The FDA said that while most peoples' immune systems can usually fight off the effects of foodborne illness, children, the elderly, and people with weakened immune systems risk serious illnesses or even death from drinking untreated juices.
That is because when fruit and vegetables are juiced, bacteria from the produce can become a part of the finished product.
Unpasteurized, or otherwise untreated juices, sold in grocery stores are required to carry warning labels for consumers, stating: "This product has not been pasteurized and therefore may contain harmful bacteria that can cause serious illness in children, the elderly, and persons with weakened immune systems."
However, with consumers choosing to drink ever more juice as a healthier alternative to fizzy sodas, the FDA is concerned that more people may be putting themselves at risk.
"The FDA does not require warning labels for juices that are fresh-squeezed and sold by the glass, such as at farmers markets, at roadside stands, or in some juice bars," it says.
Food and drinks producers and distributors face inevitable fines if any outbreak of food poisoning can be traced back to their products.
The FDA last October published the final 2004 Produce Safety Action Plan aimed at minimizing the number of foodborne illnesses that are contracted each year through the consumption of fresh produce.
The Center for Disease Control and Prevention (CDC) estimates that in the US each year, 76 million people become sick, more than 325,000 people are hospitalized, and 5,000 people die from foodborne illness.
It also says that at least 12 percent of foodborne-outbreak-associated illnesses in the 1990s were linked to fresh produce.
Outbreaks elsewhere in the world back up this theory. In 1999, unpasteurized orange juice was responsible for a food poisoning outbreak in South Australia affecting more than 500 people.
Consuming dangerous foodborne bacteria will usually cause illness in one to three days after eating the contaminated food, though can cause sickness anywhere between 20 minutes or up to six weeks later.