The aim of this review was to summarize data regarding amaranth as a potential component of lifestyle modification to improve cardiovascular risk profiles by modifying cardiovascular risk factors such as cholesterol, diabetes, and hypertension. PubMed was searched for appropriate articles.
The main inclusion criteria for articles were as follows: interventions with amaranth; conducted in humans or animals or in vitro; and reported serum lipids and lipoprotein levels, and antidiabetic, antihypertensive, and antioxidant abilities. The outcome measures were changes in serum lipids and the presence of antidiabetic, antihypertensive, and antioxidant activity.
A total of 33 articles were included herein. Regarding hypolipidemic activity, most studies investigated the effect of intervention with amaranth in animals, and fewer studies were performed in humans.
Most studies in animal models demonstrated the ability of amaranth to decrease total cholesterol and low-density lipoprotein cholesterol. Pilot studies in humans were not convincing regarding amaranth's lipid-lowering activity.
Based on this search, it is not clear which constituents are potentially responsible for the hypocholesterolemic effect of amaranth. Some authors tend to think that squalene can play a role in this effect, whereas others suggest that different components of amaranth are of greater importance (eg, sterols, oil fractions rich in fatty acids, proteins, amino acids, or fiber) for its hypocholesterolemic effect.
It is possible that several constituents are jointly responsible for this action. Regarding the antidiabetic, antihypertensive, and antioxidant activities, most studies were performed in vitro and showed good potential for all three biological effects.
Future research should focus on clarifying the effect of amaranth on high-density lipoprotein cholesterol, identifying the constituents responsible for these beneficial effects, and providing more data regarding its use in humans, ideally using randomized controlled trials. The antidiabetic, antihypertensive, and antioxidant activities found in vitro should be confirmed further in animal or human models.