I am teaching a graduate course this summer called Geriatric Nutrition. The definition for
“of or relating to old people, esp. with regard to their health care”
Whenever I teach a course, I learn something. One thing was “What is Old?” The current classification I found is specific:·
- Persons Approaching Old Age = 55 – 64 years·
- Young Old
- = 65-74·
- Old = 75 – 84·
- Oldest- old= Older than 85
Another thing I learned is the association between diet and aging. In the course, we examine the Theories of Aging. One theory that is most fascinating to me the
Telomeres are sections of DNA at the ends of our chromosomes. They protect the rest of your DNA every time a cell divides. When a cell divides, all
of the DNA cannot be copied and so a little gets cut off.
Researchers have shown that older people have shorter telomeres.
Eventually, the cells with shorter telomeres can no longer divide and, over
time tissue damage and the dreaded “signs of aging” can begin. Most cells can
replicate about 50 times before the telomeres are too short. Interestingly, cancer cells show a morality that normal cells do not. Cancer cells do not die for one thing because they switch on an enzyme called telomerase, which adds to the telomeres when cells divide. Some cells in the body can also do this (stem cells and sperm cells, for example) because they need to replicate more than 50 times in your lifetime.
I would not have suspected that diet or nutrition would affect this
process, but in searching found that there are several studies that support
The first study involved omega-3 fatty acids. Researchers measured the length
of leukocyte telomere length after five years in 608 patients with stabilized
coronary heart disease. Then they compared the baseline levels of omega-3 fatty
acids and the telomere length at the end of the study.
The hypothesis of the study was that since omega-3 fatty acids influence
or increase the levels of some important antioxidant enzymes in the body
(superoxide dismutase and catalase), it may also influence the presence of
teloramase which is responsible for adding DNA to the chromosome during
The conclusion from this study was that “a daily supplementation of
omega-3 fatty acids was associated with a significant increase in telomerase activity.”
Farzaneh-Far R et al. Association of Marine Omega-3 Fatty Acid
Levels with Telomeric Aging in Patients with Coronary Heart Disease. JAMA 2010;303:250-7.
The next study involved Vitamin D. Leukocyte telomere length was shorter in 2,
160 women (average age of 49) with lower levels of vitamin D. Telomere length was negatively correlated with C-reactive protein, a marker for inflammation and positively correlated with vitamin D, in other words, higher vitamin D levels are associated with longer leucocyte telomere length.
Richards, JB et al. Higher serum vitamin D concentrations are associated with longer leukocyte telomere length in women. Am. J Clin. Nutr. 2007;86:1420-5.
The third study in 2010 analyzed data from 2,294 women who were part of the Nurses Health Study. They evaluated blood samples and compared dietary components from self-reported questionnaires in 1990. They found that women with the highest intakes of whole grains containing primarily insoluble fiber had the longest telomeres. Additionally, those women with the highest intake of linoleic acid, primarily from corn, safflower and soy oils as well as women with higher waist circumferences had the shortest telomeres. The conclusion was that waist circumference and polyunsaturated fatty intake were negatively associated and dietary fiber as cereal fiber was positively associated with leukocyte telomere length. They found no association between telomere length and smoking, physical activity or postmenopausal hormone use.
Cassidy A et al.
Associations between diet, lifestyle factors and telomere length in
women. Am.J. Clin Nutr. 2010;92:1273-80.
Most of the authors of all three studies conclude that oxidative stress and inflammation affects telomere shortening and that diet can affect both these processes. As with all nutrition studies, further research is warranted.