KEEP TAKING THE ZINC TABLETS?
As we age, our bodies become less able to fight disease. Zinc is a key dietary mineral that seems to be connected with this process. Scientists know that zinc levels in the body decline with age, and that supplementing the diet of the elderly with zinc can have a positive impact on cellular defects associated with age. There is a potential to improve the health of Europe's rapidly ageing population with simple, cheap zinc tablets. However, too much zinc can be toxic, and certain groups of people may have adequate zinc even in old age. A three-year Specific Targeted Research Project called ZINCAGE is studying the behaviour of zinc and its related physiology in the immune cells of Europe's elderly, with a view to generating advice on who could really benefit from zinc supplementation.
In a healthy immune cell, zinc is captured within the structure of a protein called metallothionein and stored. From here, it is released into the cell nucleus when needed, forming a crucial component of enzymes involved in DNA and protein repair, cell division and chromosome maintenance. Such processes, which are vital for an effective immune system, are found to be less efficient in old age.
Metallothionein stops releasing its zinc in old people. There are several theories for why this happens, such as bad folding of the protein itself, or lack of a chemical that liberates zinc inside the nucleus. Without zinc, key proteins become oxidised and function badly. Failed maintenance of the protective sealed end of each chromosome, known as the telomere, is especially implicated in ageing - the telomere generally shortens with age.
OLIVES KEEP YOU YOUNG
Scientists at ZINCAGE will study the activity of zinc in immune cells, called lymphocytes, taken from 800 people aged between 65-85, to find out which parts of the process are not functioning. They will also test whether faults can be corrected by supplementing the diet with zinc. Subjects will come from Germany, Poland, Greece, Italy and France. Scientists will look for differences between men and women, and are also keen to identify any differences between northern and southern Europe. Southern Europeans have longer life expectancy than northerners, which has been linked to the high zinc content of olive oil in the Mediterranean diet.
The project will take samples of DNA from elderly subjects and look at the genes for proteins that interact with zinc. They will investigate whether or not the genes are different in subjects where zinc is not working properly as there may be a genetic tendency in certain groups to zinc deficiency in old age. Partners in the project will develop a DNA microchip to test the activity of all the genes associated with repair of the telomere, and to diagnose problems that may be associated with zinc availability.
THE SECRET OF LONGEVITY
The same tests will be carried out on people who are ageing very well - having reached 90 or 100 - and on people suffering severe age-related degeneration. The researchers hope to find differences among these groups - perhaps nonagenarians retain perfect zinc functions or display discernible genetic differences in how their bodies deal with zinc.
In addition, one of the aims of ZINCAGE is to provide a simple genetic screening method in order to identify people at risk of zinc deficiency and consequently the appearance of age-related diseases. The use of zinc supplements by these subjects may be useful to help them achieve successful ageing.
ZINCAGE will advance our understanding of the role of zinc in the ageing immune system significantly and give European science a competitive edge in the field. The project should provide the basis for advice on who should take zinc supplements to ward off the frailties of old age.
List of Partners
- Italian National Research Centre on Ageing (Italy)
- University of Perugia (Italy)
- Centro Nacional de Investigaciones Oncológicas (Spain)
- Harokopio University of Athens (Greece)
- University of Konstanz (Germany)
- Medical University of Lódz (Poland)
- National Hellenic Research Foundation, Institute of Biological Research and Biotechnology (Greece)
- University of Roma Tre (Italy)
- University of Paris VII (France)
- Semmelweis University (Hungary)
- Unilever Research (UK)
- University of Florence (Italy)
- University of Besançon (France)
- Imperial College London (UK)
- Istituti Ortopedici Rizzoli, Bologna (Italy)
- RWTH, Aachen University (Germany)
- Universität Tübingen (Germany)
- Full title:
- Nutritional zinc, oxidative stress and immunosenescence: biochemical, genetic and lifestyle implications for healthy ageing
- Contract n°:
- Project co-ordinator:
- Eugenio Mocchegiani, Italian National Research Centre on Ageing (INRCA), firstname.lastname@example.org
- EC Scientific Officer:
- Ana Nieto Nuez, email@example.com
- EU contribution:
- € 3M
- Specific Targeted Research Project