What happens if you eat too much ALA? Understanding the Risks

November 16, 2025 •

3 min read

According to the National Institutes of Health, while ALA from food is generally safe, consuming excessive amounts, especially from supplements, can lead to side effects. This guide explores what happens if you eat too much ALA, clarifying the difference between alpha-lipoic acid and alpha-linolenic acid and their respective safety profiles.

Quick Summary

Consuming too much ALA, particularly supplemental alpha-lipoic acid, can cause mild side effects like nausea, headache, or low blood sugar. Excessive dietary alpha-linolenic acid is generally safe from food, but high calories may lead to weight gain.

Key Points

Two ALAs: The term ALA refers to both Alpha-Lipoic Acid (an antioxidant) and Alpha-Linolenic Acid (an omega-3 fatty acid), with different sources and risks.
Supplemental ALA Risks: Excessive Alpha-Lipoic Acid (supplements) can cause nausea, headache, and low blood sugar, especially in individuals with diabetes.
Dietary ALA Safety: Alpha-Linolenic Acid from food is generally safe, but high intake of ALA-rich foods can lead to weight gain due to high caloric content.
Medication Interactions: Supplemental Alpha-Lipoic Acid can interfere with diabetes medication, thyroid hormone, and blood-clotting drugs.
High-Dose Dangers: Very high doses of Alpha-Lipoic Acid, especially in overdose scenarios, have been linked to severe neurological and organ effects.
Potential Prostate Cancer Link: Some studies suggest a possible correlation between very high dietary Alpha-Linolenic Acid intake and prostate cancer risk, though evidence is not conclusive.
Professional Consultation: Always consult a healthcare provider before beginning high-dose ALA supplementation to understand proper dosage and avoid adverse effects.

The term ALA can cause confusion as it refers to two different substances: Alpha-Lipoic Acid and Alpha-Linolenic Acid. Alpha-Lipoic Acid is an antioxidant produced by the body and also found in supplements and some foods, like spinach and broccoli. Alpha-Linolenic Acid is an essential omega-3 fatty acid found in plants like flaxseed, walnuts, and canola oil. While both are important for health, the risks associated with consuming "too much" differ significantly depending on which ALA is being discussed.

The Risks of Excessive Alpha-Lipoic Acid (ALA)

Consuming too much Alpha-Lipoic Acid, especially through supplements, is associated with a range of potential side effects. Side effects from high doses of alpha-lipoic acid supplements can include gastrointestinal issues, hypoglycemia, allergic reactions, neurological concerns, and interference with thyroid function. Animal studies also suggest high doses could affect liver enzymes.

The Effects of Excessive Dietary Alpha-Linolenic Acid (ALA)

Alpha-Linolenic Acid from food sources is generally not a major concern. Excessive intake from calorie-dense sources can lead to weight gain. Some studies suggest a potential link between high dietary ALA and increased prostate cancer risk, but evidence is inconclusive.

Differentiating Alpha-Lipoic vs. Alpha-Linolenic Acid


Feature	Alpha-Lipoic Acid (Antioxidant)	Alpha-Linolenic Acid (Omega-3 Fatty Acid)
Source	Produced in the body, found in foods like organ meats and spinach, and sold as supplements.	An essential fatty acid found in plant-based sources like flaxseed, walnuts, and canola oil.
Primary Function	Acts as an antioxidant, helping to turn food into energy.	Plays roles in heart health, inflammation, and brain function; converted to EPA and DHA.
Excessive Intake	Primarily an issue with supplemental intake. High doses can cause distinct side effects.	Typically not a concern from food sources, but high-calorie content can lead to weight gain. Potential (though debated) link to prostate cancer.
Typical Dosage	Supplemental doses are often 600-1800 mg/day for specific conditions.	Adequate Intake is 1.6 g/day for men and 1.1 g/day for women.

Understanding the Implications for Supplements and Diet

Understanding the type and source of ALA is important. While food-based alpha-linolenic acid is part of a healthy diet, the primary risks of excessive intake are linked to concentrated amounts found in supplements, particularly alpha-lipoic acid supplements. Adhering to recommended dosages is crucial for supplements. For dietary ALA, a balanced diet including sources like walnuts and flaxseed provides adequate intake without excessive calories. Consulting a healthcare professional is recommended before taking high-dose supplements.

For reliable information on dietary nutrients, including omega-3 fatty acids, the Office of Dietary Supplements at the National Institutes of Health is a valuable resource.

Conclusion

Consuming too much ALA from supplements, specifically alpha-lipoic acid, is associated with a higher risk of side effects such as nausea, headache, and potential interactions with medications. Excessive dietary alpha-linolenic acid is less problematic, although the high-calorie nature of its food sources can contribute to weight gain. Distinguishing between these two types of ALA is essential. Before starting any high-dose ALA supplementation, consult a healthcare provider to ensure safety and determine the appropriate intake for your health needs.

What are the symptoms of too much ALA?

Gastrointestinal Distress: Including nausea, vomiting, and heartburn, often from high-dose alpha-lipoic acid supplements.
Headache: A possible side effect of higher doses of alpha-lipoic acid.
Hypoglycemia: Risk of low blood sugar, particularly with supplemental alpha-lipoic acid in individuals on diabetes medication.
Skin Reactions: Potential for rashes or itching with supplemental ALA.
Weight Gain: Associated with overconsumption of high-calorie, dietary alpha-linolenic acid sources.
Severe Neurological Effects: In very rare, extreme overdose cases of alpha-lipoic acid.

Frequently Asked Questions

Alpha-lipoic acid is an antioxidant made by the body and also available as a supplement, while alpha-linolenic acid is an essential omega-3 fatty acid found in plant foods like flaxseed and walnuts.

Yes, taking excessive alpha-lipoic acid, especially through supplements, can cause side effects including nausea, vomiting, headache, heartburn, and skin rashes.

Eating seeds and nuts high in alpha-linolenic acid is generally safe. However, they are high in calories, so excessive consumption could lead to weight gain.

For diabetics, supplemental alpha-lipoic acid can potentially lower blood sugar levels. This may cause hypoglycemia, so blood sugar should be closely monitored in consultation with a doctor.

Some studies have suggested a possible link between high dietary intake of alpha-linolenic acid and a slightly increased risk of prostate cancer, but the evidence is not conclusive and more research is needed.

For alpha-linolenic acid from food, exceeding the Adequate Intake (AI) of 1.6g/day for men and 1.1g/day for women is not considered overtly dangerous, but consuming too many high-calorie sources can contribute to weight gain.

You should check the supplement's ingredient list and the product description. Alpha-linolenic acid will typically be listed as omega-3 or specifically as ALA from plant sources like flax or chia. Alpha-lipoic acid will be identified as such and often marketed for its antioxidant properties.