Amaranth: Benefits, Side Effects and Dosage

Amaranth, a group of ancient grains and leafy vegetables, has been a staple in diets around the world for centuries. From its vibrant red leaves to its tiny protein-rich seeds, amaranth is making a modern comeback thanks to its impressive nutritional profile and health benefits. But as with any food, it’s important to understand both its potential advantages and possible risks. This article explores the benefits, side effects, and optimal dosage of amaranth, synthesizing the latest scientific research for a clear, evidence-based overview.

Benefits of Amaranth

Amaranth is celebrated for its remarkable nutritional value and wide-ranging health benefits. Both its seeds (grain) and leaves are rich in essential nutrients, making it a powerful food for supporting overall wellness. Let’s explore what makes amaranth so special.

Antioxidant Powerhouse

Amaranth, both as a leafy vegetable and a grain, contains a rich array of antioxidant compounds. These include phenolic acids (such as gallic, chlorogenic, and ferulic acid), flavonoids (like quercetin, rutin, and kaempferol), and betalains, which together provide significant radical scavenging activity 1, 3, 4. Antioxidants are essential for neutralizing free radicals in the body, reducing oxidative stress, and protecting cells from damage. This can lower the risk of chronic diseases, including cancer, cardiovascular disease, and diabetes.

Anti-inflammatory Effects

Chronic inflammation underlies many health issues. Studies have found that amaranth contains bioactive peptides, especially when germinated and digested, which exhibit anti-inflammatory properties in laboratory models 5. Flavonoids and other phytochemicals in the plant may further help reduce inflammation, supporting joint health and potentially mitigating symptoms of inflammatory disorders 3, 4, 5.

Heart Health and Cholesterol

Amaranth grain is high in dietary fiber and beneficial phytochemicals that contribute to lowering plasma cholesterol levels. Its balanced protein profile and the presence of squalene, polyunsaturated fatty acids, and micronutrients also support cardiovascular health 2, 10. Regular consumption may help reduce the risk of hypertension and related heart issues.

Blood Sugar Control

Research indicates that amaranth may help in reducing blood glucose levels, making it a valuable addition to diets for people with diabetes or those seeking to manage blood sugar levels 2, 4. Its combination of protein, complex carbohydrates, and dietary fiber slows digestion and glucose absorption.

Immune System and Anemia

Amaranth’s high-quality protein and iron content support immune function and help prevent anemia 2. Its leaves and seeds are rich in minerals (iron, magnesium, calcium) and vitamins, making it useful in improving hemoglobin status and overall vitality.

Athletic Performance

One unique benefit of amaranth is its high content of dietary nitrates. A recent study demonstrated that supplementing with amaranth-derived nitrates for six days improved aerobic capacity and peak power in young athletes 8. This makes amaranth a potential natural supplement for endurance sports and physical performance.

Side Effects of Amaranth

While amaranth is generally safe and well-tolerated, especially when consumed as a food, certain considerations and potential side effects should be kept in mind, particularly with high doses or specific populations.

Kidney Effects at High Doses

Long-term animal studies using very high doses of amaranth (up to 1250 mg/kg/day) found no carcinogenic effects, but did report increased kidney calcification and some degenerative changes in female rats 6. These effects were seen at doses much higher than those typically consumed in human diets. While no direct adverse effects have been reported in humans at normal dietary levels, this suggests caution with high-dose supplementation, especially for individuals with pre-existing kidney conditions.

Gastrointestinal Disturbances

At the highest test doses in animal studies, some rats experienced poorly formed stools and red-colored feces due to the pigment content in amaranth 6. These effects are unlikely at typical dietary intakes but could occur with excessive consumption or concentrated extracts.

No Carcinogenicity or Pregnancy Risk

Importantly, no evidence of carcinogenicity has been found in animals even with long-term, high-dose exposure to amaranth 6. Moreover, studies in pregnant rats found no negative effects on embryo development, fetal weight, or implantation, even at relatively high doses 7. This suggests that amaranth is safe for consumption during pregnancy within normal dietary limits.

Allergies and Sensitivities

Although not highlighted in the animal studies, it is possible for some individuals to experience allergic reactions to amaranth, as with any food. Symptoms may include gastrointestinal upset, rash, or other allergic responses, though these are rare 2.

Dosage of Amaranth

Determining the optimal dose of amaranth depends on the form (grain, leaf, extract) and the health goal. While amaranth is a common food, research on its use as a functional ingredient or supplement has offered some dosage guidance.

Dietary Consumption

• Grain/Seed: Amaranth grain can be cooked and eaten like rice, or ground into flour for baking. Studies suggest up to 30% amaranth flour can be used in bread without significantly compromising baking properties, while boosting nutritional value 10.
• Leafy Vegetable: Fresh amaranth leaves are commonly eaten in salads, soups, or stir-fries. Agronomic studies suggest that optimal biomass yields are achieved with certain fertilization levels, but for the consumer, including a cup or two of amaranth greens in meals is typical 9.

Supplementation

• Dietary Nitrates: For athletic performance, a concentrated amaranth supplement delivering about 400 mg of dietary nitrate daily for 6 days improved aerobic capacity in young men 8. This is equivalent to a standardized extract and should not be confused with consuming raw leaves or seeds.
• Extracts and High-Dose Use: Animal studies have tested much higher doses (up to 1250 mg/kg/day) without carcinogenic effects, but kidney changes were noted at the highest doses 6. Such levels are not relevant to normal food use.

Practical Recommendations

• For general nutrition, replacing part of regular flour with amaranth flour (up to 30%) in baking, or adding a serving (about 1 cup cooked) of amaranth leaves or grains to daily meals, is safe and beneficial.
• For sports or medical supplementation, standardized extracts should be used as per research (e.g., for nitrates, 400 mg daily for up to a week), and medical supervision is advised.

Conclusion

Amaranth stands out as a nutritionally dense food with diverse health benefits, making it a valuable addition to modern diets. Here’s a summary of the key points:

• Rich in Nutrients: High levels of protein, fiber, minerals, vitamins, and unique phytonutrients.
• Health Benefits: Antioxidant, anti-inflammatory, cholesterol-lowering, blood-sugar stabilizing, immune-supporting, and athletic performance-enhancing effects demonstrated in research 1 2 3 4 5 8.
• Generally Safe: No carcinogenicity found; minor kidney effects only at extremely high doses in animal studies 6. No adverse effects during pregnancy at normal intakes 7.
• Optimal Dosage: Up to 30% of flour mix for baking, or a serving of leaves/grains daily is safe; for sports, 400 mg dietary nitrate extract for up to 6 days, if desired 8 10.
• Cautions: Excessive intake (far above food levels) may not be advisable, especially for those with kidney issues.

Amaranth is a versatile, health-promoting food that fits easily into a variety of culinary traditions. As with all foods, moderation and variety are key to reaping the most benefits while minimizing risk.