Telomere Length and Calorie Restriction Effect in Cancer Prevention

Recently, The U.S. Preventive Services Task Force, government advisory panel, advised against regular PSA tests. Their take on it:

Screening for Prostate Cancer^#

Clinical Summary of U.S. Preventive Services Task Force Recommendation

Population	Adult males
Recommendation	Do not use prostate-specific antigen (PSA)-based screening for prostate cancer. Grade: D
Screening Tests	Contemporary recommendations for prostate cancer screening all incorporate the measurement of serum PSA levels; other methods of detection, such as digital rectal examination or ultrasonography, may be included.There is convincing evidence that PSA-based screening programs result in the detection of many cases of asymptomatic prostate cancer, and that a substantial percentage of men who have asymptomatic cancer detected by PSA screening have a tumor that either will not progress or will progress so slowly that it would have remained asymptomatic for the man’s lifetime (i.e., PSA-based screening results in considerable overdiagnosis).
Interventions	Management strategies for localized prostate cancer include watchful waiting, active surveillance, surgery, and radiation therapy.There is no consensus regarding optimal treatment.
Balance of harms and benefits	The reduction in prostate cancer mortality 10 to 14 years after PSA-based screening is, at most, very small, even for men in the optimal age range of 55 to 69 years.The harms of screening include pain, fever, bleeding, infection, and transient urinary difficulties associated with prostate biopsy, psychological harm of false-positive test results, and overdiagnosis.Harms of treatment include erectile dysfunction, urinary incontinence, bowel dysfunction, and a small risk for premature death.Because of the current inability to reliably distinguish tumors that will remain indolent from those destined to be lethal, many men are being subjected to the harms of treatment for prostate cancer that will never become symptomatic.The benefits of PSA-based screening for prostate cancer do not outweigh the harms.
Relevant USPSTF Recommendations	Recommendations on screening for other types of cancer can be found at http://www.uspreventiveservicestaskforce.org.

^#  U.S. Preventive Services Task Force. Screening for Prostate Cancer – Clinical Summary. http://www.uspreventiveservicestaskforce.org/prostatecancerscreening/prostatefinalsum.htm, Current as of May 2012, accessed August 29, 2012

 

However, the Associated Press reported that many urologists are disappointed with the Panel’s decision. An excellent article on prostate cancer, including the beneficial predictive value of PSA is included in the CR Way Cancer Prevention Forum on LivingThe CRWay.com.

The famous CR Way traveler, Ralph Cornell (read more about him on LivingTheCRWay.com),was diagnosed with prostate cancer when he was 90. Ralph decided to discontinue his treatments when he was in his late 90s. Yet he lived to 104 without dying of cancer.

Despite the controversy, I elected to continue PSA testing, when my thoughtful internist, Dr. Alphonse Aversa advised me of the Task Force’s recommendation.

I started tracking PSA twenty-five years ago with Dr. Abe Levy, the calorie restrictor who introduced me to Calorie Restriction’s benefits.  As I began to track dietary intake too, I noticed that certain foods seemed to affect PSA levels. PSA statistics are confounded by the large number of overweight men who have reduced androgen output and low PSA. However, for people who follow a Calorie Restriction Way diet, the challenge is to control all lifestyle factors so that PSA can be healthfully low through natural means.  My guess is that PSA – like T3 – will is predictive of rate of cell division.

PSA may have more accurate predictive value, when combined with indicators of DNA stability. Consider this quote from a prostate cancer study¹:

“It is well established that genomic instability occurs in virtually all cancers, including prostate cancer². Telomere dysfunction is one mechanism that generates genomic instability^{3, 4}.”

 

1. Telomere DNA Content in Prostate Biopsies

2. The hallmarks of cancer.

3. Telomere dysfunction triggers extensive DNA fragmentation and evolution of complex chromosome abnormalities in human malignant tumors.

4. Telomere dysfunction increases mutation rate and genomic instability.

 

Also, consider these studies like these indicating telomere length’s predictive value for other cancers:

 

Genetic anticipation is associated with telomere shortening in hereditary breast cancer.

Shorter telomere length is associated with increased ovarian cancer risk in both familial and sporadic cases.

 

The great calorie restrictor, Bernando LaPallo, at 110, has a PSA of under 3. Our guess is that his low PSA is an indicator of DNA stability, a likely reason why Bernando has lived so long.