Telomeres and diet
Telomeres and vitamin D
Telomeres and multivitamin use
Telomeres and stress
Telomeres and stress (2nd article)
Telomeres, curcumin, and grape seed
Soy foods lower lung cancer
I was intrigued by the effect of exercise on telomeres that I wrote about in the December newsletter and wanted to know more. As I noted, telomeres are the DNA molecules that serve as “end caps” of chromosomes, protecting the integrity of the chromosome during cell division. In reviewing the literature, I found numerous articles dating back to 1998 showing the influence of nutrition and lifestyle on telomeres. Because of their importance, I decided to devote much of this issue to telomeres and how you can help preserve them.
In 1998, Australian researchers published results of studies both on cells and intervention in human subjects. A number of measures indicate the level of chromosomal damage, and they used micronucleus (MN) formation in their research, which is directly related to breakage and shortening of chromosomes. They used white blood cells (lymphocytes) as the chromosome source.
They found that in subjects from 41 to 60 years old vegetarians had the least MN formation, but in the 61 to 90 year olds there was no difference between vegetarians and non-vegetarians. The older vegetarian males had a low vitamin B12 status, which might have accounted for the difference. High serum vitamin B12 and folic acid was related to lower MN formation, but blood levels of vitamins C and E were not related. (Fenech M, Chromosomal damage rate, aging, and diet. Ann N Y Acad Sci. 1998 Nov 20;854:23-36.)
In separate studies, reported in the same article, they found that in men from 50 to 70, lower levels of B12 were related to MN formation even if the B12 status was in the normal range. In addition, MN status was directly correlated with homocysteine levels even if B12 and folic acid were in the normal range (suggesting that our theoretical normals for these two nutrients are lower than ideal). MN levels were also reduced in plasma samples taken one hour after consumption of red wine compared to samples taken just before the drinks.
In a study from England, researchers reported that leukocyte (white blood cell) telomere length (LTL) was a predictor of age-related diseases. The LTL decreases with cell division and with increased inflammation. They evaluated the relationship of higher vitamin D concentrations in women to LTL (Richards JB, et al., Higher serum vitamin D concentrations are associated with longer leukocyte telomere length in women. Am J Clin Nutr. 2007 Nov;86(5):1420-5).
Vitamin D is a potent inhibitor of the inflammatory response and reduces the turnover of leukocytes. They measured serum vitamin D levels in 2160 women 18 to 79 years old. They found that those with the highest level of vitamin D had an average of 107 more chromosomal base pairs (the components of DNA), compared to those with the lowest levels of vitamin D, which reflects five years less of telomeric aging with higher vitamin D. this benefit persisted even after adjustment for age, sunlight exposure, exercise, and other variables.
Vitamin D has been reported to have numerous benefits at levels higher than are commonly accepted as normal. However, a recent article in the New York Times by one of their health reporters (Tara Parker Pope) exuded skepticism (without saying outright that vitamin D was a waste of money, even though it is extremely cheap). If you read that article online, it is important to read the comments by readers (me among them).
National Institutes of Health researchers published an article in 2009 on the use of multivitamins and telomere length in women. They evaluated 586 women, ages 35 to 74 years, in the Sister Study. (Xu Q, et al., Multivitamin use and telomere length in women. Am J Clin Nutr. 2009 Jun;89(6):1857-63.)
They collected information on diet and supplement use using a 146-item food-frequency questionnaire. They evaluated telomere length in leukocyte DNA using a standard polymerase chain reaction (which you always hear about on crime shows).
After adjusting for a number of variables, including age, the use of multivitamins was associated with significantly longer telomere length. Compared to nonusers, those who took multivitamins had an average of 5.1 percent longer telomeres. In the analysis of food intake, those subjects with the highest intakes of vitamins C and E also had longer telomeres independent of their multivitamin use. (If simple, inexpensive multivitamins can reduce the burden of age-related diseases associated with shortened telomeres, individuals as well as society as a whole benefits).
