A compound found in broccoli sprouts apparently prevents obesity and fatty liver disease by boosting the amount of brown fat and improving the composition of gut bacteria linked to a high-fat diet, Japanese researchers say.
The mouse study also found that the compound, called sulforaphane, used potent antioxidant pathways to exert its anti-inflammatory effects in the liver. That leads researchers to believe that sulforaphane supplements might prevent the devastating effects of a high-fat diet — but they stressed that this compound should first be studied in clinical trials.
Their study, “Glucoraphanin Ameliorates Obesity and Insulin Resistance Through Adipose Tissue Browning and Reduction of Metabolic Endotoxemia in Mice,” appeared in the journal Diabetes.
Earlier studies of sulforaphane suggest that the compound may protect from cancer by acting on a gene-activating factor that boosts antioxidant events in the body.
Since obesity is known to lower the antioxidant capacity, researchers at Japan’s Kanazawa University figured that sulforaphane might also be beneficial in obesity-related processes. To find out, the team — along with colleagues at Japanese food conglomerate Kagome — fed mice a high-fat diet. Some of the animals also received a molecule that turns into sulforaphane in the body.
After 14 weeks, mice that ate the broccoli-chemical had gained 15 percent less weight than the high-fat controls. They also had 20 percent less deep-belly fat. Blood glucose abnormalities and signs of fatty liver were also not as severe as in the mice who did not receive the compound.
When comparing mice on a normal diet, with and without the compound, there was no difference between the groups.
Taking a closer look at the mice revealed that the broccoli compound increased the conversion of white to brown fat — a type of fat that maximizes energy consumption. Sulforaphane also impacted the gut flora of the mice by lowering the relative abundance of a bacterial species that drives inflammation.
Based on their findings, the researchers suggest that sulforaphane may improve liver and fat tissue inflammation and insulin resistance in a way that could benefit patients — though clinical trials of the compound would be needed to verify that.