Micronutrients and cell aging
Cell aging is a complex process in which numerous factors may be involved, and there is something that is a major part of this process: telomeres.
These structures are located at the ends of chromosomes and consist of repeated DNA sequences and associated proteins (histones) that act as a kind of protective sheath that stabilizes the DNA. When DNA duplication occurs during cell division, some of the constituent DNA units at the ends of the chromosomes (nucleotides) are not copied, causing the telomeres of the new DNA strands to become shorter and shorter with each cell replication.
The progressive shortening of the telomeres modifies the pattern of gene activation in the cells, which duplicate more slowly, then stop duplicating (senescence) and finally die (apoptosis). This cellular aging process is slowed down by an enzyme, telomerase, which forms telomeres by adding nucleotides to the ends of the new DNA strand that would otherwise be lost. This slows down aging and cell death.
Analysis of data from a cohort study of sister pairs showed that high intakes of vitamin C and E and beta-carotene, both from food and food supplements, were associated with longer telomeres in leukocytes (white blood cells) compared to women with poorer vitamin intakes. Similarly, a higher intake of vitamin B12, which increases the availability of the antioxidant glutathione, was also associated with longer telomeres.
The antioxidant and anti-inflammatory properties of the omega-3 fatty acids docosahexanoic acid (DHA) and eicosapentaenoic acid (EPA) could help prevent telomere shortening in cells involved in defense against inflammation.
Oxidative stress and inflammation are key determinants in the biological aging process and appear to be closely related to telomeres. It is therefore possible that the anti-inflammatory properties of vitamin D and other vitamins may also help to protect against telomere shortening in lymphocytes (white blood cells).
The supposed preventive effect of vitamin D on cardiovascular diseases that has been demonstrated in studies could be explained by the stabilizing action of this vitamin on telomeres: vitamin D reduces proinflammatory mediators (such as TNF-alpha or interleukin 2) that apparently cause telomere damage.
vitamin B3 (nicotinamide) could influence telomere length through various mechanisms that are important for DNA stability. Thus, for example, this vitamin seems to have an effect on the formation of DNA repair enzymes. Folic acid (vitamin B9) may also play a special role in the formation and maintenance of telomeres. This vitamin forms the precursors of DNA components (nucleotides) and promotes the stability of DNA, its associated proteins, and telomeres. Insufficient dietary intake of folic acid could lead to telomere shortening, probably due to increased DNA damage.