Lernkarten

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Sprache English
Stufe Universität
Erstellt / Aktualisiert 07.03.2021 / 11.06.2021
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0 Exakte Antworten 68 Text Antworten 0 Multiple Choice Antworten
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Cancer and Nutrition, Andersson

Cancer development

  • how does cancer develop?
    • phases
    • reasons/mechanisms
    • relation to age
    • what types of cancer are there?
Lizenzierung: Keine Angabe

Cancer development

  • can be somatic or inherited --> 90% somatic
    • functional gene on one of both chromosome pairs can compensate for mutation on other, e.g.: inherited mutation from mother can be compensated via euivalent gene inherited from father --> loss of function of both genes that will result in cancer
  • 3 phases: initiation, promotion and progression
  • cancer risk accumulates over time and is therefore higher in aged individuals
    • may affect all ages though
  • Cancer types
    • benign: slow cell multiplication
    • maligng: invades and destroys surrounding tissues, rapid cell growth
    • metastasis: affects multiple organs as cancerigenous cells spread throughout body
  • process requiring lots of time: cell's repair mechanisms (p53) are defect --> mutation is not corrected and persists in daughter-cells  --> becomes cancer / malignant as soon as cells multiply and invade other tissues
    • bad-luck-theroy: cells with high turnover are more susceptible to DNA errors
    • p53: guardian of the genome
      • mutated in >50% of cancers --> precancerous cells esacape apoptosis pathways (=quality control)
      • induces apoptosis if DNA errorr is detected
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Cancer and Nutrition, Andersson

Cancer epidemiology

  • what are the most frquenent types of cancer?
    • How do demographics and socioeconomics affect this?
  • how do mortality and incidence behave now and in the future?
Lizenzierung: Keine Angabe

Cancer prevalence

  • most frequent cancers vgl Bild
    • cancer patterns--> cancer type and total prevalences differ between countries
      • suboptimal food storage (curing --> high salt ; no fridge --> mold (aflatoxin)
      • LMIC affected by cancers related to poverty and infections --> digestive tract affected
      • high income countries: lung (smoking?), breast prostate (hormonal imbalances)
      • lifestyle factors: much higher cancer prevalences overall --> many-fold or less many-fold increase depending on cancer type (vgl. slide 36)
  • mortality lower in high income countries because of treatment options
  • Trend predicts stabilization of prevalence but increase in total numbers because of increase of world population
  • comparison between countries only possible with proper age-standarization --> higher aged associated with greater risk, so age needs to be accounted for
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Cancer and Nutrition, Andersson

Cancer assessment tools

  • what kind of studies to assess cancer risk factors?
Lizenzierung: Keine Angabe

Lifestyle factors

  • migrants studies: people with same genetic background living in different environment, on population level
  • twin studies: as migrant studies but on an individual or lower scale level
  • correlational studies: e.g. meat intake vs cancer prevalence or cancer deaths
    • will inly show trends, not highest quality data
    • national and international levels possible --> std for age imporant for comparison
  • Time-trend studies: ??
  • case-control: ??
  • intervention studies: ??
  • Cohort studies
    • current state of the art in cancer research
    • FFQ + biomarkers used
    • long-term, prospective studies

Tools

  • questionnaires: food, lifestyle and risk factors such as e.g. smoking
    • carcinogens usually found in toxicology and mechanistic studies --> informs questionnaires (and vice versa)
  • biomarkers: b-carotene
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Cancer and Nutrition, Andersson

  • Nutrition and Cancer: how are both linked to one another?
  • What other modifiable risk factors exist and how to they affect cancer risk?
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Nutrition

  • body / cell require nutrients for cell cycle and proper functioning
  • Hormonal imbalances drive cancer development
    • overfeeding, diabetes --> fats and sugars
    • obesity second largest known risk factor for cancer
      • waist circumference correlates with breast cancer
      • weight loss reduces risk of cancer
      • often accompanied by other cancer promoting states --> inflammation, lack of fibre ==> obese cancer patients are more likely to die of cancer due to obesity (or other way around?)
    • menopause: increase in risk due to changes in hormones --> lower pre-menopausal risk for same cancer type (breast)
    • pregnancy: hormonal changes during/after pregnancy protect women
  • hallmarks activated via obesity
    • insulin resistance as key driver of cancer
      • increase in estrogen due to reduced SHBG --> estrogen-dependent tumors
      • higher IGF1 levels
      • hyperglycemia --> anaerobic oxidation = cancerigenous
      • inflammation
  • importance of exercise
    • reduces inflammation, improves insulin sensitivity, stabilizes weight
    • convincing evidence for reduces colon cancer
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Cancer and Nutrition, Andersson

