My début into the world of research took place when I worked on a study investigating the health impacts of a ‘natural experiment’. In this post I describe several of these natural experiments, which come with a fascinating historical context, and have made a significant contribution to science. I go on to describe the context and impact of the Channel Islands Occupation, the subject of my initial research.
The Dutch Hunger Winter Studies
In their book Famine and Human Development Stein et al used one of the tragedies of the Second World War to examine the impact of exposure to prenatal famine on an otherwise affluent population. German forces occupied the Netherlands from May 1940. Rationing duly began, and alterations to agricultural practices were set in place to accommodate to the situation. Under favourable circumstances Dutch agriculture alone would have provided an average daily ration of 2200 calories per head, plentiful by any standards (Stein, Susser et al. 1975, p.43). In the autumn of 1944, in retaliation to a general railroad strike, the German occupying forces imposed a transport embargo on the civilian population of the western Netherlands. This resulted in a block on all imports of food and essential commodities to a densely populated area, which largely depended on such imports even outside of wartime. The embargo coupled with a particularly harsh winter resulted in starvation affecting much of the Dutch population in the west of the country. The situation provided a unique “clarity of famine events in time and space” (Stein, Susser et al. 1975, p.4), and excellent statistical records for the entire population. The Dutch famine study was the first of many studies on the Dutch Hunger Winter. The authors reported associations between famine conditions and fertility, mortality and birth outcomes. They described a famine calorie threshold and that birth outcomes were more significantly affected if exposure had occurred in the third gestational trimester.
The Norwegian occupation
The occupied Norwegians were also subjected to severe food shortages and harsh conditions during their five years of German rule (Wilcox, Skaerven et al. 1994, 1463). Their occupation was characterised by violence towards the population as a consequence of civilian defiance and a well-organised resistance movement (Petrow 1975, p.99-137). The German forces commandeered most food supplies rendering civilian ration cards redundant since often there was no food left. They also used food as a weapon to force young Norwegian men into conscription to the German army (Fuegner 2002, p.48-50). A study of the pregnancy outcomes for mothers born during the German occupation of Norway concluded that there was “no evidence that Norway’s experience during World War II affected perinatal survival, either immediately or through indirect effects on mothers born during the war” (Wilcox, Skaerven et al. 1994, 1466).
The Leningrad Siege
The siege of Leningrad (St Petersburg) prevented food and supplies from reaching Leningrad for 872 days. Between 30-40% of the population died, mostly during the winter of 1941-42 when a meagre ration of bread was all that was available. It was one of the longest and most destructive historical sieges. A study of the children born during the siege of Leningrad showed a marked drop in average birthweight of between 500-600g, with half those born in early 1942 weighing less than 2500g (Antonov 1947; Sparén et al. 2004). Stanner et al conducted analyses on 549 individuals, 361 of whom were exposed to the terrible conditions of the Leningrad siege (1941-44) in utero or in infancy. The remaining 188 participants were born at the same time but outside the exposed area. The participants underwent physical examinations and interviews to extract data on adult metabolic factors and socio-economic status. The authors found no difference between the exposed and unexposed groups, and therefore no evidence of an association between exposure to the siege and diabetes or cardiovascular disease (Stanner, Bulmer et al. 1997, p.1345). These findings contrast with Sparén et al’s analysis of 3905 men who experienced the Leningrad siege in childhood, adolescence or early adulthood (Sparén et al. 2004). In 1973 information was collected from these individuals on socio-economic factors, behaviours, anthropometric measurements and biological measurements. The findings showed that men who experienced the siege had higher blood pressure, and excess mortality from heart disease and stroke. The authors found that starvation occurring particularly around puberty was more strongly associated with high blood pressure and stroke in adulthood than at any other time (Sparén et al. 2004).
The Channel Islands occupation
Between the 30th June and 4th July 1940 the first German troops landed in Jersey and Guernsey, and five years of occupation began. Prior to the arrival of the Germans the government in London decided that the islands would be demilitarised, being too difficult to defend (Cruicksank 1975, p.74). In June 1940 a frenzied evacuation of approximately 30 000 people towards mainland Britain occurred (Cruicksank 1975, p.49). There was a panicked last-minute attempt to leave the islands, appeased somewhat by the announcement by Alexander Coutanche and Ambrose Sherwill, the Bailiffs of the Bailiwick of Jersey and Guernsey, of their intention to remain (Tabb 2005, p.52-53). In the end, almost half of the population left Guernsey, and 13% left Jersey. All islanders on Alderney, were evacuated either to England or Guernsey. The inhabitants of Sark remained on their small island governed by the Dame of Sark, Sybil Hathaway. In total approximately 66 000 inhabitants remained in the Channel Islands and prepared themselves for the worst. Their number was eventually increased by 50% once the German garrison was at its peak in 1944 (Kelleher 1986).
