By Michèle Turcotte, MS, RD/LDN

What do carrots, sweet potatoes, spinach, cantaloupe, and winter squash all have in common? If your answer is that they are all brightly colored, healthy fruits and vegetables, you're right! But there's more. They also contain powerful cancer fighting substances called carotenoids.

What Are Carotenoids?

Carotenoids are compounds responsible for the naturally occurring pigments in fruits and vegetables (think red for tomatoes, yellow for summer squash, orange for carrots and cantaloupe, and dark green for leafy vegetables). In recent years, carotenoids have received a lot of attention because of their potential anti-cancer and anti-aging compounds. Over 600 carotenoids have been identified in our food supply; however, the most abundant carotenoids in the American diet are beta carotene, alpha carotene, lycopene, lutein, beta crpytoxanthin, and zeaxanthin.

Health Benefits of Carotenoids

Carotenoids work similarly to antioxidants in the body. They have been shown to protect cells against carcinogenic chemicals that could damage DNA. Vitamin A, structurally similar to beta-carotene, may help to decrease risk by preventing tumor formation. Beta-carotene and other carotenoids have been shown in some studies to decrease the risks of developing both colon cancer and rectal cancer. It is also believed to enhance our immune system's function. In addition, beta-carotene has the ability to stimulate cell to cell communication. Researchers have discovered that poor cell to cell communication may be one of the causes of cell overgrowth, which eventually leads to cancer.

Where to Find Carotenoids

Excellent food sources of carotenoids include:

• Apricots
• Asparagus
• Broccoli
• Brussels sprouts
• Calf liver
• Cantaloupe
• Carrots
• Cayenne pepper
• Chard
• Collard greens
• Kale
• Mustard greens
• Parsley
• Peppermint leaves
• Romaine lettuce
• Spinach
• Sweet potatoes
• Tomatoes
• Winter squash.

To get the most carotenoids out of each bite, lightly cook (steam or microwave) veggies.

Carotenoids - what precautions should you take?

If you smoke cigarettes or drink alcohol, you may have lower than normal blood levels of carotenoids. Research studies have shown that, statistically speaking, smokers and drinkers eat fewer foods that contain carotenoids. Researchers also believe that cigarette smoke destroys carotenoids. However, if you do smoke or drink, use carotenoid supplements with caution.

Remember, beta carotene is the form of vitamin A found naturally in food. Vitamin A is a fat-soluble vitamin and, when taken in supplement form, can be toxic. Avoid vitamin A supplements.