If there is a color that symbolizes October, it would have to be orange. On the mainland, leaves turn orange, signaling the beginning of fall and harvest time for orange foods such as pumpkins and persimmons. And, of course, October goes hand in hand with Halloween and pumpkins.

From a nutritional standpoint, orange fruits and vegetables have a wide variety of health-promoting qualities, rivaling green vegetables.

The orange in many fruits and vegetables comes from phytochemicals called carotenoids, the best-known being beta-carotene.

This plant chemical is sometimes referred to as pro-vitamin A because beta-carotene can be split into two molecules of vitamin A by the body. Vitamin A has an important role in normal development of a fetus, including vision, and helps maintain a normal immune system throughout life.

Other carotenoid compounds — such as lutein, zeaxanthin and meso-zeaxanthin — are known to accumulate in the retina of the eye and protect against macular degeneration, a common cause of vision loss with aging.

ORANGE FRUITS

Fruits by nature contain higher levels of some vitamins — including vitamin C and folate — than vegetables. Mangoes, oranges and papayas, all commonly consumed in Hawaii, are considered excellent sources of vitamin C and good sources of folate.

Vitamin C recently has been shown to be important in decreasing the risk of cancer, cardiovascular disease and overall mortality. An additional function often overlooked is vitamin C’s ability to synthesize the fluid between joints and maintain cartilage. Many individuals with arthritis have lower levels of vitamin C in their blood, resulting in less cushioning around their joints.

Vitamin C also helps the body absorb iron from plant foods. This partnership is especially vital for those who do not eat red meat.

Folate (folic acid), whether in its natural form in foods and or synthesized in supplements, is best known for its role in preventing birth defects. But adequate folate is important throughout life in maintaining normal blood composition and preventing fatigue, muscle weakness and shortness of breath. As we age, adequate folate in the diet helps maintain good cognitive function and may help prevent some forms of dementia.

ORANGE VEGETABLES

In addition to carotenoids, orange vegetables provide a number of essential trace minerals needed in small but crucial amounts to maintain health.

One of these is copper. Inadequate copper can impair normal immune function and increase the risk of both heart disease and diseases that harm the nervous system. Deficiencies may also lead to physical and mental fatigue as well as decreased ability to synthesize antioxidants, which battle damaging free-radicals in the body.

Also found in orange veggies are molybdenum and manganese, important to the body’s ability to make adequate amounts of antioxidants. Sweet potato is a good source of manganese, and is especially important to bone development and wound healing. These minerals are needed in very low amounts, but that doesn’t make them less important to health.

THE BOTTOM LINE

These are just a few of the contributions that orange fruits and vegetables make to maintaining health. Maybe this is why many of the baby and toddler foods on the market are orange.

When it comes to methods of preparation, there is no one size that fits all for drawing the most nutrients from your produce. Generally, eat your fruit fresh when possible and steam or microwave starchy vegetables.

A good health habit is to include one to two servings of orange fruits and vegetables in your diet daily. When you see orange, think NUTRIENTS!

Alan Titchenal, Ph.D., C.N.S., and Joannie Dobbs, Ph.D., C.N.S., are nutritionists in the Department of Human Nutrition, Food and Animal Sciences, College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa. Dobbs also works with University Health Services. Their column runs on the third Wednesday of each month.