Biomarkers

Question 1

Biomarkers

Answer 1

Any biological specimen that is an indicator of nutritional status with respect to intake or metabolism of dietary components

Question 2

Biochemical assessment

Answer 2

Uses lavatory measurements of serum protein, serum lipids, serum glucose and serum micronutrient levels to assess general nutritional status and to identify specific nutritional deficiencies

Question 3

Short term markers

Answer 3

Respond to dietary intake within hours

Question 4

Medium term markers

Answer 4

Respond over weeks or months

Question 5

Long term markers

Answer 5

Large scale epidemiological studies
Eg adipose tissue toenail or hair sample

Question 6

Serum and Plasma Specimens

Answer 6

Reflect short term intake from a few days to one month

Question 7

Erythrocytes

Answer 7

Reflect longer term intake due to their half life of about 120 days

Question 8

Adipose tissue

Answer 8

Reflects long term intake
More useful to assess exposure to fat soluble vitamins

Question 9

Urine

Answer 9

Reflects short term intake
Samples collected can be 24hr overnight or spot
Suitable for recovery Biomarkers
Inconvenient

Question 10

Hair and Nails

Answer 10

Easy to store and collect
May be affected by environment particularly hair

Question 11

Faeces

Answer 11

Difficult to collect
Burdensome el
Assesses gut micro biome
Relevant to colon cancer

Question 12

Plasma Biomarkers
Fasting blood glucose

Answer 12

Indicator of diabetes
Must be repeated to ensure no false positive
3.9-5.4
5.4-6.9
7.0+

Question 13

Glycated Haemoglobin

Answer 13

An indicator of average blood sugar level for three months
Percentage of blood sugar attached to oxygen carrying protein haemoglobin

Question 14

Biomarkers are influenced by

Answer 14

Disease status
Age
Genetics
Environmental factors
Choice of specimens

Question 15

Total Iron content assessment

Answer 15

Useing mccance and windows on food composition tables
Estimate harm by dividing type specific iron by total iron
Beef/lamb 65%

Question 16

Serum iron

Answer 16

Essentially transferrin bound iron with the amount in circulation being a function of iron availability and transferrin levels

Question 17

Total iron binding capacity

Answer 17

Two iron binding sites per transferrin molecule
Indirect measure of transferrin
Usually higher when iron levels are low

Question 18

Transferrin saturation

Answer 18

Ratio of serum to TIBC
Measures proportion of transferrin bound to iron
More useful indicator of iron status
Normal levels between 20-50%

Question 19

Ferritin

Answer 19

Iron without cells is stored complexed in these proteins
Measure of iron stores

Question 20

Carbon reactive protein

Answer 20

CRP
Subjects with raised values above 10mg/l show acute inflammation

Question 21

Toenail iron analysis

Answer 21

University of Missouri
Shows a nutritional status for 12 months or more previously

Question 22

Metabolomics

Answer 22

Measuring a large number of low weight metabolites including essential amino acids and molecules not synthesised by the human body

Question 23

Epigenetics

Answer 23

DNA methylation reflecting intake of methyl donors and b Vito taking part in key methylation cycle

Question 24

Proteomics

Answer 24

Potential reflection of functional markers