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A study published in Science looks at sugar rationing in the first 1000 days of life and the risk of chronic disease in adulthood.
Dr Hilda Mulrooney, Reader in Nutrition and Health, London Metropolitan University, said:
“This is a really interesting and timely paper, given the currently high intakes of sugar in the UK population, and prevalence of chronic disease including Type 2 diabetes and hypertension.
“The potential for diet in utero to impact on long-term health risks has long been recognised, and there are a number of plausible mechanisms to explain how these may occur. In this study, the authors used data from what could be considered a natural experiment – rationing in response to World War 2. By comparing individuals exposed and not exposed to sugar rationing in utero and in early childhood, a significant effect was seen. Those exposed to rationing had significantly lower risks of Type 2 diabetes (35% lower) and hypertension (20% lower), compared to those who did not. Early childhood was especially important; only a third of the increase in risk for both type 2 diabetes and hypertension was explained by in utero exposure. This highlights the potential for early childhood diet as a risk factor for chronic disease. Given the high levels of sugar in foods and drinks aimed at toddlers and young children, this is of concern.
“The study cannot demonstrate causality; it is not possible from this sort of study design. Nonetheless it is a strong study, with several potential confounding factors taken into account and large numbers of participants (38,155 exposed to rationing and 22,028 not exposed to rationing). The groups were similar in relation to gender, race, family history of diabetes and cardiovascular disease (for which hypertension is a strong risk factor), and genetic scores calculated for obesity (which could confound for both type 2 diabetes and hypertension). In addition to sugar intakes immediately and markedly rising after rationing of sugar ended, risk of obesity was also significantly higher in those not exposed to rationing in utero and the first year of life, compared with those who were.
“This study inevitably has weaknesses, due to its type and reliance on historical data. Changes to sugar intakes were unlikely to be the only changes that occurred to participants at that time. The authors took as many factors as they could into account and the message is clear – exposure to high intakes of added sugar in utero and early childhood is a significant risk factor for chronic disease. This suggests that action to reduce the sugar content of foods and drinks aimed at or attractive to children is needed. This will not entirely reduce the risk, since diet in pregnancy is what enables in utero exposure – so action on all foods and drinks high in added sugar is needed. However this will have to be approached with care – simply replacing sugar with sweeteners will not enable the population to reduce their preference for sweet tastes.”
Jerusa Brignardello, Lecturer in Dietetics & Nutrition, Oxford Brookes University, said:
Does the press release accurately reflect the science?
“Yes, the press release is aligned with the conclusions and findings to the study. This press release emphasises in the importance of the sugar restriction during the first 1000 days of life as an early dietary intervention for the reduction of hypertension and diabetes risk.”
Is this good quality research? Are the conclusions backed up by solid data?
“This is an interesting retrospective piece of research that explores the consequences of early of sugar restriction during early life and comparing the effects of sugar consumption in the same age group after the rationing of food was lifted in the post-war UK. However, results should be interpreted with caution, as nutritional environments from the 1950s differ significantly from those of today.
“The information was obtained from the UK- Biobank with 60183 participants. However, the Biobank cohort is not nationally representative of the population and tend to represent a part of the population that was healthier and wealthy. Nonetheless, the quasi-experimental design of the exposure conditions makes this study very rigorous to study the sugar exposure in humans.”
How does this work fit with the existing evidence?
“Current evidence suggests that early exposure to sugar during pregnancy and early life may impact neonatal metabolism, obesity risk, and taste perception, which may later influence food choices and the risk of other chronic diseases. This study supports the findings related to chronic diseases and contributes to the “fetal origins hypothesis” described by British physician and epidemiologist David Baker in the 90s.”
Have the authors accounted for confounders? Are there important limitations to be aware of?
“Yes, the authors have worked on the limitations inherent in studying a cohort like this. It is important to be aware that food environments and dietary patterns in the 50s were very different compared to the current food environment. In addition, lifestyle during those years was not the same as today, and obesity was not considered for statistical purposes as a potential variable to study public health.
