The recent progress in genetic sciences helped to understand the mechanisms of gene-diet interactions at molecular degree and establish the survey of nutrigenomics. In add-on to this the world-wide epidemic of fleshiness and addition in other diet-related diseases, significance of nutrition research changed consequently. Many surveies conducted late have discovered the function that certain foods have in cistron look. One of the well established illustrations includes cardioprotective effects of fish-oils fatty acids ingestion and differences in such response between sexes and single genotypes. Increased hazard for ischaemic bosom disease and shot besides has been proven to be associated with individual nucleotide polymorphism ( SNP ) that has an consequence of metamorphosis of homocystein ( Hcy ) . Furthermore, the consequences have besides found that diet can be efficaciously used for disease intervention in many conditions without demand for taking medicines. However, due to the fact that nutrigenomics is an emerging scientific discipline, there are many ethical, societal and legal issues that invariably arise and have to be addressed. This paper reviews the literature and examines assorted clinical and epidemiological surveies that have been published in the last 10 old ages and which illustrate the coherency of the available informations and therefore the importance of nutrigenomic scientific discipline. The thesis looks besides into more inside informations at the contention and concerns standing behind this scientific discipline.
Cardinal words: * nutrigenomics * modern-day tool * disease bar *
* genetic sciences * lifestyle * individual nucleotide polymorphism *
In recent old ages, there has been increasing advancement in understanding the scientific discipline of nutrigenomics. Its progress was possible due to the go oning developments of post-genomic engineerings that has been termed the ‘trilogy of omics ‘ and are named severally: transcriptomics, proteomics and metabolomics ( Bland, 2005 ) . Those tools provided the agencies to research deeper the molecular degree and mechanisms of cause-effect and gene-diet interactions. Using this cognition, nutrigenomics is suggesting new attack in dietetic appraisal and intercession with respect to single familial profile and differences in topic ‘s genotypes. This will revolutionise class of wellness publicity and disease bar plans and supply new chances such as individualized diet tailored to single dietetic demands, life style and familial background.
The emerging field of nutrigenomics has a great importance in the Public Health sphere. In modern universe, which is confronting a drastic addition in nutrition related wellness jobs such as type 2 diabetes, overnutrition and fleshiness, focal point on nutrition research changed consequently. This dynamically spread outing scientific discipline gives a position of salvaging enormous sum of money which is presently spend in a greater grade on intervention than disease bar. Nutrigenomics can supply better penetration into nutrient interactions in our homeostatic systems and estimation possible adverse or good effects of nutrient compounds before a disease province occur. Therefore, more attending will be drawn to disease bar and advancing healthy life style than to intervention of diet-related diseases which complications are really dearly-won. In add-on, as nutrition related wellness jobs are considered as a one of the biggest concerns for Public Health and load for National Health Service, the position of avoiding unwanted costs should be a impulsive force for authorities to put in the nutrigenomics. Such actions will let this country, which is presently at really early phase in decoding gene-nutrient interactions, to carry on clinical tests and research surveies in order to lucubrate clear mechanisms involved and become meaningful in the universe of scientific discipline.
Beginnings of the construct that diet affect wellness day of the months back to the ancient times. Around 400 B.C. , Hippocrates, an ancient Hellenic who is considered as ‘the male parent of medical specialty ‘ advised doctors utilizing words: ‘Leave your drug in the chemist ‘s pot if you can healsyour patient with nutrient ‘ . Likewise, it has besides been known for a really long period of clip that human existences can change in the demands for a peculiar food or response to dietetic constituent.
The scientific discipline of nutrigenomics includes assorted familial diseases, which involve mutant in a individual cistron and hence cause upsets of metamorphosis. These frequently called ‘inherited metabolic diseases ‘ or ‘inborn mistakes of metamorphosis ‘ has been known for several decennaries and are efficaciously treated and managed by dietetic regimen or use. One of the illustrations of this upset is phenylketonuria ( PKU ) . The persons enduring from PKU are lacking in enzyme phenylalanine hydroxylase ( PAH ) and hence can non metabolise amino acerb phenylalanine ( Phe ) . The disease is cured by exclusion of nutrient incorporating Phe from the diet ( Koch, 1987 ) . Other illustrations include alcohol dehydrogenase lack, lactose intolerance and galactosemia.
Further rapid alteration in engineering and development of thoughts were initiated by ‘the age of molecular medical specialty ‘ pioneered by work of research workers such as Linus Pauling, Watson and Crick that described the construction of Deoxyribonucleic acid in 1953 ( Bland, 2005 ) . However, before the human genome was sequenced scientists did non hold knowledge about precise mechanisms of how DNA operated. Therefore, in the late 20th century, after the invention in molecular genetic sciences started with the Human Genome Project ( HGP ) ( 1990-2003 ) this cognition became widely available. The undertaking aimed to find the sequence of 3 billion chemical base brace and place legion cistrons on the 23 braces of human chromosomes that make up DNA and was successfully completed in 2003. The nature and content of human familial information helped to place familial diseases every bit good as their interaction of cistrons with dietetic factors and assorted constituents of diet ( Lander et al. , 2001 ) . Successful completion of the Human Genome Project is hence considered as the beginning of the new epoch in nutritionary scientific discipline – nutrigenomics.
