Phytonutrients, also called bioactives or phytochemicals, are plant compounds which are thought to have health-promoting qualities but are not technically considered “nutrients” (for instance, like vitamin C or potassium), which are essential to prevent classic nutrient deficiencies. Scientists are discovering that these plant-derived components are intimately involved in fighting cellular damage, a common initiation step in the pathways for cancer, aging, and a variety of diseases.
Fresh grapefruit and 100% grapefruit juice have an array of phytonutrients including flavonoids and carotenoids.
Grapefruit naturally includes many flavonoids, a class of plant compounds similar to those found in red wine (resveratrol), green tea (catechins), and chocolate (cocoa flavanols).
Naringenin is the most common flavonoid found in grapefruit, followed by hesperidin.1
Several flavonoids have been reported to have antioxidant, anti-inflammatory, and cardioprotective properties which may help protect against various diseases and conditions.2-7
Citrus variety, fruit maturity, post-harvest processing techniques, storage conditions, and the location within the fruit (e.g. peels are richer than pulp) can affect the levels of flavonoids in grapefruit juice. Thus, the amount of flavonoids in a food can vary widely. Citrus flavonoids are primarily concentrated in the peel of the fruit. Commercial processing of fresh grapefruit into grapefruit juice extracts flavonoids from the peel into the juice. For this reason, the juice tends to have a higher flavonoid content than the whole fruit.
Carotenoids are yellow, orange, and red pigments found in abundance in citrus. Grapefruit has many carotenoids, especially in pink/red grapefruit and grapefruit juices, but the most concentrated are beta-carotene, lycopene, lutein, and zeaxanthin.8
Pink/red grapefruit and 100% pink/red grapefruit juice have lycopene, the same carotenoid that makes tomatoes red. Test tube studies show lycopene has one of the highest antioxidant activities of the carotenoids.9 Although studies report mixed results, lycopene may have beneficial effects towards lowering the risk of some cancers, including prostate and lung cancer.20
Carotenoids behave as antioxidants, help our cells communicate with each other, support our immune system, and some studies show they contain properties that protect against certain types of cancer.10,11 Thousands of studies provide evidence of health benefits attributed to carotenoids including:
- reducing risk of illness10
- supporting eye health10
- protecting skin from sunburn12,13
- lessening premature aging of the skin14
- reducing risk of many cancers including breast and prostate cancer10,11,20
- supporting bone health15,16
- increasing breastmilk concentrations of carotenoids and vitamin A17,18
Within citrus are many carotenoids including beta-carotene, alpha-carotene, and beta-cryptoxanthin which can form vitamin A in the body. Vitamin A is necessary for normal eyesight, reproduction, growth and development, cell health, gene expression, and immune function.19
The amount of carotenoids in citrus can vary widely depending on citrus variety, growing conditions, fruit maturity, processing, storage, and multiple other factors. Only the pink/red varieties of grapefruit and grapefruit juice contribute to vitamin A intake. The amount of vitamin A delivered by carotenoids in one-half of a medium grapefruit (120g) is approximately 8% of the Reference intake (RI).*
Learn more about the health benefits of fresh Florida Grapefruit and Florida Grapefruit Juice.
*Reference Intake: Based on a 2000 calorie diet. Information is not intended for labelling food in packaged form. Nutrient values may vary based on variety of citrus fruit and place of origin. Check with your citrus vendor for additional information.