Pumpkins, squash, sweet potatoes – you're probably seeing these fall veggies appearing on your supermarket shelves. Yes, they are all tasty and nutritious. What else do they have in common? They are top sources of a phytochemical important for cancer prevention: beta-carotene.
You've probably heard something about beta-carotene- maybe that it's good for you hair or eyesight. When it comes to cancer risk, here are 7 things to know about this phytochemical (and impress your guests at dinner parties).
1. It's part of a big family
Beta-carotene is one of the hundreds of carotenoids, a fat-soluble family of phytochemicals that are red, orange and yellow pigments. Plants produce this orange-colored beta-carotene and we humans get almost all of this phytochemical from fruits and vegetables.
2. It protects against certain cancers
AICR research shows that eating plenty of foods high in beta-carotene lowers risk of esophageal cancers. And foods high in carotenoids lower risk of cancers affecting the lungs, mouth, pharynx and larynx.
In lab studies, beta-carotene helps maintain normal cell growth, which may be important in cancer prevention.
3. It becomes vitamin A
Beta-carotene is called a precursor to vitamin A. When you eat a food with beta-carotene your body converts it to vitamin A in the liver; a vitamin important for vision, immune function and maintaining healthy cells. Your body only converts beta-carotene into vitamin A as it's needed, so you can't get too much from eating foods. If you were to eat massive amounts of orange vegetables, your skin could develop a yellowish tinge, but there’s no worry about health risks from foods.
4. It won the Nobel Prize (sort of)
In 1831 a chemist first isolated beta-carotene from the roots of carrots. (Carotene is named from the Latin word for carrot, carota.) About 100 years later, chemist Paul Karrer identified the structure of the phytochemical and he – along with a colleague – won the Nobel Prize for it in 1938. It was the first time that the structure of any vitamin or precursor was identified. These scientists had also teased apart different forms of carotene, beta- alpha- and gamma.
5. Too much – from supplements – can be harmful
All those benefits are seen with foods containing beta-carotene, not beta-carotene supplements. In fact, research suggests that smokers who take high amounts of beta-carotene supplements are at increased risk of lung cancer. (Population studies link foods rich in carotenoids with lower risk of lung cancer.) For cancer prevention, AICR recommends not to rely on supplements.
6. It's not just in those orange foods
Sure, oranges, carrots, sweet potatoes and pumpkins are all recognizable top sources of beta-carotene. Fruits, including apricots and cantaloupe, get their orange hue from beta-carotene too. But you'll also find this phytochemical hiding in some greens.
Dark leafy greens such as spinach and kale are a great source of beta-carotene. In these vegetables, the high amounts of green chlorophyll mask the orange beta-carotene.
7. They go well with (a little) fat
Because carotenoids are fat-soluble, they are better absorbed when eaten with fat. You don't need much -- less than a teaspoon. Use it in your salad dressing, cook with a healthy fat or eat the beta-carotene food with other foods that have a little fat to help you get the most beta-carotene from your diet.
Visit AICR’s Foods That Fight Cancer for more on how winter squash, dark green leafy greens and other foods may help lower your cancer risk.