By: Dr. Andrew Baranski
Chronic metabolic disease has a pattern of increased incidence in contemporary society. Nutrition and other lifestyle factors have been much attributed to causation of chronic metabolic diseases. As means of reaching a solution a variety of dietary guidelines and recommendations have been forged through time. These recommendations provide a guideline on total caloric consumption, macronutrient amounts, and phytonutrient requirements for individuals who are perceived as healthy. Modern accepted recommendations neglect variations of genes which differ in every individual. The genetic profile of the individual can make one more susceptible to different diseases. The expression of the gene relies heavily on environmental factors such as food consumption. Existing within the genome are single-nucleic polymorphisms, and it is at these sites where distinguishing factors that make each of us an individual take place based on the relationship with the environment.¹ Focusing on the relationship between nutrition and individual genetic componentry has given rise to a new form of nutritional assessment called nutritional genomics.
The expression of a disease does not lie solely on an individual’s genotype, but environmental factors result in certain genes reaching observational status. The genotype does predispose individuals to certain diseases.¹ The laboratory data associated with a disease could be present after one individual consumes a diet rich in a certain macronutrient or phytonutrient; another individual could present with decreased or protected laboratory values associated with the same disease while consuming the same diet. HIgh-density lipoprotein (HDL) present in the optimal range has been shown to be a protective mechanism against cardiovascular disease.² The Framingham study presented that women with the APOA1 A-allele showed increased HDL numbers with increased polyunsaturated fatty acid consumption, but women with the G-allele presented decreased HDL numbers with increased polyunsaturated fatty acid consumption.¹
It is common advice given by practitioners to patients to increase omega-3 consumption by supplementing with fish oil. This advice is often given as means for cardiovascular support. In a woman with the APOA1 G-allele this could be harmful advice. The Dietary Guidelines for Americans recommends 27 grams of oil a day based on the 2,000 calorie a day pattern.³ Making recommendations based on these guidelines solely would hinder individuals with the APOA1 A-allele who could benefit from increased consumption of polyunsaturated fatty acids. To provide the highest rate of result genetic testing would be warranted.
Costa’ paper “Nutritional genomics era: opportunities toward a genome-tailored nutritional regimen,” presents many chronic metabolic diseases that have a relationship with the genome and environment. With such information being available for over a decade genetic testing is rare practice in healthcare settings. A mouth swab can provide a detailed report on 30 genes, and coupled with a nutritional questionnaire the practitioner would be able to provide strong nutritional recommendations. Evidence in the form of randomized control trials are not currently available to support genetic testing as standard of care. Much of the population wishes to be ignorant the diseases in which they are susceptible, and even if they were enlightened a change in diet would still not take place.¹ As practitioners it important to remain cognizant that each individual is unique, and there is not a standard diet that would be beneficial to every individual.
- Costa V, Casamassimi A, Ciccodicola A. Nutritional genomics era: opportunities toward a genome-tailored nutritional regimen. The Journal of Nutritional Biochemistry. 2010;21(1):457-467.
- Ali KM, Wonnerth A, Huber K, Wojta J. Cardiovascular disease risk reduction by raising HDL cholesterol – current therapies and future opportunities. British Journal of Pharmacology. 2012;167(6):1177-1194.
- U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015–2020 Dietary Guidelines for Americans. 8th Edition. December 2015