Lab Study: Purple Sweet Potatoes as Colon Cancer Fighters

Purple sweet potatoes (yes, purple) are packed with flavor, fiber, and flavonoids—and are especially high in anthocyanins, the deeply pigmented flavonoid phytochemicals found in many blue, red, or purple fruits, vegetables, and grains such as berries, red grapes, red cabbages, and black rice.purpPot_canstockphoto11111336

Now, a new lab study suggests that these brilliant-colored tubers are actually cancer-fighting powerhouses that may play a role in protection from colorectal cancer.

The study, published in Molecular Nutrition and Food Research, examined the role of a specially bred anthocyanin-rich purple sweet potato (with the secret agent-like name “P40”) in colorectal cancer prevention.

The authors of the study conducted two experiments. First, they compared the cancer-fighting effects of three different sweet potato varieties—a cream-fleshed potato called “O’Henry,” a purple-skinned, white-fleshed potato called “NC Japanese,” and the brilliant purple-skinned and purple-fleshed P40—when added to the diets of mice. They injected the mice with a known carcinogen and placed the mice into groups to receive a diet enriched with O’ Henry, NC Japanese, P40, or regular mouse chow, which served as a control. Continue reading


Broccoli, Nerf, and Activating Antioxidants

The International Agency for Research on Cancer and the US National Toxicology Program have identified more than 100 environmental substances that cause cancer, like cigarette smoke and air pollutants. Avoiding these carcinogens can be difficult so it’s important to take steps to reduce the risks that exposure carries.

A review published in last month’s issue of Topics in Current Chemistry looks at how a phytochemical found in broccoli helps protect us from these environmental carcinogens. The authors of the review are among the world’s leading experts in cancer, phytochemistry, and toxicology.

In a series of clinical trials conducted in China, they found that sulforaphane may protect us from airborne and foodborne toxins by switching on a cellular pathway that regulates cells’ abilities to protect themselves from environmental carcinogens.

Sulforaphane is the end product of a reaction between two chemicals produced in broccoli and other cruciferous vegetables that protect the plant from insect attack.  When an insect (or a human) bites into the plant, the two chemicals come together to form sulforaphane.  It is what gives broccoli its somewhat pungent flavor. Continue reading


Folate and Cancer Risk: Is Timing the Key?

Folate is a B vitamin found naturally in many green leafy vegetables, nuts, legumes, and orange juice. It is needed in the body to make and repair DNA and may play a role in protecting us against cancer. 

In 1998, the US Food and Drug Administration instituted a folate fortification program to help prevent birth defects, such as spina bifida. They used folic acid, which is the synthetic form of folate. The result was a significant drop in birth defects. But recent epidemiological data have given rise to concerns that folic acid fortification may increase the risk of colorectal cancer.

An animal study published in last month’s issue of Cancer Prevention Research suggests that the cancer-related effects of folate/folic-acid may partially be explained by when and how long you take this essential nutrient.

The researchers wanted to see what effects a diet lower in folate would have on tumor development. Folate acts by serving as a methyl group donor. Methyl groups are small molecules that can attach to DNA to influence the body’s production of proteins involved in immunity and inflammation—precursors to tumor development. Continue reading