Nutrigenomics – introduction
Different people respond differently to different foods. This is partly because we all have different genes, and our genes can affect the way our bodies deal with food. Because of this, particular food components will be more helpful to some people than to others.
Microarray results
Microarray technology has changed the way scientists can investigate and compare gene expression in different cells.
Food has different effects on different people
Our bodies need to be able to absorb the right amount of different food components, store them in the right places, and use them at the right time. All of this is controlled by our genes.
A person's genes therefore affect what happens to the food that is eaten. As a result, two different people can eat the same food, but it has different effects on them. For example, two people can eat the same amount of fatty food, and one will put on weight a lot faster than the other.
Nutrigenomics: what is it?
Nutrigenomics is the study of how our food and our genes interact. The main aim is to use information about genes to work out the effects that foods can have on an individual’s health, performance and risk of disease.
The researchers
Nutrigenomics New Zealand assembled a group of researchers from Plant & Food Research, AgResearch and the University of Auckland. These organisations formed a highly effective research group. Each organisation brought specialist expertise that was needed in order to reach a common goal.
Vegetables
Eating a varied diet that includes vegetables is part of keeping healthy.
Nutrigenomics New Zealand was set up in order to research specific questions around food and disease. The research project ran for 10 years and formally finished on 30 September 2014.
The New Zealand researchers started the project by focusing on people who have, or who might develop, inflammatory bowel disease.
Inflammatory bowel disease (IBD)
Inflammatory bowel disease (IBD) includes diseases such as Crohn's disease and ulcerative colitis. It affects the digestive system, causing inflammation and swelling of parts of the digestive tract. Symptoms of the disease may include abdominal pain, diarrhoea, vomiting, nausea, constipation, bleeding and lack of appetite. Visit Crohn’s and Colitis New Zealand to get more information.
Susceptibility to IBD
Inflammatory bowel disease (IBD) is often found in more than one person from the same family. This suggests that there might be a genetic link to getting the disease.
In fact, recent research has shown that people who have IBD often have one or more gene variants. These slight variations in the genetic code seem to increase the risk that someone will develop IBD. The onset of the disease also seems to be affected by the foods that are eaten and other environmental factors.
Unfortunately it is not easy to identify foods that should be avoided. There is no ‘best diet’ – different people find that different foods relieve the symptoms or make them worse. This is because each person has different genes, and their genes affect the way that their body responds to the food.
The research
The key objectives (aims) of the nutrigenomics research team were to:
identify gene variants linked with IBS
work out the best (and worst) foods for individual patients, based on their genetic profiles
identify eating patterns that might help to reduce the risk that family members who have affected genes will also get the disease.
Understanding interactions between diet and genes will help us to better manage complex diseases like diabetes and heart disease. Knowledge about gene-diet interactions could also be used to help optimise an individual's physical and mental performance and even slow the effects of ageing.
Collecting patient information
The first task was to find out as much as possible about people with IBD. To do this, the research team worked with large groups of volunteers who agreed to participate in the study.
Nutrigenomics: The research team
The nutrigenomics research is being carried out by researchers from the University of Auckland and government-funded research institutes (Crown Research Institutes, or CRIs): Plant & Food Research (formed by the merger of Crop & Food and HortResearch at the end of 2008) and AgResearch.
This is because the success of the nutrigenomics project depends on the input of people with a range of different skills and expertise, including nutrition, disease, genetics, food chemistry, biochemistry, statistics and ethics.
Just under 600 participants with IBD and a similar number of control subjects from Auckland took part in the research. The researchers collected details about each person's physical characteristics, disease history, diet, lifestyle and family history of the disease.
Nutrigenomics New Zealand also actively collaborated with international researchers, which enabled them joint access to data from 18 405 individuals with Crohn’s disease, 14,308 individuals with ulcerative colitis and 34,241 control subjects.
Find out more in the article, Studying genetic disease: Finding out about the person.
A second part of the research was to find out about gene variants that may be linked to the disease.
Find out more in the article, Studying genetic disease: Finding out about the genes.
Researchers then had to study the data they’d collated to try to find patterns between people's genetic combinations and their dietary preferences. For example, patients with a particular genetic combination might all report that a particular food makes their disease symptoms worse. The results of this work then led into further research about specific foods for specific people.
Testing foods in the laboratory
Foods are very complex substances and contain thousands of different molecules. Each food might contain molecules that are helpful and molecules that are less helpful. Because of this, the foods must first be separated into components.
Try this activity with your older students, Extraction and analysis of fruit components.
The effects of the separated food components are tested in a laboratory. One of the ways that researchers can do this is using laboratory models like cell lines.
The outcome
The Nutrigenomics New Zealand team not only met their objectives but exceeded expectations. These are some of the important conclusions from this research:
163 gene variants were identified as being associated with an increased risk of IBS. At the beginning of the programme in 2004, only one gene variant (NOD2) was internationally agreed to be involved, and it was anticipated that somewhere between four and eight variants were likely to be important.
They identified foods that have adverse effects on specific genotypes and also identified foods and nutrients that are likely to be especially beneficial to certain individuals. These foods were different from the types of foods they had initially envisaged.
The genetic studies emphasised that the gut microbiota plays a very important role, especially in some individuals with this disease.
It is clear that, for certain individuals, specific foods under specific conditions may trigger an inflammatory response that will trigger disease development and/or progression.
In seeking to better understand the interactions between diet and genes and how this might enable better management of disease, Nutrigenomics New Zealand was able to clarify that part of the confusion has been in not recognising the complexity of genetic susceptibility. The work has been pivotal in providing proof of principle for the important field of nutrigenetics (genetic susceptibility to dietary requirements) and also nutrigenomics.
The future
I genuinely feel that this has been a landmark project, with three very different organisations providing complementary skills in a well aligned project design. The research has provided a landmark in new study directions, and it will be important to foster the optimal outcomes from these new technologies and achievements.
Professor Lynnette Ferguson
The work of Nutrigenomics New Zealand will have important implications for innovative food companies with an interest in digestive health. For example, the genetic studies have emphasised that gut microbiota plays a very important role, especially in some individuals with IBS. While a faecal transplant is being used to benefit in some clinics in order to reduce disease symptoms, such an approach is not especially appealing to many individuals. Thus, foods with prebiotic potential and/or probiotics may provide an attractive option for many individuals.
Several members of Nutrigenomics New Zealand are now actively working at linking with the food industry.
Find out more
To find out more, Year 10 students from six secondary schools participated in a video conference with New Zealander Lynn Ferguson and North American Jim Kaput.
