Thank you for your inquiry.
The question you pose is certainly pertinent, but cannot be answered definitively at this time. We clearly know that with avoidance of the ingestion of mammalian meat and tick bites, IgE anti-alpha-gal declines, and I have personally seen it become undetectable over a period of three years. This has been well recognized by Drs. Commons, Platts-Mills, and associates, and recently mentioned in an excellent review of the topic (1). The following is a direct quote from this review:
"We have certainly noted a decrease in the level of IgE to alpha-gal in such individuals, which may, in turn, make them much less prone to symptomatic attacks".
However, to my knowledge, there are no published series of cases followed longitudinally assessed for the loss of sensitivity, and therefore, it is not possible to cite you any dependable figures. In addition, re-sensitization and a boost in sensitization can clearly occur with repeat tick bites (2), and I suppose with the ingestion of red meat as well. Therefore, even if a patient does show a significant decline in IgE anti-alpha-gal, this does not, at least theoretically, prevent re-sensitization, and therefore one would, in my opinion, be reluctant to reintroduce red meat into the diet of such patients.
So, unfortunately, for the present time, there are no evidence-based recommendations that we can give you even though we know there can be a significant decline in sensitivity with avoidance. And, at least in my opinion, caution should be taken in patients who do show significant declines in IgE anti-alpha-gal because of the possibility of re-sensitization.
You may also find the alpha-gal video by Dr. Scott Commins posted here interesting. In this video, he talks about remission due to avoidance of tick bites and diet.
Thank you again for your inquiry and we hope this response is helpful to you.
1) Anubha Tripathih MD, Scott Commons MD PhD, Peter W. Heymann MD, Thomas A.E. Platts-Mills MD, PhD, FRS. Delayed Anaphylaxis to Red Meat Masquerading as Idiopathic Anaphylaxis. The Journal of Allergy and Clinical Immunology: In Practice Volume 2, Issue 3, Pages 259-265, May-June, 2014.
2) Van Nunen, S.A., O'Connor, K.S., Clarke, L.R., Boyle, R.X., and Fernando, S.L. An association between tick bite reactions and red meat allergy in humans. Med J Aust 2009; 190: 510-511.
Phil Lieberman, M.D.