2. Review of Literature
2.1 Nutrigenomics as modern-day tool for disease bar
Harmonizing to Simopoulos ( 2003 ) , nutrition is one of the most of import environmental factors that influence wellness and disease relationship. Additionally, recent advancement in Fieldss of genetic sciences and nutrition shed a visible radiation on the familial differences in dietetic response and the function that substances in a diet have on cistron look. It has been concluded that 50 % of difference in cholesterin concentration in plasma, 75 % in bone denseness and 30-60 % of the discrepancy in blood force per unit area is genetically determined. Therefore, since the diet is a cofactor in each of these genetically influenced conditions it is clearly of import to find the mechanisms of diet-genotype interactions in persons at hazard of the disease.
It ‘s indispensable to emphasis that cistrons are non responsible for happening of peculiar disease per Se. However, there are a codification for a assorted strengths and failings that in bend contribute towards opposition or susceptibleness for peculiar disease when triggered by certain dietetic factors. What ‘s more alimentary may back up optimum familial look that promotes good map what is considered as ‘genetic potency through nutrition ‘ ( Bland, 2005 ) .
Many surveies have been conducted in a field of nutrigenomics that provided the grounds of good influence on wellness of certain substances in a diet. One of the probe demonstrated that omega-3 fatty acids have a function in equilibrating cistron look and decrease of synthesis and secernment of courier molecules that are related to type 2 diabetes, CVD and dyslipidemia hazard ( North et al. , 2003 ; Babcock et al. , 2004 ) . This clinical nutrigenomic intercession test have proven that disposal with 3-6 gms of an omega-3, eicosapentaenoic acid ( EPA ) addendum can cut down insulin opposition and hazard of vascular complications. The consequences saying of cardioprotective actions of the fish-oil fatty acids are consistent with other surveies conducted by Wang et al. , ( 2006 ) and Whelton et al. , ( 2004 ) .
The aim of FINGEN Study that enrolled 312 assorted gender aged 20-70 participants was to find the consequence of moderate EPA and DHA supplementation ( & lt ; 2g EPA & A ; DHA/d ) on the plasma fatty acid profile in respect to sex and apolipoprotein E ( APOE ) genotype of the topics ( Caslake et al. , 2008 ) . Harmonizing to the consequences obtained by Caslake et al. , ( 2008 ) consumptions of fish-oil fatty acids eicosapentaenoic acid ( EPA ) and docosahexaenoic acid ( DHA ) has a higher triacylglycerol-lowering response in adult male than in adult females. It was besides concluded that APOE4 genotype can act upon reactivity to take downing consequence achieved by fish oils. The analysis has shown a high positive tendency towards greater reaction in bearers of Iµ4 allelomorph. The FINGEN survey is considered as the most comprehensive survey that investigated the effects of fish oil supplementation on plasma lipoid and first to look into this relationship in respect to sex and APOE genotype.
Other survey that involved 755 male and 822 female topics, was designed o analyze the association between HDL-cholesterol concentration, indispensable fatty acids intake ( n-3 and n-6 polyunsaturated fatty acids – PUFAs ) and genotype APOA1 ( Ordovas, 2002 ) . The participants were divided into low, medium and high PUFA consumption groups. It has been concluded that in adult females with A allelomorph, high consumption of PUFA caused an addition in HDL-cholesterol. However in adult females homozygous for the G allele the reaction was opposite. There was no important difference in respect to males. All the interactions are shown in Figure 1. Further probe of these correlativities, may in the hereafter service as a footing for individualised nutritionary advice based on single familial make-up where adult females with A allelomorph should devour high dosage of PUFAs in order to increase HDL-cholesterol and lower the hazard of cardiovascular disease. On the other manus G/G females should follow opposite recommendations ( Ordovas, 2006 ) .
The figure shows mean ( +SE ) HDL-cholesterol concentration ( mmol/L ) by APOA1 genotype categorised into polyunsaturated fatty acid ( PUFA ) groups ( where a-? & lt ; 4 % ; a- 4 % -8 % ; a- & gt ; 8 % of energy ) in adult females ( G/G, A/A ) and work forces ( G/A ) .
