Cancer is globally increasing and is one of the major threats to healthy aging. To date we have no indications that this will change for decades. While the relationship between physical fitness and cardiovascular diseases is well documented, the relationship between cancer and cardiorespiratory fitness is less studied.
Physical activity has been shown to benefit the cancer patients in many ways, such as improved quality of life, reduced fatigue and better cardiorespiratory fitness. In addition, it is well established that being physically active reduces the risk of developing several cancer types. In fact, as much as one-fifth to one-third of several common cancer types, including breast- and colon cancer, are associated with low levels of physical activity together with obesity. However, the association between cardiorespiratory fitness and cancer survival is less well documented.
Researchers from Denmark recently published a large long time follow up study where they investigated the association between cardiorespiratory fitness and death from cancer. The study included 5131 cancer free men and tested their cardiorespiratory fitness. The men were followed up for 42 years and during the follow up period 1527 (29.8%) of them died from cancer. Interestingly, the researchers found a highly significant association between cardiorespiratory fitness and death from cancer. For every 10 mL/kg/min increase of estimated cardiorespiratory fitness (measured as maximum oxygen uptake) risk of death decreased by 17-24%. It must be mentioned that cardiorespiratory fitness was not associated with death from prostate cancer but associated with other groups of cancer.
Based on this study, it is clear that cardiorespiratory fitness should be considered in order to reduce the risk of dying from cancer. Recently a Scientific Statement on Cardiorespiratory Fitness released by the American Heart Association identified cardiorespiratory fitness as a vital sign, which should be used in clinical practice.
Perhaps the clear association they found in this study between cardiorespiratory fitness and cancer survival can also encourage and inspire us to change our lifestyle.
Guest blog: Collaborator Jasna Marinovic, Assistant professor at University of Split School of Medicine Department of Integrative Physiology
Membrane potential is one of the most basic properties of all living cells that is vital for proper cellular function and homeostasis. At rest, most cells in our body exhibit negative membrane potential, which is primarily established via continuous efflux of potassium (K+) ions through their respective channels. In excitable cells, such as cardiac myocytes, K+-channel opening affects cellular excitability, action potential frequency and duration, with resulting impact on contraction strength, ionic balance, oxygen demand, etc.
Among different subtypes of channels specialized for conducting potassium, a unique group, which is expressed at high density in membrane of cardiac cells, are the ATP-sensitive K+ (KATP) channels. Although under no-stress conditions they do not actively participate in action potential formation, their evolutionary conservation and abundance implicate their physiological importance. Indeed, the KATP channels serve as cellular metabolic sensors, opening in situations of cardiac stress and translating metabolic changes into alterations of membrane potential. Intactness of the KATP channels was shown essential for cardiac tolerance to stress and adaptations to increased workload, such as during increased blood pressure, chronic exercise, oxidative stress, as well as acute damage by cardiac ischemia. In humans, mutations in KATP channel subunits were found in a subset of patients with idiopathic heart failure and were associated with worse clinical outcome as compared to patients without the mutations.
Movember is here and it’s time to focus on prostate cancer and male health. Exercise both prevent cancer and play an important role in both treatment and rehabilitation of cancer. This year Movember has made the campaign Move that encourages people to be active. Get active with our 4 -week Movember program!
In recent published study, researchers examined the effect of aerobic exercise on breast tumors in mice to see if it had a direct effect on the tumor itself. The reason for this is that tumors can become resistant to traditional treatment because of impaired or restricted blood flow. This is problematic since the blood is our transportation system. To put it another way, then blood vessels can be considered railroad tracks in this context, and when the train (blood) does not arrive to the station to deliver the medicine, the tumor does not receive treatment.
Etter en rosa måned med fokus på brystkreft, som oftest rammer kvinner, er vi nå kommet til 1.november, som betyr at vi retter blikket mot menns helse. I år som tidligere, arrangeres Movember-aksjonen, der Kreftforeningen er en viktig faglig aktør. Menn i alle aldre oppfordres herved til å la barten gro! Dette kan du lese mer om på Medisinsk fakultet ved NTNU sin blogg. (Det ryktes at vår dekanus planlegger en anseelig mustasje og vi venter spent på resultatet..)
Vi er som alltid opptatt av å sette aktuelle saker i sammenheng med trening, og i dag resirkulerer vi derfor et blogginnlegg om prostatakreft og trening fra bloggen i fjor:
Prostatakreft er en av de mest hyppige kreftformene hos menn, og mange lever symptomfritt med sykdommen. Det finnes både saktevoksende kreftformer og mer aggressiv hurtigvoksende prostatakreft.
