Without addressing Caporella's unusual comments, Guggenheim recommended investors sell their shares and lowered its price target from $72 a share to $45, according to a research note published Friday when the stock was trading at around $54. Analysts led by Laurent Grandet cited rising competition in the flavored carbonated water industry and a drop in social media buzz about LaCroix for their decision to cut the rating.
"We continue to see a challenging competitive environment for LaCroix, especially as Topo Chico gains traction and PepsiCo intends to invest heavily behind Bubly again this year. In our view, this is the bigger issue going forward that will likely prevent LaCroix from regaining its lost market share," Guggenheim said.
Dean Crutchfield, founder of the crisis management firm Crutchfield + Partners, said Caporella's comments invite more questions than answers.
"He's actually caused himself his own mess," he said on CNBC's "Power Lunch." "There was a mess here four months ago. Now you've dug an even deeper hole. And now you've got national attention."
A lawsuit filed in October accused the popular sparkling water company of mislabeling its products as all-natural, sending National Beverage shares lower that day. The suit claimed that LaCroix included non-natural and synthetic compounds in its seltzer.
In January, National Beverage said an independent, accredited lab found that LaCroix did not contain traces of artificial or synthetic additives. At the time, Caporella said in a statement that "professional liars" used social media to attack the brand's integrity. Still, National Beverage's sales dropped 2.9 percent during the quarter to $220.9 million, compared with $227.5 million last year.
"As retail growth has remained persistently weak, the bigger issue now, in our view, is the increased level of competition in the category that will make it very difficult for LaCroix to regain its lost share," Guggenheim said.
Caporella also said the 2017 tax reform legislation led to skewed comparisons to the prior year.
"Our products are wonderful. There is nothing wrong with the brand LaCroix, and we're happy with our position in the marketplace," a National Beverage spokesman told CNBC.
contributed to this article.