Grapefruit juice protects against weight gain and diabetes

(NaturalNews) A new study conducted by researchers at UC Berkeley suggests that grapefruit juice could replace metformin, a drug used to treat Type 2 diabetes; the fruit may also be helpful in preventing weight gain as well as decreasing blood glucose levels.

Published October 8 in the peer-reviewed journal PLOS ONE, scientists studied the relationship between grapefruit consumption and weight gain in mice. The test subjects that were fed a high-fat diet gained 18 percent less weight when they drank "clarified, pulp-free" grapefruit juice compared with the control group that only consumed water, UC Berkeley News Center reports.

Even more interesting, the mice that drank grapefruit juice had "improved levels of glucose, insulin and a type of fat called triacylglycerol compared with their water-drinking counterparts."

Weight loss has been associated with grapefruit consumption since the 1930s and was considered a trendy Hollywood diet; however, the supporting research was "not well-controlled" and "contradictory," scientists say.

"There are many active compounds in grapefruit juice, and we don't always understand how all those compounds work" - Andreas Stahl

Researchers admit that the latest study was funded by the California Grapefruit Growers Cooperative but insist that the association had no influence whatsoever over the findings. Both of the study's lead scientists say they entered into the research with skepticism.

"I was surprised by the findings," said Andreas Stahl, associate professor of nutritional sciences and toxicology. "We even re-checked the calibration of our glucose sensors, and we got the same results over and over again."

Joseph Napoli, the study's other lead author, added that "we see all sorts of scams about nutrition. But these results, based on controlled experiments, warrant further study of the potential health-promoting properties of grapefruit juice."

To reach their conclusion, scientists randomly divided mice into six groups, including a control group that only drank water. The grapefruit-drinking mice received a mixture diluted with water at different concentrations and sweetened slightly with saccharin to counteract grapefruit's bitterness.

Glucose and artificial sweeteners were added to the control group's drinking water, so its calorie and saccharin contents would be equal to those of the grapefruit juice.

It's important to note that artificial sweeteners have been proven to make you fat and encourage your body to hold onto that fat longer than regular sugars; however, it's unknown whether or not the study's authors considered this fact.

The mice that consumed the high-fat diet and drank diluted grapefruit juice didn't just lose more weight than their control counterparts; they also had a 13 to 17 percent decrease in blood glucose levels, as well as a threefold decrease in insulin levels, according to the results.

The huge decrease in insulin levels indicates a greater sensitivity to the hormone. The pancreas in people with Type 2 diabetes produces extra insulin in order to compensate for increased resistance to the hormone, explains UC Berkeley.

One group of mice was given naringin, a bioactive compound that gives grapefruit their bitter taste and has been linked to weight loss, and another group metformin, a glucose-lowering drug used to treat Type 2 diabetes.

The mice were then fed a diet of either 60 percent fat or 10 percent fat for 100 days while researchers measured their metabolic health.

"The grapefruit juice lowered blood glucose to the same degree as metformin," said Napoli, professor and chair of nutritional sciences and toxicology. "That means a natural fruit drink lowered glucose levels as effectively as a prescription drug."

Scientists suspect that, while naringin helps lower blood glucose levels, there's some other ingredient in grapefruit that contributes to weight loss, because the high-fat diet mice that received naringin had lower glucose levels but didn't show a difference in weight.

"Basically, we couldn't see a smoking gun that could explain why or how grapefruit juice affects weight gain," said Stahl.

Sources:

http://www.naturalnews.com

https://www.calcitrusgrowers.com

http://www.plosone.org

http://newscenter.berkeley.edu

http://www.naturalnews.com

http://www.ncbi.nlm.nih.gov

http://science.naturalnews.com