Work Package Healthy Diets and Dietary Choice
Poor health in later life is putting an increasing strain on health and social care budgets and there is a need to ensure that physical and mental health is maintained as long as possible into old age. A growing body of evidence indicates that factors acting across life shape health risks for older people and that earlier, more vigorous and longitudinally-maintained management of risk factors is required. Strategies designed to promote healthy ageing need to take account of life-course changes particularly at the key biological and social transition points; from birth, adolescence, pregnancy, becoming a parent, menopause through to retirement. Many UK health policies designed to tackle the problem of inequality are aimed at improvement of the diet in poorer socio-economic groups but these have met with limited success because of an inadequate understanding of causality and the way in which deprivation becomes entrenched across the generations. There is a well-documented link between poor health and social status and this is even more pronounced in Scotland than in the rest of the UK. Within each social stratum there are also sub-populations that respond less well to the food consumed, are less able to maintain a healthy weight, and follow a poorer health trajectory across the life-course. Some of this variation is culturally driven but there is increasing evidence for a biological component which is innate but also modifiable. A better understanding of the health benefits of diet and nutrition would also benefit the food industry (producers, processors and retailers) in Scotland.
Aim of Research
The aim of this RD is to investigate the role of diet in determining health within and between generations and the complex interactions with social and economic status. It is designed to advance our understanding of the following key issues:
- Examine the effects of prenatal parental diet on lifelong physical and mental health of offspring, taking account of socioeconomic circumstances.
- Advance our understanding of the key dietary drivers of physical and mental health and weight maintenance across the life-course.
- Assess the impact of dietary variety and quality in women during pregnancy on infant food preferences at weaning
- Determine the importance of inter-individual variation in response to diet, weight maintenance and dietary choice
- Investigate routes to better dietary health at different life-stages through development of foods that meet nutritional needs and promote healthy ageing.
- Develop methodologies for monitoring dietary intake, dietary health, and general health and the effectiveness of intervention strategies.
All research delayed by COVID-19 was delivered between April 2021 and March 2022. The Womb to Wean study robustly established that inclusion of bitter vegetables in the maternal diet during late pregnancy increased infant exposure to these flavours in utero and subsequently led to a liking of bitter vegetable, namely spinach, at weaning. This proved to be the case for mothers who regularly included bitter vegetables in their diet naturally, and those who were habitually low consumers but were exposed to the predominantly bitter vegetable-based intervention for 24 days in late pregnancy. Presence of the bitter tasting genotype (TAS2R38) made no difference to the results. In addition, the maternal diet, along with other perinatal factors, may influence the development of the infant gut microbiota providing a further potential avenue for health improvement. All volunteers received a detailed lay summary of the overall study outcomes with respect to the taste tests at weaning, maternal and infant gut microbiota profiles, and predictors of the approach to complementary food introduction. They also received feedback on their individual maternal and infant genotype and microbiota profiles.
Elsewhere, work relevant to EU-exit was carried out in foods such as salmon and meat which are likely to be impacted by changes in trade associated with EU-exit and where it is important to establish provenance. Researchers completed an analysis of two different isotopes in multiple nutrients from different foods. Example isotopic signals indicative of food type and dietary history with the potential for development as tests of provenance were identified. Such signatures may also be useful in tracing the origin of nutrients and components within processed and highly processed foods.
Researchers have identified novel co-ordinated epigenetic signals in the human genome that have heritable characteristics. Such signals have the potential to explain apparently transgenerational effects on health and wellbeing.
A Theme researcher chaired the BBSRC Bioscience for and Integrated Understanding of Health Strategy Panel in 2021/22 and additionally contributed to BBSRC strategy development in relation to Sustainable Agriculture and Food and the Future of Bioscience and jointly chaired a combined meeting of the Sustainable Agriculture and Food Strategy and Bioscience for and Integrated Understanding of Health panels.
The research deliverable has been affected by COVID-19 related disruption over the past year but researchers have adapted and have made good progress overall.
