Inositol is a carbohydrate with a cyclic structure and almost ubiquitous inside the human body. In fact, it is present in most of its cells. It is also known as vitamin B8.
- 1. What is Inositol?
- 2. Properties of inositol
- 3. Inositol second messenger system
- 4. Benefits of inositol
- 5. Inositol to lose weight
- 6. Inositol and pregnancy
- 7. Inositol regulates the blood glucose
- 8. Inositol and mental health
- 9. Sources of inositol
- 10. Inositol deficiency
- 11. Inositol supplements
- 12. Side effects of inositol
- 13. Bibliography
- 14. Related Entries:
What is Inositol?
If we had to highlight an organic element in terms of the richness of this substance, it would be breast milk. At the same time, it proves the innate need of newborns to get a regular supply of this vitamin.
It is a substance with nutritional activity. Actually, it performs several biological tasks after being absorbed in the intestinal tract and entering the bloodstream. But unlike other vitamins, it is not essential for adults, since the body can synthesize it from glucose.
There are many chemical compounds in nature that slightly vary in terms of their structure: these are isomers.
They have nine possible structures that only change in terms of the disposition of some of their atoms. More specifically, in the arrangement of the hydrogen and OH around the carbon atoms that make up its ring structure.
Of all of them, the most abundant one is myo-inositol. In fact, it is closely connected to the nervous system of mammals (including human beings, of course) apart from other locations.
Properties of inositol
A very relevant feature when it comes inositol metabolism is the fact that the human body is programmed to perform its synthesis. Some of the main tissues where said synthesis takes place are the intestinal mucosa, the central nervous system, the liver and kidneys.
Moreover, it is present in almost all the cells of the body. It is a substance whose molecular structure is made up of phospholipids, which are important fatty compounds for the cell membrane. Above all, it is crucial for neurons or nerve cells.
Involvement in the organization of tissues:
Supporting the nerve impulse and the synthesis of neurotransmitters
Thanks to this property, inositol can help to treat many pathologies connected to the nervous system:
- Bipolar disorder
- Obsessive compulsive disorder
- Anorexia and bulimia
- Agoraphobia or fear of open spaces, as well as claustrophobia
- Attention deficit hyperactivity disorder
- Moreover, it improves the quality of sleep, the mood as well as the symptoms of anxiety and stress
In fact, it has been proven that the inositol levels in the spinal fluid of people with depression is considerably low. It seems that it is due to the dependence between inositol and the synthesis of serotonin.
Lowering the cholesterol levels at home
We can do so by combining it with choline.
Playing a lipotropic function in the liver
Stimulating the smooth muscles of the gastrointestinal tract
It contributes to regulating the peristalsis and, consequently, it combats constipation.
Supporting the enzymatic activity of many metabolic biochemical reactions
- Sight, skin and hair
- Good digestions and digestive system on point
- Proper formation of bone marrow cells, indispensable for the blood flow and immune system
Inositol second messenger system
It has a molecular structure that allows it to move easily in the outside and inside of the cells. This is a determinant feature if we want to understand its importance for vital tasks. Therefore, it performs the so called second messenger system, which is the intracellular response of the inositol molecule to a specific hormone. Consequently, it sets a series of biochemical reactions into motion that result in a specific physiological effect.
Actually, it is necessary to have a subtle communication network in order to organize and specialize cells in tissues and organs. This network has to control the cell multiplication as well as the coordination of all their tasks.
Everything begins with the first signal which is called first messenger, which can be a hormone or a releasing factor of the hypothalamus, a growth factor, etc.
Said first messenger is released in the extracellular medium and moved by the so called taxes (specific stimuli), until they reach chemical contact. This occurs in the cell plasma by a highly specific membrane receptor that work as its lock and key. From then on, the biochemical phenomena which are responsible for the vital function in each case occur. Both at the level of the membrane as well as the organelle contained in the cell cytoplasm.
