There’s been some controversy and confusion about male rats and orange juice. It is commonly said that orange juice causes cancer in male rats. Does orange juice cause cancer in male rats? Yes it does, according to The Carcinogenic Potency Project at Berkeley. The cancer is caused by d-Limonene that is found in orange juice and other common foods.
What is d-Limonene?
D-Limonene is naturally found in citrus, especially the orange. It is in the skin of the orange. D-Limonene is often used as a flavoring for processed foods. The substance is also found in mango, another fruit deemed healthy for pet rats. Be careful when giving a pet rat any table scraps with black pepper or nutmeg because they, too, have d-Limonene.
Why does d-Limonene only cause cancer in male rats?
It’s strange to think that only male rats are affected by the cancer-inducing substance. In studies, female rats are safe as are both male and female mice. According to an article cited by the Rat & Mouse Gazette, male rats have a protein in their kidneys that no other rodent has. It is called alpha2u-globulin. When a male rat has too much d-limonene, it causes the protein in the kidney to build up. The build-up causes cancer.
How much orange juice will cause cancer in male rats?
The Carcinogenic Potency Project measures the carcinogen’s potency as TD50. Let’s say an experiment is done on male rats. The TD50 is how much d-Limonene each rat must consume for half of the rats in the experiment to get cancer. The TD50 for d-Limonene is 204 milligrams per 2lbs of rat. One entire mango has about 10 milligrams of d-Limonene. That means a male rat would have to eat at least 20 entire mangoes before getting cancer. Six ounces of orange juice has 5.5 milligrams of d-Limonene. That’s nearly 2 gallons of orange juice a male rat would have to drink.
That doesn’t mean it isn’t a danger to male rats. Just giving a pet rat some orange juice in moderation could increase the risk of cancer. It just isn’t as scary as it sounds. Don’t freak out if a male rat eats a little bit of an orange.
If a male rat can’t have citrus, how does he get enough vitamin C?
Mammals are amazing creatures. A rat’s body can make its own vitamin C. There are other foods with vitamin C that do not have d-Limonene.
Can male rats have oranges without skin?
D-Limonene is found in the skin of oranges. When an orange is squeezed, the d-Limonene goes with the juices. That is why orange juice, and not oranges themselves, are bad for male rats. When giving a male rat an orange, cut off all the skin and give the rat the pulp inside. Rinse the pulp under running water, just as a precaution. Some rats don’t even like oranges or citrus. Remember that oranges are not essential to a rat’s diet, anyway.