COVID-19 mitigations have been put in place to preserve the primary aims of Womb to WEAN (weaning and acceptance of new tastes) intervention study designed to look at the effect of maternal diet on dietary choice in the offspring. Resource delivery and video calls instead of in-person visits allowed a further eleven women to carry out infant taste-tests giving the study sufficient power to convincingly establish proof-of-principle. Collection of buccal samples for bitter-taste receptor genotype analysis has resumed via an in-house designed kit and non-contact doorstep collection.
Work has been published in Scientific Reports, one of the Nature group journals, describing the use of cutting-edge molecular techniques to understand the basis for the transgenerational persistence of disadvantage that is increasingly seen in Scotland, the UK, and globally, and mechanisms by which processes set in train in early life can influence brain health in later life. Food Standards Scotland have been briefed on the results of this work. Work has also been published on the effect of a common maternal nutrient deficiency (iron) on offspring brain composition in model systems.
Researchers have analysed the relationship between healthy aging and metabolism and have identified factors linked to the decline in metabolic health with chronological age in a study of BMI, lipid profiles, blood glucose and insulin. We have identified interindividual variation and potential sex-specific predictors of metabolic health and healthy aging. Two papers have been published describing the findings.
We have further progressed the work on novel methods of monitoring dietary intake and dietary health in the population and tracking the provenance and authenticity of foods. We have completed work on the analysis of natural abundance variation in selected nutrients in plasma and their relationship to food intake. This work is designed to develop new methods to monitor population dietary health.
A Theme researcher chaired the BBSRC Bioscience for Integrated Understanding of Health; one of three panels that advise BBSRC on research strategy and funding priorities. Its remit includes research on food and health across the lifespan, healthy ageing, and combating infectious diseases of zoonotic origin.
A Theme researcher chaired the UKRI 2021 review of research across the full Agri-Food-Nutrition-Health spectrum designed to identify emerging challenges and opportunities.
A number of activities within this deliverable are focused on ways in which social and biological disadvantage originate in early life, how they may be transmitted across the generations, and how dietary and nutritional improvement can influence lifelong health and wellbeing.
Genomic predictors of human longevity have been identified and we have assessed the effect of diet and social circumstances on these. We have also determined the targeted way in which specific regions of the genome are influenced by diet while others close by are not. We have also elucidated novel genomic mechanisms for the transmission of disadvantage between the generations and have identified ways in which the early environment may influence brain development and behaviour through these pathways, and how these change with age.
The Womb to WEAN (weaning and acceptance of new tastes) intervention study is designed to look specifically at the effect of maternal diet on dietary choice in the offspring. Target recruitment for Womb to WEAN has been achieved and all volunteers complied with the dietary intervention during late pregnancy. A method for analysing study video footage has been validated and involves scoring the babies behaviours, facial expressions and rate of food-acceptance.
Studies of mechanism to explain some of the above phenomena are ongoing in model systems. Animals consuming diets resembling those of women in the poorest decile of the Scottish population resulted in changes to the fatty acid composition of the brain of their offspring.
Studies of dietary intervention and food improvement have also been carried out. Researchers have used zinc-enriched potatoes produced by the James Hutton Institute to evaluate the effect of these on human health. The human intervention study has been completed and an evaluation of the effect on biology is underway.
We have further progressed the work on novel methods of monitoring dietary intake and dietary health in the population and tracking the provenance and authenticity of foods. We have identified metabolic signatures specific to foods and their origin.
- A SEFARI researcher gave a presentation on malnutrition, childhood stunting, and how to prevent it, at the Houses of Parliament to the All-Party Parliamentary Group for Africa. The presentation set out novel approaches to the problem based on work carried out at the Rowett as part of this deliverable. These new approaches underpin work within the recently launched UKRI GCRF Action against Stunting Hub - a £19.76M investment by the UK government to alleviate child stunting, globally – in which the SEFARI researcher is the Deputy Lead. The event brought together parliamentarians, researchers and policy makers working on child undernutrition.
