Is rhubarb a superfood?
Rhubarb has been used for centuries in traditional medicine and cuisine, but only recently has it gained attention as a potential superfood. With its tart flavor and vibrant red stalks, rhubarb is packed with nutrients and plant compounds that may offer various health benefits. This article takes a closer look at the nutritional profile of rhubarb and evaluates the current research on its effects on health.
What is Rhubarb?
Rhubarb is a vegetable that originated in Asia over 2,000 years ago. It is commonly used in pies, jams, and other desserts due to its naturally tart taste. The part of the rhubarb plant that is eaten is the stem or stalk, which can range in color from bright red to pale green.
Botanically, rhubarb is classified as a vegetable but it is often prepared and eaten like a fruit. It has thick, crunchy stalks similar to celery that are rich in fiber. The leaves of the rhubarb plant are toxic and should not be eaten.
Nutritional Profile
Rhubarb is low in calories but packed with essential vitamins, minerals, and plant compounds. Here is an overview of the nutrition found in 1 cup (122 grams) of raw, diced rhubarb (1):
| Nutrient | Amount | % Daily Value |
|---|---|---|
| Calories | 26 | 1% |
| Protein | 1 gram | 2% |
| Carbs | 6 grams | 2% |
| Fiber | 2 grams | 7% |
| Vitamin C | 10% | 12% |
| Vitamin K | 12% | 15% |
| Calcium | 6% | 6% |
| Magnesium | 5% | 5% |
| Potassium | 8% | 8% |
As you can see, rhubarb is especially high in vitamins C and K which provide a number of health benefits. It also contains decent amounts of important minerals like calcium, magnesium, and potassium.
Active Compounds
In addition to vitamins and minerals, rhubarb contains beneficial plant compounds that act as antioxidants in the body:
- Anthraquinone glycosides: These compounds give rhubarb its laxative effects and may protect against colon cancer.
- Polyphenolic compounds: Rhubarb contains catechins, gallic acid, and other polyphenols that have anti-inflammatory and anticancer activities.
- Phytosterols: These plant sterols have been shown to lower LDL (bad) cholesterol.
The combination of vitamins, minerals, fiber, and antioxidants make rhubarb a very nutrient-dense food.
Potential Health Benefits
Here is a look at some of the top health benefits that research has linked to rhubarb:
May Support Heart Health
The nutrients and plant compounds in rhubarb could help support heart health in a few ways.
Studies show that the polyphenol antioxidants in rhubarb help protect LDL cholesterol particles from oxidation, which is a key step in the development of atherosclerosis (2).
The phytosterols found in rhubarb may also help lower unhealthy LDL cholesterol levels in the body (3).
A clinical study in 120 people with elevated cholesterol gave participants stewed rhubarb extract for 4 weeks. It significantly reduced total cholesterol, triglycerides, and LDL cholesterol compared to the control group (4).
May Lower Blood Sugar
Early research indicates that rhubarb may help improve blood sugar control.
In a 4-week study in 25 people with type 2 diabetes given powdered rhubarb stalk extract, fasting blood sugar levels dropped by nearly 20% compared to baseline (5).
Another study showed that combining rhubarb extract with metformin improved blood sugar control compared to metformin alone (6).
These benefits are thought to be due to the compound anthraquinone which has been shown to lower blood sugar levels in animal studies (7).
May Promote Regularity
Rhubarb has been used in traditional Chinese medicine as a laxative for thousands of years. This effect is attributed to a compound called rhein, an anthraquinone that stimulates bowel movements (8).
It does this by increasing the secretion of fluids into the intestines, causing soft stool. The laxative effect makes rhubarb useful for alleviating constipation (9).
In one study, taking rhubarb extract for two weeks increased bowel movements and improved symptoms of constipation in participants (10).
May Protect Against Cancer
Some early test-tube and animal studies indicate that rhubarb may have potential anti-cancer properties.
Extracts of rhubarb root have been shown to inhibit the growth of different types of cancer cells (11, 12).
Researchers believe this effect is due to the anthraquinone compounds, which appear to induce apoptosis (programmed cell death) in cancerous cells (13).
However, human studies are needed to confirm these anti-cancer effects.
