Red meat allergy spread by ticks: A link to heart disease?

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A bite from a lone star tick can trigger an unusual allergy that causes hives, swelling of the throat and lips, or an upset stomach when you eat red meat. But that’s not all: people with this rare red meat allergy may be particularly prone to narrowed, stiff arteries in the heart, a new study finds.

Researchers analyzed blood samples from 118 adults living in Virginia and found that 26% had evidence of a red meat allergy (that is, they had antibodies to a molecule called alpha-gal, the main allergen in red meat). Lone star tick saliva may contain alpha-gal, so when a tick bites a person, it may trigger an immune response by the body, which then recurs when the body encounters alpha-gal in red meat. Lone star ticks are found throughout the southeastern and eastern United States.

Not everyone who is sensitive to alpha-gal develops allergic symptoms after eating red meat. But they still have measurable alpha-gal antibodies in their blood, and these inflammatory molecules may harm arteries. Artery scans revealed that people with these antibodies had 30% more plaque buildup inside their arteries than those without the antibodies. The researchers, who reported their findings in the June 14 issue of the journal

Arteriosclerosis, Thrombosis, and Vascular Biology

, noted that larger studies in diverse geographic areas are needed to confirm these results.