Kale is the superfood of our generation. In smoothies, as oven-baked kale chips, or just raw in salad – it seems like it’s everywhere. If you’re a kale enthusiast yourself, you may be wondering if you can feed it to your rats, as well.
Is kale safe for pet rats to eat? Should you offer it raw or cooked? And what about the stem?
Overall, kale is a perfectly healthy food to offer your mischief. Like other leafy greens, it’s quite rich in certain micronutrients and boasts many health benefits. In fact, kale is one of the most nutrient-dense foods on the planet.
Let’s have a look at how to prepare kale for your pet rats, and all the health benefits it offers them.
Can You Feed Your Pet Rat Kale?
Is Kale Safe for Rats?
What does kale contain, exactly? Like most vegetables, it’s mainly made up of water, at around 89.6%1. It also contains carbohydrates but is overall a very low-calorie food.
Kale is also quite high in fiber. Nutritional fiber is beneficial for gut health as it helps to regulate digestions and serves as “food” for healthy bacteria in the gastrointestinal tract2.
When we look at the micronutrients, here’s where kale really shines. Kale contains incredible amounts of vitamin A, vitamin K, and vitamin C.
Vitamin A is essential for many biological processes such as cell growth and differentiation, immune function, reproduction, and vision – and it has been shown to protect against certain types of cancer3.
Vitamin K is needed for blood clotting and bone health4; and vitamin C is essential to the function of the immune system as well as connective tissue health5. Kale also boasts good amounts of calcium, manganese, copper, potassium, and magnesium1.
Like other leafy greens, kale is a fantastic source of antioxidants like quercetin and kaempferol6. Both of these compounds have been shown to decrease inflammatory processes, reduce the risk and symptoms of chronic diseases, and help combat cancer, among other things7-10.
The reason that antioxidants get such a good rap is that they can offset the cellular damage that occurs during aging and inflammation and that is caused mainly by reactive oxygen species (ROS)11. The higher in antioxidants your rats’ diet is, the better.
For overweight rats, kale makes a great snack, as it offers tons of nutrients but has very few calories. The consumption of foods with a low energy density such as kale has been shown to aid weight loss12.
These are plenty of good reasons to feed your rats kale regularly. Let’s have a look at which type of kale to offer, and how to prepare it.
Can Rats Have Curly Kale?
The different types of kale available – Tuscan kale, curly kale, Russian red kale, and others – don’t differ significantly in their nutrient or calorie content.
They are all perfectly fine for rats to eat, so whichever one is available to you will do nicely.
Can Rats Eat Kale Stems?
There is nothing inherently bad about the stems of kale. However, they tend to be quite fibrous and tough, and your rats may shun them when offered in their raw form.
If you feed your mischief cooked kale, absolutely include the stems! They are very nutritious, too.
Is Raw or Cooked Kale Better?
Cooking kale can cut down on its bitterness and make it more palatable to your rats. However, cooking kale greatly reduce its nutrient contents (especially antioxidant and mineral contents)13.
The cooking method that preserves most nutrients is steaming, so if you want to offer your rats cooked kale, this is the way to go13. However, you’ll probably find that they will also eat their kale raw.
When feeding raw kale, be mindful of pesticides. Conventionally grown kale usually has a lot of pesticide residues14, so wash it thoroughly or soak it in a mixture of water and baking soda. Organic is always the better option if it’s available.
Leafy greens are not just healthy for humans, but for rats, too. Apart from kale, you can offer your mischief Swiss chard, rocket, and even spinach.
While you may have heard that spinach is not good for your rats’ kidney health, it’s usually fine in moderation.
What Vegetables Can Rats Not Eat?
Most vegetables are perfectly healthy for rats. It’s always a good idea to offer a wide selection of different vegetables (and some fruit) to your pet rats, as this will increase the variety of nutrients that they receive.
Some vegetables should only be fed cooked, though. These include beans, artichokes, potatoes, and sweet potatoes. Many sources will tell your that raw cabbage is bad for rats, but it’s perfectly fine in moderation. Large amounts of raw cabbage can cause bloating and digestive issues, though.
If your rats have any chronic health issues such as kidney disease, discuss with your veterinarian which foods should be removed from their diet or only offered occasionally.
