On this page, you’ll discover what nutrigenetics and nutrigenomics are—the two sister sciences at the core of Holifya. You’ll also learn about genetic polymorphisms and how your DNA influences nutrition, metabolism, and athletic performance.

Nutrigenetics is the science that studies small genetic variations (polymorphisms, with “SNPs” being the most common) found within individual genes and the regions between genes. It explores the relationship between these variations and nutrients.

Our genetic makeup can affect how we respond to nutrients in terms of health. In fact, the way our body reacts to certain nutrients can vary greatly from one person to another.

These polymorphisms are what cause individual differences in response to specific nutrients (e.g., varying sensitivity to refined versus whole carbohydrates, fat absorption, and breakdown).

Nutrigenomics goes a step further by exploring the interaction between nutrients and the human genome, investigating how nutrients can influence DNA and modify gene expression. This means they can silence or activate the transcription of certain genes.

Can an optimal diet help correct a specific gene transcription profile? The answer is yes, and this is what we refer to as “molecular nutrition.” Through food, we consume molecules that can stimulate or silence certain genes, leading to either positive “homeostatic” effects or potential “dysregulation” that can impact our health.

The human DNA is 99.9% identical! Only 0.1% differs due to specific genetic variations, known as polymorphisms, with SNPs (Single-Nucleotide Polymorphisms) being the most common.

These genetic variations are what make each individual unique! On average, each person carries around 4 million SNPs.

Most of these variations have no effect (or their effects are not yet known) and are considered “neutral.” However, some can provide valuable insights, helping us tailor our lifestyle to better suit our individual needs.

Genome-wide association epidemiological studies (GWAS) have identified an association between certain gene variations and some metabolic characteristics. For example, a greater:

• Sensitivity to refined carbohydrates
• Sensitivity to fat absorption
• Difficulty burning fat
• Sensitivity or intolerance to specific substances (e.g., lactose, caffeine, alcohol)

Similarly, there are associations between gene variations and some characteristics of the musculoskeletal system and athletic performance. For example:

• Predisposition to power or endurance sports
• Tendency to joint laxity
• Tendency to muscle injury
• Susceptibility to muscle cramps
• Susceptibility to tendon weakness

The same epidemiological studies have identified an association between some point gene variations and certain common complex diseases such as chronic degenerative diseases related to ageing , for example:

• Insulin resistance, diabetes and metabolic syndrome
• Overweight and obesity
• Cardiovascular diseases, hypertension, osteoporosis, hypercholesterolemia, hypertriglyceridemia, etc.

Assessing the predisposition for a less effective (or more effective) endogenous antioxidant barrier, as well as susceptibility to producing more pro-inflammatory molecules or fewer anti-inflammatory ones, is crucial in the field of preventive medicine. This is particularly important when considering that oxidative stress and inflammation are key contributors to aging and chronic degenerative diseases associated with it.

What does genetic predisposition mean? Why is it important to consider it together with exogenous factors, such as lifestyle?

It should be noted that, while in the case of traditional monogenic diseases, which are rare (e.g., cystic fibrosis, hemophilia, sickle cell anemia, etc.), the gene variant is always associated with the disease, most of the SNPs that we analyze with nutrigenetic tests are associated with a higher (or even lower) risk of onset than the general population of specific metabolic, athletic, and disease characteristics.

The median odds ratio for a SNP is 1.33 and in some cases reaches 3. This means that on average the presence of a SNP genetic variation implies, compared to the general population, an increase in the risk of onset of 30% and only in some SNP variants the risk is even greater than 3 times.

This is why we speak of predisposition and susceptibility , since association studies have shown that particular genetic variations are significantly more frequent in subjects with specific metabolic, musculoskeletal and athletic characteristics, or with particular chronic-degenerative diseases, but they are only highlighted as risk factors and not as diagnostic indices. This variability is what we commonly define as "constitution".

In the case of some polymorphisms, such as those relating to the genes that encode the production of the digestive enzymes of lactose and fructose , genetic tests are diagnostic as they identify primary intolerance to lactose and fructose. Similarly, mutations of the MTHFR gene , due to the reduction of activity of the analogous enzyme, may lead to an increase in homocysteine ​​(cardiovascular risk) and folic acid deficiency in the blood.

Chronic degenerative diseases associated with aging are both polygenic and multifactorial. The polygenic nature of these diseases requires the simultaneous presence of multiple common genetic variants, each contributing a small risk to the disease. For instance, the presence of a single SNP (Single Nucleotide Polymorphism) variation might increase the risk of onset by 30% compared to the general population, and these variants often act synergistically.

The multifactorial nature means that for the disease to manifest, a specific interaction is needed between an individual’s genotype and external environmental factors such as diet, lifestyle, stress, pollution, and ionising radiation. These external factors account for about 60-80% of the onset of such diseases.

By combining genetic profiling with routine blood and urine tests, we can cross-reference genetic predispositions with actual functional health data. This approach helps assess how environmental factors may have “unmasked” genetic risks, offering insights into how to safeguard your health with personalised nutritional plans and supplementation if needed.