White grapefruit Citrus paradisica was a major topic among researchers from around the world who recently met at a two-day symposium in Philadelphia to present scientific evidence showing that oranges, lemons, grapefruit and tangerines have the ability to fight the nation's top-killing diseases such as cancer, obesity and heart disease. Highlights from the symposium included:

Citrus Compounds May Prevent Colon Cancer, two recent studies provide new evidence that citrus fruits contain compounds that may help prevent colon cancer, the second leading cause of cancer death in the United States. Jairam Vanamala and Nancy D. Turner from Texas A&M University isolated citrus bioactive compounds and fed freeze-dried grapefruit (which has similar properties to whole grapefruit) to animals with colon cancer and reported a reduced number of colon cancer lesions. Rikako Suzuki of Kanazawa Medical University in Japan found that nobiletin, a chemopreventative compound found in oranges and other citrus fruit, also helped prevent colon cancer in animal studies.

Human Study Confirms that Grapefruit Promotes Weight Loss, the famous Grapefruit Diet has been around for years, and new evidence shows that grapefruit does indeed result in significant weight loss. Scripps Clinic scientist Ken Fujioka conducted a 12-week study on 100 obese men and women and concluded that eating one half of one grapefruit before meals resulted in an average weight loss of 3.6 pounds with some participants losing more than 10 pounds. The research indicates a physiological link between grapefruit and insulin, as it relates to weight management. Dr. Fujioka speculates that the chemical properties of grapefruit reduce insulin levels and encourage weight loss.

Insulin assists with the regulation of fat metabolism. Therefore, the smaller the insulin spike after a meal, the more efficiently the body processes food for use as energy and the less it's stored as fat in the body.

Grapefruit may possess unique chemical properties that reduce insulin levels, which promote weight loss. "Whether it's the properties of grapefruit or its ability to satiate appetites, grapefruit appeared to help with weight loss and decreased insulin levels leading to better health" stated Dr. Fujioka.

Peels Contain Compounds That May Lower Cholesterol, when it comes to lowering cholesterol, we may be throwing away the best part of citrus fruits. According to a joint study by the USDA and KGK Synergize published in the Journal of Agriculture and Food Chemistry, compounds found in the peels of oranges and tangerines called polymethoxylated flavones (PMFs) have the potential to lower cholesterol. The researchers showed that feeding hamsters a high cholesterol diet containing 1 percent PMFs lowered the amount of "bad" LDL cholesterol by 32 to 40 percent. A recent pilot study with human subjects showed that PMFs reduced total cholesterol, LDL cholesterol and triglycerides by 23 and 26 percent. A larger human study is currently underway. The discovery of new health benefits may encourage consumers to add citrus peel, or zest, to everyday meals such as soups, salads, salsa, or sprinkled on top of chicken or fish.

Grapefruit may help reduce the risk of cancer in smokers. Researchers at the University of Hawaii found that grapefruit can also reduce the risk of cancer caused by smoking. A controlled study of 49 smokers showed that drinking six ounces of grapefruit juice three times daily slowed the activity of a liver enzyme called CYP1A2, which helps activate the cancer-causing substances found in tobacco smoke.

Consuming fresh fruit juice offers many health benefits, however, research shows that whole fruit has even more nutritional benefit due to the fiber content. Oranges and grapefruit rank #1 and #2 in fiber out of the top 20 most-consumed fruits and vegetables, Juices, even those with pulp, are an insignificant source of fiber. In addition, a typical serving of juice includes higher amounts of calories and sugars than a typical serving of whole fruit.

These new research findings presented at the symposium build on previous research that underscores the health benefits of fruits and vegetables for disease prevention:

• According to Dr. Andy Morris of HealthSouth Heart College in Birmingham, Alabama, each serving per day of fruits or vegetables, including citrus, cuts the risk of heart attack by 6%.
• The February 23 issue of The Archives of Internal Medicine reported that for every 10 grams per day increase in overall fiber consumed, there was a 14 percent reduction in the risk of heart attacks and 27 percent lower risk of coronary heart disease death. Simply eating one orange per day will increase one's daily fiber intake by 7 grams.
• According to the American Institute for Cancer Research, if everyone in the U.S. ate at least five servings of fruits and vegetables per a day, cancer rates would fall by as much as 20 percent.
• A study from University of Arizona found that antioxidants in lemon peel help reduce the risk of skin cancer by up to 30%³.

Citrus fruits are included in dietary programs from the world's leading nutrition organizations including USDA's Dietary Guidelines for Americans, Produce for Better Health (PBH) Foundation's 5 A Day Program, American Heart Association, American Cancer Society and the National Cancer Institute.

Sources:
1. Code of Federal Regulations, Title 21: Food and Drugs, 2002. Appendix C to Part 101 - Nutrition Facts for Raw Fruits and Vegetables
2. U.S. Department of Agriculture, Agricultural Research Service. 2002. USDA Nutrient Database for Standard Reference, Release 15. Nutrient Data Laboratory home page at www.nal.usda.gov/fnic/foodcom.
3. Hakim IA, Harris R, and Ritenbaugh C, Citrus Peel Use Is Associated With Reduced Risk of Squamous Cell Carcinoma of the Skin, Nutrition & Cancer, 2000, 37 (2): 43-50.

Notes:

Prescription drugs may interact with many foods including grapefruit. Anyone with questions about how their medication might interact with their diet should talk to their doctor or pharmacist for more information. For the majority of Americans, there is no reason to stop enjoying the delicious, healthy benefits of grapefruit.