WEDNESDAY, Feb. 27 (HealthDay News) -- Bisphenol A (BPA) and phthalates, two types of chemicals in plastics that have been linked to a number of health effects, could still find their way into your body even if you avoid foods that are shipped, stored or cooked using plastic materials, new research suggests.

The findings are based on a small study that followed 10 families for five days. Half of the families got catered meals made with fresh, local ingredients that were not stored or prepared with plastics.

The other half got a handout on how to avoid BPA and phthalates in their diet, such as not microwaving foods and drinks in plastic containers and avoiding food in cans, which are often lined in BPA-containing material.

"We fully expected to see reductions in the catered-diet group, and hoped the other group would also have reductions" in their levels of these chemicals, said study author Dr. Sheela Sathyanarayana, an assistant professor of pediatrics at the University of Washington in Seattle.

Instead, the researchers found that all but one person in the catered-diet group had a spike in phthalate levels in their urine during the five-day diet intervention, and a more modest increase in their BPA levels. In contrast, the group that got handouts had steady levels of these chemicals over the study period.

The researchers then tested the ingredients in the catered diet to track down the source of phthalate exposure and detected high levels in milk, butter and cream, and also in some of the spices, such as cinnamon and ground coriander.

"Several studies have found that high-fat dairy tends to contain high concentration of phthalates, maybe because of phthalates in the plastic tubing that milk goes through to get to the final containers, and it may be in animal products, such as feed," Sathyanarayana said.

Overall, the more processed the food, the more likely it could come into contact with materials that contain phthalates, and phthalates can easily leach from these materials into food, Sathyanarayana explained. Spices could be one type of highly processed food, she added.