In 2004, it was shown that telomere length could also be reduced by life stress. Chronic stress has long been associated with poor health, including impaired immune function and increased heart disease, as well as accelerated aging. Researchers evaluated 58 premenopausal women, including 19 “control” mothers with a healthy child, and 39 mothers with a chronically ill child (“caregivers,” predicted to be under higher levels of chronic psychological stress). All subjects completed questionnaires to evaluate levels of “perceived stress.”
They collected blood samples to evaluate telomerase activity and telomere length (telomerase is the enzyme that preserves telomere length). They also used a urine test to measure oxidative stress. Within the caregiver group, those who had been so for longer had significantly lower telomerase activity and significantly shorter telomeres than those who had fewer years as a caregiver or the controls. (Epel ES, et al., Accelerated telomere shortening in response to life stress. Proc Natl Acad Sci U S A. 2004 Dec 7;101(49):17312-5.)
These findings were independent of body mass index, smoking, or multivitamin use, and were independent of age (caregivers and controls were different regardless of age). In both caregivers and controls, high perceived stress was also associated with shorter telomeres.
Comparing telomeres length in white blood cells with other research that relates it to aging rates, these researchers estimated that the high stress group had aged the equivalent of 9 to 17 years more than the control group with low stress. Strikingly, they also had 48 percent lower telomerase activity than the controls. Chronic psychological stress also led to increased oxidative stress.
Another study of stress and telomeres in 2009 showed similar results. Evaluating 647 women aged 35 to 74 years, researchers used a questionnaire to evaluate their perceived stress. They then measured their telomere length and their urinary stress hormones.
Those women with higher stress levels had shorter telomeres, with an adjusted difference of 129 fewer base pairs (age alone can decrease base pairs by about 27 per year, so 129 would correlate to about 5 years of aging). (Parks CG, et al., Telomere length, current perceived stress, and urinary stress hormones in women. Cancer Epidemiol Biomarkers Prev. 2009 Feb;18(2):551-60.)
In addition to age, shorter telomeres were associated with smoking and obesity, as well as with higher levels of stress hormone metabolites in the urine. More specifically, they saw short telomeres in women over 55 and those with recent major losses (an average of 420 fewer base pairs). This suggests that a combination of influences can accelerate aging, and perhaps stress reduction (as well as weight reduction and quitting smoking) can slow the process. Research is in progress to test this.
An Australian study in mice suggests telomere benefits from dietary components. In a mouse model of Alzheimer’s Disease (AD) researchers noted that telomeres were significantly shortened. In cells from the inside of the cheek (buccal mucosa), the AD mice had a 91 percent reduction in telomere length, reflected in a high micronucleus (MN) frequency. (Thomas P, et al., Grape seed polyphenols and curcumin reduce genomic instability events in a transgenic mouse model for Alzheimer's disease. Mutat Res. 2009 Feb 10;661(1-2):25-34.)
When the mice were fed grape seed extract and curcumin (a turmeric extract) containing high levels of polyphenols, they saw a 7- to 10-fold decrease in MN frequency. This has not been done in humans, but research has already shown that curcumin may help prevent AD, and it is also anti-inflammatory and helps to prevent cancer. Research is increasingly revealing new benefits from a variety of phytochemicals that are available in the diet and as dietary supplements.
A new Japanese study shows that consuming soy foods may lower the risk of lung cancer. In a prospective study of 36,177 men and 40,484 women, 45-74 years old, researchers evaluated their soy intake based on a validated questionnaire. The subjects had no history of cancer at the start of the study, and they were followed for 11 years. (Shimazu T, et al., Isoflavone intake and risk of lung cancer: a prospective cohort study in Japan. Am J Clin Nutr. 2010 Jan 13. [Epub ahead of print]).
Soy intake ranged from a low of 34 Gms/day (just over an ounce) to a high of162 Gms per day (about five ounces). Among those subjects who never smoked, the risk of lung cancer in the high-soy intake group was less than half that among those with low-soy intake.
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