The Shocking Anti-Cancer Effect of Sweet Potatoes

What’s sweeter than potatoes? Sweet potatoes. They’re filling. They taste like candy. And they are incredibly powerful at protecting you against cancer.

In this article I’m following up on the previous article about potatoes and focusing specifically on the unpublicized anti-cancer effects of sweet potatoes.

Sweet potatoes come in a variety of colors ranging from orange to red to dark purple – and the darker the color the more nutrients in the potato.


Sweet potatoes contain a host of phytochemicals – potent plant-derived nutrients with protective and disease-preventing properties. You get phytochemicals from most unprocessed plant foods, such as flavonoids from fruits or terpenes and carotenoids.


Carotenoids are a special type of phytochemical. They play two important roles simultaneously:

  • Carotenoids act as antioxidants and protect against oxidative damage
  • Carotenoids inhibit cancer cell growth and improve immune function

The sweet potato contains over 600 carotenoid compounds, and every one of them is a cancer-fighting beast. One such carotenoid is beta-carotene (vitamin A), which is an antioxidant that protects you against DNA damage, thereby significantly reducing your risk for cancer.

But that’s not the only cancer-fighting properties for which sweet potatoes have been discovered. If you are a science geek, this next part is for you.

Sporamin: The Anti-Cancer Protein

In the 1930s, a very unique protein with anti-cancer effects named sporamin was discovered. Sporamin makes up almost 80% of the proteins in a sweet potato. That’s a lot.

Scientist tested the sporamin protein against various types of cancer, and found that it was a very effective at fighting against leukemia cells in a petri dish. But we know that humans don’t live in a petri dish, so researchers then tested sporamin against tongue cancer cells and found that sporamin rapidly diminished tongue cancer cell viability.

Unlike most proteins in food that get completely digested, sporamin resisted digestion in the stomach and small intestine, and appeared in the blood intact. In most cases, when proteins leak into the blood, they initiate an immune response.

In this case however, sporamin actually improved cancer survival without adversely activating the host’s immune system.


Sporamin was then tested on colorectal cancer patients. Colorectal cancer claims the lives of 9% of all cancer related deaths in the US, and the primary cure for colorectal cancer is surgical removal of the colon. But this surgery alone only works if the disease is detected in the early stages, since micrometastases are found outside the colon in the later stages.

If you recall biology class in college, metastasis is the spread of a cancer from its original location to other sites in the body. On a microscopic level, micrometastasis is a type of metastasis in which the newly formed tumors are too minuscule to be detected by modern imaging techniques. The problem is that micrometastasis promotes cancer recurrence, but escapes visual detection.

Scientists are always on the search for powerful anti-metastatic agents. Over the years, sporamin has been shown to have anti-metastatic effects in various cancers.

It turns out that sporamin not only slows the growth of colon cancer cells, it decreases cancer cell migration and invasion, both in a test tube and in humans. And in the world of cancer prevention and treatment, that’s a big deal.


If eating a potato that tastes like candy can protect you against cancer proliferation and metastasis, this is one of the best tasting medicines you’ll ever consume. Eat them frequently, and enjoy every last bite.

Take Home Message

  • The sporamin protein found in sweet potatoes can reduce the rate of both cancer proliferation and metastasis
  • In addition to sporamin, sweet potatoes contain over 600 carotenoid compounds
  • Clinical studies have shown that sporamin is absorbed in the bloodstream intact, unlike most dietary proteins
  • Sweet potatoes are one of the best tasting medicines you will ever eat


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Contributing author: Caralyn Roberts has been living with type 1 diabetes since 1989, and has been applying a plant-based low-fat diet for more than 6 months with incredible results. Caralyn is a graduate of the Type 1 Training Club and has more than 20 years of experience as an avid researcher in the health and fitness industry.

About The Author

Cyrus Khambatta

Diagnosed with type 1 diabetes at the age of 22, I have spent over a decade learning the fundamentals of nutrition at the doctorate level. My goal is to share my knowledge of practical nutrition and fitness with people with prediabetes, type 1 and type 2 diabetes. Diabetes is an OPPORTUNITY to attain excellent health. Reversing the effects of insulin resistance can be a fun and enjoyable process if the right system is in place. That's why I've spent over 10 years developing a rock solid system that can minimize blood glucose variability and insulin resistance.

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