Nutrients and Gene Regulation 12 09 2012 The genome Strands of ALL the DNA Deoxyribonucleic acid Contains all genetic information in the body housed in cell nucleus and mitochondria Gene vs genome o Genes are the DNA sequences in the genome that are expressed in the form of protein or RNA to a limited extent Not all DNA sequences in the genome are expressed How many genes we have o 20 000 30 000 genes RNA Ribonucleic acid Three major types o The intermediate product of the gene after transcription 1 Messenger RNA mRNA intermediates between genes and proteins o functional units required for translation 2 Transfer RNA tRNA carry amino acids 3 Ribosome RNA rRNA part of ribosome Gene Expression Summary Nuclear DNA makes mRNA copy mRNA leaves nucleus DNA stays behind mRNA attaches to ribosomes composed of rRNA tRNA has been collecting amino acids from cytoplasm tRNA s give up their amino acids to the proteins being synthesized in the ribosome an enzyme then bonds one amino acid to the next the protein is then released if the stop codons follow How is nutrition related to genetics Vitamins work at the genetic level to turn gene expression on or off Some nutrients when in excess can cause damage on DNA Some antioxidant nutrients can counteract oxygen free radicals and thus inhibit oxidation on DNA Nutrients involved in gene expression Iron Selenium Some amino acids phenylalanine Vitamin D Calcium Nutrient regulation of gene expression at translational level Iron o Iron effects mRNA translation of proteins involved in iron storage translation o When iron is high mRNA of an iron storage protein undergoes o When iron is low mRNA of an iron storage protein is blocked from translation Selenium degradation Nutrigenomics o Selenium deficiency results in selenoprotein mRNA The study of how naturally occurring chemicals in foods alter gene expression in each individual Identification and understanding of population differences and similarities in gene expression or phenotype in response to diet How is nutrition relation to human genetic diseases Defects in genetic code cause nutrition related diseases mutations o Hereditary hemochromatosis A human autosomal recessive disorder Cause excessive iron accumulation due to mutations in genes involved in iron absorption Symptoms liver cirrhosis cancer diabetes and heart failure o Phenylketonuria Inborn error of metabolism A genetic disorder with mutations in the gene that metabolites phenylalanine Buildup of phenylalanine results in brain damage What is the dietary limitation for PKU patients Artificial sweeteners things that have phenylalanine o Sickle cell disease One amino acid in the protein strands of hemoglobin takes the place of another causing the red blood cell to change shape and lose function Epigenetics The science of heritable changes in gene function that occur without a change in the DNA sequence Modifications on DNA methylation on cytosine one of the four DNA bases decreased gene expression Modifications on histone proteins for example acethylation on The B vitamins folate and B12 are essential for transferring methyl histone groups Significance of nutrigenomics Identification of specific genes may better focus treatment Early detection may aid with prevention or may cause undue worry Can use as better assessment of nutritional status Use to set RDAs more accurately Sustainability Agriculture Nutrition and Food 12 09 2012 Our diets and the environment Large scale conventional farming o Conventional farming depletes soil of nutrients o Fertilizer runoff causes algae overgrowth dead zones o Pesticides and herbicides kill insects and native plants o Loss of land environmental destruction deforestation o Energy intensive In the US the food industry uses 20 of the nation s fuel to run farm machinery and produce fertilizers and pesticides and to prepare package transport refrigerate and otherwise store cook and wash our foods Food processing o Solutions organic sustainable locally grown produce o 6 560 calories of fuel are used to produce a can of corn o 2 100 calories of fuel are used to produce a diet soda 500 for the soda 1600 to make the can o solution eat food that is less processed Large scale meat production o Manure results in soil and water pollution o Animals are fed grain 1 5 of all cropland in the US is used to produce grain for livestock more than for people o energy intensive takes 8 lbs of grain to produce one lb of weight gain in a cow o greenhouse gas the amount of pollution produced by a cow is comparable to that by a car in a day o solution eat less meat if eating meat find locally sustainably raised grass fed water bottles energy efficient dishwashers only running full dishwasher reusable grocery bags reusable pans dishes rather than disposables Reduce Reuse Recycle The future of oil oil and foods extreme oil may replace dwindling supplies but it comes at a heavy economic and environmental cost peak oil is the phenomenon whereby global oil supplies peak then decline with extraction growing increasingly costly today s globalized industrial food system depends on oil for fueling farm machinery producing pesticides and transporting goods biofuels production links oil prices to food prices adaptations of food systems for peak oil era reduce oil in food production increase food system energy efficiency and renewable energy change food consumption pattern low oil foods reduce food transportation distance alternative energy algae biofuel why algae o 1 Grow rapidly turning carbon dioxide and sunlight into oil o 2 Not picky about water quality o 3 No need for nutrient rich land little no competition with food production o 4 Lower carbon oxide green house gas USDA Certified Organic products USDA implemented organic standards in 2002 Established regulations for organic farming and labeling of organic How the rules regulation organic matters are decided o The National Organic Standards Board NOSB typically meets twice per year in various locations around the US During meetings they listen to public comments discuss their agenda items and then vote in a public forum Prohibits use of toxic and persistent chemicals in favor or more earth friendly practices o Crop rotation o Planting cover crops o Releasing beneficial insects o Adding composted manure Field must be free of synthetic pesticides and fertilizers for 3 years before a certified organic crop can be grown on it Use of proper manure composting techniques to prevent against
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