Monday, May 16, 2011
New, Inexpensive Blood Test Tells You "How Long You Will Live" ... But You Can Cheat and Live Longer
Scientists have developed a simple blood test to determine how long you will live.
By measuring the length of your "telomeres", the ends of chromosome.
Basically, telomeres allow our cells to divide. When we're young, our telomeres are long, and we can produce new cells with ease.
As we age, our telomeres shorten, and it is harder to produce new cells. With fewer new cells to replace the older ones, we age.
As the New York Times' Gretchen Reynolds explained last year:
Telomeres are tiny caps on the end of DNA strands — the discovery of their function won several scientists the 2009 Nobel Prize in medicine. When cells divide and replicate these long strands of DNA, the telomere cap is snipped, a process that is believed to protect the rest of the DNA but leaves an increasingly abbreviated telomere. Eventually, if a cell’s telomeres become too short, the cell ‘‘either dies or enters a kind of suspended state,’’ says Stephen Roth, an associate professor of kinesiology at the University of Maryland who is studying exercise and telomeres. Most researchers now accept telomere length as a reliable marker of cell age. In general, the shorter the telomere, the functionally older and more tired the cell.
The University of Texas Southwestern Medical Center at Dallas, Department of Cell Biology and Neurosciences proved in 1996 the basic hypothesis using cell cultures:
We ... test[ed] the hypothesis that elongation of telomeres would extend the lifespan of cells in culture... The lifespan of these hybrid cells was longer than that of the hybrids in which telomeres had not been elongated. These observations provide the first direct evidence supporting the hypothesis that telomere length determines proliferative capacity of human cells.Ethics
Mark my words, a tidal wave of ethical issues has been released by the new, inexpensive (around $700 U.S. dollars) blood test for telomere length.
Initially, every life insurer in the world will demand that all applicants get the test, for obvious reasons. If you're telomeres are really short, you won't live as long ... which radically shifts the actuarial data. Indeed, as shown below, short telomeres might even outweigh risk factors such as smoking.
While life insurance will be the area most directly impacted by the new blood test, many other areas of life could be affected as well. For example, health insurers may want their insureds to get tests as well, on the theory that people with shorter telomeres will need more medical care ... and should thus pay higher premiums. As the Independent notes:
The results of the tests might ... be of interest to companies offering life-insurance policies or medical cover that depend on a person's lifetime risk of falling seriously ill or dying prematurely.
Employers may want their candidates to take the blood test. After all, why spend years training someone who might soon kick the bucket?
Even lovers might insist their would-be spouses get a test before saying I do. It's no fun to have kids with someone who won't be there to raise them.
How to cheat
Exercise lengthens telomeres. As the Post-Gazette writes:
People who exercise regularly are up to nine years younger, biologically, than sedentary people of the same chronological age, according to a new study by a team of British researchers.
You already knew that people who keep fit live longer than people who don't. Studies have shown they're less likely to have heart attacks, or to suffer from diabetes, cancer and other degenerative diseases. What makes this study by a team from Kings College in London different from all others that have come before it is that it may explain why.
"Exercise helps protect against the slowing-down mechanism."
The British researchers studied 2,400 twins. Their research focused on telomeres, the caps at the end of chromosomes, the structures that carry genes.
When we're young, our telomeres are long. But every time a cell divides, telomeres get shorter. When telomeres get too short, the cell can no longer divide. Cells die. Muscles weaken, skin wrinkles, eyesight and hearing fade.
Prof. Tim Spector and Dr. Lynn Cherkas of Kings College, and Prof. Abraham Aviv of the New Jersey Medical School found the telomeres in those who exercised vigorously were significantly longer than those in their twins who didn't. The difference was still significant even if the twin who exercised smoked or was overweight.
"These data suggest that the act of exercising may actually protect the body against the aging process," said Mr. Spector, who is a professor of genetic epidemiology. The study was published last month in the Archives of Internal Medicine.
"Overall, the difference in telomere length between the most active subjects and the inactive subjects corresponds to around nine years of aging," Dr. Cherkas said.
To maximize the anti-aging effect of exercise, you need to work out vigorously for at least three hours a week, the researchers said.
"It is not just walking around the block," said Prof. Spector. "It's really working up a sweat."
But people who work out at a moderate pace for an hour to an hour and a half a week can still reduce their biological age by as much as four years, the researchers said.
The study indicates that exercise "is actually a buffer against oxidative stress," said Dr. Moira Davenport, director of sports and emergency medicine for Allegheny General Hospital.
Oxidative stress is what damages and kills cells.
"Oxygen is essential to life itself. But it is also inherently dangerous to our existence. The same process that causes a cut apple to turn brown or iron to rust is the cause of all the chronic degenerative diseases we fear and even the aging process itself," said Dr. Ray Strand, a specialist in nutritional medicine.
"As oxygen is utilized within the furnace of the cell to create energy, occasionally a charged oxygen molecule is created, called a free radical," Dr. Strand said on his Web site, nutritional-medicine.net. "If this free radical is not readily neutralized by an antioxidant, it can go on to create more volatile free radicals, damage the cell wall, vessel wall, proteins, fats, and even the DNA nucleus of our cells."
And the New York Times' reported last year:
It ‘‘was striking,’’ recalls Dr. Christian Werner, an internal-medicine resident at Saarland University Clinic in Homburg, ‘‘to see in our study that many of the middle-aged athletes looked much younger than sedentary control subjects of the same age.’’