Give an overview of which factors increase or decrease cancer risk

Lizenzierung: Keine Angabe

Multiple nutritional factors influence cancer risk

  • Increase risk
    • Red and processed meats: 1.2% increase
      • Red and processed meats increase risk for colorectal cancer, white meat and fish decrease it marginally
      • Nitrosamines, saturated fats and ROS stress due to heme as potential drivers
    • Alcohol
      • Genotoxicity of acetaldehyde + other à vgl Bild
      • Increases risk for many cancers
      • Decreases risk for kindey cancer
  • Decrease risk
    • Dairy and fish decrease certain cancer risks à vgl Bild
    • Fibre
      • Overall chance of contact between carcinogens & enterocytes is reduced
        • Faster transit times
        • Binding of carcinogens
        • Greater bulk à lower likelihood of contact
      • Reduce insulin resistance
      • Bioactive compounds of wholegrains
    • Fruit
      • Decrease in cancer risk limited
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Cancer and Nutrition, Andersson

 

  • What strategies exist to prevent cancer?
    • How do they work?
    • On what levels?

 

 

Cancer prevention

  • Individual level
    • Healthy weight and physically active
    • Diet rich in fruits, vegetabes and beans
    • Limit intake of SSB, red meat, fast food, alcohol
    • Do not use supplements for cancer prevention
    • Breast feed
  • Government
    • Incentives to fruit and vegetable consumption
    • Clear nutritional labels
    • Nutritional education and personalized advice
    • Healthy meals for the masses à schools, workplaces, institutions
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Cancer and Nutrition, Andersson

  • Which micronutrients affect cancer risk, and how?
Lizenzierung: Keine Angabe

Micronutrients

  • B-carotene
    • Plasma levels have sotrnger correlation with cancer prevention than dietary intake à shows that plasma markers are more reliable
    • Supplementation increased cancer incidence in asbestos workers and smokers
      • B-carotene not recommended for cancer prevention, backed up by meta-analysis
      • Doses of 20-30mg/d
      • study had to be stopped
      • no deleterious effects observed with vit A and E
  • Folate
    • Double edged sword: due to methylation, folate can promote cancer growth once tumorous cells have developed
    • Higher intake not found to increase cancer risk in 5.5y RCTs yet
    • Epidemiological studies show inverse relation between intake and development of colorectal cancer
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Nutrition & CVD, Faeh

CVD epidemiology

  • how situation in CH
  • how do Swiss CVD trends compare to international CVD trends?
    • what are strengths and weaknesses of CH treatment and screening strategies?

 

Lizenzierung: Keine Angabe

CVD epidemiology

  • CH
    • CVD: increasing rates ever since population infectious diseases could be prevented/reduced --> opulations ages and becomes prone to CVD
      • Since 1980 and current trend: declining CVD mortality --> CH one of the highest ranking countries in terms of ortality because time to reach hospital after event is short and treatment excellent
      • cancer: trend remains stable
    • mortality vs.  incidence values available for CVD
      • changes in mortality are due to treatment or screening --> decrease in mortality due to improvements in treatment
      • changes in incidence reflect efficacy of preventive measures
      • CH: decreasing mortality but increase in incidence, especially for males --> treatment has improved, preventive measures seem ineffective
    • Age as an important factor for CVD: mortality increases as of 65, at 85+ becomes most common cause of death
      • individuals <65 can still suffer from CVD
    • death remain stable while hospitalization is increasing --> screening improved? (slide 8)
      • healthcare and socioeconomic burden big, despite decreasing mortality
    • Regional and societal differences
      • higher class less prone to CVD --> also less smokers
      • Romandie less affected than Deutschschweiz
  • International
    • trends also declining
    • similar trends in US, DE, FR, and CH
    • Switzerland ranks amongst lowest CVD mortality countries --> treatment and screening efficacous