- A review on adolescent pregnancy was commissioned from a SEFARI researcher for a special issue of Journal of Endocrinology. The topic formed the basis of an invited talk at a conference in the USA, which brought together experts and researchers on nutritional needs before and during pregnancy, and considered how this impacts the lifelong health of mother and offspring. The aim of the meeting was to develop a consensus statement of recommendations to inform policy nationally and internationally.
Novel approaches to determining epigenetic integrity relevant to human health have been developed. Genomic regions of interest in relation to health and the interindividual response to diet with longer term health consequences have been identified and analysed in relation to the Scottish Index of Multiple Deprivation. Preliminary data from animal studies investigating diet and early epigenetic programming have identified potential mechanisms which may result in changes in the behavioural phenotype. Infant taste preferences develop early in life and may be influenced by exposure to flavours from the mother’s diet, which are experienced by the baby through her amniotic fluid and breast milk. The ‘Womb to WEAN’ study, which is exploring how foods eaten in pregnancy might affect the foods babies prefer during infancy, is now underway. The Zinc in Potatoes study which is looking to see whether biofortification can improve human health (‘health by stealth’) is almost complete. Elsewhere work is ongoing to identify determinants of inter-individual variation in glucose regulation and the links to health status.
A RD scientist is the deputy lead of a 5-year GCRF Hub grant led by the London International Development Centre (LIDC) and the London School of Hygiene & Tropical Medicine (LSHTM). The new £19.76m UKRI GCRF ‘Action against Stunting Hub’ (including >£1m to SEFARI research in epigenetics and microbiota) brings together an interdisciplinary team from 18 institutions to tackle the problem of stunting in children. It aims to reduce child stunting by up to 10% across communities in India, Indonesia and Senegal, and it will also support new regional platforms on maternal and child nutrition proposed by UNICEF, linking the work of the Food and Agriculture Organisation, The World Bank, and the World Health Organization at the country level.
RD research on the perinatal programming of food preferences was presented at a Maternal and Infant Nutrition Event hosted by the Scottish Government. The event, for stakeholders and practitioners from across Scottish Government, NHS Health Scotland and Food Standards Scotland, with an interest in early years, reflected on what works for both prevention and early intervention, to address childhood obesity at its earliest point. SEFARI research was discussed, as one of only two case studies presented, and highlights how an intervention study from the Theme aims to provide evidence and proof of concept to underly future public health advice.
Innovative food formats with a high fruit and vegetable content were evaluated for palatability in non-pregnant and then pregnant women: these foods form the basis of an intervention to assess whether maternal dietary variety in late pregnancy impacts food preference/acceptance at weaning. Transgenerational effects have been identified that have implications for dietary and lifestyle choices in parents and the persistence of disadvantage across the generations. A new mechanism for the inter-individual variation in the response to dietary fats has been identified and used to develop a novel approach to estimating the individual and population health risks associated with dietary fat intake. The human intervention trial ‘Zinc in Potatoes’ which compares the effect of normal and zinc-enriched potatoes on human zinc and health status continues. New methods developed in year 1 to measure a biomarker (a component of the sirtuin/nicotinamide adenine dinucleotide (NAD) system) which identifies early signs of poor health are now being used to investigate diet and lifestyle and how they regulate health status and biological aging.
A long-standing policy issue has been whether to fortify flour with folic acid to protect the foetus against neural tube defects during pregnancy. Researchers have completed modelling of folic acid fortification scenarios, which was presented to the UK Scientific Advisory Committee on Nutrition (SACN) in London (Mar-17). This work was done to inform ministerial choices, should Scotland decide to proceed with fortification.
Researchers re-evaluated projected obesity trends in Scotland in relation to socioeconomic status and long term health implications and presented this analysis at an invited Scottish Parliament Information Centre (SPICe)/Scotland's Futures Forum seminar (‘Fitter or Fatter). The seminar explored the policies that will make the biggest difference in tackling Scotland's obesity problem, and will help inform the Parliament’s scrutiny of the forthcoming Scottish Government obesity strategy
Studies have shown that our food preferences follow us from childhood through to adulthood, so it is important to form good habits from the beginning. Foods frequently rejected by children include those with the greatest importance for later health such as fruit and vegetables. A scoping exercise has determined the current preferences, attitudes and barriers to fruit and vegetable consumption in the Scottish population. Attitudes were generally positive however there was still a proportion of women surveyed who didn’t meet the 5-a-day recommendations 7 days per week with some never doing so.
