In the letter, the group has linked Toxic hitmaker's recent health problems to her meat and dairy intake.
"On behalf of everyone at PETA, please accept our best wishes for Britney, and I hope you'll allow me to share some information that could be helpful to you in your admirable efforts to look after her mental and emotional health," The Daily Telegraph quoted PETA president Ingrid E. Newkirk, as stating in the letter.
"We have heard that Britney asked for ice cream while she was in the hospital. There could, in fact, be a connection between her diet and her mental-health problems. Numerous reports indicate that in bipolar patients who have hidden dairy sensitivities (a fairly common condition), the disorder can worsen if the patient consumes dairy products. And a significant body of research-including evidence cited by the Centers for Disease Control and Prevention-has linked parasites that are often found in undercooked meat (Toxoplasma gondii) to the development of schizophrenia," the group added in the letter.
Newkirk went on to suggest that Britney should switch to vegan diet to help sort out her head. "While switching to a vegan diet might very well benefit Britney's mental health, it would undoubtedly benefit her physical health," Newkirk said.