In recent years, kale juice has become a popular health drink claimed to provide a variety of benefits. Some proponents say that kale juice can help “detox” the body by removing toxins and promoting the function of the liver and kidneys. But what does the science say? Is there evidence that kale juice can serve as an effective detox?
What is a detox?
First, it’s important to understand what “detoxing” actually means. In the health world, a detox generally refers to the process of removing toxic substances from the body. Some common reasons people look to detox include:
- Promoting liver health and function
- Enhancing kidney and urinary function
- Removing environmental toxins
- Increasing energy levels
- Improving skin health
- Aiding in healthy weight management
There are many different ways people attempt to detox their bodies, from juice cleanses to elimination diets to saunas. Using certain foods and drinks is one popular way people aim to detox.
Kale juice nutrients
To understand if kale juice can detox, it helps to know why kale is considered a nutritious vegetable in the first place. Here are some of the key nutrients found in kale juice:
|Vitamin C||Powerful antioxidant that supports immune function and detoxification|
|Vitamin A||Important for eye and skin health; has antioxidant properties|
|Vitamin K||Supports bone health and blood clotting|
|Magnesium||Essential mineral involved in over 300 processes in the body|
|Potassium||Helps control blood pressure and counters sodium in the diet|
|Iron||Supports the transport of oxygen in the blood|
|Calcium||Critical for bone health, muscle function, and nerve signaling|
Kale is especially high in antioxidant vitamins A and C, which can help neutralize harmful free radicals in the body. It also contains glutathione, a potent antioxidant compound that plays a major role in liver detoxification.
Does kale juice detox the liver?
One of the main claims around kale juice is that it can support detoxification by stimulating the liver. As the body’s main detox organ, the liver filters out toxins, produces bile to help digest fats, and removes waste products from the blood. Multiple animal and human studies have found that kale contains compounds that could protect liver health:
- A rat study showed that kale extract could help protect against liver injury caused by an overdose of acetaminophen, which is processed by the liver.1
- Sulforaphane, a compound in cruciferous vegetables like kale, has been found to protect liver cells from free radical damage in animal studies.2
- Human studies suggest that consuming cruciferous vegetables like kale is linked to better liver enzyme function.3
So compounds found specifically in kale, like sulforaphane and other antioxidants, may help support liver function and protect liver cells. However, more research is needed to know whether juicing kale provides the same effects as consuming it whole.
Kale juice and kidney detox
Some advocates of kale juice also claim that it can help detoxify the kidneys and support their function. As the body’s natural filtration system, the kidneys remove waste products from the blood while retaining vital nutrients and minerals.
Not many studies have looked specifically at kale juice and kidney health. But we do know that kale contains high amounts of vitamin K, potassium, and magnesium, all of which are important for proper kidney function.4 The antioxidants in kale juice may also help protect kidney cells from oxidative damage caused by toxins.5
That being said, those with kidney disease or on dialysis may need to moderate their intake of potassium-rich foods like kale juice. As always, it’s best to talk to your healthcare provider about diet changes if you have any kidney issues.
Other potential benefits of kale juice
In addition to possible detox benefits, some other potential advantages of drinking kale juice include:
|Weight loss||Kale is low in calories and high in fiber and water, which can help promote fullness and reduce calorie intake|
|Heart health||The antioxidants in kale juice may help lower cholesterol and blood pressure|
|Immune function||Kale is high in vitamin C, A, and antioxidants that support the immune system|
|Cancer prevention||Sulforaphane and other compounds in kale have been studied for their anti-cancer effects|
|Skin and hair health||The vitamin A in kale promotes healthy skin and hair|
|Detox support||Kale provides antioxidants and nutrients that may aid detoxification|
The vitamins, minerals, fiber, and phytochemicals in kale juice could contribute to these benefits. However, most existing research looks at kale itself, rather than kale juice specifically.
Downsides of juicing kale
Juicing kale does remove the insoluble fiber found in whole leaves. Fiber slows digestion and helps promote fullness. Without it, the natural sugars in kale are absorbed more rapidly into the bloodstream.
Juicing also concentrates the nutrients and oxalic acid in kale. Oxalic acid can contribute to kidney stone development in those prone to the condition. And too much vitamin K from kale juice can be harmful for people taking blood thinning medication.
Finally, kale contains goitrogens, compounds that may interfere with thyroid function if consumed in excess. Goitrogens are deactivated when cooked, so eating raw juiced kale daily could potentially affect thyroid hormones.
Is kale juice safe and effective for detoxing?
Overall, the antioxidant, anti-inflammatory, and detox-supporting compounds found specifically in kale lend some credibility to using kale juice for cleansing. Compounds like sulforaphane and glutathione may promote liver health and function in particular.
However, there isn’t yet solid evidence proving that juicing kale provides detox benefits over just eating it regularly as part of a healthy diet. More research is still needed on kale juice specifically.
For now, here are some tips for safely incorporating kale juice into a detox regimen:
- Drink only fresh, cold-pressed kale juice to preserve nutrients.
- Keep portions to 1⁄2-1 cup kale juice per day to avoid excess oxalic acid.
- Pair kale juice with whole fruits, veggies, proteins, and healthy fats for balanced nutrition.
- Don’t fast or use kale juice as a meal replacement for more than 1-2 days.
- Listen to your body and stop juicing if you feel unwell.
- Talk to your doctor before juicing if you have kidney issues, take blood thinners, or have thyroid problems.
Kale juice can be a healthy addition to a balanced detox routine when used properly. But relying solely on juicing for long periods is not recommended or proven effective. For the best detox support, focus on eating a wholesome, nutrient-dense diet with plenty of antioxidant-rich produce like kale.
The bottom line
Some research suggests compounds like sulforaphane in kale could provide liver-protecting and detox-supporting effects. However, there is currently limited evidence on whether juicing kale is any more beneficial than simply eating it for detox. For now, adding small amounts of fresh kale juice to a varied, healthy diet may help provide antioxidants and nutrients that support your body’s natural detoxification systems. But be sure to pair it with fiber-rich whole foods and speak to your doctor before using kale juice to detox if you have any medical conditions.