American children are no strangers to raisins – one of the most popular treats found at snack time in schools nation-wide.
These delicious snacks may come from real fruit, but they go through a lengthy process to make it from the field to your lunchbox.
There are many ways to produce dried fruit, including the traditional method of drying them out in the sun.
However, modern, large-scale food production companies typically remove the water content of the fruit by using industrial dehydrators.
This process is used to create prunes, dates, apricots, figs, apple rings as well as dried pears and peaches. While most dried fruits are made from fresh ingredients, some variations like pineapple, papaya, and kiwi are sourced from canned fruit.
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Dried fruit is also known to contain artificial flavour, color, sweeteners, and preservatives. This is often true for dried berries, mango, and, sometimes, raisins.
Normally, the natural acids in fruit and their low moisture content would be enough to ward off fungi and bacteria as the fruit is dried and stored (1,2). Unfortunately, the extra additives and large-scale manufacturing process make processed fruit products more prone to spoil.
How Raisins are Made
One of the chemicals most commonly used to preserve dried fruits is sulphur dioxide, an antioxidant closely related to other sulphites commonly added to foods like wine and cold cuts. In recent years, sulphites have come under fire for their negative impact on human health, including the fact that they scavenge vitamins from foods (3).
This preservative is often used in golden raisin, dried peaches, apples and apricots to conserve their color and flavour. It’s been used in food production since the 1800s (4,5). However, sulfites are restricted from use on fresh and raw fruits and vegetables (6).
It can be difficult to find out whether or not certain foods contain sulphites since the FDA only requires foods containing more than 10 parts per million of sulphites to list the ingredient on their food labels.
This is problematic because certain people can be sensitive to the ingredient, including asthmatics. These individuals may have difficulty breathing within minutes of eating a food containing sulphites. If not treated promptly, the results can be fatal.
The Problem With Sulfites
It doesn’t take a lot of sulphites to cause major damage: 3,7mg is the lowest levels of contamination at which a product can be recalled out of health concerns while 10mg is enough to seriously injure someone or even cause death. In sulphite-sensitive individual, these effects are amplified (7).
Dried raisins and prunes are some of the worst contenders when it comes to sulfate contamination, as they contain between 500 and 2,000 parts per million (ppm). In perspective, wine only contains between 20 and 350 ppm (8).
Although sulphur dioxide is considered safe by FDA standards, it’s actually a highly reactive gas produced from fossil fuel combustion at power plants and industrial facilities (9).
Short-term exposure to the chemical is known to cause serious respiratory illnesses. As an environmental pollutant, sulphur dioxide interacts with other compounds to form volatile chemicals that penetrate into the lungs to cause respiratory disease and worsen pre-existing heart disease.
Other suspected effects include developmental problems, gastrointestinal and liver disease, neurological disturbances, irritable bowel syndrome, behavioral disturbances, skin rashes, asthma, folate deficiency, and more.
The dangerous effects of raisins are compounded by the fact that non-organic grapes go through an extensive pesticide treatment. According to the USDA Pesticide Data Program, grapes are known to contain 56 pesticide residues, including 8 known or probable carcinogens, 17 suspected hormones disruptors, 10 neurotoxins, and 4 developmental or reproductive toxins (10).
If you experience allergy-like symptoms when eating raisins, you may have a sulphite sensitivity. To stay on the safe side, always purchase organic raisins and grapes or stay away from dried fruit altogether.