This week’s WOW was performed down at Ultimate Exercise and was focused on chest, back and neck. Wendy did her every 14th day Big 4 and the kids each did a Big 3 workout. The volume and intensity felt spot on (I quite immediately at failure…no deep inroad) and today I feel pleasantly sore, but energized. My WOW is as follows:
SuperSlow Systems Pulldown, MedX Chest Press, Nautilus Pullover with SS retrofits, MedX Chest Press (vertical handles with adduction squeeze), SS Systems Neck Flexion, MedX Compound Row with SS cam, SS Systems Neck Extension.
MedX Chest Press, SuperSlow Systems Pulldown, MedX Overhead Press, MedX Leg Press, TSC Neck Flex/Ext
The Kids did MedX Leg Press, MedX Chest Press and SS Systems Pulldown.
This week I am still hooked on myokines, but this time from a public health standpoint. Ever since I have been in medical school, there has been a huge push for public health screening. This has been driven by medical specialty societies, government agencies and the media. The Susan G. Komen foundation has been hugely influential in influencing breast cancer “awareness” and mammography screening, to the extent that you can’t watch a major sporting event without pink cleats, towels and ribbons. Screening for colon cancer via colonoscopy got major support after Katy Couric’s husband tragically died of colon cancer in his early 40’s. Not to be outdone by the ladies, the major men’s screening issue has been PSA testing for prostate cancer. Behind all of these assumptions is the idea that early detection would save lives. Over and over we hear the anecdotes… “thank god they found (and removed) that lump, polyp or nodule” or… “if only it had been picked up earlier, then he/she may have faired better or survived”. These are all narratives that our brains like to generate when we try to make sense of events that may be random and tragic. These narratives are what drive our efforts to detect and fight back unforeseeable events that lead to tragedy, whether it be cancer, terrorism or school shootings. But once we are hip deep in this kind of activity, we must look at our efforts and ask: does it work? Does taking our shoes off at the airport really help prevent terrorism? Or are we creating our own needle-in-the-haystack scenario? Does our exposure to radiation, blood draws and fiber optics up our posterior actually ward off the random and the tragic? To answer this question, let me offer some analysis from the Number Needed to Treat Website. Click on each link to read the real data on medical screening.
The problem with screening that becomes more and more sensitive is that it detects lesions that may never end up causing true disease. Each of us carries nests of cancer cells all over our body. The vast majority of times these cells are destroyed by immune surveillance and apoptosis (cell suicide) triggered by chemical messengers. Research is starting to show that myokines may be a major force against nascent cancer cells. Check out this article discussing the role of myokines in warding off colon cancer.
Gut. 2013 Jun;62(6):882-9. doi: 10.1136/gutjnl-2011-300776. Epub 2012 Jul 31.
A novel myokine, secreted protein acidic and rich in cysteine (SPARC), suppresses colon tumorigenesis via regular exercise.
Aoi W, Naito Y, Takagi T, Tanimura Y, Takanami Y, Kawai Y, Sakuma K, Hang LP, Mizushima K, Hirai Y, Koyama R, Wada S, Higashi A, Kokura S, Ichikawa H, Yoshikawa T.
Several epidemiological studies have shown that regular exercise can prevent the onset of colon cancer, although the underlying mechanism is unclear. Myokines are secreted skeletal muscle proteins responsible for some exercise-induced health benefits including metabolic improvement and anti-inflammatory effects in organs. The purpose of this study was to identify new myokines that contribute to the prevention of colon tumorigenesis.
To identify novel secreted muscle-derived proteins, DNA microarrays were used to compare the transcriptome of muscle tissue in sedentary and exercised young and old mice. The level of circulating secreted protein acidic and rich in cysteine (SPARC) was measured in mice and humans that performed a single bout of exercise. The effect of SPARC on colon tumorigenesis was examined using SPARC-null mice. The secretion and function of SPARC was examined in culture experiments.
A single bout of exercise increased the expression and secretion of SPARC in skeletal muscle in both mice and humans. In addition, in an azoxymethane-induced colon cancer mouse model, regular low-intensity exercise significantly reduced the formation of aberrant crypt foci in wild-type mice but not in SPARC-null mice. Furthermore, regular exercise enhanced apoptosis in colon mucosal cells and increased the cleaved forms of caspase-3 and caspase-8 in wild-type mice but not in SPARC-null mice. Culture experiments showed that SPARC secretion from myocytes was induced by cyclic stretch and inhibited proliferation with apoptotic effect of colon cancer cells.
These findings suggest that exercise stimulates SPARC secretion from muscle tissues and that SPARC inhibits colon tumorigenesis by increasing apoptosis.
Next, check out this study that shows how myokines inhibit the proliferation of breast cancer cells.
Am J Physiol Endocrinol Metab. 2011 Sep;301(3):E504-10. doi: 10.1152/ajpendo.00520.2010. Epub 2011 Jun 7.
Exercise-induced muscle-derived cytokines inhibit mammary cancer cell growth.
Hojman P, Dethlefsen C, Brandt C, Hansen J, Pedersen L, Pedersen BK.
Regular physical activity protects against the development of breast and colon cancer, since it reduces the risk of developing these by 25-30%. During exercise, humoral factors are released from the working muscles for endocrinal signaling to other organs. We hypothesized that these myokines mediate some of the inhibitory effects of exercise on mammary cancer cell proliferation. Serum and muscles were collected from mice after an exercise bout. Incubation with exercise-conditioned serum inhibited MCF-7 cell proliferation by 52% and increased caspase activity by 54%. A similar increase in caspase activity was found after incubation of MCF-7 cells with conditioned media from electrically stimulated myotubes. PCR array analysis (CAPM-0838E; SABiosciences) revealed that seven genes were upregulated in the muscles after exercise, and of these oncostatin M (OSM) proved to inhibit MCF-7 proliferation by 42%, increase caspase activity by 46%, and induce apoptosis. Blocking OSM signaling with anti-OSM antibodies reduced the induction of caspase activity by 51%. To verify that OSM was a myokine, we showed that it was significantly upregulated in serum and in three muscles, tibialis cranialis, gastronemius, and soleus, after an exercise bout. In contrast, OSM expression remained unchanged in subcutaneous and visceral adipose tissue, liver, and spleen (mononuclear cells). We conclude that postexercise serum inhibits mammary cancer cell proliferation and induces apoptosis of these cells. We suggest that one or more myokines secreted from working muscles may be mediating this effect and that OSM is a possible candidate. These findings emphasize that role of physical activity in cancer treatment, showing a direct link between exercise-induced humoral factors and decreased tumor cell growth.
With the scientific data that is accumulating, I think there needs to be a shift in public health efforts. Rather than relying on early detection and medical intervention, we need to rely on lifestyle modifications that probably make detection of these tiny lesions irrelevant. With the right lifestyle approach, we might never need to subject ourselves to the terror of a false-positive or the agony of the invasive procedures that follow. Perhaps such hypersensitive screening can be used as a research tool to follow the natural course of these lesions with and without lifestyle interventions. I suspect that we will find that the vast majority of these finds never result in clinically significant disease. As we study meaningful strength exercise, I think we may find that the apoptosis of these lesions is more rapid and certain in those that invoke strength exercise. Most importantly, I think there needs to be a major public health focus to determine if strength exercise might serve as the major preventative health intervention for all categories of disease. Why cure cancer when you can prevent it?
Post your WOW’s and your thoughts (that are relevant to this post).