Who Should Avoid Rhubarb?
While rhubarb is a popular ingredient in desserts and certain dishes, its medicinal properties and high oxalate content mean it is not safe for everyone. The following groups of people should generally avoid consuming rhubarb, particularly in concentrated, medicinal amounts, unless specifically advised by a healthcare professional.
Individuals with Kidney Conditions
People with a history of kidney stones or existing kidney disease should steer clear of rhubarb. Rhubarb is notably high in oxalates, particularly oxalic acid. Ingesting high levels of oxalates can increase the risk of forming calcium oxalate kidney stones, the most common type of kidney stone. For those with pre-existing kidney disease, consuming rhubarb could potentially worsen kidney function. Even some reports link rhubarb-containing supplements to kidney failure. The leaves, which are toxic due to their extremely high oxalic acid content, should never be consumed.
Those with Gastrointestinal (GI) Issues
As a stimulant laxative, rhubarb can have a powerful effect on the bowels and is contraindicated for certain digestive conditions. People with inflammatory bowel diseases (IBD) such as Crohn's disease, ulcerative colitis, or irritable bowel syndrome (IBS) should not take rhubarb as it can exacerbate symptoms. In addition, anyone experiencing a bowel obstruction, appendicitis, or undiagnosed abdominal pain should avoid it. Chronic misuse as a laxative can lead to electrolyte imbalances, especially potassium loss, and long-term dependence.
Pregnant and Breastfeeding Individuals
For expecting and nursing mothers, it is generally recommended to avoid rhubarb in medicinal quantities. While small, cooked food amounts are usually considered safe, higher concentrations may pose risks. Specifically, anthraquinones in rhubarb root can cross into breast milk, potentially causing a laxative effect in the nursing infant. During pregnancy, the risk of uterine contractions with large doses is a concern, though anecdotal reports of miscarriage are not supported by strong evidence. The safest course of action is to stick to food amounts or avoid it altogether.
Individuals with Liver Problems
For those with existing liver conditions, consuming rhubarb may worsen liver function. Some medications can also harm the liver, and combining them with rhubarb could increase the risk of liver damage. Therefore, people with liver disease should be cautious and consult their doctor before using rhubarb, especially in medicinal forms.
People on Certain Medications
Several drug interactions make rhubarb unsafe for individuals taking specific medications. The stimulant laxative effect can decrease potassium levels, which can be particularly dangerous when combined with other drugs.
Notable Drug Interactions:
- Digoxin (Lanoxin): Low potassium from rhubarb can increase the risk of digoxin side effects.
- Warfarin (Coumadin): The laxative effect can cause diarrhea, increasing the risk of bleeding in those on warfarin.
- Diuretic Drugs ('Water Pills'): Taking these with rhubarb can cause potassium levels to drop too low.
- Corticosteroids: These medications also decrease potassium, so combining with rhubarb could lead to critically low levels.
- Cyclosporine: Rhubarb can reduce the absorption of this immunosuppressant, decreasing its effectiveness.
- Oral Drugs: Rhubarb, as a laxative, can decrease the absorption of other medications taken by mouth, reducing their efficacy.
Other Vulnerable Populations
- Children under 12: Rhubarb root preparations are not recommended for children under 12. The risk of toxicity from oxalic acid, even in the stalks, is higher in smaller individuals.
- Individuals with Gout: Some foods high in oxalates, including rhubarb, have been advised against for people with gout as oxalates can increase uric acid levels.
Summary of Rhubarb Precautions
Here is a comparison of scenarios where rhubarb consumption is safe versus unsafe.
| Condition / Population | Food-Grade Rhubarb (Stalks) | Medicinal Rhubarb (Root/Concentrate) |
|---|---|---|
| Healthy Adults | Generally safe in moderation | Use cautiously and for short-term periods only |
| Kidney Disease/Stones | Avoid or limit due to high oxalate content | Strictly contraindicated due to high oxalate content |
| Inflammatory Bowel Disease | Avoid or limit intake | Strictly contraindicated as it can worsen inflammation |
| Pregnancy/Breastfeeding | Cooked stalks are generally safe in moderation | Avoid; can pose risks to mother and infant |
| Taking Warfarin | Limit intake and consult a doctor | Avoid; increases bleeding risk |
| Taking Diuretics | Limit intake and consult a doctor | Avoid; can cause low potassium |
| Children under 12 | Monitor intake; avoid leaves | Avoid completely |
How to Reduce Risk When Consuming Rhubarb
If you are not in one of the high-risk categories, you can minimize potential issues with rhubarb by following these practices:
- Stick to the Stalks: The leaves are toxic due to their high oxalic acid content and should never be consumed.
- Cook Thoroughly: Cooking rhubarb reduces the oxalate content, making it safer to eat.
- Combine with Calcium: Pairing rhubarb with calcium-rich foods like milk or yogurt can help bind the oxalates, reducing their absorption.
- Limit Frequency: Do not use rhubarb root preparations for extended periods as a laxative, as this can lead to dependence and electrolyte imbalances.
Conclusion
While many people can enjoy rhubarb's tart flavor in culinary dishes, it's crucial to be aware of its potential health risks, especially when taken in medicinal doses. Individuals with kidney stones, inflammatory bowel disease, liver problems, or those who are pregnant, breastfeeding, or taking specific medications must exercise significant caution or avoid rhubarb altogether. Always discard the toxic leaves and consult a healthcare provider if you have any pre-existing conditions or are on medication. By understanding these precautions, you can ensure your safety and well-being. For more information on drug interactions and safety, consult reputable medical resources like WebMD's rhubarb monograph.
Note: The information provided here is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before making any changes to your diet or health regimen.
What are the risks of taking rhubarb for extended periods?
Long-term use of rhubarb, particularly as a laxative, can lead to chronic diarrhea, potassium loss, muscle weakness, and in rare cases, kidney issues. It can also lead to laxative dependence.
Why is rhubarb bad for people with kidney stones?
Rhubarb is very high in oxalates, and for individuals prone to kidney stones (especially calcium oxalate stones), high oxalate intake can increase the risk of stone formation.
Can rhubarb affect my medication?
Yes, rhubarb can interact with certain medications. Its laxative effect can decrease the absorption of oral drugs and cause a drop in potassium, affecting medications like digoxin, corticosteroids, and diuretics.
What parts of the rhubarb plant are toxic?
Rhubarb leaves contain high concentrations of toxic oxalic acid and should never be eaten. Only the stalks are edible, and even they contain oxalates.
Is it safe to eat cooked rhubarb during pregnancy?
Cooked rhubarb stalks are generally considered safe in moderation during pregnancy, but large or concentrated medicinal amounts should be avoided due to potential risks like uterine contractions and transfer of anthraquinones through breast milk.
What gastrointestinal conditions are contraindicated with rhubarb?
Rhubarb should not be taken by people with a bowel obstruction, appendicitis, inflammatory bowel diseases like Crohn's or ulcerative colitis, or undiagnosed abdominal pain.
How can I reduce the oxalate content when cooking rhubarb?
You can reduce the oxalate content by thoroughly cooking the rhubarb and discarding the cooking water. Pairing it with a calcium source, like dairy, can also help bind the oxalates.