Myo-inositol and diacylglycerol
Between these receptors, there is a very important one that uses G proteins. These are bound to nitrogen bases called guanines (which make up the DNA). Said elements regulate the release of two new intracellular messengers, the second messengers, being: myo-inositol and diacylglycerol. Both are at the last link of the communication chain that goes immediately before the physiological effect.
How does it perform this task
One of these methods consists of regulating the calcium content inside the cells. This occurs when inositol triphosphate projects itself on a cytoplasm organelle called endoplasmic reticulum. Inside, it makes it easier to release the calcium reserves that activate the neurotransmitters. On the other hand, inositol also regulates the osmosis (cell coating innate permeability), making it easier to move the water and the dissolution elements through the membrane.
Another great example of the significant changes of inositol is the response to the release of insulin from the pancreatic islets. This is a physiological pathway that works as a sensitizing agent of said hormone.
It is closely linked to changes in insulin resistance, where inositol also plays an important role by preventing some of its alterations: obesity or hyperlipidemia (high blood fat levels).
Several studies have assessed the amount of inositol there is in the central nervous system. Their conclusions were that a prolonged inositol deficiency can result in the onset of severe neurological disorders. We will develop two of them in detail down below.
Benefits of inositol
To sum up, it is a neuronal failure caused by the degeneration of neuronal tissue.
This disorder involves an irregular neuronal signalling. However, the scientists claim that inositol can help to correct this irregularity even when the degenerative process has hindered the physiological capacity of its own cells.
Scyllo-inositol stands out due to its potential to stabilize the deposits of a glycoprotein called β-Amyloide. In fact, it is closely related to different degeneration processes that happen throughout the body.
More specifically, we will focus on its effects on the hippocampus. It is a prominence located inside the brain which is directly connected to the memory and spatial orientation. In fact, its deterioration seems to be determinant in the symptoms of Alzheimer’s disease according to a study. It lasted a year and a half and it was conducted on with patients suffering from mild and moderate Alzheimer.
It is also worth mentioning that the cyclohexanehexol-inositol isomer also seems to contribute to reducing the accumulation of the β-Amyloid deposits.
Obsessive compulsive disorder
This is a disorder that involves compulsive attitudes and obsessive thoughts.
Role in the reproduction
Most women who suffer from this experience a high degree of insulin inefficiency when it comes to its role in the tissues. In the past, this encouraged research trials to assess if there was a cause-effect relationship between inositol and insulin resistance.
Their conclusions showed how the patients recovered their insulin sensitivity after taking myo-inositol for three months. In turn, it also lowered the risk of suffering polycystic ovary syndrome in the women who took the supplement
At the ovule level, myo-inositol seems to play a role in its maturation. In fact, it becomes an effective marker to identify those that are ready to be fertilized. Actually, women who suffer polycystic ovary syndrome have more high-quality oocytes after taking myo-inositol.
- Prebiotic properties
- Cardiovascular system protector
- Immune response stimulant
- Detoxifying effect
- Cosmetic function: nails, hair, skin
Inositol to lose weight
Some people lose weight when taking myo-inositol supplements. This can be partly due to the cell sensitization against insulin. Therefore, anyone who is insulin resistant can lose weight regularly by taking supplements of this substance.
But if we refer to weight loss supplements, we cannot forget the combination of choline and inositol. Both contribute to regulating the fat metabolism, enhancing the biochemical processes. Consequently, it improves its transport and combustion in order to obtain energy for the organism. That is the reason why they are commonly known as fat burners.
A good time to take them can be before sleeping at night, since they can stimulate the fat burning process while we sleep.
Inositol and pregnancy
When a woman wants to become pregnant, the sooner she starts taking nutrients to improve the fetal development, the better. Specially in terms of supplying folic acid and inositol.
Among those caused by an inositol deficiency, the most common ones are spina bifida and anencephaly.
To avoid them, it is necessary provide a proper inositol and folic acid supply. Supplementation comes into play in order to lower the risk of malformations. However, we should start taking it before the fertilization, as long as it is a planned pregnancy.
