COW’S MILK LINKED TO INCREASED RISK OF HEART DISEASE AND DEATH

IMMUNITY: A study finds that people with or without obvious food allergies faced the risk of cardiovascular complications…

By WSAM Correspondent

Sensitivity to common food allergens such as cow’s milk and peanuts could be an important and previously unappreciated cause of heart disease, new research suggests, and the increased risk of cardiovascular death includes people without obvious food allergies.

In a paper published in The Journal of Allergy and Clinical Immunology that describes analyses led by Dr Corinne Keet, paediatric allergy and immunology professor in the University of North Carolina’s Department of Paediatrics, the researchers show that the people who produced IgE antibodies to cow’s milk and other foods were at significantly increased risk of cardiovascular mortality.

This was true even when traditional risk factors for heart disease, such as smoking, high blood pressure, and diabetes were accounted for. The strongest link was for cow’s milk, but IgE to other allergens such as peanut and shrimp were also significant among those who eat the foods.

IgE is the antibody that a person’s body makes in its system. For an example, an allergy blood test involves measuring a substance called immunoglobulin E (IgE) in a person’s blood. IgE is the antibody that a person’s body makes in its system. If a person has allergies, he or she may have more IgE in their blood than normal.

This troubling finding represents the first time that IgE antibodies to common foods have been linked to increased risk of cardiovascular mortality, the researchers report. The findings do not conclusively prove that food antibodies are causing the increased risk, but the work builds on previous studies connecting allergic inflammation and 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,” said Keet, who co-authored the study. “We were surprised by these findings because it is very common to have IgE to foods, 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,” she said.

This research used data from 4 414 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. Participants were enrolled in MESA from 2000-2002 and followed for up to 19 years. Participants were enrolled in NHANES from 2005 to 2006 and data on mortality up to 14 years were tracked.

Total and specific IgE was measured to cow’s milk, egg, peanut, shrimp, and a panel of aeroallergens for the NHANES group. IgE to cow’s milk, peanut, dust mite and timothy grass were measured in the MESA group. In NHANES, 229 cardiovascular deaths were recorded and 960 deaths from MESA were also reported. Milk sensitisation was particularly associated in both NHANES & MESA. Researchers also discovered that food sensitisation to shrimp and peanut were both additional risk factors for heart disease.

It is also important to note that associations in the findings related to food sensitisation rather than clinical allergy, Keet says. 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 food frequency questionnaires were not showing symptoms of a food allergy. Thus, the findings that showed how associations were strengthened when researchers excluded those who avoided the food suggest that these findings were most relevant to those who have not been diagnosed with food allergy.

She says the results raise questions about whether these apparently non-allergic individuals may have long-term consequences from consuming foods to which they are sensitised.

Because discovering the link between milk sensitisation with cardiovascular death is new, Keet says there’s more to explore as far as the relevance of food sensitisation and diet in cardiovascular disease development.

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