“Therefore, the risk found in the UK-Biobank cohort that was exposed to sugar rationing may be different if that is compared to other populations given the differences in lifestyle, dietary habits, food environment, and obesity prevalence. Consequently, the extrapolation of the results presented in the work of Gracner et al. should be interpreted with caution, for example, if these results will be used to build machine learning models for risk predictions for the current population. However, these results contribute to the “Baker hypothesis” or “Fetal origins hypothesis” showing how a simple nutritional intervention as cutting sugar during this crucial period of pregnancy and early life affect in the reduction of risk of diabetes and hypertension in later life.”
What are the implications in the real world? Is there any overspeculation?
“As mentioned previously, the food environment, lifestyle, and physical activity are very different from those in their 50s. Therefore, the results found in this research should be a call for attention for women in the stages of preconception, pregnancy, and parents of children in early life. In addition, this should reinforce the actions of policymakers for the promotion of low sugar intake during these critical life stages in parents and children. Finally, the food industry should consider reformulating products targeted at these groups in light of the evidence, prioritising the well-being of future generations.
“I do not believe there is overspeculation in this article, as it has undergone peer review, meaning that multiple academics have evaluated the research, including its methodology, results, discussion, and conclusions.”
Dr Katie Dalrymple Lecturer in Nutritional Sciences, Kings College London said:
“This study provides further epidemiological evidence which supports the Developmental Origins of Health and Disease (DOHaD) hypothesis. DoHaD suggests that certain environmental influences during critical periods of growth and development during early life may have significant consequences on a child’s long-term health. Given the complexity of this research question, the study relies on observational data and an event study design to draw meaningful conclusions of the relationship between nutrition in early life and the development of chronic diseases. Whilst it is important to consider confounding factors which may have occurred between the exposure and the outcome and potential bias of the Biobank cohort, the results are consistent with existing DoHaD literature, and they support the notion of public health initiatives which focus on sugar reduction.”
Amanda Adler, Professor of Diabetic Medicine and Health Policy from the University of Oxford’s Radcliffe Department of Medicine said:
“The investigators take advantage of the ‘natural experiment’ of post-war food rationing to test the theory that exposure to sugar rationing in utero and in early childhood prevents or delays the onset of type 2 diabetes and hypertension years later.
“The investigators observed that people conceived during rationing indeed had lower rates of disease when compared to people conceived after rationing ended.
“But, we still don’t really know if the children less likely to get diabetes later in life were indeed the ones not exposed to sugar in utero or after birth – even in a setting of rationing.
“It may be that at the same time rationing ended and people consumed more sugar, they also changed other habits becoming, for example, less physically active. So, this may have influenced in part their risk for diabetes later in life.
“It’s intriguing and entirely possible that a lower exposure to sugar in utero via the mother would lead to life-long benefits.
“This study is an open invitation to clinical trialist to clarify the ‘right’ levels of sugar to add to the diet for pregnant or lactating women, and for their infants.”
‘Exposure to sugar rationing in the first 1000 days of life protected against chronic disease’ by Gracner et al. was published by AAAS in the journal Science at 18:00 UK time on Thursday 31st October.
DOI: 10.1126/science.adn5421
Declared interests
Dr Hilda Mulrooney “In terms of conflicts, I am a committee member of the Obesity Group of the British Dietetic Association, a committee member of the European Specialist Dietitians Network for Obesity and a Council member for Public Health to the Nutrition Society. I am not paid by any of these organisations and not representing them in these comments.”
Jerusa Brignardello “In 2013 I was awarded scholarships from Kraft Foods to attend to the Young Global Nutrition Leader in the International Unions of Nutrition Societies and International Nutrition Foundation. I worked as International Nutrition Consultant for the World Food Programme at United Nations in the Latin American and Caribbean Bureau between 2013 and 2014 . I have worked in Nutrigenomix which is a company for nutritional genetic testing based in Canada between 2012 and 2017. Also, as a clinical trial coordinator for Nestle Switzerland in 2010 and as consultant for Nestle Chile doing activities related to science communication in gut health topics in 2024. In 2018 I received a funding from the American Egg Board from USA to do research in food biomarkers, while I studied at Imperia College London- UK. I am not aware about significant industry funding in my department at Oxford Brookes University. I do not have any conflicts of interest related to this research for my own research.”
Dr Katie Dalrymple “I worked for Danone for 4 years (2012-2016) before I did my PhD.”
Amanda Adler “No conflicts of interest to declare.”