The Many Health Benefits of Bell Peppers

Bell Peppers



Written by:
Larry Trivieri Jr.

Looking for a food that is packed with nutrients, rich in dietary fiber, and capable of protecting against cancer, heart disease, and diabetes? If so, then look no further than the bell pepper family. Available in a variety of colors (most commonly green, red and yellow) bell peppers are a rich source of important vitamins and minerals, including more than twice the vitamin C content found in oranges.[i] Other essential nutrients that bell peppers contain include vitamins B1, B2, B3 (niacin), B5 and B6, as well as vitamin E, vitamin K, folate, magnesium, manganese, potassium, and, most especially, vitamin A. But the real secret behind the health benefits bell peppers provide has to do with two special classes of nutrients called carotenoids and flavonoids, both of which have been found to provide a variety of antioxidant and immune-enhancing benefits.[ii]

Research has shown that both carotenoids and flavonoids also help enhance health due to their ability to promote healthy cell growth while inhibiting the growth of unhealthy cells. Because of their antioxidant properties, these nutrients protect the body’s cells, tissues, and organs from damaging oxidative stress caused by unstable oxygen molecules known as free radicals. These same nutrients also help to prevent and reverse chronic inflammation, which has increasingly been shown to be a primary risk factor for a wide range of health conditions, ranging from arthritis and gastrointestinal disorders, to cancer and heart disease.

There are literally hundreds of different types of carotenoids and flavonoids. Research has found that both classes of nutrients provide the greatest amount of health benefits when a variety of both substances are eaten together, rather than separately. Bell peppers contain over 30 different carotenoids, as well as a variety of flavonoids, making them one of the richest food sources for both types of nutrients. In addition, both classes of nutrients have been shown to enhance the beneficial effects of other nutrients, including the vitamins and minerals that bell peppers also contain.

In addition, bell peppers are also rich in sulfur-containing compounds. In recent years, cruciferous vegetables such as broccoli, cauliflower, onions and garlic have been touted as important health foods because they all contain high levels of sulfurous compounds, which have been shown to have anticancer properties. More recent research indicates that the sulfurous compounds found in bell peppers can provide similar benefits.

Now let’s take a look at how making bell peppers a regular part of your diet can help protect you against three of our nation’s most serious health problems.

Cancer: Many of the wide variety of nutrients bell peppers contain have been shown to protect against free radical damage and chronic inflammation, both of which are contributing factors in the development of cancer. This makes bell peppers an excellent dietary choice to help reduce cancer risk. Its long been known that vitamins A, C and E, all of which are contained in bell peppers, can help protect against various types of cancer due to their antioxidant effects.[iii]  Research with mice administered with human prostate cancer cells has also shown that the carotenoid lycopene, which bell peppers also contains, works synergistically with vitamin E to help reduce prostate tumor growth by as much as 75 percent.

More recently, research has established that vitamin B6 can play an important role in protecting against lung cancer. An analysis of more than 500,000 people, for example, has shown that vitamin B6 can reduce the risk of developing this deadly form of cancer by more than 50 percent.

Recent research has also found that apigenin, a flavonoid found in bell peppers, shows promise for against certain types of breast cancer, especially among women who receive the hormone progestin for menopause. The research found that apigenin inhibits cancer progression by inducing apoptosis (cell death), reducing cancer cell growth and proliferation, and inhibiting the expression of certain cancer genes. In addition, other recent studies have examined the sulfurous compounds bell peppers contain, especially the class of enzymes known as cysteine S-conjugate beta-lyases and their role in a sulfur-containing metabolic pathway. Findings indicate that these enzymes and pathway are likely responsible for providing some of the anticancer benefits that cellular and animal studies reveal bell peppers have, including for cancers of the gastrointestinal tract.

Diabetes: The incidence of type-2 diabetes in the United States is increasing at an alarming rate, despite the fact that it has long been established that this condition is entirely preventable through proper diet and regular exercise. Foods rich in fiber, such as bell peppers, can help prevent and control diabetes because of the way dietary fiber helps regulate the body’s rate of insulin production, thus preventing insulin spikes. Conversely, diets that are low in fiber-rich foods can dramatically increase the risk of type-2 diabetes developing and make symptoms worse when it is already present.

