Red Amaranth (Amaranthus cruentus)

Red amaranth (Amaranthus cruentus) is an ancient grain rich in bioactive compounds including betalains, lysine, and iron that support hemoglobin synthesis and cardiovascular health. Its high lysine content enhances iron bioavailability, making it particularly effective for addressing iron deficiency anemia.

Origin & History

Red Amaranth (Amaranthus cruentus) is an annual herbaceous plant native to Central and South America, recognized by the USDA as a nutrient-dense food for its high iron and protein content.[1][7] The plant's red-pigmented leaves are the primary source, typically prepared through aqueous extraction methods like steaming or by being dried into a powder for dietary use.[2][8]

Historical & Cultural Context

Amaranth species, including red varieties, have been used for millennia in Mesoamerican traditional medicine by cultures like the Aztecs and Mayas to address anemia, inflammation, and nutritional needs.[1][3][6] Its use as a nutritive green and medicinal extract is also documented in traditional African and Asian systems for similar purposes.[1][3][6]

Health Benefits

["\u2022 Supports Healthy Hemoglobin Levels: A 2024 meta-analysis of clinical trials found that amaranth-containing foods significantly improved hemoglobin levels, with a notable effect in postpartum women (mean difference of 0.85 g/dL). Evidence is moderate, with some study limitations noted.[1]", "\u2022 Protects Cells from Glycation: In-vitro evidence shows that aqueous extracts from steamed leaves protect human lens cells against high-glucose injury by reducing advanced glycation endproducts (AGEs) and reactive oxygen species (ROS). This evidence is preliminary.[2]", "\u2022 Provides Antioxidant Action: Preclinical research on human cells demonstrates that red amaranth extract upregulates key antioxidant and protective pathways, including Nrf2 mRNA (12-38% increase) and mitochondrial membrane potential (18-51% increase). This evidence is preliminary.[2]", "\u2022 May Reduce Inflammation: In-vitro studies suggest amaranth extracts can lower the gene expression of pro-inflammatory cytokines such as IL-1, IL-6, and TNF, indicating potential anti-inflammatory effects. This evidence is preclinical.[3]", "\u2022 Supports Healthy Lipid Metabolism: In animal models, amaranth powder was shown to reduce liver triglycerides, cholesterol, and phospholipids, though the specific pathways were not identified. This evidence is from animal studies.[3]"]

How It Works

Red amaranth's high lysine content (6.2% of total amino acids) enhances iron absorption in the duodenum by reducing iron to its ferrous state. The grain's betalain pigments provide antioxidant protection through free radical scavenging, while its complete amino acid profile supports hemoglobin synthesis by providing essential building blocks for heme production.

Scientific Research

The strongest human evidence comes from a 2024 systematic review and meta-analysis (PROSPERO CRD42023476402) of RCTs, which concluded that amaranth consumption significantly improves hemoglobin levels.[1] One included RCT (n=21) found red spinach extract tablets increased hemoglobin more than iron capsules alone. However, large-scale clinical trials specifically for Amaranthus cruentus in other conditions like diabetes or cancer are currently lacking, with most other evidence being preclinical.[1][2][3]

Clinical Summary

A 2024 meta-analysis of clinical trials demonstrated that amaranth-containing foods significantly improved hemoglobin levels, with the most pronounced effect in postpartum women showing a mean difference of 0.85 g/dL compared to controls. The evidence quality is considered moderate due to some study limitations including varied intervention protocols and small sample sizes in several included trials. Most studies examined whole amaranth grain consumption rather than isolated supplements, limiting direct supplementation guidance.

Nutritional Profile

Red Amaranth (Amaranthus cruentus) provides approximately 371-374 kcal per 100g dry weight. Macronutrients: protein 13-15g/100g (notably high for a grain, containing all essential amino acids with lysine at ~5.4g/100g protein, a key limiting amino acid in most cereals); carbohydrates 65-69g/100g; dietary fiber 6-7g/100g (mix of soluble and insoluble); fat 6-8g/100g (rich in unsaturated fatty acids, particularly linoleic acid ~50% of total fatty acids, and squalene at 4-8% of oil content — unusually high compared to other grains). Micronutrients per 100g dry weight: iron 7-9mg (high but with moderate bioavailability due to phytate and oxalate content; germination or fermentation improves absorption by ~30-40%); calcium 150-160mg; magnesium 248-266mg; phosphorus 455-460mg; zinc 2.9-3.3mg; potassium ~366mg; manganese ~3.3mg. Vitamins: folate ~82mcg; vitamin E (tocopherols) ~1.2mg; B vitamins including thiamine (~0.12mg), riboflavin (~0.20mg), niacin (~0.92mg). Bioactive compounds: betacyanins (responsible for red pigmentation, primarily amaranthine and isoamaranthine) at 15-68mg/100g fresh weight depending on variety and growing conditions — these are water-soluble pigments with antioxidant and anti-glycation properties; total polyphenols 100-350mg GAE/100g; rutin and quercetin derivatives present at measurable levels (~10-30mg/100g dry weight). Starch digestibility is moderate; amaranth starch has a relatively small granule size (1-3 microns) and higher digestibility than many other ancient grains, though resistant starch fraction (~5-10%) contributes to fiber benefits. Bioavailability notes: phytate content (0.6-1.0g/100g) can reduce mineral absorption; soaking, sprouting, or fermentation is recommended to enhance mineral bioavailability. Protein digestibility-corrected amino acid score (PDCAAS) is approximately 0.75-0.90, higher than most plant proteins.

Preparation & Dosage

Clinically studied forms include amaranth powder mixed into foods like bread and leaf extract tablets, though precise dosages were not consistently quantified in the research.[1][8] In-vitro studies used aqueous extracts at 0.25-1% concentrations for cellular tests, which does not translate to human dosing.[2] No standardized extracts or established dosage ranges for human supplementation have been reported. Consult a healthcare provider before starting any new supplement.

Synergy & Pairings

Iron, Vitamin C, Folate (Vitamin B9), Vitamin B12

Safety & Interactions

Red amaranth is generally well-tolerated as a food ingredient with no serious adverse effects reported in clinical studies. Individuals with amaranth allergies should avoid consumption, and those with celiac disease should verify gluten-free processing. No significant drug interactions have been documented, though the high fiber content may affect absorption timing of medications. Pregnant and breastfeeding women can safely consume red amaranth as part of a balanced diet.