Dieta e Integratori per i Fumatori

Danni del Fumo

Il fumo, si sa, determina gravi danni all'organismo, minando la salute cardiovascolare, peggiorando l'efficienza fisica e favorendo la comparsa di alcune forme di tumori.

Purtroppo, gli scienziati non sono ancora riusciti a identificare un farmaco o un approccio nutrizionale specifico per annullare totalmente i pericolosi danni del fumo.

A tal proposito, molti studi sono stati condotti per valutare l'importanza della vitamina C nella prevenzione dei danni dal fumo. Sebbene il suo effetto non sia "miracoloso", vi sono diverse evidenze scientifiche a sostegno dell'utilità di una specifica integrazione per ridurre i danni del fumo.

The recommended intake for smokers is 35 mg/day higher than for nonsmokers, because smokers are under increased oxidative stress from the toxins in cigarette smoke and generally have lower blood levels of vitamin C.

Vitamin C

A few human studies using conditions of oxidative stress have demonstrated the importance of vitamin C (ascorbic acid) in the recycling of oxidized α-tocopherol back to its reduced state (see Figure 2). Oxidative stress caused by cigarette smoking accelerates the depletion of plasma α-tocopherol in smokers compared to nonsmokers (17). In a double-blind, placebo-controlled trial in 11 smokers and 13 nonsmokers given α-tocopherol and γ-tocopherol that was labeled with deuterium (hence traceable), supplementation with vitamin C reduced the rate of vitamin E loss in plasma, most probably by regenerating tocopheryl radicals back to nonoxidized forms (18).

Piombo

Several cross-sectional studies report an inverse association between vitamin C status and blood lead level (BLL). In a study of 747 older men, BLL was significantly higher in those who reported total dietary vitamin C intakes averaging less than 109 mg/day compared to those who reported higher vitamin C intakes (127). A much larger study of 19,578 people, including 4,214 children from 6 to 16 years of age, found higher serum vitamin C levels to be associated with significantly lower BLL(128). A US national survey of more than 10,000 adults found that BLL were inversely related to serum vitamin C levels (129).

Cigarette smoking or second-hand exposure to cigarette smoke contributes to increased BLL and a state of chronic low-level lead exposure. An intervention trial in 75 adult male smokers found that supplementation with 1,000 mg/day of vitamin C resulted in significantly lower BLL over a four-week treatment period compared to placebo (130). A lower dose of 200 mg/day did not significantly affect BLL, despite the finding that serum vitamin C levels were not different from those in the group who took 1,000 mg/day.

The mechanism for the relationship between vitamin C intake and BLL is not known, although it has been postulated that vitamin C may inhibit intestinal absorption (130) or enhance urinary excretion of lead.