Various nutrients have also been shown to protect against type-2 diabetes, including vitamin E and the carotenoid cryptoxanthin, both of which are found in bell peppers. In a study conducted at the National Public Health Institute in Helsinki, Finland, researchers observed more than 4,000 men and women between the ages of 40 and 69 for more than 20 years. At the start of the study, all of the participants were free of type-2 diabetes. At the study’s conclusion, the researchers not only found that people who consumed diets rich in vitamin E and cryptoxanthin were less likely to develop type-2 diabetes, but that their risk of doing so was decreased by 31 percent by vitamin E-rich foods alone, and more than 40 percent by foods containing cryptoxanthin.

Heart Disease: Doctors have known for decades that free radical damage is a primary cause of heart disease, including heart attack and stroke. More recently, scientists have discovered that chronic inflammation also plays a significant role, as, of course, does elevated cholesterol, and also homocysteine levels. Bell peppers, because of the wide array of heart-healthy nutrients they contain, offer significant protection against all of these risk factors.

The vitamins, carotenoids and flavonoids that bell peppers contain have all been shown to protect against free radical damage. Vitamins A, C and E, in particular, help to neutralize and eliminate free radicals that cause cholesterol to become oxidized and a threat to your heart and arteries. Quercitin and luteolin, two other nutrients found in bell peppers, offer similar protective effects. Bell peppers are also a good source of lutein and zeaxanthin, two other carotenoids known to protect cardiovascular health. Additionally, folate, B6 magnesium, and potassium, all of which are found in bell peppers, are also very good for the heart. Magnesium and potassium can also help regulate and lower blood pressure levels, while folate and B6 both help to keep homocysteine levels in check.

Selecting and Using Bell Peppers
The typical growing season for bell peppers lasts from July to November, but in most parts of the country they are available year-round.[iv] Here are some tips for getting the most benefit from them:

Choose peppers that are rich in color, have tight skin, and do not have any soft or dark spots on their skin.

Bell peppers can be refrigerated for up to 10 days without losing their nutritional value. When ready to use them, first rinse them with cold, not hot, water. (Hot water can diminish their antioxidant properties.)

Bell peppers are best eaten raw in salads or lightly steamed or sautéed to make a side dish.[v] Avoid other cooking methods, as these can destroy the peppers’ nutrient content.

To obtain the most benefit, make bell peppers a regular part of your meals.

Johansson M, Relton C, Ueland PM. Serum B vitamin levels and risk of lung cancer. JAMA. 2010 June;303(23):2377-85.

Limpens J, et al. Combined lycopene and vitamin E treatment suppresses the growth of PC-346C human prostate cancer cells in nude mice. J Nutr. 2006 May;136(5):1287-93.

Mafuvadze B, et al. Apigenin induces apoptosis and blocks growth of medroxyprogesterone acetate-dependent BT-474 xenograft tumors. Hormones and Cancer. 2012;3(4):160-7

Montonen J, et al. Dietary antioxidant and risk of type 2 diabetes. Diabetes Care. 2004 Oct;32(10):1823-25.

Schwiertz A, Deubel S, Birringer M. Bioactivation of selenocysteine derivatives by beta-lyases present in common gastrointestinal bacterial species. Int J Vitam Nutr Res. 2008; Jul-Sep;78(4-5):169-74.

[i] Source: “Culinary Nutrition News: Fighting Phytochemicals.”

[ii] Source: “NIH Senior Health: Eating Well As You Get Older.” May 2012.

[iii] Source: “Ringing a Bell with Consumers: Consumer Preferences Studied for Bell Pepper Selection.” Summer 1998.

[iv] Source: “Vegetable and Fruit for Health: Bell Peppers.” 2008.

About the Author

Larry Trivieri Jr.

Mr. Larry Trivieri Jr. is a frequent contributor to Integrative Health Review, the National University System Center for Integrative Health’s free open-access health resource. Larry Trivieri Jr.

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