Barclays analyst Karen Short says club retailer Costco can remain strong in the battle against e-commerce competition like Amazon simply because of its food offerings, according to a survey by her company.

"The survey indicated more than 80 percent of customers go to Costco specifically for food," she said. "This tells us analytically that Costco is very protected from Amazon."

The survey specifically said that 81 percent of respondents visit Costco for groceries, a number consistent with both millennials and baby boomers. 

"Given Costco's high quality merchandise in food, low prices, and the frequency of purchase for these items, we believe that the company's customers will remain loyal and believe Costco's price positioning and quality in food insulates it from Amazon," Short says.

Short also raised her price target for Costco from $170 to $185, a nine-percent upside from last week's close.