuropathy.
- A lack of Inositol can lead to a relaxation of the smooth muscle fibers of the intestinal wall responsible for maintaining peristalsis, becoming a predisposing factor for constipation.
How to manage Inositol supplements effectively and safely
We must start from the premise that a varied diet and sufficient quantity ensures that the daily demands of this peculiar vitamin are met. Most specialists agree that we need, on average, around one gram of Inositol daily. Getting it is simple with a balanced diet, but when we follow a deficient diet or suffer some disorder it is very likely for our body to require dietary supplementation.
The main factors that increase the needs of Inositol in the body are:
- A deficient diet, poor in fresh foods buy high in processed foods with lots of additives.
- Tobacco, alcohol or drug addictions
- Organ conditions in those where Inositol is synthesized, basically: stomach mucosa, liver, kidney and central nervous system.
- Situations of overexertion, stress or anxiety.
- Consumption of large amounts of beverages rich in caffeine or other stimulants (coffee, tea, cola, etc.).
- Undergoing antibiotic treatments, which are known hinder intestinal absorption. There are other drugs that weaken Inositol, since they generally neutralise vitamins, contraceptives for example.
- Excessive urination as a consequence of taking diuretics or drinking too much water
Any type of Inositol supplementation can provide easily high quantities of this substance, the normal dose is between 0.5 and 2 grams a day. However, in intense therapeutic treatments, as for depression, up to 12g a day could be necessary and tolerable.
The doses for treating psychiatric disorders, previously referred to, are normally between 10 and 12 grams a day, which are normally taken through hydro-soluble powder, since in capsules it is more difficult to reach the necessary daily dose. Capsule supplementation is normally used by those who only need a small dose, no more than 2 grams.
Patients that start a treatment with Inositol are normally advised to start off with moderate doses and gradually raise them, since an abrupt start with large amounts, close to the maximum recommended dose, can lead to suffering side effects (gastrointestinal discomfort, diarrhea and sickness).
But in larger quantities (as mentioned, doses between 13 and 16 grams), the body can experience adverse reactions that are usually associated with intense sweating that gives to the body a pungent smell similar to fish, as well as vomiting and excessive salivation. However, some abnormal manifestations such as a slight drop in blood pressure, with subsequent dizziness and loss of consciousness, have already been described at a rate of 7.5 grams per day.
Possible side effects of Inositol
Referring to extreme cases, 10g of Inositol per kilo of bodyweight has been considered lethal, therefore there is a wide safety margin for therapeutic dosage. A part from some deviations, everything seems to indicate that, in general, this substance is well tolerated.
The side effects previously mentioned for ordinary doses are mild and located, almost entirely, in the digestive apparatus, in other words, sickness, diarrhea, flatulence, etc.
However, it is not an easy tolerable substance for everyone, since for some people, the use of Inositol is contraindicated for certain people. In children with attention deficit hyperactivity disorder (ADHD), therapeutic doses not only don´t have any positive effect, but could also aggravate their symptoms. During pregnancy it must also be avoided, since it stimulates the smooth muscle tissue of the uterus, caused by calcium liberation, than can cause contractions that could lead to premature birth or abortion. It is neither suitable for people affected by bipolar disorder, since there are serious suspicions that it could lead to manic episodes.
Likewise, it is interesting to know that during pregnancy, the mother becomes more resistant to insulin so as to ensure the continuous supply of glucose that the fetus needs for its correct development.
This frequently leads to the appearance of gestational type 2 diabetes, whose treatment requires good advice regarding diet and lifestyle. In pregnant women unable to maintain uniform and correct blood glucose levels, it is usually decided to prescript a hypoglycemic medication that, on the one hand, is non-toxic for the mother and the fetus, and on the other, keeps blood glucose levels stable.; this could be Myo-Inositol.
An important precaution involves caffeine intake, which should be reduced to a minimum if Inositol supplements are being taken, as it is known to have a neutralizing effect.
Inositol supplements, what´s available?
In the market there is a large variety of Inositol supplements. As indicated in previous chapters, there are nine isomers of Inositol, but most of them contain Myo-Inositol. This aspect must be taken into account when reading the label, since it is not uncommon for the prefix “Myo” to be omitted and to be referred to simply as Inositol; in which cases it should be understood that the product in question contains the Myo-Inositol isomer.
There are two other Inositol isomers that are frequently incorporated into supplements, designed to address specific health conditions.
One of them is called Inositol hexaphosphate, which is chosen mainly for its reputed anti-cancer action.
Myo-Inositol has a recognized anticancer effect by itself. However, Inositol hexaphosphate (IP6) stands out above the rest of derivatives as a substance that must be taken into account to prevent and treat cancer. However, both are often prescribed for simultaneous consumption because they seem to establish a strong synergy that enhances the qualities of each one separately.
The second one is D-chiro Inositol. It is not usual to find it isolated in a supplement, what´s more, it usually comes combined with Myo-Inositol, a combination that is commonly prescribed for treating polycystic ovarian syndrome.
Women suffering from this disorder of the reproductive system (polycystic ovary syndrome), have two substances close to hand: Myo-Inositol and D-chiro Inositol.
Some base their treatment of Myo-Inositol on 4 grams a day (powder seems more advisable than capsules).