Inositol regulates the blood glucose
Some people take myo-inositol in order to control the blood sugar levels, and it seems to provide good results.
It is advisable to start taking a small dose (between half a gram or a gram daily). Moreover, we should monitor the blood glucose levels for several months until we find the right dose.
The dose that seems to work most of the time is a couple of grams a day.
Inositol and mental health
There is evidence of the efficacy of combining omega-3 fatty acids and Inositol for psychological disorders such as mood swings. But the therapeutic possibilities, both as monotherapy and mixed therapy, have not been tested until recently on common manic-depressive disorders during childhood (up to 12 years) and non-severe bipolarity.
Well, apparently it has had promising results:
Sources of inositol
We could start by saying that food tends to contain the myo-inositol isomer to some extent. However, the ones with the highest content of this semi-essential vitamin are whole grain cereals and citrus fruits (although lemon is an exception). They would go at the top of the list, while dairy products and meat are at the bottom. But let’s take a closer look to this subject.
- Raisins (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)
- Brussels sprouts (0.81)
- Cabbage (0.70)
- Asparagus (0.68)
- Spinach (0.66)
- Artichoke (0.6), specially in its heart
- Pepper (0.57)
- Tomato (0.54)
- Onion (0.27)
- Lettuce (0.16)
- Cucumber (0.15)
- Carrots (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 thereof:
- 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)
- Sardins (0.12)
- Clams (0.03)
- Whole milk (0.04)
- Yogurt (0.1)
- White (2.83), red (2.49) and green beans (1.93)
- Male sterility, since it contributes to the production of spermatozoa in the testicles.
- Ocular diseases, since the eyes are precisely the area with the highest inositol concentration. A lack of this element could be responsible for nigh blindness and photophobia. The latter basically consists of an extreme difficulty to stand direct light.
- Other nerve problems: as a vitamin, one of its functions is regulating the enzyme mechanisms that regulate the balance between copper and zinc from the neurons. A deficiency involves a loss of this balance in favor of copper. In fact, this could alter the nervous system, causing anguish, insomnia, phobias, etc.
- It seems that its deficiency also worsens neurological problems in diabetic people, causing what is known as diabetic neuropathy.
- A lack of inositol can result in a relaxation of the smooth muscles of the intestinal walls. These are in charge of performing the peristalsis, which can be a predisposing factor for constipation.
We need to follow a varied diet that will ensure that we meet the daily requirements of this peculiar vitamin.
Actually, it is quite simple to meet this amount with a balanced diet. However, if we follow a poor diet or if we suffer some kind of disorder, our body will probably need supplementation.
You need to take inositol if you…
- Follow a poor diet, lacking fresh products and filled with processed and addictive products
- Are addicted to tobacco, alcohol or drugs
- Suffer disorders that affect the organs that synthesize inositol, basically the stomach mucosa, liver, kidney and central nervous system
- Experience overexertion, stress or anxiety
- Take drinks that are rich in caffeine or other stimulants (coffee, tea, cola, etc.)
- Have to take antibiotics, since they can hinder its absorption by the intestines. There are other medicines that lower the inositol levels because they neutralize vitamins, like contraceptives
- Urinate too much because you are taking diuretics or because you are drinking too much water
Inositol supplementation protocol:
The standard dose moves between 0.5 and 2 grams daily. However, if we want to treat a depression, we will probably need up to 12 grams daily.
The dose to treat psychiatric disorders that we mentioned previously moves between 10 and 12 grams daily. Most of the times, people choose water soluble powder format.
In general, it is advisable to start with a moderate dose and assess how we feel and increase them gradually. If we start taking high doses from the very beginning, we will experience some of the side effects from inositol supplementation (gastrointestinal discomfort, diarrhea and nausea).
When to take inositol
Above all, it is important to take into account that softgels or gels have a higher myo-inositol bioavailability. Therefore, we will be able to take a third part of the dose in order to benefit from its therapeutic effects.
