Tuesday, May 28, 2013

Cardiorespiratory Fitness and Cancer Risk

Lakoski SG, et al "Cardiorespiratory fitness and risk of cancer incidence and cause-specific mortality following a cancer diagnosis in men: The Cooper Center longitudinal study" ASCO 2013; Abstract 1520.

The risk of developing and dying from two types of cancer was recently shown to be reduced by high levels of cardiovascular fitness in a study presented at a press conference prior to the 2013 American Society of clinical oncology annual meeting. The study conducted by Susan Lakoski, M.D. involved more than 17,000 men over a 20 year span with a mean age of 50 years. A comparison was made between different levels of cardiovascular fitness. Comparing the men with the highest level of fitness compared to those with the lowest level of fitness the risk of lung cancer was reduced by 68%. For colorectal cancer the risk reduction was 38%. Even a small improvement in fitness level resulted in a 14% reduction in the risk of death by cancer and a 23% reduction in risk of dying from cardiovascular disease. While the study could not establish a cause-and-effect between fitness and cancer risk, the association between the two was unmistakable.





Friday, May 24, 2013

Cardiovascular Disease Prevention with a Mediterranean Diet

N Engl J Med. 2013 Apr 4;368(14):1279-90. doi: 10.1056/NEJMoa1200303. Epub 2013 Feb 25.

Estruch R, Ros E, Salas-Salvadó J, Covas MI, Corella D, Arós F, Gómez-Gracia E, Ruiz-Gutiérrez V, Fiol M, Lapetra J, Lamuela-Raventos RM, Serra-Majem L, Pintó X, Basora J, Muñoz MA, Sorlí JV, Martínez JA, Martínez-González MA; PREDIMED Study Investigators.

A very impressive study was recently published in the February issue of The New England Journal of Medicine. The lead author Ramon Estruch M.D., PhD reported on the effect of the Mediterranean diet on heart attack and stroke. Using diet alone they were able to reduce the incidence of death from heart attacks and strokes by 30%. The study involved over 7000 people in Spain who were overweight, smokers, diabetics, or had other risk factors for heart disease. The study was originally designed to compare a low-fat diet with two variations of the Mediterranean diet. One of the Mediterranean diet groups was instructed to use at least 4 tablespoons of extra-virgin olive oil a day, the other group received a combination of walnuts almonds and hazelnuts and was asked to consume an ounce of the mix each day. One of the problems with the study was that the low-fat diet group were unable to adhere to the diet and were therefore allowed to eat their regular diet. This study therefore is not a fair comparison between the Mediterranean diet and the low-fat diet but the results are nonetheless compelling. One of the advantages of the Mediterranean diet over the low fat diet is that the food is more palatable and it's a program that is easier to maintain.




Thursday, May 23, 2013

The Association Between Physical Activity in Leisure Time and Leukocyte Telomere Length

Lynn F. Cherkas, PhD; Janice L. Hunkin, BSc; Bernet S. Kato, PhD; J. Brent Richards, MD;
Jeffrey P. Gardner, PhD; Gabriela L. Surdulescu, MSc; Masayuki Kimura, MD, PhD;
Xiaobin Lu, MD; Tim D. Spector, MD, FRCP; Abraham Aviv, MD

This is a totally fascinating study that looked at the association between physical activity during leisure time and relative age in biologic twins. The study concluded that inactive subjects may be biologically older by 10 years compared with more active subjects of the same chronologic age. This was a huge study involving over 2400 biological twins. All of the subjects completed a questionnaire which detailed their self-reported physical activity level during their leisure time and at work for the past 12 months. They were broken down into four categories from inactive to heavy activity. The relative age was determined by measuring the length of a segment of their DNA called the telomere. The telomere is a inactive segment of DNA that acts like a bookend dividing the signaling part of the DNA. As the person ages the length of the telomere gets less and less over time. Since both the twins were born at exactly the same time, comparing the lengths of their telomeres allowed an estimate of their relative difference in age. The results of the study showed that comparing the most inactive to the most active twin revealed an age difference averaging 10 years. Essentially exercise or activity had made one of the twins biologically 10 years younger than the other.