Forskere har i flere runder undersøkt om trening kan bidra til å redusere risikoen for prostatakreft, ettersom alder og familiehistorie hittil har vært de viktigste kjente risikofaktorene. Hvis man klarer å finne atferdsendringer som reduserer risiko vil det være lettere å drive forebyggende arbeid. Grunnen til at det var naturlig å undersøke om trening kunne virke forebyggende var at det er kjent at fysisk aktivitet kan nedregulere både kjønnshormoner, insulin og muligens diverse insulinlignende veksthormoner i blodet. Disse hormonene er nødvendige for at prostataceller kan dele seg, og ettersom kjennetegnet til kreft er uhemmet vekst var det ikke utenkelig at hormonendringen fra trening kunne virke krefthemmende.
Usikkerhet i starten En reviewartikkel av Oliveria og Lee fra 1997 tok for seg 17 studier av trening og prostatakreft, men kunne ikke bekrefte at trening reduserte risikoen. Et flertall av studiene konkluderte at trening muligens kunne redusere kreftrisikoen, mens andre ikke klarte å finne noen effekt. Noen få fant til og med at fysisk aktivitet kanskje kunne øke risikoen for prostatakreft. Forfatterne konkluderte at fremtidige studier også måtte ta hensyn til hva slags fysisk aktivitet det var snakk om, og hvor regelmessig folk bedrev den.
I 2005 viste forskere fra den amerikanske kreftforeningen (American Cancer Society) at selv om trening sannsynligvis ikke reduserte den totale risikoen for prostatakreft, kunne det redusere risikoen for aggressiv prostatakreft. Selv om det er godt nytt, tok heller ikke denne undersøkelsen høyde for hva slags fysisk aktivitet mennene bedrev – selv blant de med høyest aktivitetsnivå var det for det meste turgåing som gjaldt.
Treningsintensitetens rolle Av spesiell interesse for de av oss som er opptatt av treningsintensitet, kan man også nevne en studie fra University College of London Medical School fra 2001. Etter å ha korrigert for alder, røyking, kroppsmasseindeks, alkoholinntak og sosiale forskjeller fant de at den totale risikoen for alle typer kreft var redusert ved trening, men bare hvis den var av middels eller høy intensitet. Regelmessig trening var helt nødvendig for risikoreduksjonen for de krefttypene det gjaldt, og det var en klar dose-responssammenheng mellom treningsmengde og reduksjon av risikoen for prostatakreft.
Altså ser det ut til at det lønner seg å drive med regelmessig høyintensitetstrening for å redusere risikoen for både prostatakreft generelt, og spesielt den aggressive kreftformen. Og det må man kunne regne som gode nyheter!
God movember – og lykke til med både trening og bartevekst!
The prevalence of overweight and obesity has increased markedly over the past two decades and has reached global epidemic proportions worldwide. According to World Health Organization estimates in 2008, more than 1.4 billion adults worldwide, 20 years or older, were overweight (BMI ≥ 25) and more than 500 million were obese (BMI ≥ 30). The percentage of Norwegians being overweight has increased by 7% during the last 10 years, and in 2008, 1 in 4 Norwegians was overweight.
Obesity or increased weight is associated with the risk of type-2 diabetes, cardiovascular disease and risk of various cancers. The observational data during the last 25 years show that obesity causes approximately 14% of cancer deaths in men, and up to 20% of cancer deaths in women. The magnitude of this effect is huge, in large part because obesity and diabetes are now so common, and it seems that cancer loves the metabolic environment of the obese person. In Norway alone, 35% of deaths were caused by tumour-related diseases in 2010. Although few data exist on the association of weight gain or weight loss on altering the risk of cancer, evidence suggest that increase in weight during adulthood is associated with increased risk of cancer. In contrary, weight loss over the years may be associated with a reduced risk of cancer incidence. The best evidence in this regard comes from the bariatric surgery studies that suggest a decreased risk of cancer incidence and death associated with a large weight loss after the surgery. Therefore, assessment of the relationship between changes in weight or obesity status over time with the risk of cancer development has clinical implications for general public health perspective, and the advice given to people to modify body weight.
Various strategies have been proposed and implemented to control the obesity pandemic, including healthier choice of food and regular physical exercise. The role of aerobic fitness in the prevention of obesity related cardiovascular disease is well-established. Similarly, observational data show that high levels of fitness are associated with decreased cancer mortality risk, independent of obesity status. Overweight or obese fit individuals had lower risk of cancer deaths compared with unfit counterparts, and it seems that high levels of aerobic fitness and physical activity modify the association of obesity-related cancers. The prevention and control of overweight and obesity through life-style changes, i.e., healthy eating, engage in more physical activity have substantial benefits to reduce the obesity-related cancer risk.