YSN-ASM Science Café | Eat, Therefore I Am: an Insight into Personalised Nutrition

This session of Science Café KL featured YSN-ASM member Associate Professor Dr Razinah Sharif. Dr Razinah is a lecturer at Universiti Kebangsaan Malaysia (UKM) and Director of the Biocompatibility Laboratory at UKM. She is also a researcher the Centre for Healthy Ageing and Wellness, Faculty of Health Sciences (H-Care) UKM.

Have You Ever Wonder Why You Cannot Gain Weight? Have You Ever Wondered Why You Can Gain Weight Easily? Can Knowing More About Your Genes Help You to Eat Move and Live Better? In this Science Café session, Dr Razinah shares how nutrition affects your DNA and how your genes respond to what you eat.

The main causes of obesity are the environment you are in, your genes, or your lifestyle. However, for most of us, it is not just attributed to one or the other – Dr Razinah stated that it may be caused by all of the above.

There is not one gene that is responsible for obesity, making determining the cause of obesity more complicated. A selected expression of genes may cause one to have extreme obesity, while another may cause someone to have an issue with body fat or a less-than-ideal waist-to-hip ratio.

Dr Razinah proceeded to elaborate on the FTO gene, the most important gene that normally covers every cause of obesity. It is responsible for mitochondrial thermogenesis, your energy expensditure. If the FTO gene is functioning well, it encourages the body to expend energy properly. The gene is also involved in adipogenesis, helping to produce fat cells. The gene also helps in the browning of fat tissues; having more brown fat cells as opposed to white fat cells, as well as regulating your food intake.

It is important to have the FTO gene functioning well. Having said that, Dr Razinah stresses on the importance of a healthy lifestyle with a balanced diet and adequate exercise as it is incorrect to blame obesity solely on the genes.

Do We Need to Test our DNA to Identify the Right Diet and Exercise?

Dr Razinah continued her talk with using a case study that is related to the topic. The first one is about caffiene’s effects in relation to genetics. She explained that genetic variations may determine how fast caffeine is metabolised. How fast someone metabolises caffeine may have an effect on their athletic performance.

Continuing her talk, Dr Razinah explained what happens when caffeine enters the body. Once consumed, caffeine is rapidly absorbed and broken down into compounds that have various effects on different organs. One of the organs that is majorly affected by caffeine is the brain.

Caffeine directly influences the brain by blocking the effects of adenosine, a compound that relaxes the brain and makes someone tired. To the body’s nerve cells, adenosine and caffeine are identical; therefore, this allows caffeine molecules to bind to the adenosine receptors, preventing adenosine’s ability to make someone drowsy.

However, the effects of caffeine are not permanent. Over time, the body eliminates unabsorbed caffeine via the liver and exits your body through urine, which explains the pungent coffee scent.

According to Dr Razinah, the CYP1A2 gene is responsible for making the enzyme necessary to metabolise caffeine. Variations of this gene may make someone become a fast or slow metaboliser of caffeine. Those who are slow metabolisers of caffeine may have the compound longer in their bodies. This may cause headaches, jitters or anxiety. A higher risk of high blood pressure may also be present. Slow metabolisers may put their heart health at risk by consuming too much caffeine as caffeine’s prolonged presence in the body makes the heart work harder.

Single Nucleotide Polymorphisms (SNPs)

SNPs, (pronounced “snips”) is a DNA sequence variation occurring when a single nucleotide adenine (A), thymine (T), cytosine (C), or guanine (G]) in the genome (or other shared sequence) differs between members of a species or paired chromosomes in an individual. This variation affects how enzymes work in your body – the expressions of genes will influence various mechanisms in the body. This includes the caffeine metabolism mentioned just now – the speed at which caffeine is metabolised is affected by SNP.

Understanding SNPs can help us understanding the relationship between genetics and nutrition. This is where nutrigenomics come in. Nutrigenomics is the study of the effects of food and food constituents on gene expression, and how genetic variations affect the nutritional environment. It focuses on understanding the interaction between nutrients and other dietary bio-actives with the genome at the molecular level, to understand how specific nutrients or dietary regimes may affect human health.

Dr Razinah informed viewers on the focus of her research at the Masters, PhD and also what she is currently doing: DNA damage. She likens DNA to a house; when there is damage to the structure of the house, we will call someone to repair the damage. Similarly, DNA can be damaged by various causes, we will need DNA repair mechanisms to take place. DNA damage can be caused by various factors, such as our own metabolism, pollution and from the environment. More recently, it has been found that stress, lifestyle choices and nutrition may also cause DNA damage. In turn, DNA damage is often associated with chronic diseases, such as obesity, cancer, diabetes, heart disease and hypertension.

Next, Dr Razinah explains what happens when DNA is damaged. Ideally, a proper DNA repair mechanism will take place, resulting is cells being viable again. A misrepair may also happen, causing a mutation. When no repair mechanism takes place, it will result in cell death.

Dr Razinah went on to explain her study which began in 2008 on evaluating the toxicology of some Malaysian processed food products, working in conjunction with MAKNA. Her study focused on preserved food such as dried anchovies, salted fish and belacan (fermented prawn paste). A common cause of the harmful effects of preserved food is the high sodium content, as well as the nitrosamine produced as a result of the preservation process. That said, Dr Razinah said that these local delicacies are not to blame for all the DNA damage that happens to the body; it is the dose makes the poison and taking these food in moderation is key to minimising the damage.

