theory of prac 10% Flashcards
what are the Nutrigenomics research strategies
- Promise a healthy world and control your health
- Ultimate goal is that the food can be match to the individual’s genotype
- Need a lot of research
what is the nitrogenomics research strategies research cycle
- hypothesis and research question is carried out
- experiment
- test hypothesis
a. accept hypothesis-> part of the theory can be formulated
b reject hypothesis-> fomulate hypothesis and research question again
Mechanism-based approach
- Address the relation between nutrition. Health. Disease, Genome and the genes
- Important to develop sound research question
- Can be done by look specific food (e.g. fruit) or specific nutrients (e.g. calcium)
- By focus on effect on diet or specific organ (e.g. liver, colon) or disease (e.g. T2D or risk of develop these disease
- The influence of genes can be more specific investigate look at 1 or few genes or at specific metabolic pathway e.g. gluconeogenesis
- However it is also possible the study of diet at transcriptome, proteome and metabolome level, this means look at as many as biological parameters as possible.
- More focused Research question is what is the role of n-3 fatty acids on PPAR alpha in liver?
- Once the research question is formulated, the research start. At the end this will lead to between understanding of nutrition and disease
- This approach is mechanism based approach
Holistic approach
- Use the same genomic approach as mechanism base approach.
- However it does not primary focus on understanding specific mechanism, rather it focused on complex relation between nutrition, genomics, health and disease.
- Some genes are expressed and some not, the specific expression can be measured by oligonucleotide microarray
- They compare expression profile e.g. compare between people eat fish, and some don’t. this can be show what the effect of fatty acid and other component in fish on gene expression but for most genes detected in this experiment, exact function is not known.
- This approach unlikely to solve the mechanism by fatty acid in fish influence health
- This approach provide us with genomic signatures
- Genomic signature describe the expression profile associate with specific nutrients or diet or disease, also proteomics and metabolomics can be used to develop the genomic signatures.
- Can consider the genomic signature as fingerprint of physiological or pathophysiological state or finger print of phenotype
- In the future, develop database for characteristic signatures. With this database, perhaps it will be possible to predict whether someone with a particular signature will be benefits with certain supplement. Moreover, these signature might indicate whether the person is at risk of getting some diseases. The signature could serve as an early biomarker for disease
- Holistic based approach may also give on rise on hypothesis on a particular hypothesis, they use mechanism base approach.
Are the personalized diets indeed PERSONAL diets?
The following issues must be mentioned in your conclusion:
- Less than 0.07% of all genes are screened for variations. There are many more (unknown) variations which could be important for a personalized diet advice.
- The “personal diet advice” is not very personal. Is is nearly the same as the general guidelines of “The American Hearth Association” (especially for macronutrients).
- Some of the general guidelines (regarding micronutrients) are stressed more than others, based on certain variations. This is a “personal” part of the advice.
- Most guidelines given in the personalized diet advice is not only of relevance for the specific individuals with certain variations but also for individuals without these variations.
Note that some companies also base their advice on results of lifestyle and food questionnaires the customer filled in. This advice is of course personal, but not based on the genome. Some times such advice is called “personalized diet advice”. However, most of the time this advice is called “tailored advice”. In this course “personalized diet advice” is defined as diet advice based on genetic tests.
How many genes, do you think, are approximately in the human genome?
it is not exactly known of how many genes the human genome consists, but their number is estimated around 25.000.
Which of the techniques below is most probably used by the companies that give a personalized diet advice?
a multiplex technique: several SNPs can be detected simultaneously.this one is most likely used by the companies. With this technique a small number of SNPs can be screened at once. It can be largely automated, therefore the costs are low. However, there are other techniques, like these, to analyze many SNPs simultaneously, which also could be used by the companies.
what r the micronutrients
folate calcium Vitamin B6 vitamin D vitamin B12
what r the macronutrients
saturated fats
carbohydrates
cholesterol
n-3 fatty acids
what does antioxidants, caffeine, fruit and vege belong
they dont belong to micro or macro nutrients
Compare the diet advice in the report with the general dietary guidelines of the American Hearth Association and the general dietary guidelines for Americans. What is your conclusion about macro and micro nutrients
For macronutrients the advice given in the report is almost the same as the general guidelines of the American Heart Association. In general, this is also the case for micronutrients. However, some advice regarding micronutrients is stressed more than others depending on variations in some genes or a persons food pattern. Correct your answer if necessary.
Are the personalized diets indeed PERSONAL diets?
The following issues must be mentioned in your conclusion:
- Less than 0.07% of all genes are screened for variations. There are many more (unknown) variations which could be important for a personalized diet advice.
- The “personal diet advice” is not very personal. Is is nearly the same as the general guidelines of “The American Hearth Association” (especially for macronutrients).
- Some of the general guidelines (regarding micronutrients) are stressed more than others, based on certain variations. This is a personal part of the advice.
- Most guidelines given in the personalized diet advice is not only of relevance for the specific individuals with certain variations but also for individuals without these variations.
Note that some companies also base their advice on results of lifestyle and food questionnaires the customer filled in. This advice is of course personal, but not based on the genome. Some times such advice is called personalized diet advice. However, most of the time this advice is called tailored advice. In this course personalized diet advice is defined as diet advice based on genetic tests.
-
which of the human chromosomes contain MTHFR
chromosome 1
what does MTHFR do
the MTHFR gene encodes for the enzyme methylenetetrahydrofolate reductase, which is involved in the metabolism of folate.
5-methyltetrahydrofolate serves as a methyl donor to remethylate homocysteine to methionine. this process requires vitamin B12. elevated levels of homocysteine are associate with a high risk of heart diseases.
what is the gene product of the PPAR gamma gene
“The peroxisome proliferator-activated receptors (PPARs) are members of the nuclear hormone receptor subfamily of transcription factors.”
what is the association of PPAR gamma with adipose tissue
PPAR gamma activation is association with higher fatty acid and glucose uptake
what is the association of PPAR gamma with muscle
PPAR gamma activation is association with higher glucose usage in muscle
what is the association of PPAR gamma with liver
PPAR gamma activation is association with higher fatty acid storage in the liver and lower glucose production in the liver
what is the association of PPAR gamma with pancreas
PPAR gamma activation is association with higher activity of beta cells in the pancreas. the beta cell secrete insulin
give an important polymorphism in the PPAR gamma gene
an important polymorphism in the PPAR gamma gene is “Pro12Ala)
Pro12Ala polymorphism
the Pro12Ala polymorphism is associated with a REDUCED trranscription of the PPAR gamma gene
There is evidence that this polymorphism is also associated with a LOWER BMI, a LOWER fasting glucose level, a HIGER level of HDL cholesterol and a INCREASED insulin sensitivity.
Therefore the Pro12Ala polymorphism may DECREASE the risk of insulin resistance, DECREASE the risk of T2D and DECREASE the risk of heart disease. so the polymorphisms in PPAR gamma gene can have a lot of effects.