( Modified from Ordovas, 2006 )
Another well-studied illustration that proves the significance of nutrigenomics examined the effects of homocysteine ( Hcy ) in cut downing ischaemic bosom disease and shot. Current probes have recognized several familial polymorphisms that have an consequence on metabolic tract of Hcy. One of most widely studied is methylentetrahydrofolate reductase ( MTHFR ) C677T polymorphism. Peoples with homozygous type in this individual nucleotide polymorphism ( SNP ) , estimated 10-15 % of general population, have diminished ability of transition of folic acid into active 5-methylene tetrahydrofolate ( 5-MTHF ) signifier ( Gerdes et al. , 2004 ) . This in consequence cause impaired transition of Hcy to methionine. Persons will necessitate higher dosage of vitamin Bc or disposal with 5-MTHF to keep low degrees of Hcy and cut down hazard of homocysteine related cardiovascular diseases ( CVD ) and neural-tube defect ( Molloy et al. , 1997 ) . As reported by Molloy ( 1997 ) dietary referenced values sing folate consumption every bit good as other foods, may hold to be adjusted. This is due to the fact that they apply merely to general population and do non take into history persons familial fluctuations and metabolic abnormalcies that may compromise position of some foods and well increase 1s demands.
The nutrigenomic and lifestyle intercession may besides function as a replacement for medicines, which are frequently associated with many concerns. This is due to the fact that drugs are unnaturally manufactured and hence, they can do serious inauspicious effects and at the same clip they are normally expensive. The application of drugs is besides associated with a ulterior phase of disease that really frequently manifests irreversible alterations. There is a assorted scope of conditions that can be cured without medicines such as high cholesterin, acne, depression and digestive ailments ( Bland, 2005 ) . A survey conducted in 2001 by the National Institutes of Diabetes and Digestive and Kidney Diseases investigated the influence of diet and exercising on hazard of developing type 2 diabetes mellitus ( DM ) . The findings were truly consistent and in consequence the survey was terminated a twelvemonth early, reasoning that diet and physical activity can significantly cut down the hazard of developing type 2 DM ( Hawthorne, 2003 ) .
2.2 Controversy in a field of nutrigenomics
Nutrigenomics as a comparatively new scientific discipline raises many concerns in respect to ethical, societal and legal issues ( Castle & A ; Ries, 2007 ) . Its practical application is associated with familial testing in order to uncover sensitivity to conditions that can be prevented with dietetic intercession. However, as the scientific discipline has non existed long plenty and involves many interconnected Fieldss such as genetic sciences and nutritionary scientific discipline there is no ordinances specific to this field. For that ground, the European Nutrigenomic Organisation ( NuGO, 2007 ) has formulated bioethics guidelines to assist turn to issues for concerns in nutrigenomic surveies such as informations protection and privateness.
Due to the addition in marketing genotyping services, nutrient and addendums designed for single demands, it is besides indispensable to see concerns associated with direct to consumer ( DTC ) selling ( Castle et al. , 2006 ) . These include protection of consumers from unproved trials, and addendum regimens with no scientific cogent evidence, insurance companies which may utilize the familial information for hazard evaluation of their clients.
The experiment conducted by United States Government Accountability Office has drawn the attending to that job. The GAO examined consequences from familial samples of 14 ‘fictitious consumers ‘ sent to 4 nutrigenomic companies advertised on the cyberspace ( US GAO, 2006 ) . It has been concluded that the consequences made medically unproved health-related anticipations so puzzling that did non supply valuable information for consumers. In add-on, expensive addendums sold by them were non as falsely claimed designed in conformity to single DNA and were potentially harmful. Therefore it is of import to turn to the ethical and legal issues originating from the current state of affairs. First of all, support nutrigenomic instruction and advancement in research and at the same clip develop agencies to protect consumers from disreputable companies.
In decision, the reappraisal of literature and assorted epidemiological and clinical surveies has explained the great importance of nutrigenomics. This scientific discipline has an tremendous potency, since non that long ago we have learned that nutrient is more than implement to supply Calories and prevent diseases associated with foods lacks. But besides, carry of import information that affect cistron look, proteins as merchandises of cistron look and metamorphosis comprised of all the procedures happening in the organic structure. In add-on, scientific discipline of nutrigenomics can be considered as a tool that might be used oppose to general dietetic guidelines that are non taking in consideration familial fluctuations happening between persons. It is hence of import to spread out the cognition of nutrigenomics, as its application will be much more cost-efficient in chronic diseases direction than the present system of public wellness, based on a construct that ‘one size tantrums all ‘ . Clinical nutrigenomics will let greater preciseness in accomplishing favorable results, due to application of individualized intercession. In consequence, it can function to increase results of intercession every bit good as cut down unneeded health care outgo. Nutrigenomics will besides alter the nature of wellness attention, and enable people to larn how to nurture themselves to protract and optimise their life span in good wellness. Persons that will habituate familial testing will besides hold greater grade of conformity to the recommended diet and hence improved results.
However, there is still much to make in respect to probes into clear mechanisms of nutrient-gene interactions and a assortment of ethical concerns to turn to. Undoubtedly, the field of nutrigenomics is a scientific discipline of the hereafter that will hold a singular significance and influence on the country of human genomics and molecular nutrition.