Sensitivity to common food allergens could be an important and previously unappreciated cause of heart disease, new research suggests.
Antibodies to certain foods may up the risk even for people who do not have obvious food allergies.
Sensitivity to common foods including dairy and peanuts could increase an individual’s risk for cardiovascular disease. The increased risk could equal or exceed the risks posed by smoking, as well as diabetes and rheumatoid arthritis, researchers report.
“What we looked at here was the presence of IgE antibodies to food that were detected in blood samples,” said researcher Dr. Jeffrey Wilson, an allergy and immunology expert at UVA School of Medicine. “We don’t think most of these subjects actually had overt food allergy. Thus, our story is more about an otherwise silent immune response to food. While these responses may not be strong enough to cause acute allergic reactions to food, they might nonetheless cause inflammation and over time lead to problems like heart disease.”
UVA Health scientists and collaborators looked at thousands of adults over time and found that people who produced antibodies in response to dairy and other foods were at elevated risk of cardiovascular-related death. This was true even when traditional risk factors for heart disease, such as smoking, high blood pressure and diabetes were considered. The strongest link was for cow’s milk, but other allergens such as peanut and shrimp were also significant.
The 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 prior studies connecting allergic inflammation and heart disease.
Approximately 15 percent of adults produce IgE antibodies in response to cow’s milk, peanuts and other foods. While these antibodies cause some people to have severe food allergies, many adults who make these antibodies have no obvious food allergy. The new research found that the strongest link with cardiovascular death was in people who had the antibodies but continued to consume the food regularly — suggesting they didn’t have a severe food allergy.
Inspired to investigate the possibility that common food allergies could be harming the heart after members of the UVA team previously linked an unusual form of food allergy spread by ticks to heart disease, the allergy was first identified by UVA’s Dr. Thomas Platts-Mills.
The allergy — commonly if inaccurately called the “red meat allergy” — sensitizes people to a particular sugar, alpha-gal, found in mammalian meat. The symptomatic form of the allergy, known as “alpha-gal syndrome,” can cause hives, upset stomach and breathing difficulties and potentially deadly anaphylaxis with three to eight hours after affected people eat beef or pork. (Poultry and fish don’t contain the sugar, so they don’t trigger a reaction.)
A team including Wilson, Platts-Mills and collaborators from UVA, as well as Dr. Corinne Keet of the University of North Carolina, reviewed data collected from 5,374 participants in the National Health and Examination Survey (NHANES) and the Wake Forest site of the Multi-Ethnic Study of Atherosclerosis (MESA) to see if other food allergies could be affecting the heart. Of the individuals, 285 died from cardiovascular causes.
Milk was associated with a significantly higher risk of cardiovascular death, the researchers found, as well as peanut and shrimp.
“We previously noted a link between allergic antibodies to the alpha-gal red meat allergen and heart disease,” Wilson explained. “That finding has been supported by a larger study in Australia, but the current paper suggests that a link between allergic antibodies to food allergens and heart disease is not limited to alpha-gal. In some ways, this is a surprising finding. On the other hand, we are not aware that anyone has looked before.”
The UVA researchers have linked allergic antibodies to common foods with cardiovascular mortality for the first time. The researchers speculate that allergic antibodies to food may be affecting the heart by leading to the activation of specialized cells, called mast cells. Mast cells in the skin and gut are known to contribute to classic allergic reactions, but are also found in the cardiac blood vessels and heart tissue. Persistent activation of mast cells could drive inflammation, contributing to harmful plaque buildup that can cause heart attacks or other heart damage, the researchers believe.
However, the theory has not yet been proven as fact. Other genetic or environmental factors could be at play. Or it’s possible that cardiovascular disease could increase the risk for food sensitization.
“This work raises the possibility that in the future a blood test could help provide personalized information about a heart-healthy diet,” Wilson said. “Though before that could be recommended, we still have a lot of work to do understand these findings.”
The findings are published in the leading allergy journal, the Journal of Allergy and Clinical Immunology. The research was supported by the National Institutes of Health’s National Institute of Allergy and Infectious Disease and AAAAI Foundation Faculty Development Award.