The emerging field of nutrigenomics

Nutrigenomics is a relatively new field of research in which genetics and nutrition come together. These merging disciplines (nutrition and genetics), optimise the efficacy of diets and how dietary consumption affects gene expression. This essentially helps to improve health, mitigating disease and illness risk and attempting to scientifically predict how certain genotypes will respond to certain diets. The science behind such tests is indeed complex as it requires understanding the body’s response to certain foods and eating regimes on the level of an individual’s genes.

Diet and health are intrinsically related and nutrigenomics sets out to make this a fundamental notion; one that will hopefully become widespread and a part of personalised health management.

Nutrigenomics goes beyond traditional ‘one-type-suits-all’ diets and the many generalised assumptions. This scientific discipline seeks to tailor any eating regime to the individual in question. It is based on the scientifically established premise that each person’s genes make him or her unique. Nutrigenomics has explained the different responses to dieting as well as the variations in results between people on the same dietary plan/eating regime. Intake of the same nutrient in different individuals will produce different effects as the concentrations, rates of absorption, metabolism and the rate at which the nutrient in question is broken down, used or excreted will vary.

Nutrigenomics, which includes diet DNA testing, seeks to create a diet that is closely tailored to the needs of that individual; a healthy eating plan to which they are more likely to respond positively. Nutrigenomics will aid to distinguish those people who will react positively on one type of diet and those who will achieve poor results or no results.

The dieting challenge

Have you ever wondered why people on the same diet achieve such different results? When undertaking a study that is to have reliability and validity, scientists grouped participants into groups; age, gender and any pre-existing medical conditions were taken into consideration and people grouped according to certain criteria and demographics.

When the first studies were carried out, spurred by these different results achieved between people on the same diet, scientists could only turn their glance towards genetics as the most likely culprit. They have, in fact, proved that our genes play a vital role in how much weight we lose or even whether we lose any weight in the first place.

Some examples

One of the main areas of many studies within the field of nutrigenomics is cancer. The shift is now towards this potentially lucrative market (if ever a cure is discovered). Pharmaceutical companies have, for example, been focusing far less on other more costly and less lucrative drug development projects - most research for new antibiotics has come to a standstill as the mutation rate of bacteria vis-à-vis the 10-year patent pharmaceutical companies have on new drugs developed have made this area unprofitable in light of other treatments for other diseases.

Red meat and cancer

One of the highly contended foods is red meat - just how healthy or unhealthy is this food and how does it antagonise our genes?  The American Institute for Cancer Research (AICR) has linked cancer of the colon and rectum to red meat consumption, showing that consumption is directly proportional to risk; people who consume 100 grams of unprocessed meat per day had an elevated risk of 15-20% of developing these types of cancer. Processed meats posed even higher risks with just 50 grams of processed meat resulting in the same risk factor as unprocessed meats. But it is not only the meat itself that may affect our chances of developing cancer, it is also the way it is cooked. Meats cooked for longer periods of time and above 148°C are known to have higher levels of cancer-causing heterocyclic amines and mutagenic polycyclic aromatic hydrocarbons (mutagenic simply refers to chemicals that are able to cause mutations in our DNA).

Certain fruits like tomatoes have been shown to reduce the risk of cancer; they contain lycopene in abundance, the antioxidant phytochemical that helps also prevent heart disease. They have also found that apples contain a chemical that can fight Crohn’s disease, a disease which targets the digestive lining causing anything from diarrhoea to malnutrition. Variations in absorption or excretion of phytochemicals influence the extent to which nutrients derived from plants impact the individual. Based on this genetic difference, people should consume specific fruits or vegetables depending on their genotype.

Other examples include alcohol - for years blamed by many as being a toxin, calorie ridden, harmful substance - a socially accepted evil. However, nutrigenomics has now found that alcohol, in moderation of course, can actually help lower chances of heart disease. People who consumed alcohol moderately were found to have higher levels of high density lipids or HDLs.

The future is promising. Further studies will further clarify and explain these complex interactions and augment response to dieting, improving health and wellbeing and reducing disease susceptibility.