To Sum Up
Kale is a superfood for rats, too! It’s packed with vitamins, minerals, and antioxidants. Rats will usually eat raw kale, but you can offer it cooked, too. However, the cooking processes will remove some of the healthy nutrients. You can offer kale frequently, as it’s very low in calories.
1. U.S. Department of Agriculture. FoodData Central – Kale, raw. 2019. https://fdc.nal.usda.gov/fdc-app.html#/food-details/168421/nutrients.
2. Bourquin LD, Titgemeyer EC, Fahey GC, Jr. Vegetable fiber fermentation by human fecal bacteria: cell wall polysaccharide disappearance and short-chain fatty acid production during in vitro fermentation and water-holding capacity of unfermented residues. J Nutr 1993;123:860-869. https://pubmed.ncbi.nlm.nih.gov/8387579/.
3. Doldo E, Costanza G, Agostinelli S, et al. Vitamin A, cancer treatment and prevention: the new role of cellular retinol binding proteins. BioMed research international 2015;2015:624627-624627. https://pubmed.ncbi.nlm.nih.gov/25879031.
4. Bügel S. Vitamin K and bone health. Proc Nutr Soc 2003;62:839-843. https://pubmed.ncbi.nlm.nih.gov/15018483/.
5. Sorice A, Guerriero E, Capone F, et al. Ascorbic acid: its role in immune system and chronic inflammation diseases. Mini Rev Med Chem 2014;14:444-452. https://pubmed.ncbi.nlm.nih.gov/24766384/.
6. Olsen H, Aaby K, Borge GI. Characterization and quantification of flavonoids and hydroxycinnamic acids in curly kale (Brassica oleracea L. Convar. acephala Var. sabellica) by HPLC-DAD-ESI-MSn. J Agric Food Chem 2009;57:2816-2825. https://pubmed.ncbi.nlm.nih.gov/19253943/.
7. Calderón-Montaño JM, Burgos-Morón E, Pérez-Guerrero C, et al. A review on the dietary flavonoid kaempferol. Mini Rev Med Chem 2011;11:298-344. https://pubmed.ncbi.nlm.nih.gov/21428901/.
8. Chen AY, Chen YC. A review of the dietary flavonoid, kaempferol on human health and cancer chemoprevention. Food Chem 2013;138:2099-2107. https://pubmed.ncbi.nlm.nih.gov/23497863/.
9. Stewart LK, Soileau JL, Ribnicky D, et al. Quercetin transiently increases energy expenditure but persistently decreases circulating markers of inflammation in C57BL/6J mice fed a high-fat diet. Metabolism 2008;57:S39-46. https://pubmed.ncbi.nlm.nih.gov/18555853/.
10. Murakami A, Ashida H, Terao J. Multitargeted cancer prevention by quercetin. Cancer Lett 2008;269:315-325. https://pubmed.ncbi.nlm.nih.gov/18467024/.
11. Liguori I, Russo G, Curcio F, et al. Oxidative stress, aging, and diseases. Clin Interv Aging 2018;13:757-772. https://pubmed.ncbi.nlm.nih.gov/29731617/.
12. Rolls BJ, Roe LS, Beach AM, et al. Provision of foods differing in energy density affects long-term weight loss. Obes Res 2005;13:1052-1060. https://pubmed.ncbi.nlm.nih.gov/15976148/.
13. Armesto J, Gómez-Limia L, Carballo J, et al. Effects of different cooking methods on the antioxidant capacity and flavonoid, organic acid and mineral contents of Galega Kale (Brassica oleracea var. acephala cv. Galega). Int J Food Sci Nutr 2019;70:136-149. https://pubmed.ncbi.nlm.nih.gov/30037287/.
14. Wanwimolruk S, Kanchanamayoon O, Phopin K, et al. Food safety in Thailand 2: Pesticide residues found in Chinese kale (Brassica oleracea), a commonly consumed vegetable in Asian countries. Sci Total Environ 2015;532:447-455. https://pubmed.ncbi.nlm.nih.gov/26093223/.
Nina has a degree from the Veterinary School in Zurich, with a special focus on microbiological research. Nina has a passion for sports, nutrition and the outdoors and she loves all pets, but rats have a special place in her heart. When she’s not working or reading and writing about all things related to pet health, she loves to travel and surf.
As a small animal veterinarian, Nina is your go-to expert on pet health and nutrition.