Food sensitivity linked to increased risk of cardiovascular death

Sensitivity to common food allergens such as cow’s milk and peanuts could be a cause of heart disease, according to new research — and the increased risk for cardiovascular death includes people without obvious food allergies.

Dr Corinne Keet, from the University of North Carolina School of Medicine, led analysis into two longitudinal studies showing that the people who produced immunoglobin (IgE) antibodies in response to cow’s milk and other foods were at significantly increased risk of cardiovascular mortality. These findings, published in The Journal of Allergy and Clinical Immunology, represent the first time that IgE antibodies to common foods have been linked to increased risk of cardiovascular mortality — and while the research does not conclusively prove that food antibodies are causing the increased risk, it does builds on previous studies connecting allergic inflammation and heart disease.

Data from 4414 adults who participated in The National Health and Examination Survey (NHANES) and 960 participants in 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 for up to 19 years, while NHANES participants were enrolled from 2005–2006 and data on mortality was tracked for up to 14 years.

In NHANES, 229 cardiovascular deaths were recorded, while 960 deaths from MESA were reported. Milk sensitisation was particularly associated in both NHANES and MESA. Researchers also discovered that food sensitisation to shrimp and peanut were both additional risk factors for heart disease.

“People who had an antibody called IgE to foods that they regularly eat seemed to be at increased risk for dying from heart disease,” Keet said. “We were surprised by these findings because it is very common to have IgE to foods (about 15% of American adults have IgE to common food allergens), and most people don’t have any symptoms when they eat the food. As allergists, our thinking has been that it is not important if people have IgE to foods, as long as they don’t have symptoms when they eat the food.”

Although researchers did not have access to information about clinical food allergy in either cohort, they expect that individuals who report regularly eating a food allergen on questionnaires were not showing symptoms of a food allergy. Thus, the researchers suggest that their findings were most relevant to those who have not been diagnosed with food allergy. Keet said the results raise questions about whether these apparently non-allergic individuals may have long-term consequences from consuming foods to which they are sensitised.

The study states that, until recently, cardiovascular disease had not been identified as a long-term complication of food sensitisation. However, there is now substantial evidence for the importance of allergic-type immune pathways in normal cardiac physiology and heart disease. Because discovering the link between milk sensitisation with cardiovascular mortality is new, Keet said there is more to explore as far as the relevance of food sensitisation in cardiovascular disease development.

“While this study provides good evidence of an association between sensitisation to these allergens and death from cardiovascular disease, there is much work to be done to understand if this is a causal relationship,” she said.

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