New study links food allergies to increased risk of heart disease death

Sensitivity to common food allergens like cow’s milk and peanuts may be an important and previously undiagnosed cause of heart disease, new research suggests — and the increased risk for cardiovascular death includes people without obvious food allergies.

In a published research paper Journal of Allergy and Clinical Immunology In two longitudinal studies that describe an analysis led by Corinne Keith, MD, PhD, professor of pediatric allergy and immunology in the UNC Department of Pediatrics, the authors show that those who developed IgE antibodies to cow’s milk and other foods had a significantly increased risk of cardiovascular death. This was true even when traditional risk factors for heart disease such as smoking, high blood pressure and diabetes were taken into account. The strongest association was with cow’s milk, but IgE was also significant among those who ate foods with other allergens, such as peanuts and shrimp.

This alarming finding represents the first time that IgE antibodies to a common food have been linked to an increased risk of cardiovascular death, the researchers reported. The findings don’t conclusively prove that food antibodies are causing the increased risk, but the work builds on previous research linking allergic inflammation and heart disease.

People who regularly eat foods that have antibodies called IgE seem to have a higher risk of dying from heart disease.

Corinne Keet, MD, Ph.D., the paper’s corresponding author, is a professor of pediatric allergy and immunology in the UNC Department of Pediatrics.

“We were surprised by these results because it’s so common to have IgE to foods (about 15% of American adults have IgE to common food allergens), and most people don’t have symptoms when they eat the food. As allergists, we’ve thought that people who have IgE to foods It doesn’t matter, as long as they don’t have symptoms when they eat the food,” he said.

Funded by an AAAAI Faculty Development Award from the National Institute of Allergy and Infectious Diseases and his colleague Jeff Wilson of the University of Virginia, the study used two methods to examine the relationship between IgE sensitization to food and cardiovascular mortality. Data from 4,414 adults who participated in the National Health and Examination Survey (NHANES) and 960 participants at the Wake Forest site of the Multi-Ethnic Study of Atherosclerosis (MESA) cohort were used. Participants were enrolled in MESA from 2000–2002 and followed up to 19 years. Participants were enrolled in NHANES from 2005 to 2006, and mortality data were tracked for up to 14 years. Total and specific IgE were measured to cow’s milk, egg, peanut, shrimp, and a panel of aeroallergens for the NHANES group. IgE to cow’s milk, alpha-gal, peanut, dust mite and timothy grass was measured in the MESA group. In NHANES, 229 cardiovascular deaths were recorded and 960 deaths were reported from MESA. Milk sensitivity was specifically associated with both NHANES and MESA. Researchers also found that food sensitivities to shrimp and peanuts are associated with increased risk for heart disease.

It is also important to note that the associations in outcomes are related to food sensitivities rather than clinical allergy. Although the researchers did not have access to information about clinical food allergy in either group, they expected that individuals who reported eating a food allergen regularly on a food frequency questionnaire would not show symptoms of food allergy. Thus, the findings that showed how associations were strengthened when researchers excluded food avoiders suggest that these findings were most relevant to those who had not been diagnosed with a food allergy. Keith said the findings raise questions about whether these apparently non-allergic individuals may have long-term consequences from consuming sensitive foods.

The study notes that apart from two recent reports linking IgE to the unusual carbohydrate allergen alpha-gal with coronary artery disease, cardiovascular disease has not previously been identified as a long-term complication of food sensitivity. However, there is now considerable evidence for the importance of allergic-type immune pathways in normal cardiac physiology and heart disease. Because the discovery of a link between milk sensitivity and cardiovascular death is new, Kitt says the relevance of food sensitivity and diet to the development of cardiovascular disease remains to be explored.

“More research is needed on how sensitization to common food allergens relates to cardiovascular disease,” he said. “Although this study provides good evidence of an association between sensitization to this allergen and death from cardiovascular disease, much work needs to be done to understand whether this is a causal relationship.”