New Zealand Food Safety (a unit of the Ministry for Primary Industries) today published the results from the 2016 New Zealand Total Diet Study, which shows the food New Zealanders eat has a high level of safety in regard to chemical hazards which might be present in the food supply.
Exposure to agricultural chemicals and contaminants from food remains low and for the first time in two decades dietary intake of iodine is sufficient for good health.
The study, which is carried out on average every five years, is a national survey of a range of common foods consumed in a typical diet.
It is used to assess New Zealanders’ overall exposure to chemicals, such as agricultural compounds, environmental contaminants and nutrients, and to identify any potential food safety risks. It is also used to monitor trends and changes in levels over time.
The ministry’s specialist advisor for toxicology and environmental chemistry, Dr Andrew Pearson, says more than 4300 individual food samples were tested for the 2016 study for 301 agricultural chemicals and 10 contaminants and nutrients.
The number of food types tested was increased to 132 to capture new food trends, and for the first time the study has looked at Pacific Island ethnicity diets.
“Overall we found that the New Zealand food supply continues to be safe in terms of exposure to chemicals, and generally there is a sufficient level of nutrients for health,” Dr Pearson said.
Both contaminants and nutrients can come from a variety of sources, such as those naturally occurring in the environment, natural processes (like volcanic activity), and materials used in food preparation and storage (such as tin from cans).
In terms of contaminants, the ministry tested for aluminium, arsenic, cadmium, lead, mercury, and tin.
Dietary levels of cadmium and mercury have remained consistent with results from the previous studies. Lead levels, on the other hand, have decreased and the declining trend is continuing.
Aluminium was tested for the first time and higher-than-expected levels were found in some foods.
“While the potential health risk is low, we are actively working with industry to reduce the level of aluminium in these foods,” Dr Pearson said.
The ministry tested a range of common nutrients, such as iodine, selenium, sodium, and zinc. Approximately half of the foods were also tested for fluoride.
The study found New Zealanders are still consuming higher-than-needed levels of sodium in their diets but they are getting the right levels of selenium and zinc, both of which are essential in supporting a healthy metabolism.
An increase of iodine was found in New Zealanders’ diets. This is linked to bread being fortified with iodised salt.
This means that for the first time since the 1990s iodine intakes are estimated to be at a level in the population which is needed for good thyroid function.
The ministry tested three types of agricultural chemicals that are commonly used in agriculture – insecticides, fungicides and herbicides. The test for the first time also included two chemicals commonly found in disinfectants used in the food production industry and in homes.
“We tested more agricultural chemicals than in any previous TDS and although about 40% of the samples had a detected level of agricultural chemical residue, all of the exposures in the diet were very low, and far below the levels that would be a food safety risk,” Dr Pearson said.
“All in all, the results from the 2016 TDS are very reassuring, and show the New Zealand diet is safe and wholesome.
“The levels of agricultural chemicals and contaminants in our diets remain low and most of the latter are naturally occurring in the environment, so the fact they are showing up in our foods is unavoidable.
“In addition, we are eating foods that are providing us with the right levels of nutrients needed to maintain a good diet.”
The next study will likely be conducted in 2021.
Source: Ministry for Primary Industries