Genetics - Nutrition

Question 1

What is nutrigenetics?

Answer 1

The science of the effect of genetic variation on the dietary response.

Question 2

What is nutrigeomics?

Answer 2

The role of nutrients and bioactive food compounds the gene expression

Question 3

What is epigenetics?

Answer 3

The heritable transmission of phenotype without a change in the underlying DNA sequence

Question 4

Describe relationship between genetic polymorphisms and obesity and food addiction

Answer 4

• Consumption of favourite foods increases dopamine contractions, activation reward pathways in the brains, resulting in reinforcing effects of pleasure
• Obese individuals have reduce levels of dopamine D2 receptors and they inversely related to body weight
• Other gene variants linked to appetite and obesity include those for leptin receptors, linked with binge eating disorder

Question 5

What nutritional responses does genetics influence?

Answer 5

• Appetite control
• Taste control
• Oral health
• Response to individual food compounds

Question 6

What are some environmental effects on DNA?

Answer 6

• Point mutations
• Base modification as a result of reactive molecules
• Chromosome breakage and rearrangement
• Chromosome loss or gain e.g. in tumour cells
• Gene silencing as a result of inappropriate methylation of CpG at promoter sequences
• Silencing of house keeping genes as a result of DNA hypermethylation of CpG in promoter regions
• Accelerated telomere shortening dysfunction

Question 7

How can diet alter expression of genetic information?

Answer 7

• Acts as ligands from transcription factor responses
• Be metabolised by primary or secondary metabolic pathways, altering concentration of substance, or intermediates, or altering signal transduction pathways
• Exogenous nutrients can affect gene expression directly, e.g. DNA methylation and indirectly e.g. cell signalling