On the whole the occupation was relatively peaceful. The German troops were generally respectful towards the islanders and were appreciative of their sojourn in islands that were far away from the violence occurring elsewhere in Europe. This is not to say that life was easy for the islanders. There was a plethora of restrictions imposed on the civilian population including curfews and the requisitioning of vehicles. Houses were also taken over by the Germans for billets, agricultural activities were strictly monitored and fishing was restricted to within three miles off the coast (Cruicksank 1975). In September 1942 the deportation of about 1200 non-native born individuals living in the islands to internment camps in Europe took place, an order that came directly from Hitler in retaliation for the incarceration of German troops and civilians in Iran (Harris 1980). Further deportations occurred in February 1943. Although events like these brought the reality of war to the islanders, in fact they were not far away from the brutality, violence and hatred that prevailed in continental Europe. Only a few miles away the German forces were using the island of Alderney as a prison camp, where prisoners of war from the eastern front, traitors and Jewish civilians from France were forced into slavery and suffered severe malnutrition, torture and death (Bunting 2004).
Since the islands’ agricultural network was established for exporting a few foods to Great Britain such as tomatoes, courgettes, flowers and potatoes, the insufficiency of food stocks was a problem from the beginning of the occupation. The islands therefore relied heavily on imports for most other foodstuffs (except milk) as well as all other commodities before the occupation (Sanders 2005, p.1-56). They could no longer rely on imports from Britain once the occupation began, and therefore looked to alter their agricultural infrastructure with the aim of becoming self-sufficient. Elderly millers came out of retirement to help set up the islands’ flour stocks, and the herds of dairy cows were maintained at their full strength to provide adequate rations of milk (Sanders 2005, p.5-6). All extra supplies had to be imported from occupied France, where islanders, with permission from the Germans, would travel around purchasing required goods (Bunting 2004, p.85). General rationing was introduced in July 1940 on meat, sugar, flour and butter. Bread was rationed from February 1941 and potato rationing started in December of the same year (Bunting 2004, p.122).
The chief medical officer of health in Jersey, Dr. R.N. McKinstry monitored the nutrition provided to the population in official rations throughout the occupation. McKinstry pointed out in his report that although the energy provision of the diet was plentiful for sustaining life, it was not a balanced diet and lacked essential fats and protein. Children were given one-third of a pint of full milk every day at school, and those up to the age of 10 were able to attain their necessary energy requirements from the rations and extras available. Once children entered their pre-pubescent years and adolescence it was more difficult for them to keep a balanced diet or sufficient calories. According to McKinstry this affected their immunity and caused them to suffer from malnutrition. He carried out measurements of the heights and weights of primary school children in 1943 and compared them to similar data collected before the occupation. He found evidence of moderate decreases in the average heights and weights of children, an average decrease of 4.15 lbs in weight and 0.65 inches in boys and of 3.6 lbs and 0.55 inches in girls. He subsequently collected similar measurements when the occupation had ended. McKinstry noted evidence of rapid recovery in their weight but not as much in their height. He concluded that the children had recovered remarkably well from the effects of food shortage (McKinstry 1946; Kelly and Ellison 2002; Ellison and Kelly 2005).
As well as observing changes in their anthropometric status, McKinstry also observed that there was a marked improvement in the condition of the children’s teeth during the occupation. This observation was confirmed by a study into the incidence of dental caries in children who were in the islands throughout the war. Bransby and Knowles collected information in 1945 soon after liberation and again in 1947. The study found a marked increase in the number of caries and general deterioration in the condition of the teeth among the children between 1945 and 1947. The authors attributed the overall deterioration to the children’s diet which saw a large increase in sugar and confectionary consumption after liberation (Bransby and Knowles 1949).
