It’s well known that cash-strapped Americans are trading down and giving up nonessential items like restaurant meals, designer clothes and vacations. But switching from Budweiser or Heineken to Busch and Natural Light? Yes, even that, according to July 4 sales data from Information Resources Inc.

Budweiser may be getting crowded out by discount brands. (Getty Images)

The days leading up to Independence Day are usually the biggest-selling period of the year for beer brands, according to Ad Age. If that’s any indication, 2009 isn’t shaping up to be a good year for some of the nation’s biggest brands.

Heineken sales sank 18% from the previous year in grocery, convenience and drug stores during the two-week period ended July 5, followed by Budweiser at 14%. Corona Extra sales dropped 11%, while Miller Lite declined 9% and Bud Light fell 7%. Coors Light sales held up better, falling less than 1% from a year ago.

Meanwhile, sales of “subpremium” beers including Busch, Natural Light and Keystone posted “substantial gains”, according to Ad Age, which didn’t provide the specifics.

It’s a sign that despite the cheap, frat-party image of those brands (and debatable taste), consumers are focused on one thing right now: the bottom line.