Black Cumin Shows Promise for Lowering Cholesterol in Clinical Trial

A black seed with a long history in cookery and traditional medicine has demonstrated potential to reduce cholesterol in a recent clinical trial.

Laboratory experiments using cultured cells also indicate that it could hinder the development of mature fat cells.

Black cumin and its traditional uses

Black cumin (Nigella sativa) is a flowering plant indigenous to western Asia and eastern Europe. Its seeds are widely used as a spice, including in curries and as a topping for vegetables.

Archaeological findings indicate that people have grown cumin for millennia. In folk medicine, it is commonly taken as an oil, paste, powder or extract.

Only in recent years has Western science begun to examine cumin more closely. Although the evidence remains limited, early findings-largely from cell and animal research-point to potentially overlooked health benefits from this familiar spice, including possible antioxidant and anti-inflammatory effects.

Clinical trial finds changes in cholesterol

In a recent clinical trial conducted by researchers at Osaka Metropolitan University in Japan, 22 participants consumed 5 grams of black cumin seed powder daily. After eight weeks, they had lower bad cholesterol and higher good cholesterol. No comparable changes were seen among the 20 participants in the control group.

The authors propose that these benefits, achieved with about a spoonful of cumin powder per day, could eventually support cardiovascular health and reduce the risk of later heart problems.

"This study strongly suggests that black cumin seeds are useful as a functional food for preventing obesity and lifestyle-related diseases," says food scientist Akiko Kojima-Yuasa.

"It was so gratifying to see black cumin comprehensively demonstrate actual, demonstrable blood lipid-lowering effects in a human trial."

The results add to several other small preliminary cumin trials, which have indicated possible benefits for weight loss and cholesterol levels.

Evidence on cumin remains mixed

However, the findings have not been consistent, and some of the available evidence is disputed.

For example, a prominent 2015 trial reported that daily cumin capsules could produce the same results as cholesterol-lowering medication such as orlistat. The scientific journal subsequently marked the findings with an ‘expression of concern’, a notice commonly issued where misconduct or unreliable results are suspected. It is unclear which of those possibilities applies in this case.

Since then, several other clinical trials have identified cholesterol-lowering effects from cumin, though the benefits were smaller.

The latest research by Kojima-Yuasa and colleagues indicates that black cumin may limit fat formation through effects on crucial genetic regulators involved in metabolism. Further research is required.

"We hope to perform longer-term and larger-scale clinical trials to investigate the effects of black cumin on metabolism," says Kojima-Yuasa.

"We are particularly interested in investigating its effects on insulin resistance in diabetes and inflammatory markers."

The study was published in Food Science & Nutrition.