A new Danish study links inflammatory eating to higher type 1 diabetes risk, spotlighting mid-pregnancy as a critical window for prevention.
Study: Association between a pro-inflammatory dietary pattern during pregnancy and type 1 diabetes risk in offspring: prospective cohort study. Image Credit: Rimma Bondarenko / Shutterstock
A diet high in foods with the potential to promote low-grade inflammation during pregnancy may raise that child's risk of developing type 1 diabetes, suggests Danish research published online in the Journal of Epidemiology & Community Health.
This dietary pattern was associated with a 16% heightened risk for every one standard deviation (1-unit) increase in a dietary measure of inflammatory food intake, the findings show.
Type 1 diabetes is an autoimmune disorder characterised by the destruction of insulin-producing β-cells in the pancreas, necessitating lifelong insulin treatment.
New cases of type 1 diabetes have been rising steadily, increasing by an average of 3–4% every year, especially in developed nations, strongly suggesting a significant role for environmental factors, note the researchers.
And since the immune system develops and establishes itself in early life, and to a certain degree before birth, there is a strong case for exploring the role of the mother's diet during pregnancy, especially as mounting evidence suggests that diet is a modifiable contributory factor to low-grade systemic inflammation, they explain.
To explore this further, the researchers drew on data from pregnant women in the Danish National Birth Cohort (DNBC) (January 1996 to October 2002).
They calculated a score based on the inflammatory potential of the mother's usual dietary intake (EDII score) in mid-pregnancy, using a comprehensive food frequency questionnaire that covered 38 food groups (360 separate items), which was completed around 25 weeks into pregnancy.
Foods that were associated with higher inflammatory scores included red meat, low-fat dairy, pizza, margarine, potatoes, low-energy drinks, French fries, and savoury snacks. Foods associated with lower inflammatory scores included alliums (onions and garlic), tomatoes, whole grains, coffee, green leafy vegetables, fruit juice, dark meat fish, tea, and fruits.
In all, 67,701 mother-child pairs were included in the final analysis.
Information on type 1 diabetes diagnoses in children was obtained through registry linkage to the Danish Registry of Childhood and Adolescent Diabetes. Some 281 children (0.42%) developed the condition during an average tracking period of 17 years. Their median age at diagnosis was 10.2 years.
The mothers' average EDII scores ranged from −5.3 to 4.1, with higher scores indicating higher dietary intake of inflammatory foods.
Higher EDII scores were associated with younger maternal age, lower alcohol consumption, shorter breastfeeding period, and less favourable socioeconomic circumstances. They were also associated with higher BMI (weight) and a tendency to smoke beyond the first 12 weeks of pregnancy.
There was no significant difference in total energy intake between those women with the highest and lowest EDII scores. However, a higher daily intake of red meat, low-fat dairy, pizza, margarine, potatoes, low-energy drinks, French fries, and savoury snacks was reflected in higher EDII scores.
On the other hand, higher daily intake of alliums (onions and garlic), tomatoes, whole grains, coffee, green leafy vegetables, fruit juice, dark meat fish, tea, and fruits was reflected in lower EDII scores.
The risk of a child's type 1 diabetes was associated with their mother's EDII score, rising by 16% for each unit (1 SD) increase in score up to the age of 18, after accounting for potentially influential factors. This estimate reflects the risk increase associated with a one-standard-deviation rise in the EDII score.
This risk wasn't affected by the child's sex or weight at birth, but it did seem to be affected by the mother's intake of gluten and whether she smoked during her pregnancy.
A 10 g increase in estimated gluten intake was associated with a 36% increase in risk. However, this association was observed in an additional statistical model, not the primary adjusted model.
Interestingly, smoking throughout pregnancy was associated with a lower risk of type 1 diabetes in the child, although smoking only during the first 12 weeks had no clear effect.
This is an observational study, and as such, it can't establish cause and effect. The researchers were unable to account for the child's diet.
But they write: "A low-grade inflammatory state secondary to an altered immune cell profile, which triggers pro-inflammatory pathways, is increasingly acknowledged as a critical early-life factor influencing offspring health."
They caution: "The precise mechanisms by which diet modulates the immune response remain elusive, although some clues can be offered for specific dietary components."
They add: "Of particular note is the fact that three factors during mid pregnancy, a pro-inflammatory dietary pattern, gluten, and smoking, seemed to predict the child's risk of type 1 diabetes independently. This suggests that mid-pregnancy may be a critical period during which the fetus is particularly susceptible to maternal lifestyle influences in relation to the individual's later risk for developing type 1 diabetes during childhood or adolescence."