Plant sterols or phytosterols: what are they and what are they for? Let’s see if and when it is useful to take them in the form of a supplement.
Surely we have all heard about plant sterols or phytosterols, especially in relation to their beneficial effect on the cardiovascular system, but let’s try to deepen what they are, if they are really useful for our health, where we can find them and how to take them.
What are plant sterols
Plant sterols are chemical compounds found in plants. Their name comes from their chemical structure, which is very similar to that of cholesterol. Cholesterol is found in animal organisms, including humans, and not in plants, which instead contain phytosterols, where they are a fundamental constituent of cell membranes. In practice, therefore, phytosterols are the plant equivalent of cholesterol. At least 250 different types are known, of which the most common are sitosterol, campesterol, stigmasterol.
What are phytosterols used for
Phytosterols in plants are part of the cell membranes, therefore they are fundamental components of plants. It is widely demonstrated that in humans phytosterols have the ability to decrease plasma cholesterol levels since, having a chemical structure similar to that of cholesterol, it seems to be able to inhibit the absorption of cholesterol in the intestine since they are absorbed at the intestinal level. instead of cholesterol, thus causing an increased elimination of the same through the faeces and consequently a reduction in the bloodstream.
The real mechanism of action is not yet well known, but many scientific data suggest that plant sterols are able to reduce blood levels of total cholesterol and LDL cholesterol (the bad cholesterol) quite effectively, without however modifying HDL cholesterol ( good cholesterol).
It also seems that phytosterols have a role, albeit less than that played against cholesterol, in reducing triglyceride levels, but only when these are moderately high.
Where are plant sterols found in foods
As already mentioned, plant sterols are contained in plants and we humans cannot synthesize them, for this reason we can only take them from foods of plant origin and, of course, there are foods that contain more than others. Its seeds are particularly rich and therefore the vegetable oils obtained from it, dried fruit (including pistachios, walnuts, hazelnuts and almonds), legumes. Among the vegetables, broccoli, cabbage and cauliflower contain discreetly, and even some fruits. It is therefore easy to understand how the Mediterranean diet provides a good supply of phytosterols.
Phytosterols in food: practical table
We have just said that phytosterols, being chemically fats, are contained in greater quantities in the seeds and oils obtained from them, but also in legumes, vegetables and some fruits. Let’s see in more detail which foods contain the most phytosterols and in what quantities.
|Food||Phytosterol content (mg / 100 g)|
|Dried broad beans||124|
How many plant sterols per day
It is estimated that, following a balanced diet, an average of 150 to 450 mg of phytosterols are introduced through foods per day, an amount that could increase for those following a vegetarian diet, even up to 700 mg per day. Scientific studies show that an intake of plant sterols between 1.5 and 3 grams per day is able to lower the blood concentration of cholesterol.
It has also been shown that these molecules could also have antioxidant effects which would therefore contribute to the beneficial effects on the cardiovascular system and also to the health of the intestinal microbiota by promoting the growth of beneficial bacterial species.
In this way, phytosterols would help us prevent cardiovascular diseases by acting at different levels: reducing the risk of atherosclerosis, reducing oxidative stress and improving intestinal absorption of nutrients thanks to the action on the microbiota.
Plant sterol supplements: when and how to use them
If you lead a healthy and dynamic life and follow a varied and balanced diet, the quantities of plant sterols you take can cover the needs of our body, but it may happen that these conditions are no longer valid and that adequate quantities of these are not taken. compounds or that there is an excess in blood cholesterol concentration. Only on medical advice it is therefore possible to take phytosterol supplements to treat “high cholesterol”.
Since it has been seen that many of us lead a diet low in phytosterols, given their presence exclusively in foods of plant origin, foods have been formulated with added phytosterols, such as yogurt or milk, which are able to provide the quantity of phytosterols considered optimal for lowering blood cholesterol levels, but only if taken daily and regularly and in the correct dosages.
Another alternative is to take phytosterols in capsule form, which can be found in pharmacies and parapharmacies. Phytosterol supplements are usually taken once a day next to one of the main meals. It is necessary to remember, however, that the use of supplements does not disregard a varied and balanced diet and above all that it must be undertaken under medical advice and is not equivalent to the use of any drug that the doctor may prescribe.
The contraindications of plant sterols
Following the use of phytosterol supplements, some side effects have been observed, affecting the gastrointestinal system, such as diarrhea or constipation and abdominal bloating. Some studies also show that the use of phytosterols could inhibit the absorption of carotenoids and fat- soluble vitamins.
Among the contraindications to use there is instead the individual hypersensitivity to the active ingredient and also a genetic pathology, the familial phytosterolemia, for which those affected, having an altered absorption of sterols in the intestine and a reduced excretion of the same, it could accumulate sterols with consequent increase in blood concentrations, which, instead of reducing cardiovascular risk, would increase it. The subject is still debated, but it is necessary to inform the patient.
In addition, the use of phytosterol supplements could potentially the effect of any hypocosterolemic drugs, such as statins, so those already undergoing drug therapy should consult their doctor. Since some phytosterols have been shown to have a hypoglycemic action, even those who follow a therapy for the treatment of diabetes should pay attention to the use of plant sterol supplements as they could enhance the action of hypoglycemic drugs.
Thyroid dysfunctions such as hypothyroidism and hyperthyroidism can alter plasma cholesterol levels and some drugs used for the treatment of thyroid diseases can in themselves also affect blood cholesterol levels. In this case the phytosterols would interfere in the treatment. Those taking oral anticoagulants should also seek medical advice before taking phytosterols as supplements.
Phytosterol supplements: where to buy them and which ones to choose
If your doctor recommends taking phytosterol supplements, it would be advisable to buy them at a pharmacy or parapharmacy, but you can also buy them online making sure you do so from authorized stores. If, on the other hand, the doctor recommends the use of fortified foods, such as yogurt and milk, we can find these products in supermarkets and grocery stores. In any case, it is always better to seek advice from a doctor or a nutrition expert and avoid “do it yourself”.