Nutritional Genomics Overview

Nutritional Genomics

• Nutritional genomics is the study of the interaction between nutrients and the genome.
• It's divided into two parts: nutrigenetics and nutrigenomics.

Learning Outcomes

• Identify different areas within nutritional sciences
• Understand the role of various areas in nutritional genomics
• Define nutritional genomics
• Identify examples of nutritional genomics
• Discuss the prospects of nutritional genomics

Nutritional Sciences

• Clinical Nutrition: Deals with nutrition and health, nutrition and disease, and dietary therapy.
• Molecular Nutrition: Examines nutritional biochemistry, nutritional proteomics, and nutritional genomics.
• Community Nutrition: Focuses on food choices, food and nutrition policy, nutritional epidemiology, nutritional education & intervention, and food security.

The Cell and the Gene

• The cell's components are described: mitochondrion, ribosome, rough endoplasmic reticulum, plasma membrane, smooth endoplasmic reticulum, free ribosome, centriole, nucleus, nucleolus, chromatin, nuclear pore, nuclear envelope, Golgi complex etc.
• A genome is the total of all chromosomes.
• Genes are pieces of DNA that code for proteins.
• DNA has a sugar-phosphate backbone and nucleotide base pairs (Adenine-Thymine and Guanine-Cytosine).

DNA

• DNA is deoxyribonucleic acid, a molecule carrying genetic information.
• DNA is organized in a double helix structure composed of two strands.
• Complementary base pairs are essential for DNA structure: Adenine (A) with Thymine (T) and Guanine (G) with Cytosine (C).

Gene

• A gene is a segment of DNA that codes for a specific protein.
• Genes contain exons (coding regions) and introns (non-coding regions).

From Gene to Protein

• DNA is transcribed into mRNA.
• mRNA carries genetic information from the nucleus to the cytoplasm.
• mRNA is translated into proteins at ribosomes.
• Specific examples of DNA and mRNA sequences and resulting amino acids are provided.

Diet-Gene Interactions

• Nutritional genomics is the study of diet-gene interactions.
• Nutrigenetics explores how genetic variations affect dietary responses.
• Nutrigenomics examines how dietary and nutrient impacts influence genes.

Nutrigenetics

• Genetic polymorphisms are variations in genes across individuals.
• Single Nucleotide Polymorphisms (SNPs) are the most common form of genetic variation.
• SNPs are defined as single nucleotide differences from the standard gene sequence.
• SNPs can impact an individual's response to diet.
• Example: MTHFR gene and folate metabolism (677C→T), affecting homocysteine metabolism.
• There is impact on the production of amino acids or the lack of synthesis.

Nutrigenomics and Folate

• Genes influence dietary folate requirements.
• The MTHFR gene codes for an enzyme crucial for folate metabolism.
• Changes in the MTHFR gene can cause a polymorphism, altering homocysteine metabolism and possibly cardiovascular disease risk.

Homocystinuria Metabolism

• Folate and B12 are crucial for homocysteine metabolism.
• Variations in genes related to folate metabolism (e.g., MTHFR) can impact the production of homocysteine.
• Elevated homocysteine levels are linked to cardiovascular disease.

Examples of Known SNPs

• Examples of known SNPs in various processes (folate metabolism, iron homeostasis, bone health, lipid metabolism, obesity) and their health impacts are outlined.

Genetics and Obesity

• Case studies and scientific studies linking genetics to obesity are referenced.

Nutrigenomics

• Diet can directly impact gene expression and DNA structure.
• Carcinogens or free radicals can damage DNA, causing mutations or altering DNA sequences.
• Epigenetics involves changes in gene expression without altering the DNA sequence.
• Folate is crucial for DNA methylation.

Application of Nutritional Genomics

• Increased comprehension of the connection between diet and disease.
• Improved dietary recommendations tailored to individuals.
• Enhanced public health strategies for preventive disease management.

Challenges of Nutritional Genomics

• Knowledge gaps and conflicting results are present.
• The prevalence of mutations and their impact on individuals varies.
• Ethical concerns regarding gene testing exist.

Ethics? (MyCellf Program)

• Commercial gene analyses are available, providing a snapshot of health profiles but without a clear focus on disease.
• A combined analysis of multiple genes related to bone health, heart health, antioxidants, detoxification, insulin sensitivity, and inflammation is available (MyCellf).
• Comprehensive health summaries and suggestions for optimal health are offered without a clear disease focus.
• Pricing of health analysis tools is stated.

Conclusions

• Human nutrition and diets are complex.
• Multidisciplinary approaches to nutrition are needed.
• Public health nutrition guided by nutritional genomics can be more effective in both disease management and disease prevention.

What do you think?

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