Nutrition and Cancer Flashcards
__% of cancers result directly from inheriting genes associated with cancer
5-10%
what causes the majority of cancers
alterations or damage accumulated over time to the genetic material within cells
what are IMPORTANT ENVIRONMENTAL FACTORS IN THE DEVELOPMENT OF CANCER
food
nutrition
physical activity
what is the hallmark of cancer
unregulated cell growth and/or cell death
When a person is not suitably nourished, either through under- or overnutrition, this impacts the tissue ______, compromising both structure and function.
microenvironment
Overall dietary patterns can indirectly influence cell growth by way of changes in general 1, 2 and _3_effects.
- metabolic
- regulatory
- endocrine
how does metabolic syndrome increase cancer risk
through metabolic disturbances that promote genetic instability
inflammatory state associated with obesity and metabolic syndrome is one mechanism that promotes cancer
Nutrient excess can lead to the production of _____
reactive oxidative species (molecules generated during fuel production by the mitochondria)
–> oxidative stress –> damages cellular structures and trigger an inflammatory response
Nutrient excess can also impair functioning of the 1 giving rise to unfolded proteins which can itself induce inflammation
A third response to nutrient excess is the accumulation of 2 molecules (driven mainly by fructose) further increasing inflammation
- endoplasmic reticulum
2. long-chain fatty acyl coenzyme A
Inflammation can limit further exposure to nutrients by blocking the action of ____
insulin
The binding of insulin or IGF-1 to cell surface receptors activates the 1 pathway leading to downstream activation of the 2 complex, a central regulator of cell growth and mitogenesis.
- PL3K/Akt
2. mTOR
Data strongly suggests that endogenous hyperinsulinemia may be one obesity-related factor enhancing cancer ___ and ___
growth and metastases
In women with ____ a worse prognosis has been noted in those with higher circulating levels of insulin.
breast cancers
Energy excess and cancer:
what factors are associated with cell growth, carcinogenesis and tumor promotion
Hormones and growth factors – insulin, insulin derived growth factor1 (IGF1), vascular endothelial growth factor (VGEF), estrogen Immune cells and inflammatory factors - macrophage infiltration, cytokines
Clinical and epidemiologic evidence suggests that elevated levels of circulating _____ or ____ are associated with increased risk and/or poor prognosis of endometrial, pancreatic, renal, prostate, colon and pre and postmenopausal breast cancer
insulin or C-peptide (cleavage product of proinsulin)
High circulating levels of insulin also upregulate the hepatic synthesis of 1 which is a major endocrine and paracrine regulator of tissue growth and metabolism as it both suppresses 2 and initiates cell cycle progression from 3 phase
- insulin derived growth factor-1 (IGF-1)
- apoptosis
- G1 to S
**increased circulating IGF-1 is associated with increased risk and/or worse prognosis for several types of human cancers
_____ production is induced by insulin and IGF-1 and mediates cancer cell proliferation and tumor growth by inducing angiogenesis
higher levels in obese people, decreases with weight loss
Vascular Endothelial Growth Factor (VGEF)
A growing body of evidence in humans suggests strong associations between VGEF levels and ___ cancers
aggressive
what does estrogen stimulate, inhibits and induce?
stimulate cell proliferation
inhibit apoptosis
induce VEGF and angiogenesis
In postmenopausal women a major contributor to estrogen production is ___ , where the enzyme aromatase converts adrenal androgens into estrogen
adipose tissue
____, a selective estrogen receptor inhibitor, has been shown to significantly reduce the development of postmenopausal breast cancer
Tamoxifen
How does Leptin: an adipocytokine secreted by adipose tissue, relate to cancer?
what happens to leptin as fat stores increase
increase in fat –> increase in leptin
leptin can stimulate cell proliferation and cell survival in colon, breast, endometrial and prostate cancer cells.
Leptin can modulate tumor growth by increasing the expression of VEGF
how does Adiponectin: an adipocytokine secreted by adipose tissue, relate to cancer
what happens to adiponectin as fat stores increase
As fat stores increase levels of adiponectin decrease
adiponectin induces apoptosis and inhibits cell growth and proliferation in breast, colon, endometrial and prostate cancer cells.
inhibit angiogenesis by inducing apoptosis of endothelial cells.
Higher adiponectin concentrations have been associated with a lower risk of post-menopausal breast cancer and endometrial cancer
Obesity leads to subclinical inflammation in visceral and subcutaneous white fat and is characterized by ____ surrounding necrotic adipocytes
macrophages
