♦ Grapefruit juice is healthy from a weight management point of view

♦ It could help us regulate our blood glucose levels

Grapefruit juice has an interesting pedigree in dieting circles. Back in the 1930s the Hollywood diet advocated taking a grapefruit or its juice with every meal as well as cutting down on the calories. At the time it looked like a slimming fad.

It has long been considered a healthy fruit juice and now a study in mice suggests that drinking this juice when eating fat laden meal lowers weight gain by up to 20% (Chudnovsky et al., 2014). It could even replace prescription drugs like metformin that are used in lowering blood glucose levels when managing diabetes. Albeit, this was a study with mice so as usual caution is exercised when translating to the situation with human beings but such a study causes some excitement when extrapolated to us.

The study led by Professor Joseph Napoli at the University of California in Berkeley showed that when mice were fed a fat rich diet for three months, those mice also given grapefruit juice to drink gained 18% less weight than those a on a placebo –water. All the mice had the same diet and drank the same amount of water. However, analysis of the blood showed those mice drinking grapefruit juice had lower blood sugar over a range of 13 to 17 percent and a three fold reduction in their  insulin levels.  All groups were matched in calorie content. The scientists believed that grapefruit juice was as good at managing insulin levels as the diabetes drug metformin.

Grapefruit juice interacts with the metabolism of several drugs which does not make suitable for everyone, however

The mechanisms for action by grapefruit were not assessed. The juice did not contain pulp but may have contained a fibre component. It also contains a number of polyphenolic type compounds such as flavanones (Di Donna et al., 2013)  and a variety of limnoids which are not found elsewhere. Could the same result on weight gain  be seen with orange juice or other citrus juices ?

References

Chudnovskiy, R., Thompson, A., Tharp, K., Hellerstein, M., Napoli, J. L., & Stahl, A. (2014). Consumption of Clarified Grapefruit Juice Ameliorates High-Fat Diet Induced Insulin Resistance and Weight Gain in Mice. PloS one, 9(10), e108408.

Di Donna, L., Taverna, D., Mazzotti, F., Benabdelkamel, H., Attya, M., Napoli, A., & Sindona, G. (2013). Comprehensive assay of flavanones in citrus juices and beverages by UHPLC–ESI-MS/MS and derivatization chemistry. Food chemistry, 141(3), pp. 2328-2333.