In Mr. LaRocca’s work, people were tested both for their V02max — or maximum aerobic capacity, a widely accepted measure of physical fitness — and their white blood cells’ telomere length. In subjects 55 to 72, a higher V02max correlated closely with longer telomeres. The fitter a person was in middle age or onward, the younger their cells.
‘‘one could speculate,’’ he concludes, ‘‘that any form of intense exercise that is regularly performed over a long period of time’’ will improve ‘‘telomere biology,’’ meaning that with enough activity, each of us could outpace the passing years.
An extract of the Chinese herb astragalus has been engineered by a large California biotech company to produce a supplement which helps protect telomeres.
But many otherwise healthy and reasonably-priced foods and supplements can also protect your telomeres as well.
As Dr. Andrew Weil notes:
A study in Hong Kong suggest[ed] that people who drink green tea regularly may be younger, biologically, than those who don't drink green tea or consume only small amounts. The science here is somewhat complex, so bear with me while I summarize this fascinating new study. The researchers looked at the length of telomeres, repeating DNA sequences at the ends of chromosomes. (One expert suggests thinking about telomeres as the caps on the ends of shoelaces that prevent the laces from unraveling.) In cells, telomeres prevent chromosomes from fusing with one another or rearranging - undesirable changes that could lead to cancer and other life-threatening diseases.
Researchers looked at telomere lengths of 976 Chinese men and 1,030 Chinese women, all over the age of 65. All the study participants completed a food frequency questionnaire.
The researchers reported that telomere length was associated only with tea drinking – participants with the highest intake, three cups per day of tea, had longer telomeres than participants who drank an average of only one quarter of a cup of tea daily. Most participants drank green tea while a few drank black tea. The investigators reported that the average difference in telomere length corresponded to "approximately a difference of five years of life" and that the "antioxidative properties of tea and its constituent nutrients may protect telomeres from oxidative damage in the normal aging process."
In the same article, Weil notes that vitamins C and E also lengthen telomeres:
A recent U.S. study found that telomere length was longer in women who took multivitamins regularly. Here, researchers looked at multivitamin use in a group of 586 women between the ages of 35 and 74. They found that higher intakes of the antioxidant vitamins C and E from food were associated with longer telomere length. The findings were published in the June 2009 issue of the American Journal of Clinical Nutrition.
Here's Weil on Omega 3s:
Researchers at the University of California, San Francisco, have found another action of omega-3s that may help explain why they offer benefits for the heart. The investigators found that the more omega-3 consumed by patients with coronary heart disease, the slower the structures called telomeres at the ends of chromosomes shrank.And see this.
Folate, vitamin B6, and vitamin B12 play key roles in converting homocysteine into methionine, one of the 20 or so building blocks from which the body builds new proteins. Without enough folate, vitamin B6, and vitamin B12, this conversion process becomes inefficient and homocysteine levels increase. In turn, increasing intake of folate, vitamin B6, and vitamin B12 decreases homocysteine levels.
Indeed, antioxidants in general helped protect telomeres. As the journal Circulation Research noted in 2004 (please excuse the hyper-technical language):
Aging is associated with a rise in intracellular reactive oxygen species (ROS) and a loss of telomerase reverse transcriptase activity. Incubation with H2O2 induced the nuclear export of telomerase reverse transcriptase (TERT) into the cytosol in a Src-family kinase–dependent manner. Therefore, we investigated the hypothesis that age-related increase in reactive oxygen species (ROS) may induce the nuclear export of TERT and contribute to endothelial cell senescence. Continuous cultivation of endothelial cells resulted in an increased endogenous formation of ROS starting after 29 population doublings (PDL). This increase was accompanied by mitochondrial DNA damage and preceded the onset of replicative senescence at PDL 37. Along with the enhanced formation of ROS, we detected an export of nuclear TERT protein from the nucleus into the cytoplasm and an activation of the Src-kinase. Moreover, the induction of premature senescence by low concentrations of H2O2 was completely blocked with the Src-family kinase inhibitor PP2, suggesting a crucial role for Src-family kinases in the induction of endothelial cell aging. Incubation with the antioxidant N-acetylcysteine, from PDL 26, reduced the intracellular ROS formation and prevented mitochondrial DNA damage. Likewise, nuclear export of TERT protein, loss in the overall TERT activity, and the onset of replicative senescence were delayed by incubation with N-acetylcysteine. Low doses of the statin, atorvastatin (0.1 µmol/L), had also effects similar to those of N-acetylcysteine. We conclude that both antioxidants and statins can delay the onset of replicative senescence by counteracting the increased ROS production linked to aging of endothelial cells.
Finally, a positive mindset and relaxation protect telomeres. As Bill Andrews - Ph.D. in Molecular and Population Genetics, former Director of Molecular Biology at biotech giant Geron from 1992 to 1997, one of the principal discoverers of the components of human telomerase, an enzyme that makes telomeres grow, inventor on 35 U.S. issued patents related to telomerase, awarded 2nd place as "National Inventor of the Year" - says:
But then on the mental side it has been shown that people who have a lot of mental stress have shorter telomeres. Elizabether Blackburn has published some great papers finding people who are caregivers for Alzheimer's patients have shorter telomeres because they are clearly under a lot of stress. So meditation might be something that can prevent telomere shortening.
Even pessimism, people who are pessimistic have been shown to have shorter telomeres. If you ask a person a question like do you think you will live to be 100 and they say "no" they probably won't because thier telomeres are going to be shorter. But if they answer "yes" the probably will because their telomeres are going to be longer.
So, I try to be very opltimistic, not pessimistic. I try to cause everybody else to have stress, not me.
For more on the benefits of meditation on health and brain functions, see this, this and this.