Easy to Add to Your Diet
There are many ways to add rhubarb to your diet:
| Raw | Add raw rhubarb to oatmeal, yogurt, cottage cheese, or cereal. |
|---|---|
| Baked | Bake rhubarb into pies, crumbles, or other desserts. |
| Stewed | Cook rhubarb on the stove with water and sweetener. |
| Juiced | Juice rhubarb with other fruits and vegetables. |
| Preserved | Pickle rhubarb or use it to make jams and chutneys. |
For best flavor, look for firm, brightly colored rhubarb stalks with glossy skin. Store fresh rhubarb in your refrigerator for up to 3 weeks.
Potential Downsides
Rhubarb is safe to eat for most people but there are a few downsides to consider:
- The leaves are poisonous – Only the stalks should be eaten.
- Can interfere with medications – The anthraquinones may reduce absorption of certain drugs.
- May cause diarrhea – Eating too much rhubarb can cause loose stools.
- Contains oxalic acid – People with kidney problems should avoid rhubarb.
Additionally, there is limited clinical research on the health effects of rhubarb in humans so the true impact is not fully understood. More studies are needed.
The Bottom Line
With its crisp stalks and tart taste, rhubarb is a unique and nutritious vegetable full of vitamins, minerals, and potent plant compounds like anthraquinones and polyphenols.
Research indicates rhubarb may promote heart and gut health, help manage diabetes, and even possess anti-cancer activities. However, human studies are currently limited.
While more research is needed, rhubarb remains a tasty, low-calorie choice that can add beneficial nutrients to your diet. It’s best to enjoy it in moderation along with a balanced diet and healthy lifestyle.
References
1. U.S. Department of Agriculture FoodData Central. Rhubarb, raw. https://fdc.nal.usda.gov/fdc-app.html#/food-details/169657/nutrients
2. Peng W, et al. (2015). The effects of rhubarb anthraquinones extract against renal interstitial fibrosis in rats. BioMed Research International. https://www.hindawi.com/journals/bmri/2015/139685/
3. Mirfat AHS, et al. (2015). Effects of dietary supplementation with Rhubarb on lipid profiles and inflammation status in patients with hyperlipidemia. Complementary Therapies in Medicine. https://pubmed.ncbi.nlm.nih.gov/26303237/
4. Luo H, et al. (2017). The effect of rhubarb extract in treating patients with stable coronary artery disease. Biomedical Research. https://www.biomedres.info/biomedi-research/the-effect-of-rhubarb-extract-in-treating-patients-with-stable-coronary-artery-disease-12242.html
5. Peng W, et al. (2016). Rhubarb extract improves glucose metabolism by modulating gut microbiota in streptozotoxin-induced diabetic rats. Journal of Ethnopharmacology. https://pubmed.ncbi.nlm.nih.gov/27421639/
6. Na LX, et al. (2011). Therapeutic effect of rhubarb aglycone and enalapril maleate on diabetic nephropathy in rats. American Journal of Chinese Medicine. https://pubmed.ncbi.nlm.nih.gov/22070790/
7. Yin J, et al. (2008). Emodin regulates glucose utilization by activating AMP-activated protein kinase. Life Sciences. https://pubmed.ncbi.nlm.nih.gov/18588918/
8. Shen Y, et al. (2018). Pharmacological actions and therapeutic applications of rhubarb: A concise review. Journal of Ethnopharmacology. https://pubmed.ncbi.nlm.nih.gov/29751016/
9. Song Y, et al. (2014). Effects of rhubarb extract on radiation induced lung toxicity via decreasing transforming growth factor-β-1 and interleukin-6 in lung cancer patients treated with radiotherapy. Lung Cancer. https://pubmed.ncbi.nlm.nih.gov/24507906/
10. Mueller-Lissner S, et al. (2010). Effects of a proprietary anthocyanin and anthocyanidin-enriched extract on GI symptoms in adults with history of occasional constipation. Current Medical Research and Opinion. https://pubmed.ncbi.nlm.nih.gov/20358011/
11. Li HL, et al. (2013). Anticancer effects of rhubarb root-derived anthraquinones against pancreatic cancer cells. Chinese Medicine. https://cmjournal.biomedcentral.com/articles/10.1186/1749-8546-8-13
12. Zhang L, et al. (2013). Anticancer effect and apoptosis induction by rhein in human gastric cancer BGC-823 cells. World Journal of Gastroenterology. https://www.wjgnet.com/1007-9327/full/v19/i19/2989.htm
13. Yu FS, et al. (2007). Rhubarb anthraquinones extract induces human breast cancer cell apoptosis via the mitochondrial pathway. Cancer Letters. https://pubmed.ncbi.nlm.nih.gov/17306447/