Vegetable oils are good sources of omega-3 fatty acids, which can help lower cholesterol and reduce the risk of heart disease and other chronic conditions.
They can also be made from plants that don’t require as much energy to grow as grass.
But a recent report from the USDA Food Safety and Inspection Service says that many of the plants used in vegetable oils are contaminated with harmful substances like lead, arsenic, mercury and other heavy metals.
“They’re not as beneficial as some of the other kinds of plant-based oils,” said Elizabeth R. Jones, a nutritionist at the University of California at Davis and an expert on omega-6 fatty acids.
“But they’re pretty good.”
The report is based on a review of more than 1,400 samples from a broad range of plant and vegetable oils that had been tested for the presence of these contaminants.
Many of the contaminants, including lead, lead arsenate, mercury, cadmium, arsenic and cadmides, are found in plant oils, including soybean, corn, sunflower and canola oils.
The USDA also found that some of these oils have higher levels of a particular chemical called phenol, which is used to make certain kinds of flavoring.
Some of these chemicals, called flavanols, have been linked to the development of certain types of cancer and birth defects in animals.
The report found that most of the vegetable oils tested had levels of flavanol levels that were in the low to mid-range.
Some oils had levels that exceeded the EPA’s recommended limit of 15 parts per billion, while others were found to have levels well above the EPA limit of 5 ppb.
Some brands also contained potentially harmful chemicals called phthalates, which are used in feminine hygiene products, dental fillings and cosmetics.
Phthalates are found naturally in plastic toys and clothing, and can leach into drinking water, soil and food, and are used widely in the manufacturing and processing of plastics.
While some of them are known to pose a health risk, the majority of the oils tested contained less than 1 ppb, the report found.
The levels in the oils were lower than in foods, including vegetables and some dairy products.
But the report also found a higher rate of contamination in some oils, particularly the soybean oils, compared with other oils, with concentrations higher than 5 ppbi in some products.
Among the oils with high levels of contaminants, some contained as much as 20 percent by weight of phthalate-containing ingredients.
Some vegetable oils were found in some foods, such as soybean oil, and others contained in other foods, like corn oil.
Some oil brands contained no phthalrates at all, while some contained at least a small amount of phytosterols, which help the body absorb some of this fatty acid.
The high levels in some vegetable oils could be due to the oils’ use in cooking and as preservatives in foods and beverages.
Some foods, especially those containing soybeans, may contain more than the EPA guideline for phytostearins, according to the report.
Jones said the problem with using vegetable oils for cooking is that they contain many more calories than other foods.
“I don’t think you want to use vegetable oils in cooking,” she said.
“The only way you’ll get a lot of calories out of them is to use a lot more calories in cooking.”
The USDA found that more than half of the vegetables tested had higher levels than EPA limits.
Many other vegetables tested were found lower than the limit for phytic acid, which helps the body break down the fats and oils in foods.
The researchers did not find a link between vegetable oils and increased risks for cancer, birth defects or other health problems.
However, they did find that some vegetables, particularly those with high amounts of phystic acid, have high levels that may cause more cancer in people.
Many types of foods and drinks, such a white wine, may have high amounts or may not have enough physts, the USDA report said.
One of the most common ways of making vegetable oils is by blending them with other ingredients.
Other ingredients included soybean meal, which contains a physterol, and corn starch, which has a phytotoxic component.
In the case of soybean and corn, the researchers said, phytosanoids, the chemicals used to protect against them, are more likely to be found in the soybeans.
“There are also other things in soybeans that could be more toxic than the phytothecenes,” said Jones.
“It’s really important that you don’t just use a product that you’ve been told to use, but also try it in a variety of different ways.”
A few oils have been proven to be safe for people who have had heart disease or other conditions, but not for people without these conditions, said Jones, who is not affiliated with any companies that make vegetable oils. She added