When capsules are used, it is often combined with Metformin, a drug normally used for antidiabetic purposes. In other cases, a combination of Myo-Inositol and D-chiro Inositol is chosen, on which there is considerable consensus that it significantly improves the clinical and metabolic profiles of patients. Within this pathology we can also mention that there is usually an increase in fertility because it improves the ratio between the LH and FSH hormones that are manufactured by the pituitary gland and in turn usually normalize the menstrual cycle.
The synergy of Myo and D-chiro Inositol plays a major role in the normalization of hormonal imbalances in the reproductive system, as well as in ovulation and menstrual cycles. At the same time, it also significantly reduces levels of circulating androgens (such as testosterone), responsible for the appearance of excess body hair and acne and in line with polycystic ovarian syndrome.
It can be added, as a curiosity, that b are more likely to achieve better results in combined treatments of Myo and D-chiro Inositol.
Inositol and weight loss
There are people who experience weight loss when taking Myo-Inositol supplements. It can be understood that, for the most part, this effect is a consequence of a sensitization of the cells to the action of insulin. It is concluded that anyone who manifests insulin resistance can lose weight regularly taking supplements of this substance.
In this line, the experts have advanced a bit, up to the point of establishing as recommended dose the four daily grams, quantity for which the satisfactory results seem to be very probable.
But if we refer to supplements to lose weight we can not forget the role of the choline in combination with Inositol. Both contribute to regulate fat metabolism, accelerating the biochemical processes and, consequently, favoring its mobilization and combustion in order to obtain energy for the organism. That is the reason for which they are popularly known as fat burners.
A good time to take them can be before going to sleep at night, since they promote the combustion of fats while you sleep.
The effects of supplementation on blood glucose regulation
It is true that there are people who follow a stable Myo-Inositol consumption to control blood sugar levels, and seem to show good results.
Regarding this, it should be said that it is advisable to start with a small amount of substance (you can move between half and a gram daily) and have blood glucose levels monitored for several months until you find the right dose.
The dose that in the majority of recorded cases seems to approximate the ideal is a couple of grams per day.
Inositol as a tool to improve mental health.
There consolidated evidence of the efficacy of the combined administration of Omega-3 fatty acids and Inositol for psychological disorders such as mood swings, but until recently the therapeutic possibilities, both in the form of monotherapy and mixed therapy, have not been tested on the increasingly common manic-depressive disorders of childhood (up to 12 years), as well as in the pictures of non-severe bipolarity.
So, a promising conclusion seems to have been drawn:
The combined treatment of Omega-3 fatty acids (particularly EPA or eicosapentaenoic acid) and Inositol introduces correction mechanisms of manic-depression symptoms at these ages, that are comparable, in terms of efficacy, with the derivatives of psychotropic drugs that are associated with significant side effects and contraindications.
Supplementation before pregnancy
When a woman intends to become pregnant, she should not wait for the pregnancy test confirmation to start supplying her body with the nutrients that require an optimal fetal development, especially folic acid and Inositol.
From the University of Washington School of Medicine they confirm that the latter protects the fetus from the feared malformations of a key organ in embryonic and fetal development, the neural tube, whose formation occurs within the first month of pregnancy and affects the future spinal cord, brain and spine.
Among those caused by Inositol deficiency, the most common are spina bifida and anencephaly.
To avoid them, it is necessary to supply the organism with the necessary Inositol and Folic Acid contributions, which means to begin its supplementation, to minimize the risk of malformations, before fertilization, always, obviously, when it is a planned pregnancy.
How to take Inositol supplements
In order to achieve the highest possible reduction of insulin resistance in the cases already discussed, of polycystic ovary syndrome, most experts recommend concentrating the administration of Inositol in one dose before breakfast.
Regarding the differences that the physical presentations have on the the necessary dose, it is important to take into account that in soft capsules or gels, the bioavailability of Myo-Inositol is higher, which makes it possible to take the third part of the dose, while maintaining the probabilities of achieving analogous effects at the therapeutic level.
Consequently, as opposed to hard capsules, gels can be a very valid alternative in cases of considering supplementation for mental health purposes.
Practically speaking, we are talking about replacing the 12 grams per day required to produce psychopharmacological effects for 4 grams of Myo-Inositol.
In white crystalline powder form, its consumption requires to be dissolved and mixed vigorously in a glass of water, giving a soft sweet flavor or fruit juice. Bulk powder is much cheaper than capsules, which contain, mostly, between 500 and 750 mg of Inositol, making it necessary to ingest a large amount in order to achieve appreciable benefits.
Safety and quality, benchmarks when choosing between Inositol supplements
Inositol is a well known supplement, elaborated by several laboratories, regularly submitted by the Governmental Organs of the country of origin, to rigorous sanitary controls and following the Good Manufacturing Practices (GMP) standards. These manufacturers continually test supplements before commercialising them to rule out the presence of contaminants such as heavy metals or microorganisms. They also submit them to demanding tests of identity, purity and power.
When choosing a supplement, it is advisable to ensure that it has the least number of ingredients considered "superfluous". As an example, the capsules contain magnesium stearate as a lubricant, while the water-soluble powders usually do not contain any additional ingredients.
When needed, we recommend buying Inositol 500mg from HSN Essentials, which offers 500mg in each service taken.
Ultimately, we must recommend that the decision to take a regular and scheduled dose of Inositol in any of its isomers, should always be supervised by a specialized professional who fully assesses all personal and medical aspects.