nutrition and health

Antioxidant Vitamins Against Infarct

What are they?

Antioxidant vitamins are three types of fairly heterogeneous molecules, both for their chemical-physical characteristics and for the food sources that contain them.

The antioxidant vitamins are:

  • Vitamin A and β-carotene
  • C vitamin
  • Vitamin E

Water-soluble antioxidant vitamins

C vitamin

The only water-soluble antioxidant vitamin is vitamin C or L-ascorbic acid. This vitamin has the ability to oxidize into dehydroascorbic acid and to be reversibly reduced; intervenes in numerous functions of hydroxylation, promotes the reduction of folic acid and promotes the absorption of iron by reduction of Fe3 + to Fe2 +.

As far as its antioxidant activity is concerned, vitamin C participates in the processes of cellular defense by FIGHTING THE FREE RADICALS of oxygen by donating an electron to the tocopheryl radical; in this way, vitamin C restores the anti-radical activity of another antioxidant vitamin: vitamin E or tocopherol.

Almost all of the vitamin C taken with food is absorbed, while at high doses almost 85% remains in the faeces.

Vitamin C deficiency was a typical sign of sailors who, having no fresh fruit and vegetables to eat on long journeys by sea, developed scurvy . Today, fortunately, the lack of vitamin C does not reach similar levels even though it is not uncommon for food to be a little lacking (especially in the third age population - about 9% of the elderly); the excess of vitamin C is not healthy but doses up to 10g / day "seem" safe.

Vitamin C is contained in foods of vegetable origin (citrus fruits, kiwi, peppers, tomatoes and green leafy vegetables) FRESCHI; on the contrary, the loss of vitamin C is proportional to the storage time, to washing (by dilution) to cooking, to light and to oxidation.

The recommended ration of vit. C for the adult should not be <10mg and should instead fluctuate between 45-60mg / day; smokers have a greater need (about + 30mg), as well as pregnant women (+ 10mg) and nurses (+ 30mg).

Liposoluble antioxidant vitamins

Vitamin A and β-carotene

Vitamin A or retinol and β-carotene have the same vitamin function, even if for each retinol unit there are six β-carotene (and many more for the other 500-600 carotenoid species). The retinol, present in animal foods, is stored in good quantities in the liver which (in case of need) releases it into the circulation (quantity <20mg / dl in the blood indicates the imminent depletion of stocks); on the contrary, carotenoids are pigments that are found mainly in vegetables and fruit.

Vitamin A is essential for cellular differentiation (including the immune system), but the real antioxidant function is better attributable to carotenoids which (despite having a low vitamin A type function) neutralize singlet oxygen (a powerful PRO-oxidant).

Vitamin A and β-carotene deficiency is closely related to visual disturbances (crepuscular blindness) and high incidence of tumors due to oxidative stress; toxicity occurs with doses of 300mg / day.

The recommended rations range from 350 retinol equivalents (RE) in children up to 900 RE in the nurses.

NB. RE = 1 mg of retinol = 6 mg of β-carotene = 12 mg of other active carotenoids.

Vitamin E

Vitamin E includes different forms of tocopherols: α, β, γ and δ tocopherol, although the most active is α- tocopherol; Vitamin E is absorbed in the small intestine, also thanks to the action of bile acids, up to 20-40% of the total ingested. In the blood, vitamin E moves bound to the transport lipoproteins and the body's richer deposits are made up of adipose tissue.

The antioxidant action of vitamin E consists in blocking the degeneration of polyunsaturated fatty acids (PUFA), including the essential ones (AGE), activated by peroxylipidic free radicals ; this SHIELDING action represents one of the major defenses that the organism has against the stress of AGEs contained in cell membrane phospholipids (for the same reason, tocopherols are frequently used as an antioxidant additive in vegetable oils rich in PUFA fatty acids).

Vitamin E deficiency is almost unknown and does not occur in normal individuals, while intestinal disorders are attributable to pharmacological excess (> 2000mg / day).

Vitamin E is contained in lipids of vegetable origin; its seeds and all its dried fruit are rich, some cereals, wheat germ, fresh fruit and vegetables, soy and peanuts. Unfortunately, despite its spread, vitamin E is also very sensitive; they damage it: light, heat, alkaloids, iron and copper. For this reason it would be advisable to introduce at least 0.4mg of tocopherol equivalent (TE) with the diet every gram of PUFA taken with the diet; eg on a 2000kcal diet and relative 5.5-5.6g of PUFA, about 2.2-2.3mg / day of vitamin E would be needed.

ACE against heart attack

Scientific research has now amply demonstrated that the lack of ACE vitamins (and indeed the true one also of selenium) favors the onset of unfortunate events affecting the cardio-circulatory system. However, if it is true that the lack of antioxidants predisposes to ischemic heart disease, it is equally true that a diet rich in ACE vitamins proves to be protective from myocardial infarction and atherogenesis in general.

Analyzing the importance of antioxidants in the diet, it emerged that there is an inverse relationship between plasma levels of antioxidant vitamins and MORTALITY due to ischemic heart disease, as well as an inverse relationship between the consumption of FRESH and VEGETABLE fruit rich in antioxidant vitamins and cardiovascular MORTALITY; furthermore, a correlation between low levels of vitamin E and the presence of angina pectoris (cardiac pain) is also suspected.

This simply translates into a PROTECTIVE function of antioxidant vitamins (and in particular of vitamin E) on atherosclerotic pathologies.

It's not all! Tocopherols also seem to hinder the oxidation of transport lipoproteins while preserving their integrity and efficiency, therefore also the natural uptake by hepatic and peripheral receptors, preventing interstitial deposition as a trigger for atherogenesis.

Warning! Vitamin E supplementation may be contraindicated in patients with ANTICOAGULANT treatment.

Bibliography:

  • Post-infarction and associated diseases. Preventive, curative and associated pathologies. Volume II - A. Zangara - Piccin - page 431: 433.