Consuming grapefruit, including Ruby Red grapefruit, may help you lose weight, according to studies conducted in California and Canada. One half of a medium red grapefruit provides 52 calories and adds fiber, vitamin C and calcium to your diet. If you take any kind of medications, consult your doctor before eating any kind of grapefruit. Grapefruit can cause dangerous side effects if combined with certain drugs.
Fat-Burning Flavonoid
A flavonoid in Ruby Red grapefruit may help you lose weight. A study led by Erin Mulvihill of the University of Ontario showed that grapefruit contains a fat-burning flavonoid, a type of antioxidant. Mulvihill and colleagues fattened rodents on a diet of lard and sugar. They added a grapefruit flavonoid to the rodents' diets. The animals lost all of the weight gained from eating sugar and lard. The grapefruit flavonoid burned off fat cells, according to the study, published in "Diabetes" in October 2009.
Flavonoid and Calories
While a flavonoid in Ruby Red grapefruit may possess the ability to burn fat, this promising research does not yet prove meaningful to humans, according to Murray Huff, a fellow-researcher in Erin Mulvihill's grapefruit study. Huff told "The Toronto Star" that humans would need to drink between six and eight cups of grapefruit every day to achieve the weight loss benefits of grapefruit flavonoid. But a single cup of Ruby Red grapefruit juice contains 96 calories, and eight cups contain 768. Until -- unless -- scientists find a way to extract the grapefruit flavonoid from the fruit and put it in pill form, you would more likely gain than lose weight if you tried the reproduce Mulvihill's experiment at home.
Grapefruit and Insulin
Another study suggests that you could lose a little weight by adding Ruby Red or other grapefruit to your diet. Ken Fujioka, a researcher at Scripps Clinic in La Jolla, Calif. divided 100 obese persons into three groups. About one third ate half a grapefruit before meals, another third drank a cup of grapefruit juice before meals and the remaining group took a placebo. The study did not specify whether Ruby Red grapefruit was used. The participants in the study who consumed grapefruit or grapefruit juice lost about 1/3 pound a week during the 12-week trial. The grapefruit eaters lost slightly more -- 3.6 pounds compared to 3.3 pounds after 12 weeks for the juice drinkers. Those who took placebos lost an average of 1/2 pounds in 12 weeks.
Drug Interactions
All forms of grapefruit, including Ruby Red grapefruit, can cause serious drug interactions with a variety of medications, including oral contraceptives, statins, antidepressants, anti-anxiety medications, calcium channel blockers and immunosupressants. This is because grapefruit is a CYP34A enzyme inhibitor, which means that if you have grapefruit in your system, it will prevent your body from properly breaking down medications. This ends up elevating the level of medication in your bloodstream and increasing your chances of side effects that include heart attacks and strokes.
References
- "Journal of Medicinal Food: The Effects of Grapefruit on Weight and Insulin on Weight and Insulin Resistance: Relationship to the Metabolic Syndrome; Ken Fujioka et al; Spring 2006
- "The Toronto Star"; Grapefruit Glory: Joseph Hall; July 15, 2009
- Weight Loss Resources: The New Grapefruit Diet Review; Juliette Kellow
- "Diabetes"; Naringenin Prevents Dyslipidemia, Apolipoprotein B Overproduction, and Hyperinsulinemia in LDL Receptor--Null Mice With Diet-Induced Insulin Resistance; Erin Mulvihill et al; Oct. 2009
- The Harvard Medical School Family Health Guide: Grapefruit and Medication: A Cautionary Note; February 2006
- "The New York Times"; Experts Reveal the Secret Powers of Grapefruit Juice; Nicholas Bakalar; March 21 2006
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