Featured articles 2014

Maternal protein intake in pregnancy may increase risk of offspring overweight

Studies in animal and humans have suggested that maternal consumption of macronutrients (fat, protein, and carbohydrates) during pregnancy may influence the size, level of body fat, and the response to glucose in the offspring. We examined whether maternal total protein intake as well as protein from animal and vegetable sources influence the offspring body mass index and risk of overweight 20 years after birth. We looked at the replacement of carbohydrates for protein rather than a strict increase in protein intake since this may be more representative of real life where persons replace one macronutrient for another instead on increasing their consumption of macronutrients (and therefore also energy). Our results showed more than a two-fold increase in the risk of overweight in the offspring when women replaced carbohydrates for animal protein.

This effect size was stronger for the female offspring. To investigate which animal sources may account for this increase in risk we looked specifically at food groups (meat, fish, dairy) in relation to the same outcomes. Intake of meat and meat products similarly increased the risk of overweight two-fold, but only in female offspring. While these results are intriguing they need to be confirmed in other studies, especially those with good information on offspring dietary intake and lifestyle after birth, for which we only had limited information. 

Ekaterina Maslova, Dorte Rytter, Bodil H Bech, Tine B Henriksen, Morten A Rasmussen, Sjurdur F Olsen, and Thorhallur I Halldorsson. Am J Clin Nutr October 2014 ajcn.082222

Link to journal press release

Link to article

Link to SSI press release (in Danish)


New Ways of Characterizing Dietary Patterns

The study of dietary patterns in relation to human disease is important as people’s eating habits tend to include specific food items in combination with one another. For example, an individual who eat a lot of vegetables may also eat more legumes and fruit. Conversely, someone who eats fast food on a regular basis may also have a high consumption of sugar-sweetened beverages and other processed foods. Composition of dietary patterns in research is either done according to current recommendations or some established eating patterns like the Mediterranean diet, or by using statistical tools. When patterns are created using statistical tools the results have traditionally been reported in the form of tables with many different foods and their correlation with a specific dietary pattern. In this paper, Rasmussen and colleagues took at different approach and visualized this data in striking spider plots (examples are shown below). The idea was to create figures that made it more easy to identify the most important foods and nutrients that make up a dietary pattern and to compare dietary patterns across studies without having to compare every single number in a table. It is, for example, clear from the spider plots below that a Western-type diet is rich in French fries, white bread, mixed meats, and pork. The paper also used these dietary patterns to look at which pattern was most strongly related to the risk of preterm birth. They found that a Western-type diet increased the risk, while a Seafood-based diet slightly reduced the risk of preterm birth.

This paper provides a novel and exciting avenue for communicating and comparing more complex scientific findings. This is especially important considering that the amount of data collected and analyzed in new and ongoing studies is just getting larger. New tools are therefore needed to make the results from these data more digestible to other scientists and the greater public.

Spider plot figure

Rasmussen MA, Maslova E, Halldorsson TI, Olsen SF. Characterization of Dietary Patterns in the Danish National Birth Cohort in Relation to Preterm Birth. PLoS ONE 2014; 9(4): e93644.

Link to article


Maternal exposure to persistent organic pollutants (POPs) in pregnancy and long-term risk of asthma in offspring.

Persistent organic pollutants (POPs) are a group of chemical compounds that were previously used in various industrial and commercial applications. POPs are a threat to human health and are therefore no longer produced. Although they were banned from production since the late 1970’s, they still persist in the environment because of their resistance to biologic degradation. Humans can therefore still be exposed, mainly from consumption of predatory and fatty fish.

Although previous research has suggested that exposures to POPs during pregnancy may be harmful to a child’s developing immune system, few studies have examined long-term effects. In this study we investigated exposure to certain POPs in pregnancy and the risk of developing asthma that persists into adulthood. More specifically, we looked at exposure in pregnancy to polychlorinated biphenyls (PCBs), the pesticide hexachlorobenzene (HCB), and dichlorodiphenyldichloroethylene (p,p’-DDE).

We measured POP levels in blood samples taken in late pregnancy from 872 pregnant Danish women who were asked to participate in a study in 1988-1989. We then used registry information about the offspring’s use of asthma medication from age 6 to 20 years to determine which offspring were likely to suffer from asthma.  We found that, at age 20, offspring of mothers with the highest blood concentrations of HCB in pregnancy had almost double the risk of having asthma compared to offspring of mothers with the lowest blood concentrations. We found a similar relationship with one particular PCB compound, dioxin-like PCB-118. This compound is structurally related to dioxins that have a high toxic potential. For PCB compounds that look less like dioxin, we found similar increased risks, but these associations did not reach statistical significance.  Maternal concentrations of p,p’-DDE did not appear to influence the offspring’s risk of asthma.

Our results support the current guidelines from the Danish National Board of Health that pregnant women and women who plan to become pregnant should limit their intake of predatory fish, for example perch, tuna, and salmon, or contaminated fish from the Baltic Sea to no more than a 100 g per week.

Hansen S, Strøm M, Olsen SF, Maslova E, Rantakokko P, Kiviranta H, Rytter D, Bech BH, Hansen LV, Halldorsson TI. Maternal Concentrations of Persistent Organochlorine Pollutants and the Risk of Asthma in the Offspring: Results from a Prospective Cohort with 20-years of Follow-up. Environ Health Perspect 2013.

Link to press release in Danish

Link to article