Not all islanders experienced food shortage equally. There was an increase in the death rate, particularly among elderly members of the population who suffered from the sudden change in diet, which was excessive in fibre, and made it more difficult for them to withstand infections and illness. There was also the psychological strain of the restrictions and impositions of the occupation that took its toll on these more vulnerable people (Sanders 2005, p.153). The social inequalities that were already pervasive in society before the war exacerbated the difficulties in acquiring food. A middle class family of three adults could achieve a diet of 2 640 calories per day per head in the winter of 1943-44, while a working class family of two adults and six children receiving state benefit had an energy consumption of 1 677 calories per day per person (Banks 1945). The harsh conditions were particularly difficult for the poorer islanders who faced years of being unable to supply their families with the necessities of life (Anquetil, p.8). Attempts were made to improve the situation by opening communal ovens and soup kitchens which provided cheap meals for town workers and allowed economies to be made on fuel (Falla 1968, p.91; Mollet 1992, p.18).
The occupation was characterised by two periods of severe food shortage. The first was in the winter of 1941-42 when foodstuffs and essential commodities fell to an extreme low with a completely depleted stock of potatoes. This resulted in the semi-starvation of the population and the death rate among the elderly and weak rose suddenly (Plumb 1988). The second period was after the D-Day landings in 1944 when the Channel Islands were completely cut-off from mainland Europe where essential supplies had been procured. The conditions seriously deteriorated throughout the latter part of 1944. Under such extreme circumstances the German troops were equally as susceptible to the lack of food and fuel as there was no longer a stock from which they could commandeer supplies. Several accounts describe German soldiers breaking into houses at night to steal the remaining crumbs from a meal, rummaging in refuse seeking scraps of food and capturing the islanders’ pet cats and dogs as a source of meat (Maugham 1971, p.190; Bunting 2004, p.244). By early 1945 the official rations provided no more than 800 calories per day per person (Sanders 2005, p152). The situation would have turned into a catastrophe had the Red Cross vessel Vega not arrived at the end of December with food parcels for the islanders (McKinstry 1946). The atmosphere of doom in the islands changed dramatically on the arrival of the Vega, and as one islander remembers: “with food in one’s stomach the outlook seemed to change overnight” (Anquetil, p.32). Thereafter, and until liberation in May 1945, the Vega continued to supply the islanders with food and essentials on a monthly basis (Maugham 1971, p.129).
The consequences of wartime environments on the welfare of the population
The nature of each wartime situation is unique, depending on the relationship between the occupying forces and the particular population as well as on events occurring elsewhere in the war. The Dutch Hunger winter and the Leningrad siege had clear consequences for the birthweight of newborn babies. Both situations were acts of brutality where the starvation of the population was a weapon of war intended to cause extreme suffering and death. The Dutch Hunger Winter was sudden and had acute consequences for an otherwise affluent population. The result was starvation among people who had not had the time to acquire the essential skills for survival (Sanders 2005, p.155). The Leningrad siege was severe and chronic, lasting for over two years within a population that was already deprived. The occupations of Norway and the Channel Islands were very different, but were not deliberately brutal in the same way as a siege. The long-term exposure to deprivation experienced by islanders and the Norwegian population allowed them to adapt to their scarce environment, and they became extremely resourceful at making the most from the little they did have. When the islands faced their toughest period from late 1944 to early 1945 the population was well practiced in its survival skills. If it had not been for the arrival of the Red Cross parcels in December 1945 the situation may well have changed from a feat of human endurance and adaptability to a tragedy of war.
A legacy for lifecourse research on health?
Health researchers have used natural experiments to determine the impact of periods of upheaval upon the health of populations. Such ‘natural experiments’ carry with them our interest in wartime situations, the resilience of innocent civilians in the face of adversity, the social and political climate of the time, and the lessons we have and, more often, have not learnt. From the original Dutch Famine study, Stein et al formulated a ‘critical periods hypothesis’ which suggested that
“the development of organ systems are most vulnerable at the period of maximum growth: interruption of development at such a critical period is likely to be irreversible or, at the least, subsequent development is likely to be retarded” (Stein, Susser et al. 1975, p.6).
Thus, the impact of poor nutrition during the crucial foetal growth period could have lasting detrimental effects on an individual’s development. This contributed to the development of the early origins of adult disease hypothesis, and the lifecourse conceptual framework in health research.
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