Physical Activity and Cancer Risk Reduction - Mechanisms** Flashcards
(44 cards)
What are the three ways PA and cancer risk reduction is related?
- Indirect association between physical activity and cancer
- The direct effect of physical activity itself on cancer
- The effect of obesity on cancer
What is the indirect association b/w cancer and PA?
Correlation between two variables due to the presence of a common third variable - the confound
- each variable is closely related to this confound
Example of a confound
Although PA reduces risk of cancer, so do other lifestyle factors like diet and smoking
What is an effect of pre-existing disease?
Causes a person to reduce PA
How does fibre reduce the risk of cancer?
- Binds carinogens
- Altering gastrointestinal flora
- Increasing speed of transit
How is physical activity related to dietary fibre?
- Active people tend to eat more fibre
- PA reduces cancer risk when it’s the confound of a fibre filled diet
What do antioxidants do?
“clean up” free radicals
How is physical activity related to antioxidants?
- Active people tend to eat more antioxidants
- PA reduces risk of cancer when it’s the confound of antioxidants in the diet
How are vitamins related to PA and cancer risk?
- Active people are more likely to take Vitamin D and other supplements
- Some studies show large doses of vitamins may decrease cancer risk
How is socioeconomic status related to physical activity and cancer risk?
Active people tend to be
- Wealthier
- Live in less polluted areas
- Less likely exposed to occupational carcinogens
All the factors above can reduce cancer risks
How are sex hormones a direct affect on cancer risk?
They increase cell proliferation and decrease cell apoptosis
What is Plasma Testosterone?
It’s associated with risk of some hormones sensitive cancers in men
What is Plasma Estrogen?
Associated with risk of some hormone sensitive cancers in women
What level of sex hormones in the blood reduces cancer risk?
Reduced/low sex hormone levels in the blood
What in relation to the menstrual cycle increases breast cancer risk?
More menstrual cycles in a lifetime means a greater risk of developing breast cancer
What is protective in women against risk of cancer development? (x3)
- Late menarche (starting periods later in life 12-13 years)
- Early menopause
- Pregnancy
Less estrogen exposure to breast tissue the better
How can heavy exercise in girls be helpful in reducing breast cancer risk?
Heavy exercise delays menarche and reduces the total number of cycles in a lifetime
How is Physical activity and Estrogen related to reducing cancer risk in Premenopausal adult women?
Physical activity is associated with decreased levels of circulating estrogen and progesterone
How is Physical activity and Estrogen related to reducing cancer risk in Postmenopausal adult women?
Physical activity is associated with decreased serum estrogen and androgens
What are androgens?
Male sex hormones associated with increasing cancer risk
What cancer risk is increased when taking anabolic steroids?
Liver cancer risk increases
How might Physical Activity related to Androgens to reduce prostate cancer risks? Is this conclusive?
Physical activity may reduce cancer risk by reducing circulation of androgens
Inconclusive at this time
How are Insulin and Insulin like Growth Factor (IGF) related to cancer?
These are promoters for breast and colon cancer cells because they increase sex hormones and cell proliferation
What can control Insulin and IGF?
Physical activity strongly controls them by counteracting the increase in sex hormones and cell proliferation