Consequently, gels can be a great alternative if we want to improve our mental health.
In fact, we are talking about transforming the 12 grams that we need daily into 4 grams of myo-inositol.
On the other hand, if we want to use white crystalline powder, we will have to simply mix it in water or fruit juice. If we mix it with water it will have a slightly sweet flavor. Moreover, powder tends to be cheaper than capsules. The latter tend to have between 500 and 750mg of inositol, so we will have to take several ones in order to experience its benefits.
How to choose a supplement?
At the beginning of the article, we mentioned that there are nine inositol isomers, but most of them have myo-inositol. We need to take this into account when reading the product label. Sometimes, the brand omits the prefix ‘myo’, so we need to understand that the product in question has a myo-inositol isomer.
There are another two inositol isomers that are usually added to supplements:
For instance, women who suffer polycystic ovary syndrome can benefit from these two substances: myo-inositol and D-chiro inositol.
Some of them solely base their treatment on 4 grams of myo-inositol daily (powder is better than capsules).
Capsules tend to contain a blend with metformin, which is an anti-diabetes medication. In other cases, people tend to combine myo-inositol and D-chiro inositol. In fact, people believe that it can significantly improve the clinical and metabolic profiles of patients.
The synergy between myo and D-chiro inositol plays an important role in normalizing hormone imbalances in terms of reproduction. Moreover, it can also help with ovulation and menstrual cycles. At the same time, it also significantly reduces the circulating androgen levels (like testosterone). They are responsible for the onset of body hair and acne, as well as the polycystic ovary syndrome.
Actually, obese and overweight women tend to obtain better results from a combined treatment of myo and D-chiro inositol.
Side effects of inositol
A lethal dose would be 10 grams per kilo of body weight. But therapeutic doses are quite safe overall. So, we could say that this is a very safe and well tolerated substance in general.
The following people must not take inositol by any means:
- Children with hyperactivity disorder
- People with bipolar disorder
- Pregnant women
Interestingly enough, women develop a state of insulin resistance during pregnancy. Its purpose consists of taking glucose from the bloodstream to the fetus in order to get the supply it needs to grow.
Quite frequently, this leads to the onset of gestational type 2 diabetes. Its treatment requires good counselling when it comes to the diet and lifestyle. In fact, pregnant women who cannot regulate their glucose levels tend to take hypoglycemic medication. On the one hand, it can be atoxic for the mother and fetus. On the other hand, it can keep the glucose levels stable; this could be myo-inositol.
- Carlesso A, Chintha C, Gorman AM, Samali A, Eriksson LA. Binding Analysis of the Inositol-Requiring Enzyme 1 Kinase Domain. ACS Omega. 2018 Oct 31;3(10):13313-13322. doi: 10.1021/acsomega.8b01404. Epub 2018 Oct 16.
- Canepa P, Dal Lago A, De Leo C, Gallo M, Rizzo C, Licata E, Anserini P, Rago R, Scaruffi P. Combined treatment with myo-inositol, alpha-lipoic acid, folic acid and vitamins significantly improves sperm parameters of sub-fertile men: a multi-centric study. Eur Rev Med Pharmacol Sci. 2018 Oct;22(20):7078-7085. doi: 10.26355/eurrev_201810_16180.
- Hu L, Zhou K, Li Y, Chen X, Liu B, Li C, Gong X, Ma F. Exogenous myo-inositol alleviates salinity-induced stress in Malus hupehensis Rehd. Plant Physiol Biochem. 2018 Nov 1;133:116-126. doi: 10.1016/j.plaphy.2018.10.037.
- Shears SB, Wang H. Inositol phosphate kinases: Expanding the biological significance of the universal core of the protein kinase fold. Adv Biol Regul. 2018 Oct 27. pii: S2212-4926(18)30148-9. doi: 10.1016/j.jbior.2018.10.006.
- Choline and inositol
- Nutrition and supplementation before, during and after pregnancy