Ji, K, YL Kho, Y Park and K Choi. 2010.
Influence of a five-day vegetarian diet on urinary levels of antibiotics and phthalate metabolites: A pilot study with “Temple Stay” participants. Environmental Research. http://dx.doi.org/10.1016/j.envres.2010.02.008.

Synopsis by Emily Barrett

People who adopted a vegetarian diet for just five days show reduced levels of toxic chemicals in their bodies. In particular, levels of hormone disrupting chemicals and antibiotics used in livestock were lower after the five-day vegetarian program. The pilot study suggests that people may be able reduce their exposure to potentially dangerous chemicals through dietary choices, such as limiting consumption of animal products like meats and dairy.

What did they do?

Twenty-five participants lived in a Buddhist temple and adopted the monks’ lifestyle – including their traditional vegetarian diet – for five days.

At the beginning of their “Temple Stay,” participants completed a questionnaire about what they had eaten in the previous 48 hours. They gave a urine sample to provide information on level of exposure to antibiotics and phthalates before the program began. None of the participants had taken any antibiotics or pharmaceutical drugs in the previous month. After five days of following a traditional Buddhist monk lifestyle and diet, participants again gave a urine sample so that levels of chemicals in their bodies after the program could be assessed.

Because it is difficult to measure levels of phthalates directly, researchers typically measure levels of their breakdown products in the urine samples. In this case, the scientists looked at levels of six different phthalate breakdown products as well as concentrations of three commonly used antibiotics and two of their breakdown products.

The researchers compared levels of phthalates and antibiotics in the body before and after the program. They also examined how the foods eaten in the days prior to the start of the Temple Stay related to the before levels of chemicals in their urine. What did they find?

Participants varied greatly as to which antibiotics were detected in their bodies at the start of the study. By the end of the study, in many cases, participants’ antibiotic concentrations were too low to be accurately measured. For those samples that could be measured, moreover, both urinary levels of the antibiotics and the estimated daily intake of antibiotics had decreased after the Temple Stay.

Every participant had measurable levels of all six phthalate breakdown products at both the beginning and end of the study. However, after the five-day program, levels of all but one had dropped significantly, as had the estimated daily intake of phthalates.

The researchers also found that the foods participants ate in the 48 hours before starting the program were related to the concentrations of antibiotics and phthalates in their bodies. Beef, pork and dairy were associated with starting urinary levels of the various antibiotics, suggesting that those foods may be major inadvertent routes of exposure to the pharmaceuticals. Similarly, levels of one particular phthalate breakdown product were related to number of servings of dairy products consumed in the previous 48 hours.