8. nutrition and cancer

Question 1

Dietary factors affecting cancer

Answer 1

obestiy- insulin+ insulin related growth

red/ processed meat- nitrates+ amino acids, high cooking temp- carcinogens

saturated animal fats- signalling pathway and insulin resistance

alcohol -

• Ethanol produced free radicals when metabolized which promotes tumorigenesis

Question 2

protective dietary factors against cancer

Answer 2

oily fish

fruit, veg, vit D, fibre, phytochemicals, dairy calcium

• Glucosinolates & isothiocyanates = increase elimination/metabolism of carcinogens (Nitrosamines)

Vitamin D- proliferation, differentiation and apoptosis involvement

Dietary fibre speeds up colonic transit time- less time in the colon for carcinogens to be absorbed

Question 3

advice of diet and lifestyle

Answer 3

• Maintenance of normal body weight
  
  • Physical activity according to guidelines (150 min of moderate activity per week)
• Variety of fruit and vegetables
  
  • At least 400g/day
  • Phytochemicals
• Increased intake of plant foods rich in complex carbohydrates
  
  • Grains, cereals, pulses for main source of energy
• Limit intake of red meat, animal fats, & processed foods
  
  • Less than 7% energy requirements from saturated fat
• Limit alcohol consumption

Question 4

Under nutrition in cancer patients

Answer 4

Mainly seen in gastrointestinal, pancreatic, head and neck, and lung cancers

• At the time of diagnosis approximately 75% of cancer patients are undernourished, with a significantly lower fat-free mass (muscle) than healthy controls. Imbalance with fat mass and fat free mass
• Patients with highest weight loss are those with cancer of oesophagus, stomach, and larynx (when nutrient intake is impaired).
• Patients with stage III/IV disease have reduced energy and protein intakes.
  
  • Anorexia- reduced appetite
  • Taste changes
  • Dysphagia-difficulty swallowing
  • Nausea
  • Vomiting- side effects of treatment
  • Diarrhoea
  • Other disease/treatment related factors
  • Hypermetabolism

Question 5

Cachexia define

Answer 5

chronic hypermetabolic state characterised by rapid weight loss, anorexia and severe loss of muscle mass.

• cancer patients, certain infectious diseases (e.g. malaria, TB, HIV, cystic fibrosis), and chronic alcoholics.
• hypermetabolism in malignancy

Question 6

physiology of cachexia in cancer

Answer 6

IL1 responsible for stimulation for appetite, inflammation is powerful suppressor

increased basic metabolic rate and total energy expenditure compared to starvation where it decreaes

increased inflammation vs no inflammation in starvation

Question 7

Nutrition therapy for cancer patients

Enteral nutrition support

Answer 7

• Provided when patients are expected to (or have) not received adequate nutrition for 7 days
• Small bowel feeding administered with pump over 8-20 hours
• Protein hydrolyzed so easier to absorb
• Long term- gastrostomy tube- no need pump, more food can be infused in
• Sometimes if need to bypass stomach and go straight to small bowel- pump, not as much food, infuse over long periods of time

Question 8

Parenteral nutrition support- avoids GI

Answer 8

• when GI tract is not functional, accessible, or safe to use e.g. colon cancer
• Central (TPN) – bigger volumesor peripheral (PPN) vein
• Fat provided as triglyceride emulsion for essential fatty acids and energy
• Carbohydrate provided as dextrose to prevent protein breakdown and hyperglycaemia
• In veins

Enteral preferred over paraenteral