New Zealand flower extract helps curb hunger during intermittent fasting: Study

By Danielle Masterson

- Last updated on GMT

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Related tags Weight loss intermittent fasting Amarasate Obesity

Intermittent fasting has gained traction in the United States as a way to lose weight. Amarasate, a weight-management extract, is being touted as an effective anorexigenic agent for such a diet.

About half of American adults have at least one diet-related chronic disease like heart disease, high blood pressure, type 2 diabetes, obesity, and certain cancers, according to the 2015–2020 Dietary Guidelines for Americansreport​. Modern excesses in the Western diet have resulted in increased rates of these types of diet-related conditions. 

In addition to diseases, a poor diet can wreak havoc on the microbiome. Research suggests that eating a high-fat, high-sugar diet kills essential bacteria in the gut, throwing it off balance and causing the immune system to malfunction.

Dietary interventions are a common initial remedy, which typically include modifying diet composition and imposing food choice restrictions. However, restrictive diets often result in poor compliance.

Watching the clock 

Intermittent fasting (IF) is an unconventional diet that is emerging as an alternative to other types of diets. It does not require changes in food choice or diet composition. Instead, IF relies on time-restricted eating, reduction in daily caloric intake or complete water-only fasting days.

Fasting is believed to support a healthy metabolism, heart health and brain health, as well as healthy blood sugar levels, which could reduce the risk of type 2 diabetes.

Researchers in New Zealand wanted to further the success of the diet trend by finding a way to make it easier to follow. 

"Despite such health benefits, increased hunger near the end of the fasting period can make it harder to stick to, and reduce the desire to repeat it,"​ said Dr. Edward Walker, lead author of the study. 

Scientists turned to extract Calocurb, a New Zealand-grown bitter hop flower extract that aims to manage food cravings and portion control. The extract is trademarked by brand name Amarasate and owned by government-funded Plant & Food Research​ (PFR). 

When specific cells in the small intestine sense certain bitter compounds in food, a hormonal response is triggered that signals the brain to stop eating. Amarasate works by triggering this "bitter brake.”

Study details

For the study, 30 adult men were required to fast for 24 hours on the same day of the week for three subsequent weeks. The participants were given a high or low dose of Amarasate, or a placebo. Both groups given Amarasate reported a statistically significant (>10%) reduction in hunger. Nor did they experience the same lunchtime hunger the placebo group did 18 hours into their fast.

The study by eight Plant & Food Research scientists was then peer-reviewed and published in the international scientific journal Nutrients​. 

Dr. Walker said the findings suggest Amarasate may be used for reducing hunger during intermittent fasting and show that bitter compounds may regulate appetite independently of meal timing.

"This study determined the efficacy of a bitter extract to regulate appetite towards the end of 24 hour period of a water-only fasting and showed that the targeted delivery of Amarasate can reduce hunger and increase fullness during the late stages of the fast,"​ said Dr Walker.

From the bush to the states 

Amarasate was developed by Plant & Food Research, New Zealand's largest government research institute, before being commercialized by nutrition and e-commerce company, Calocurb Ltd, in 2018.

The product contains three ingredients: hops flower, rosemary, and canola seed oil. The ingredients are encapsulated in Capsugel’s patented Licaps capsule, which helps with its targeted release mechanism. 

Although the product was developed in New Zealand, the company’s CEO told NutraIngredients-USA in 2018​ that “it was specifically developed for the US market.”

The product hit the US market in 2018 and is currently being sold online under the name Calocurb. A 30-day supply of 45 capsules costs $49.95. 



 2019, 11(11), 2754;

"New Zealand Bitter Hops Extract Reduces Hunger During a 24 h Water Only Fast"

Authors: E. Walker, et al

Related topics Research

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