Introduction to Nutrigenetics

We all are different from the colour of eyes, curls of your hair to your skin complexion. This is attributed to genetics. We have come a long way in understanding the impact of our genes on how we look & how our bodies work. Before digging into nutrigenetics, let us first need to understand the basics of genetics.

Gene & Genotype

A gene is a section of DNA that contains instructions for you to produce protein each of which has specific function in your body. Specific version of every gene you carry is called genotype. Each gene has some specific function/job to do & how effectively your gene functions depends upon your genotype for that gene. These variations in genotypes are called SNP-Single Nucleotide Polymorphisms. The instruction is that genes come in the form of code made using a sequence of nucleotides represented by letters A, T, C & G. A change in code is usually, addition, deletion or substitution of one of these letters. This means that the protein made these codes would be imperfect & would not perform the function as effectively.

SNP can be compared to a spelling mistake. By including a wrong letter in your word, you would still be able to read the word but it may reduce the impact of the message.

Phenotype

Your phenotype is how you look, who you are & how your body works. Your genes determine some of your physical characteristics however most of the characteristics arise due to combination of your genes & environment. Environment would include diet, general lifestyle, smoking & exercise

What is Nutrigenetics

Nutrigenetics is a link between nutrition & genes. This involves how genetic variations can impact an individual’s response to diet. This involves how effectively nutrients are digested, absorbed & utilized. Nutrigenetic risks are classified as monogenic & complex.

A monogenic disorder is caused by change in single gene.For such disorders, a genetic test of single gene can be used to evaluate. An example of monogenic disease can be Lactose Intolerance(LCT). LCT gene contains instruction for production of Lactase, an enzyme required to digest Lactose. Around 70% of the world population have different variations of LCT genes that prevent Lactase from being produced. Without lactase, lactose found in dairy products is not broken down negatively impacting your gut health & resulting in bloating & cramps.

Complex risk factors

Genetic risk related to chronic diseases & nutrition are more complex than monogenic diseases. Most lifestyle diseases are associated with several genes related to diet & environmental factors. For instance, genes such as FTO & PPARG are related to Obesity. However, it does not mean that you will definitely gain weight. However if you have these genes & follow a western high fat diet, you are more likely to be obese as compared to those who do not have these genetic variations.

We are aware that nutrition plays a major role in our fitness & keeping us away from lifestyle & chronic diseases. Although public health recommendations are based on what general population requires, it does not account for individual differences. This is where genetics personalised nutrition comes into play. Improvement in your weight loss is just a starting point. Your requirements for nutrients such as Vitamin, C, D, B & E & Omega-3 can also be tailored to your genes to reduce the risk of chronic diseases. Genetics help us learn which nutrients will suit best to protect our bodies.

However it does not entirely boil down to genes. Although using nutrigenetics is beneficial for personalised nutrition, it should never be used in isolation. Personalised nutrition is based on the following three factors:

1) Public health recommendations.
2) Phenotype measures
3) Your genotype

It is important to note that Nutrigenetics will not determine your future well being. The most important thing is to make right nutritional choices based upon your gene make up, goals & lifestyle.