Eat Well with Amanda Kuit

Amanda Kuit talks nutrigenomics – the next generation food-medicine for better health. This insight creates opportunities to prevent disease and improve quality of life through food and tailored diets.

Food can be intrinsically linked to memories: love, happiness or sadness, but ultimately food is our fuel. While food can be a friend; it can also be an enemy.

Eating the ‘right’ food is vital for maintaining long-lasting health. Part of this includes not eating specific food that aggravates an allergy. But, what is the ‘right’ food? Should you eat huge amounts of fat or should you only eat spinach? Humans, in comparison to all other living creatures on earth, are the most confused species with regards to what they should eat.

The ‘right’ food depends a lot on who you are; the secret behind this comes down to genes. Each of us has a unique body code (genes) and, indeed, research has shown that food affects gene expression – the process through which the deoxyribonucleic acid (DNA) making up our genes is converted to ribonucleic acid (RNA), resulting in production of proteins.

The various proteins, formed at discrete points in this process, function as enzymes, hormones, and other substances on which life depends. Therefore, this interaction with food is of considerable significance.

The amount, form, and, even, the frequency of food consumed can affect protein manufacturing, resulting in less protein being produced; less optimal functional forms of proteins; or no protein at all. Depending on individual genetic variations and age, these effects may result in varying individual responses to diet and drugs.

Discoveries in genetics and other new fields of study (e.g. genomics, nutrigenomics, proteomics, metabolomics, and bioinformatics) make it possible to understand the varying individual effects of dietary nutrients in processes of our bodies at the molecular level. This insight creates opportunities to prevent disease and improve quality of life through food and tailored diets.

Let’s start with nutrigenomics: this combines the study of nutrition and genetics to discover the different ways people respond to food, based on their genetic makeup. While humans are very similar genetically, we all have slight differences in our genetic blueprints which set us apart from other people. These tiny variations determine the effect nutrients have on our bodies and how we metabolise the food we eat.

Personalised nutrition hinges on this two-way relationship between nutrients and genes. On one hand, the nutrients we consume can affect the way our genes are expressed; on the other hand, our genes are able to influence how our bodies respond to these nutrients.

The goal, for nutrigenomic scientists, is to unravel this complex interaction so that tailored diets can be developed which complement a person’s unique genetic profile. Not only will this optimise the health of the individual, but it may also work on a larger scale to help prevent society-wide diseases, such as obesity, Type 2 diabetes, cardiovascular disease, cancer and malnutrition.

Let’s use specific foods, as an example, to explain nutrigenomics based on recent studies: 

  1. Olive oil is the main source of fat in the Mediterranean diet. Positive effects have been observed on genes. Gene regulation, due to the functional components of olive oil, such as oleic acid, biophenols and vitamin E, point to a role that these molecules can prevent early aging. (BioFactors, 43(1):17–41, 2017).
  2. Olives and their constituents with antioxidant, anti-inflammatory and anti-tumour properties create optimism towards the novel therapeutic strategy. In this review, olives and their constituents have medicinal value, and are summarised in terms of therapeutic approach in the disease management via antioxidant, antimicrobial, anti-tumour and modulate the various genes normal mechanism of action. (Int J Clin Exp Med. 2014; 7(4): 799–808.)
  3. Folate is a great example of how the food we eat can affect our genes; it is produced from folic acid – an essential form of vitamin B found in nuts and green vegetables, such as broccoli and Brussels sprouts. It is needed by the body to make DNA, and deficiency in   this nutrient has been connected to a higher risk of developing cancer (low folate levels lead to changes in the DNA strands, which make them more susceptible to breaking).
  4. As folate is vital for DNA synthesis, it also plays an important role during foetal development when cell division and growth are at their peak. Specifically, folate ensures that the spinal cord of the baby develops properly. It is so crucial to this process that women are strongly advised to take folic acid supplements before and during pregnancy.

Nutrigenomics also shows us how our genes can determine our response to certain foods. A great example of this is lactose intolerance. People who are lactose intolerant are unable to digest the natural sugars present in milk and other fresh dairy products.

This is because the gene responsible for making the necessary enzyme (lactase) is ‘switched off’, leaving their bodies unable to produce it. As a result, these people react badly to consuming dairy products, suffering from side effects, such as abdominal pain, bloating, diarrhoea and nausea.

It is in your power to change your genetic destiny in many ways and food can be one of those tools that could either be a potential trigger for disease or it could modify gene expression. The nutrients we consume can change a gene’s performance by acting on its control region…on or off!

Before you start eating olives and broccoli, try to exclude/change the following triggers that influence your genes far worst than food can fix it:

  • Stop smoking – you don’t know if you have the protective genes that will allow you to live a long and healthy life, despite smoking. 
  • Don’t be overweight – obesity will influence genetic expression in a disease promoting pathway. According to the World Health Organisation, more than 60% of the global disease burden will be attributed to chronic disorders associated with obesity by 2020. Meanwhile in the US, the prevalence of obesity has doubled in adults and tripled in children during the past three decades. Studies show that two obese parents’ genetic profiles can impact on embryo and foetal development.
  • Don’t sit longer than 30 minutes – this, in our modern world, is very difficult but is something that we all need to try and achieve. The current human genome was moulded and refined through generations of time. The basic framework for physiologic gene regulation was selected during an era of obligatory physical activity, as the survival of our Late Palaeolithic (50 000-10 000 BC) ancestors depended on hunting and gathering. A sedentary lifestyle, in such an environment, probably meant elimination of that individual organism. The present day human genome is different; primarily as a consequence of expressing evolutionarily in an environment that is predominantly sedentary. In this sense, our current genome is maladapted, resulting in abnormal gene expression, which in turn frequently manifests itself as clinically diseases. Some of these genes still play a role in survival by causing premature death from chronic diseases produced by physical inactivity (J Physiol. 2002 Sep1;543(Pt 2): 399–411).
  • Sleep at least six to eight hours per night – without waking up. Sleep has a distinct physiological function that will influence your circadian clock genes. Like olives, sleep can help turn genes on or off. 

Most of us have a mixture of genes that make us susceptible to disease, and we have genes that protect us from harm. By knowing where you stand on this genetic spectrum, you can adjust your lifestyle choices accordingly. Genes determine our vulnerability but it is our lifestyle that determines to what extent these vulnerabilities will affect health and longevity.

Nutrigenomics is about knowledge: first you need to understand your own lifestyle, disease profile, family history and biochemical results. Then you can start applying nutrigenomics after genetic testing. Genetic testing on its own will not guarantee health or longevity; given the present state of our knowledge, it is still too early, in most cases, to state specific foods with precision.

What is obvious is that lifestyle changes, especially food, is not a one-size-fits-all approach. There are, however, nutrients that stimulate higher levels of protein synthesis which we all can use. To the right is a colour chart and above are vegetable drinks to help you incorporate them in your diet each day of the week.


MEET OUR EXPERT - Dr Amanda Kuit

Amanda Kuit is a registered dietitian. She started her practice in 1994, and developed unique diets while working with oncology patients. She has a special interest in biochemistry. All her diets and advice are based on new methodologies including nutrigenomic, metabolomics, and biotransformation.