New methodologies were developed for measuring the ‘epigenetic clock’ which has been proposed as a predictor of morbidity and early mortality. Work has now begun to investigate the role of diet in determining health between and within the generations and the complex interaction with social and economic status.
A diet typical of Scottish women from deprived areas in Scotland was developed for studies on effects and reversibility in model systems. Elsewhere, a human intervention trial looking at whether biofortification of potatoes with zinc can improve zinc status and health is underway. Finally, chronological age isn’t always a good predictor of metabolic health therefore new tests were developed to assay biomarkers which can identify early signs of poor health and act as a better proxy of long-term health.
Researchers briefed the Scottish Government Child and Maternal Health Division, summarising their work on epigenetics, obesity trends in pregnancy and how the research can inform policy in these areas
Research from 3.2.1 relevant to the current priorities of RESAS and Scottish Government will be taken forward in the new SRP 2022/27 in project RI-B5-05.
Imprinting methylation in SNRPN and MEST1 in adult blood predicts cognitive ability (2019) – paper published in PLoS One by Marlene Lorgen-Ritchie et al.
Long-term exposure to chemicals in sewage sludge fertilizer alters liver lipid content in females and cancer marker expression in males. (2019) – paper published in Environment International by Panagiotis Filis et al.
Acute dietary zinc deficiency in rats exacerbates myocardial ischaemia/reperfusion injury through depletion of glutathione. (2019) – paper published in the British Journal of Nutrition by Karen Skene et al.
Competition for nutrients in pregnant adolescents: consequences for maternal, conceptus and offspring endocrine systems. (2019) – a review article published in the Journal of Endocrinology by Jacqueline Wallace
Saturated Fat and Health Report (2019) – a report from the Scientific Advisory Committee on Nutrition chaired by Paul Haggarty.
Imprinting methylation predicts hippocampal volumes and hyperintensities and the change with age in later life. (2021) – a paper published in Scientific Reports by Lorgen-Ritchie et al 11, 943.
Presentations & reports
A Theme researcher gave evidence to two sessions of the Scottish Parliament Health and Sport Committee on behalf of SEFARI. The session in Dec-20 considered the “Provisional UK Common Framework on Nutrition labelling, Composition and Standards” and the session in January 2021 considered the “Provisional UK Common Framework on Food and Feed Safety and Hygiene (FFSH)”. Written evidence and transcriptions of the discussion highlighted the challenges facing Scotland and the UK in respect of the post-Brexit arrangements regarding food regulation.
The importance of nutrition in pregnancy and lactation: lifelong consequences (2022) – paper published in Obstet Gynecol by Marshall NE et al
Does interpregnancy BMI change affect the risk of complications in the second pregnancy? Analysis of pooled data from Aberdeen, Finland and Malta (2022) – paper published in Int J Obes (Lond) by McClurg DP et al
Prenatal flavour programming: a novel route to improve children's liking of bitter vegetables - briefing note shared with key personnel at FSS, The Scottish Government's Maternal and Child Health Division and First Steps Nutrition
Presentations & commentaries
Three posters were presented at the Proceedings of the Nutrition Society summer conference. They were 1) Validation of taste-tests conducted by mother-infant dyads in the home environment to assess infant taste preferences; 2) An intervention to increase consumption of bitter vegetables in late pregnancy reduces infants’ disliking of bitter vegetables at weaning and 3) The diversity of first foods offered at weaning is predicted by indices of maternal diet quality, breastfeeding and parity
In one of the most important UK public health decisions in decades the UK Government announced in September 2021 that it will introduce the mandatory fortification of non-wholemeal wheat flour with folic acid in order to reduce the incidence of neural tube defect affected pregnancies. In recognition of their contribution to the field, a SEFARI scientist was asked by the Lancet to provide a commentary on the announcement - UK introduces folic acid fortification of flour to prevent neural tube defects