Common Digestive Side Effects
Even when taken in recommended amounts, flaxseed oil can cause several gastrointestinal issues, which are often more pronounced with higher consumption. These side effects are typically manageable but can be uncomfortable for some individuals.
Bloating, Gas, and Diarrhea
Excessive gas and bloating are among the most frequently reported side effects. This can be caused by the body adjusting to the new supplement, particularly in higher quantities. Higher amounts of flaxseed oil have been shown to cause loose stools and diarrhea. Taking the supplement with plenty of water can help mitigate these effects.
Stomach Upset and Dry Mouth
For some, flaxseed oil can lead to a general feeling of stomach upset or discomfort. Another potential but less common side effect is a dry mouth. These issues can often be alleviated by reducing the amount or taking the oil with a meal.
Potential for Intestinal Obstruction
In rare cases, consuming large amounts of flaxseed—the seeds themselves, not the oil—taken without enough fluid can potentially lead to an intestinal blockage. While this is more common with the seeds due to their fiber content, it's a reminder of the importance of proper consumption and hydration when using flaxseed products.
Serious Health Risks and Precautions
Beyond common digestive complaints, there are more serious health risks and important precautions to consider before using flaxseed oil, especially for specific populations.
Increased Bleeding Risk
Flaxseed oil has natural blood-thinning properties. This means it can slow blood clotting, and when taken in combination with anticoagulant or antiplatelet drugs (like warfarin, aspirin, or heparin), it can significantly increase the risk of bruising and bleeding. Due to this risk, it is highly recommended to stop taking flaxseed oil at least two weeks before any scheduled surgery.
Hormonal Effects and Pregnancy
Flaxseed and flaxseed oil can act like the hormone estrogen. For this reason, there is a risk that high amounts taken during the second or third trimesters of pregnancy could increase the risk of premature birth. Because of this, pregnant and breastfeeding individuals should avoid flaxseed oil unless specifically advised by their doctor. Furthermore, individuals with hormone-sensitive conditions like breast, ovarian, or uterine cancers should also exercise caution.
Allergic Reactions
Although rare, allergic reactions to flaxseed oil are possible. Symptoms of an allergic reaction can include skin rashes, swelling (especially of the face, tongue, or throat), severe dizziness, and trouble breathing. Anyone experiencing these symptoms should seek immediate medical attention.
Drug and Supplement Interactions
Flaxseed oil has the potential to interact with several types of medications and supplements. It is crucial to consult a healthcare provider before combining flaxseed oil with other treatments.
Blood Thinners (Anticoagulants)
As noted, flaxseed oil's effect on blood clotting can be amplified by anticoagulant and antiplatelet medications, leading to a higher risk of bleeding.
Blood Pressure Medications
Flaxseed oil may lower blood pressure. Taking it with antihypertensive drugs could cause blood pressure to drop too low, potentially leading to dizziness or fainting.
Diabetes Medications
Flaxseed may lower blood sugar levels in some individuals. Combining it with diabetes medications could cause blood sugar to fall dangerously low. Blood sugar levels should be monitored closely in these cases.
Absorption of Other Medications
Flaxseed oil can interfere with the absorption of other oral medications. To avoid this, it is recommended to take oral medications at least one to two hours before or after consuming flaxseed oil.
Flaxseed Oil vs. Whole or Ground Flaxseeds
Flaxseed oil and whole or ground flaxseeds have different properties and potential side effects. The oil contains concentrated omega-3s, while the seeds contain fiber and lignans not present in the oil.
| Feature | Flaxseed Oil | Whole or Ground Flaxseeds |
|---|---|---|
| Fiber Content | None | High (Soluble & Insoluble) |
| Lignans | None | High (Antioxidant compounds) |
| Key Benefit | Pure omega-3 fatty acids (ALA) | Fiber for digestion, ALA, and lignans |
| Digestive Effects | Can cause diarrhea in high amounts | Can cause bloating, gas; helps with constipation |
| Constipation Risk | Low | Higher if not consumed with enough water |
| Potential Toxicity | None from mature seeds | Raw or unripe seeds are potentially poisonous |
Who Should Avoid Flaxseed Oil?
For safety, certain individuals should either avoid or use flaxseed oil with extreme caution and under medical supervision. This includes:
- Pregnant and breastfeeding women.
- Individuals on blood-thinning medications.
- Patients taking blood pressure or diabetes medications.
- People with hormone-sensitive conditions or cancers.
- Anyone scheduled for surgery within two weeks.
- Individuals with a known allergy to flaxseed.
Conclusion: Balancing Benefits and Risks
While flaxseed oil is generally safe for most healthy adults in recommended amounts, the potential for side effects, drug interactions, and special precautions cannot be ignored. The most common issues are mild digestive complaints, but more serious risks like increased bleeding and hormone-like effects warrant careful consideration, especially for certain populations. Consulting a healthcare provider before starting any new supplement is the best way to ensure it is appropriate and safe for your individual health needs.
For those seeking the benefits of flaxseed, discussing the potential risks and interactions with a professional is the most responsible approach. Knowing the differences between flaxseed oil and ground flaxseed is also key to managing expectations and potential effects, particularly concerning fiber intake. A balanced and informed perspective is essential for safely incorporating this supplement into your diet.
