Was your mother right when she told you to eat your vegetables? You know you need vitamins and minerals but why not just take a vitamin pill? Now you’re also told you need antioxidants: what are they and what do they do?
What are Vitamins?
Vitamins are organic compounds, required in small amounts, which the body uses in nearly all metabolic processes. People need thirteen different vitamins to maintain health. Since the body cannot manufacture most vitamins, vitamins must come from food or supplements.
Vitamins may be either water soluble or fat soluble. The four fat‐soluble vitamins are A, D, E and K. The water‐soluble vitamins are the eight B vitamins and vitamin C. Water soluble means that the vitamins dissolve in water: they pass easily through the body via perspiration and urine. This is why your body needs vitamin C and the B‐complex vitamins every day, and why vegetables, fruits, and juices are best eaten throughout the day for optimal health. Fat‐soluble vitamins are absorbed through the large intestine and are stored in the liver and fatty tissues. Fat soluble vitamins do not need to be replenished daily, since they store well in the body.
How Does Cooking Affect Vitamins?
Cooking in water depletes the water‐soluble vitamins. To prevent vitamin loss, cook vegetables in as little water as possible – steaming is best. If you do boil vegetables, save the nutritious, vitamin‐rich liquid and add it to soups or sauces. Also, cooking vegetables for as little time as possible preserves water‐soluble vitamins: this is why stir‐frying is such a healthy cooking method. Note that cooking does not deplete fat‐soluble vitamins.
What are Minerals?
Just as vegetables need minerals to grow, so do people. Minerals are needed for proper cell function. The primary minerals required by the body include calcium, magnesium, and phosphorus. Needed in smaller amounts are the trace minerals including chloride, chromium, copper, fluoride, iodine, iron, manganese, molybdenum, potassium, selenium, sodium, and zinc.
What are Antioxidants?
Antioxidants are naturally‐occurring substances – such as vitamin C, vitamin E, and beta‐carotenes – that protect the body from the effects of oxidation. Oxidation, the use of oxygen by the body, results in oxygen molecules that are highly unstable, called free radicals. These free radicals, which either carry an extra electron, or lack an electron, attack neighbouring cells to either release or steal the extra electron, and therefore stabilise. While free radicals occur naturally in the body, they are also produced by chemicals, smog, cigarette smoke, and other pollutants, causing a free‐radical overload. Antioxidants inhibit oxidation and neutralise free radicals. While the body produces some antioxidants, nutrients from food play an important role in keeping free radicals in check, especially when the body is subjected to environmental stress.
Vegetables are an important source of natural antioxidants. Many vegetables contain beta‐carotene, also called pro‐vitamin A, which is an antioxidant that the body converts into vitamin A. A provitamin simply means a substance that the body can convert into a vitamin. A carotene is an orange pigment used into photosynthesis: it’s what makes carrots orange. In leafy greens it’s harder to detect: as a rule, the darker the green, the more beta‐carotene. The green chlorophyll in the darker lettuces, such as romaine, camouflages the presence of the orange beta‐carotene, which is easy to detect in carrots and pumpkins, for example.
Vitamins in Vegetables vs. Vitamin Supplements
While vitamins are rather simple structures that can easily be reproduced synthetically, vitamins in vegetables and other foods contain a complex inter‐relationship of nutrients that is still not well understood. While vitamin supplements may be beneficial, there is no substitute for a healthy diet. It’s also important to note that it’s possible for the body to get toxic amounts of the fat soluble vitamins (A, D, E, and K) if taken in too high a dose, since they are stored in the body. The water soluble vitamins – vitamin C and the B vitamins – do not carry a risk of toxicity, as they are not stored.
Synthetic beta carotene also poses a risk, especially to people who smoke. A 1994 study in The New England Journal of Medicine found that smokers taking beta‐carotene had 18 percent more lung cancer than those taking a placebo. A second study published in 1996 in the Journal of the National Cancer Institute found smokers receiving a combination supplement of beta‐carotene and vitamin A supplements had 28 percent more lung cancers and 17 percent higher death rates than those receiving a placebo.
Understanding the role of vitamins, minerals and antioxidants in maintaining a healthy body will help you to choose a better diet that includes lots of vegetables: not only making you feel better, but giving you more energy and a natural defense against disease.