Next, she elaborated on the effects of Zinc on DNA damage, which was her PhD research. Her research illustrated the U-shaped Dose-Response Curve, which shows the zone of homeostasis (balance) where intake of Zinc is optimal, preventing deficiency of said micronutrient while at the same time reducing risk of toxicity. This is where Dr Razinah cautions against taking supplements unnecessarily, instead relying on food sources to obtain nutrients.

Another one of Dr Razinah’s research that she highlighted was on the effect of intermittent fasting on the cognitive function of older adults with mild cognitive impairment. The study found that intermittent fasting reduced DNA damage related to mild cognitive impairment. Additionally, the study also identified possible pathways related to formation of ketone bodies and activation of endogenous antioxidants.

Based on the above researches carried out by Dr Razinah and her team of capable scientists, it shows that DNA damage and lifestyle, particularly dietary choices, have a direct link. A service called MyGenomSihat is provided at the Centre for Healthy Ageing and Wellness at which Dr Razinah is based. The service is a personalised counselling based on one’s stress levels, nutriome (combination of micronutrients and their doses) analysis, genome health, dietary analysis as well as anthropometry (the scientific study of the measurements and proportions of the human body) status. After a six-week intervention, MyGenomSihat consistently showed a significant reduction of DNA damage among users of the service.

The Future of Personalised Nutrition

There are not many companies in Malaysia that offers personalised nutrition, despite it being a rapidly growing segment of the health and wellness market. The current focus of personalised nutrition is on the microbiome. There are a myriad of bacteria, fungi and viruses in our body and the composition is unique to each of us. Knowledge of individualised microbiomes is essential to pinpoint what diseases a person is susceptible to as well as the functions of these bacteria, fungi and viruses to elevate levels of the good ones and reduce the bad ones.

Dr Razinah explained that the Western world has better access to personalised nutrition thanks to the higher availability of the services there. They have access to apps that are able to monitor their diet based on genetic testing as well as the right exercises that are tailored to the person. In fact, genetic testing, it can be identified whether someone responds better to cardio workouts or weightligting to maintain their health.

There are several components that make up personalised nutrition, such as:

• Nutrigenetics
• Nutrigenomics
• Industrial products
• Genome-wide association studies (GWAS)
• Omics technology
• Development of biomarkers
• Gene-diet interactions

SNPs and the concept of DNA damage is a big part of personalised nutrition. Dr Razinah encourages everyone to do a genetic test.

Before closing the session, Dr Razinah also mentioned the role of functional foods in reducing DNA damage. The functional food used in her research was honey sourced from stingless bees (madu kelulut). Her research found that madu kelulut is able to reduce inflammation in the body and reduce DNA damage.

Q&A Session

After her presentation, Dr Razinah also addressed some questions from viewers.

Any studies on the effects of caffeine on DNA damage?
Dr Razinah explained that while she did not conduct studies on it, there are other studies that have linked caffeine to DNA damage, especially in higher doses. She recommends a maximum of two cups of coffee a day, while taking into account the type of coffee consumed (instant, freshly ground, kopi kampung, etc). Dr Razinah also mentioned that most of these studies are carried out by in the West using the Western population, and not much on the Asian population.

Isn’t fermented foods good for the digestive system?
What makes fermented foods healthy for the digestive system is the presence of probiotics that helps digestion and maintain the gut microbiome. However, nitrosamines and certain carcinogens are also by-products of fermentation. Dr Razinah once again reiterates the saying “the dose is what makes the poison”

How could we know if the supplement that we are taking is optimal or is too much?
Dr Razinah recommends taking a blood test to properly identify whether someone is deficient in certain nutrients. That said, Dr Razinah said that fruits and vegetables (notably local fruits such as jambu batu) are adequate enough to meet vitamins and mineral deficiencies.

Can a vegetarian get DNA damage from consuming vegetarian chicken or fish in the long-term?
Dr Razinah recounted her study, where she observed that those who are most prone to being zinc-deficient are vegetarians, due to the lack of meat in their diet. Also, a compound called phytic acid present in vegetables blocks the absorption of minerals such as zinc and iron. However, being a vegetarian does not necessarily put someone at high risk of DNA damage; this can be prevented by maintaining a well-balanced diet to ensure all vitamins and minerals are sufficient.

Do you recommend intermittent fasting aside from the puasa sunat?
Yes, she does – Dr Razinah prefaced her answer with a brief introduction to intermittent fasting, dividing it into “dry” and “wet” fasters. Dry fasting is done when someone omits food and drink for the time chosen; wet fasting is when someone just omits food but drinks water during their duration of the fast.

Dr Razinah explained that the most common intermittent fasting practice is the 16-8 method, where one fasts for 16 hours and having a “window” of eight hours to consume their caloric intake for the day. The reason of the fasting period is to ensure that the body utilises its glycogen storage and resort to getting energy from its own fat cells. Some benefits from intermittent fasting include weight loss, reducing insulin resistance, reducing inflammation, maintaining heart health, and of course, reducing cellular damage.

I take supplements because I am concerned about the pesticides used in growing fruits and vegetables.
Dr Razinah echoed the concern expressed through this statement, but she said that it is not really a cause for concern as there are regulations for responsible usage of pesticides to minimise exposure to consumers. That said, Dr Razinah also said that a healthy liver would also help to metabolise any pesticide residues and remove them from the body.

Does taking zinc supplements improve our health?
Dr Razinah said that taking zinc supplements will improve someone’s health if they are deficient in it.

Will our diet cause DNA damage in the long run? Is there any way of reversing this DNA damage?