Smart Fuel: Eggplant

Ever had the debate about whether a tomato is a fruit or a vegetable? Well, perhaps next time you could back up your argument for tomatoes being a fruit by noting that the eggplant, which is widely perceived to be a vegetable, is actually a fruit, and a berry at that!

Counting tomato, sweet peppers and potatoes among its relatives, this member of the nightshade family was once feared in some European cultures. According to reports, early versions of the eggplant were so bitter that people believed that they must also have a bitter disposition, earning the poor eggplant (or aubergine as it is called in France and much of Europe) a reputation as a cause of insanity, leprosy and cancer.

But today the eggplant is less bitter and we know now that it’s actually pretty darn good for you! Specifically, eggplant is seen as an excellent source of fiber and a good source of potassium – which is important for keeping the body hydrated and also plays a role in regulating blood pressure. However, eggplants are perhaps best known for their high levels of chlorogenic acid, a potent antioxidant that is thought to offer protective benefits against cancer and an assortment of viruses.

A second important chemical compound, meanwhile, is nasunin, a potent antioxidant found in the skin of the eggplant that is thought to protect cell membranes from damage, with one animal study suggesting that its free radical fighting properties are particularly important for the health of brain tissue. In addition, nasunin also serves as an iron chelator to prevent iron accumulation in the body, which if unregulated, can spur free radical production. In regulating this accumulation, nasunin also protects blood cholesterol from peroxidation, prevents against cellular damage that can lead to cancer and heart disease, and reduces the accumulation of iron in the joints, which is thought to be a primary cause of rheumatoid arthritis.

But before you sign up for extra eggplant, you should know that this vegetable does have a dark side! Specifically, eggplants (and several other members of the nightshade family of plants) contain a substance called solanine that, if not destroyed in the intestine, could prove toxic. In fact, one horticulturist hypothesized that osteoarthritis sufferers might be unable to break down solanine in the gut and suggested that eliminating the substance from the diet might relieve arthritis symptoms. While researchers have never put this diet to the test, solanine-free diets are sometimes prescribed by physicians for arthritis sufferers.

When selecting an eggplant, opt for those that are firm and heavy for their size. Their skin – which can range in color from a deep dark purple to a near translucent white or even come covered in tiger-like stripes – should be smooth and shiny with no visible dents, discoloration or other visible flaws. To test for freshness, gently press your thumb on its skin: A ripe eggplant will spring back. To store, place uncut and unwashed in a plastic bag in the refrigerator’s crisper draw and plan to use within about five days.