‘C’ is for citrus, of course, but it's also the essential vitamin that these juicy fruits provide in abundance. While the traditional reputation of vitamin C as an ideal cure for the common cold is still under scientific debate, it can provide us with plenty of other health benefits. For instance, according to the US Academy of Nutrition and Dietetics, ingesting vitamin C in sufficient doses can help reduce the duration and severity of winter infections - which may be where the idea of it as the ultimate flu-fighter comes from.
Brightly coloured citrus fruits are also bursting with minerals, flavonoids and carotenoids like beta-carotene, lutein and zeaxanthin, which act as natural antioxidants - and every member of the citrus family offers its own distinct boost to health. Consider this your baseline guide.
Grapefruit may be more of an acquired taste, but to dismiss the daddy of the citrus family is to throw away a great source of flavonoids. These plant compounds are especially good for the heart, and a recent American study on patients recovering from bypass surgery found that antioxidant-rich red grapefruit helped to lower LDL (‘bad’) cholesterol and triglyceride levels and restore healthy cardiac function.
Sure, lemons contain enough acid to turn your face inside out with the bitterness, but they actually produce alkaline responses in body fluids, helping to balance out pH levels. They are especially kind to the liver, dissolving uric acid and liquefying bile. Urologists love lemons because they work so well against kidney stones by forming urinary citrate, which prevents crystals from developing. Lemon juice and lemon oil flush toxins and bacteria from skin and hair too, which is why they are used in so many beauty products.
Whether sweet or sour, limes are known for having saved sailors and soldiers from scurvy over the centuries, when they were consumed by the barrel to help combat the general absence of vitamin C on long voyages and marches into battle. Even today, some employers dispense limes as standard to workers in polluted industrial environments like mines and foundries. The peel and pulp are especially rich in polyphenols and terpenes with antioxidant, antibacterial and disinfectant properties.
Sometimes regarded as the orange’s frivolous little brother, the mandarin is sweeter and easier to peel, but it still contains most of the same health-enhancing properties as its bigger, rounder sibling, albeit in smaller doses. In fact, the mandarin packs quite a punch in terms of the phytochemical synephrine. According to a study by the US Department of Agriculture, certain strains of mandarin provide more of that natural decongestant than any over-the-counter pill that you might buy when you’re feeling bunged up.
So robust that they have a whole colour named after them, oranges contain so much juice that they offer one of the biggest gram-for-gram doses of vitamin C of any citrus fruit. They give a big hit of fibre, too – about 3g in a medium-sized (145g) orange. Most of that is soluble and helps to lower cholesterol, as well as regulating glucose levels. The insoluble fibre ends up in the gut, where it aids digestion and does its bit to keep us regular.