Oranges’ Healing Phytonutrients
In recent research studies, the healing properties of oranges have been associated with a wide variety of phytonutrient compounds. These phytonutrients include citrus flavanones (types of flavonoids that include the molecules hesperetin and naringenin), anthocyanins, hydroxycinnamic acids, and a variety of polyphenols. When these phytonutrients are studied in combination with oranges—vitamin C, the significant antioxidant properties of this fruit are understandable.
But it is yet another flavanone in oranges, the herperidin molecule, which has been singled out in phytonutrient research on oranges. Arguably, the most important flavanone in oranges, herperidinhas been shown to lower high blood pressure as well as cholesterol in animal studies, and to have strong anti-inflammatory properties. Importantly, most of this phytonutrient is found in the peel and inner white pulp of the orange, rather than in its liquid orange center, so this beneficial compound is too often removed by the processing of oranges into juice.
A Healthy Dose of Vitamin C for Antioxidant Protection and Immune Support
You may already know that oranges are an excellent source of vitamin C but do you know just how important vitamin C and oranges are for good health? Vitamin C is the primary water-soluble antioxidant in the body, disarming free radicals and preventing damage in the aqueous environment both inside and outside cells. Inside cells, a potential result of free radical damage to DNA is cancer. Especially in areas of the body where cellular turnover is especially rapid, such as the digestive system, preventing DNA mutations translates into preventing cancer. This is why a good intake of vitamin C is associated with a reduced risk of colon cancer.
Free radical damage to other cellular structures and other molecules can result in painful inflammation, as the body tries to clear out the damaged parts. Vitamin C, which prevents the free radical damage that triggers the inflammatory cascade, is thus also associated with reduced severity of inflammatory conditions, such as asthma, osteoarthritis, and rheumatoid arthritis.
Free radicals also oxidize cholesterol. Only after being oxidized does cholesterol stick to the artery walls, building up in plaques that may eventually grow large enough to impede or fully block blood flow, or rupture to cause a heart attack or stroke. Since vitamin C can neutralize free radicals, it can help prevent the oxidation of cholesterol.
Vitamin C, which is also vital for the proper function of a healthy immune system, is good for preventing colds and may be helpful in preventing recurrent ear infections.
A Glass of Orange Juice More Protective than Vitamin C Alone
Consuming vitamin C supplements does not provide the same protective benefits as drinking a glass of orange juice, shows research by Italian researchers in the Division of Human Nutrition at the University of Milan, Italy (Guarnieri S, Riso P, et al., British Journal of Nutrition).
Seven healthy test subjects were given each of three drinks, two weeks apart: blood-orange juice containing 150 milligrams of vitamin C, fortified water containing 150 milligrams of vitamin C, and a sugar and water solution containing no vitamin C. Blood samples were collected immediately before the drink was consumed, then every hour for 8 hours, and finally 24 hours after consumption of each drink.
Blood samples were exposed to hydrogen peroxide, and free radical damage to DNA was evaluated at 3 and 24 hours. Only when orange juice was consumed was any protective effect seen. After drinking orange juice, DNA damage was 18% less after 3 hours, and 16% less after 24 hours. No protection against DNA damage was seen after consumption of the vitamin C fortified drink or the sugar drink.
While another study, which looked at much larger quantities of vitamin C, did show a protective effect from the vitamin alone, this research indicates that not only is the protection afforded by fruit more complex, but smaller amounts of nutrients like vitamin C are all that are needed for benefit.
Said lead researcher, Serena Guarnieri, “It appears that vitamin C is not the only chemical responsible for antioxidant protection.” In oranges, vitamin C is part of a matrix involving many beneficial phytochemicals (for example, cyanidin-3-glucoside, flavanones and carotenoids).”But how they are interacting is still anyone’s guess,” she added. Fortunately, we don’t have to wait until scientists figure this out to receive oranges’ DNA-protective benefits. Practical Tip: For the best DNA protection, skip the vitamin C—fortified bottled drinks and enjoy a glass of real (preferably organic as organic foods have been shown to contain higher amounts of phytonutrients), freshly squeezed orange juice—or simply eat an orange!
Owing to the multitude of vitamin C’s health benefits, it is not surprising that research has shown that consumption of vegetables and fruits high in this nutrient is associated with a reduced risk of death from all causes including heart disease, stroke and cancer.
Protection against Cardiovascular Disease
A 248-page report, “The Health Benefits of Citrus Fruits,” released December 2003 by Australian research group, CSIRO (The Commonwealth Scientific and Industrial Research), reviews 48 studies that show a diet high in citrus fruit provides a statistically significant protective effect against some types of cancer, plus another 21 studies showing a non-significant trend towards protection.
Citrus appears to offer the most significant protection against esophageal, oro-phayngeal/laryngeal (mouth, larynx and pharynx), and stomach cancers. For these cancers, studies showed risk reductions of 40-50%.
The World Health Organization’s recent draft report, “Diet, Nutrition and the Prevention of Chronic Disease,” concludes that a diet that features citrus fruits also offers protection against cardiovascular disease due to citrus fruits—folate, which is necessary for lowering levels of the cardiovascular risk factor, homocysteine; their, potassium, which helps lower blood pressure, protecting against stroke and cardiac arrhythmias; and the vitamin C, carotenoids and flavonoids found in citrus fruits, all of which have been identified as having protective cardiovascular effects.
One large US study reviewed in the CSIRO report showed that one extra serving of fruit and vegetables a day reduced the risk of stroke by 4%, and this increased by 5-6 times for citrus fruits, reaching a 19% reduction of risk for stroke from consuming one extra serving of citrus fruit a day.
The CSIRO Report also includes evidence of positive effects associated with citrus consumption in studies for arthritis, asthma, Alzheimer’s disease and cognitive impairment, Parkinson’s disease, macular degeneration, diabetes, gallstones, multiple sclerosis, cholera, gingivitis, optimal lung function, cataracts, ulcerative colitis and Crohn’s disease.
Finally, the CSIRO Report notes that as low fat, nutrient-rich foods with a low glycemic index, citrus fruits are protective against overweight and obesity, conditions which increase the risk of heart disease, certain cancers, diabetes, high blood pressure and stroke, and add to symptoms of other conditions like arthritis.
An orange has over 170 different phytonutrients and more than 60 flavonoids, many of which have been shown to have anti-inflammatory, anti-tumour and blood clot inhibiting properties, as well as strong antioxidant effects.
Phytonutrients, specifically, the class of polyphenols, are high in citrus with oranges containing 84mg Gallic Acid equivalents/100mg. The polyphenols so abundant in oranges have been shown to have a wide range of antioxidant, anti-viral, anti-allergenic, anti-inflammatory, anti-proliferative and anti-carcinogenic effects. Although most of the research has centered on citrus polyphenols—possible role in cancer and heart disease, more recently, scientists have begun to look at their role in brain functions such as learning and memory.
An increasing number of studies have also shown a greater absorption of the nutrients in citrus when taken not as singly as supplements, but when consumed within the fruit in which they naturally appear along with all the other biologically active phytonutrients that citrus fruits contain.