Nutritional genomics

Question 1

What is a single nucleotide polymorphism (SNP)?

Answer 1

A variation in a single nucleotide in a specific position in the genome.
hree variants arepossible (eg. CC, CT, TT)
Has to be present in >1% of a given population

Question 2

What can explain interindividual variability?

Answer 2

By genes

Question 3

What is Nutritional genomics?

Answer 3

Umbrella term for nutrigenetics and nutrigenomics

Question 4

What is nutrigenomics?

Answer 4

How nutrients affect the gene

Question 5

What is nutrigenetics?

Answer 5

how the genes effect the food we eat

Question 6

What is nutrigenetics?

Answer 6

Nutrigenetics points to understanding how the genetic background of an individual impact to the diet

Question 7

How is interindividual variation data observed?

Answer 7

In studies you look at the mean value and not at the individual changes in people

Question 8

How can PUFA influence gene expression?

Answer 8

• Can enter cell membrane – forms a complex with receptor and enter the nucleus of the cell where DNA sequence are
• PUFA binds to PPAR
• Form the complex PUFA-PPAR which binds to RXR in the nucleus
• The complex binds to regulatory elements on the gene and starts transcription (eg. CPT1)
• CPT1 increases with PUFA – transporter for fatty acids and involved in oxidation of fatty acids – this protein involved oxidising fatty acids to energy
• PUFA and liver fat connection – PUFA can lead to increased oxidation of fats instead of storage

Question 9

Give one example of nutrigenomics?

Answer 9

PUFA’s effect on gene expression.

Can lead to increased oxidation of fats instead of storage

Question 10

What is the function of CPT1?

Answer 10

The gene encodes for an enzyme involved in fatty acid oxidation

Question 11

What defines lactose persistance?

Answer 11

Continued activity of the enzyme lactase that breaks down lactose to glucose and galactose

Question 12

How common is lactase persistance in Sweden vs South Europe?

Answer 12

> 90% in Scandinavia

and 15-54% in South Europe

Question 13

How does lactose intolerance occur?

Which gene is involved?

Answer 13

MCM6 contains two of the regulatory regions for LCT, the gene encoding the protein lactase, located in two of the MCM6 introns, approximately 14 kb (-13910) and 22 kb (-22018) upstream of LCT. The (-13910) region, in particular, has been shown to function in vitro as an enhancer element capable of differentially activating transcription of LCT promoter. T–> C.

Mutations in these regions are associated with lactose tolerance into adult life

Question 14

What is the common polymorphism in Europe: -13910*T

Answer 14

Lactase percistance.
T–> C
The ancestral allele is C and the derived allele associated with lactase persistence – is T
Increased LCT promotor activity –> Lactase

Question 15

Is lactose persistance nutrigenetics or nutrigenomics?

Answer 15

Nutrigenetics

Question 16

How can people respond to soda consumption?

Answer 16

Varying genetic responses.
People with high BMI the soda consumption associated with obesity increase
Lower BMI don’t get the same response to soda

Question 17

What is the function of CYP1A2?

Answer 17

Produces enzymes to break down caffeine in the liver

Question 18

Gene variants in CYP1A2 lead to ?

Answer 18

different gene variants codes for different amount of the protein ex. 2 vs 200 – break down superfast and need more time
- If produce less enzyme – caffeine will stay in blood longer – increased risk of cardiovascular disease – more enzymes reduce the risk of cardiovascular disease

Question 19

What does this lead to “A–>C in position 734 (rs762551)” ?

Answer 19

It reduces the activity of the enzyme (CYP1A2*1F)

Increased risk of hypertenzion

Question 20

How can caffeine effect sport performance?

Answer 20

Can increase (CC) but also decrease (AA) depending on genes.

Question 21

What is DTC and does it work?

Answer 21

(direct-to-consumer) provides people access to their genetic information.
No it seems people don’t like being told what to do?

Question 22

Limitations of field of Nutrigenomics?

Answer 22

• Little is known
• methodological limitations
• many diseases such as CVD, diabetes and obesity are polygenic and multifactorial
• Genetic information may shift focus from other important modifiable risk factors
  Is genetic info enough to change behaviour ?