Nutrigenomics

Question 1

Nutrigenomics

Answer 1

The study of the interaction of nutrition and genes, especially with regard to the prevention or treatment of disease.

Question 2

Gene

Answer 2

Made up of DNA, our physical unit of heredity

Question 3

Trait

Answer 3

An inherited characteristic such as shyness

Question 4

Phenotype

Answer 4

How genetic and environmental influences come together to create physical appearance and behaviour.

Question 5

Genomics

Answer 5

The study of genes. Determines how they interact and influence biological pathways, networks, and physiology.

Question 6

Nucleotide

Answer 6

Each nucleotide contains a deoxyribose(sugar), a phosphate group, and one of four bases ―A (adenine), C (cytosine), T (thymine) or a G (guanine).

Question 7

Codon

Answer 7

A sequence of 3 nucleotides that ’code for’ a specific amino acid. Codons make up ’genes’, which relate to specific functions.

Question 8

Codon for Methionine

Answer 8

AUG

Question 9

Single nucleotide polymorphisms (SNPs)

Answer 9

Differences in single bases in the sequence of a gene (a genetic variation in humans).

SNPs are a normal occurrence (roughly 4–5 million SNPs in one person’s genome). Many SNPs have very little effect.

Some however, can change enzyme or protein function leading to differences in phenotype.

Example: A SNP on genes for oestrogen metabolism can result in oestrogen dominance and increase the risk of breast cancer.

Question 10

SNP Identification

Answer 10

Each gene is identified by an rs (reference SNP).
Each SNP is futher classified by base change and position along the gene.

Question 11

Heterozygous

Answer 11

1 chromosomal variant, usually indicating some potential change of function

Question 12

Homozygous

Answer 12

Variants in both chromosomes, with greater change of function.

Question 13

Areas of particular concern

Answer 13

Methylation
Detoxification
Neurotransmitter/hormone synthesis and metabolism
Vitamin conversion / receptor function

Question 14

Vitamin A

Answer 14

Gene: BC01
‒BCO1 A379V TT alleles (= 32% reduction in enzyme activity).
‒BCO1 R267S AT orTT plus BCO1 A379V CT or TT variant alleles (= 69% lower beta-carotene conversion).
Vitamin A deficiency symptoms: Impaired night vision, frequent infections, skin conditions (e.g., acne).
*SNP recommendations: Increase preformed vitamin A from food (e.g., liver, fish oils) or supplements, especially if plant-based.

Question 15

Vitamin D

Answer 15

Gene: VDR
*SNPs: At rs1544410,theA allele is associated with reduced bone density risk while the G allele is associated with a decreased risk of osteoporosis.
*Vitamin D deficiency symptoms: Rickets and osteomalacia, osteoporosis, immune dysfunction (↑ infections, autoimmunity, allergies, asthma).
*Recommendations: Ensure optimal vitamin D levels with regular testing, sun exposure, food sources (e.g., mushrooms, oily fish, eggs) and supplementation

Question 16

Fatty Acids

Answer 16

*Genes: Fatty acid desaturases are involved in EFA conversion. FADS 1 codes forDelta 5 Desaturase and FADS2 Delta 6 Desaturase.
*There are complex relationships between SNPs and type of fat consumed. FADS1rs174537 GG genotype may increase conversion of high dietary omega-6 to inflammatory AA, more so in African Americans. FADS2 rs174570 T allele is associated with lower GLA, AA, and EPA levels.
*Consider EPA / DHA / ALA from fish oils / algae / flaxseed oils.