The “one size fits all” approach to medicine and health may be coming to an end, replaced with a new, personalized approach to health and wellness. The fields of precision medicine and personalized nutrition seek to understand and use an individual’s unique traits, characteristics, and exposures to identify and tailor a health plan that is uniquely suited to them.
Precision or personalized health can help determine the optimal dosage of a medicine, disease treatment plan, dietary recommendations, or supplements to fit specific needs. Precision medicine and nutrition can also provide individualized strategies for competitive athletes, improve motivation to follow a treatment plan, and may increase the effectiveness of interventions.
A personalized approach to health attempts to account for all of the attributes that make the patient unique, all the way down to the cellular level.
Nutrient-gene interactions, also called nutritional genomics, consists of two fields that investigate the relationship between diet and genes: nutrigenomics and nutrigenetics. Nutrigenomics investigates the effects of nutrients on gene expression while nutrigenetics dissects differences in responses to dietary nutrients due to genetic differences.1 Nutrigenomics examines how food and nutrients from the diet can alter gene expression and ultimately protein levels. Nutrients that can influence gene expression include:1
- vitamin A
- vitamin D
- the isoflavone genistein
- the essential omega-3 fatty acid docosahexaenoic acid (DHA)
Dietary patterns can also alter gene expression. For example, one study found that over-consumption of fried foods and sugar, along with a sedentary lifestyle, can increase the expression of genes involved in obesity.2
Nutrigenetic studies investigate the relationship between genetic variants, called single nucleotide polymorphisms (SNPs) and the response to food or nutrients. Most SNPs do not cause any functional difference in metabolism, but research is uncovering many that can have an effect on the body. For example, a SNP in the MTHFR gene results in faster clearance of the vitamin folate while a SNP in the CYP1A2 gene causes individuals to be more sensitive to caffeine.3 Better understanding of the relationship connecting nutrients and genes can help inform a dietary plan that is better suited to the precise needs of a patient.
Epigenetic modifications are a form of genetic regulation that do not involve direct changes to DNA sequences. Instead, epigenetic programming can silence or enhance gene expression through other modifications, resulting in a unique gene expression profile between individuals. One of the major mechanisms of epigenetic modifications is DNA methylation. When a DNA sequence is hyper-methylated, expression typically decreases, but if methyl groups are lacking during a critical window of development, genes may be hypomethylated, causing increased expression.4
Methylation patterns at specific development stages can influence development of conditions later in life including metabolic disorders, cardiovascular diseases, and cognitive disorders.5-7 Methylation is also vitally important in cancer development, with epigenetic mechanisms contributing to nearly every type of cancer.8-10 Mechanistically, altered methylation of oncogenes or tumor suppressors can result in impaired DNA integrity, disrupted cellular homeostasis, and tumorigenesis.8,10 Currently, the ability to determine methylation patterns is not realistic for the population, but one day, with advances in technology, it may be possible to optimize medicine and nutrition recommendations based on a person’s methylation profile.
A diverse, healthy gut microbiome can help modulate processes in the body including immune response, inflammation, and cognitive functions.11 An individual’s microbiome is a unique component of the body, made up of specific bacteria and determined by genes, food choices, lifestyle, use of medications including antibiotics, and environmental exposures.12-14 Studies have demonstrated the benefits of using the specific microbiome composition to tailor dietary recommendations and medications, and for the treatment for gastrointestinal conditions.12,13
Why is Personalized Nutrition Important?
Generalized nutrition recommendations can be a useful tool for educating large groups of people; however, personalized nutrition allows for the consideration and optimization of unique characteristics and requirements. This can allow people to feel more connected to their body through a deeper understanding of it. Removing some of the mystery from health topics such as weight loss, exercise, and detoxification can help people reach their goals faster and in a sustainable way. Additionally, personalized nutrition can also result in better outcomes for a variety of complex, chronic diseases, which are a huge burden for the global economy, as well as for the individuals afflicted by them.15