A study published online today in the European Heart Journal research showed the first concrete evidence that acute under-nutrition during the time that children grow up can have a significant impact on their future health.

Researchers conducted a study on women who were children, teenagers or young adults during the Dutch famine in 1944-45 and discovered that an increased risk of coronary heart disease in later life is linked to under-nutrition, particularly in the adolescent years.

The authors of the accompanying editorial, state that the discovery stresses the importance for policy makers and health professional to take these findings into account for designing and implementing disease screening and prevention programs.

Researchers from the University Medical Center in Utrecht and the University of Amsterdam conducted a study of 7,845 women who were aged between 0-21 and were living in The Netherlands at a time when a combination of circumstances at the end of the Second World War resulted in severe food shortages in the west of The Netherlands. During the period from October 1944 official daily rations for the general adult population dropped from 1400 calories to between 400-800 calories at the height of the famine from December 1944 to April 1945. Six months later, the liberation of the Netherlands ended the famine abruptly.

Female participants for the study were recruited from 1993 to 1997 through a breast cancer-screening program that was followed up until the end of 2007. The researchers divided the women into three groups. The first group consisted of women who were unexposed, i.e. women who reported being “hardly” exposed to hunger and weight loss during the famine; the second group containing those severely exposed, i.e. women who reported being “very much” exposed to hunger and weight loss with the third group containing those with moderate exposure, i.e. the remaining women whose famine experience was somewhere between these two experiences.

They discovered that the risk of coronary heart disease in comparison with unexposed women, was marginally higher overall for women with moderate exposure to the famine, and significantly higher among those who had been severely exposed.

Women with severe exposure, who were aged between 10-17 at the start of the famine had a statistically significant 38% increased risk of coronary heart disease in later life compared to those who had been moderately exposed. Women who were unexposed had no increased risk. The researchers adjusted factors that could misconstrue the results, such as age at start of the famine, smoking, and education (as a measure of socio-economic status) and discovered a 27% increased risk of coronary heart disease for the severely exposed women compared to those unexposed.

Additional examinations revealed that the risk of stroke seemed to be lower for women of all ages exposed to famine, compared to those who were not exposed. Women who were exposed to famine at the ages between 18 to 21 years (ages that are not sensitive growth periods) seemed to have a lower risk of stroke compared to those who were unexposed, although this lower risk was not statistically significant.

The authors imply the relevance of the study’s results for today by commenting that:

“The Dutch famine of 1944-45 is a ‘natural experiment’ in history, which gave us the unique possibility to study the long-term effects of acute under-nutrition during childhood, adolescence, and young adulthood in otherwise well-nourished girls and women. Our findings support the notion that disturbed postnatal development, particularly in adolescence, can have important implications for adult health. The contemporary relevance of our findings is that famine and under-nutrition are still a major problem worldwide; the first millennium developmental goal is to eradicate extreme hunger. Since the incidence of CVD [cardiovascular disease] is the number one cause of death globally, and rising in many parts of the world, further research into the impact of under-nutrition during sensitive periods of growth and maturation is warranted.”

Annet van Abeelen (a PhD epidemiology student at the Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht and at the department of Clinical Epidemiology, Biostatistics and Bioinformatics, Academic Medical Center, University of Amsterdam (The Netherlands) who is the first author of the study), added that more research was needed to confirm the findings and to explore the possible mechanisms underlying the effects of famine on the risk of future heart disease.

She commented:

“However, our study pinpoints the crucial role childhood plays in adult health. More knowledge in this field may lead to unique opportunities for prevention in the future.

According to the developmental origins of chronic disease hypothesis, as first proposed by Professor David Barker, nutritional influences early in life may change the structure and function of the body. While these changes may be beneficial for short-term survival, they may lead to chronic diseases in later years. Our study indicates that growth that has been hampered by under-nutrition in later childhood, followed by a subsequent recovery, may have metabolic consequences that contribute to an increased risk of diseases later in adulthood.”

The authors have several possible explanations for the effects of famine on coronary heart disease, such as unhealthy lifestyles, changes in metabolism, or traumatic stress, but commented that each of these required further research. Ms van Abeelen added that more research was also required for the findings on stroke considering that these results were based on just 235 stroke cases.

Professor Kausik Ray and colleagues at St George’s University of London (London, UK), writes in an accompanying editorial:

“These results add further weight to the suggestion that adolescence is a particularly sensitive period open to epigenetic modifications and that dietary mismatch in post-famine nutritional availability contributes to coronary disease risk.”

The authors highlight that according to the United Nations Food and Agriculture Organization 925 million people worldwide are undernourished and that a recent report by the Association of Teachers and Lecturers in the UK revealed, that three-quarters of their students arrived at school hungry with these numbers increasing since the start of the global recession.

Prof Ray and colleagues relate to studies of people who starved during the Chinese famine (1959-61) and the siege of Leningrad (1941-44) in their comment:

“Taken together there appear to be consistent data showing that nutritional status in childhood may impact significantly on chronic diseases processes in later life. The findings of these recent studies could have significant practical impact on immigrant populations who try to adapt to the relatively more affluent and nutritionally rich environments, particularly those escaping from man-made and natural catastrophes. For instance, first-generation Asians in the UK have a higher incidence of cardiovascular disease than Caucasian counterparts. As cardiovascular disease carries the largest economic and population burden in developed countries and is fast approaching similar importance in developing countries, further work is now needed to better understand the mechanisms behind these associations and devise public health strategies which could have a significant impact on disease burden in years to come.”

Written by Petra Rattue