Our research explores the ways in which nutrition at each point in the lifespan affects long-term health and response to disease.
Across the lifespan food is a major determinant of health. Liggins scientists were among the first in the world to identify associations between a lack of appropriate nutrition during the early stages of life and developmental changes leading to chronic adult conditions such as obesity and diabetes, learning and behavioural disorders and effects on subsequent generations.
The quality of nutrition throughout life is an important aspect of maintaining health and reducing disease later in life. Our research focuses on identifying the factors that link good nutrition to long-lasting health.
Human nutrition
Food contains a complex array of chemicals that directly affect genes, cell signalling and metabolic pathways within our bodies. We identify the key genetic and cellular mechanisms that link good nutrition to long-lasting health.
We’re particularly interested in:
- Food structures and impact on digestion and metabolism
- Differences in digestion, metabolism, and nutrient use and requirements in elderly people
- Understanding food intolerance and manipulation of foods or food structures that can change short or long term tolerance to foods
- How dietary interventions can change the microbiome
- How we can use metabolites as biomarkers of dietary intake, to better understand nutrient bioavailability and metabolism
- Understanding dairy intolerance, and how this differs from lactose intolerance
Current research
Food intolerance
Our food intolerance research focuses primarily on dairy. Many people referred for intolerance testing are not diagnosed as lactose malabsorbers, despite self-reported digestive symptoms following dairy consumption. This is probably because the characteristics of non-lactose dairy intolerance have not previously been studied. We’re attempting to characterise dairy intolerant digestive responses in order to identify the spectrum of phenotypes that exist, and find better ways to diagnose and manage intolerances, through a number of clinical trials.
Dynamic responses to meals
With each meal, nutrients enter the body and activate the genetic and molecular responses required for nutrient storage, metabolism and immunity. We are building comprehensive profiles of the signalling and responses that occur in circulating immune cells, adipose tissue and muscle.
Currently we are investigating the dynamic post-meal gene, inflammation and metabolomic responses to fats (including dairy, soy and palm) and proteins (including dairy, soy and red meat). The response can be affected by a person’s specific health status, for example gut health (tolerance to foods), healthy people versus those at risk of chronic disease, and the elderly. We even consider how food structure (e.g. cheese versus milk) affects digestion and metabolism.
Nutritional strategies in ageing
Human ageing is associated with the loss of muscle mass and insulin resistance. Reduced muscle mass may lead to falls, fractures and loss of independence. Increased insulin resistance is implicated in the accelerated loss of muscle mass and is a key step in the development of diabetes. Our studies explore the interplay between gene expression, epigenetic regulation and stem cell renewal in human muscle.
We’re particularly interested in the bioavailability of nutrients, and the effects these have on metabolism. Recently we’ve looked at micronutrient metabolism in older people, which might provide insights into changes in nutritional requirements as we age.
We also look at the longer-term impact of diet on overall health – in older people and those at increased disease risk – to see how changes in the composition of the diet (for example protein intake) affects their metabolism, functional status, microbiome and quality of life. An aspect of this research is identifying better ways to assess health and nutritional status, and developing a screening tool to facilitate early detection of micronutrient insufficiency in New Zealand’s elderly population.
Molecular nutrition and non-communicable disease (NCD) prevention
Nutrients control the programming and expression of many thousands of genes. Some of our research investigates the mechanisms through which nutrients control genes, particularly in adipose tissue and muscle. We examine the molecular actions of bioactive lipids, including omega-3 fatty acids and phospholipids, on tissue growth, inflammation and insulin sensitivity.
This research helps develop our understanding of the metabolic changes that occur in ageing which necessitate age-specific nutritional strategies. Building knowledge about how food type and form influences vitamin availability in older people provides insight into food-based strategies that can be used to improve vitamin adequacy in the ageing population.
Long-term, these mechanisms could be manipulated for the development of interventions using bio-available micronutrients to restore pathway deficits, either in the form of supplements or tailored food interventions. Given the prevalence of micronutrient deficiencies in the ageing population, these intervention strategies, applied through clinical practice or food development, have the potential to improve micronutrient adequacy and support successful ageing for older New Zealanders.
Investigators
Professor Richard Mithen
Dr Amber Milan
Dr Chris Pook