Health Benefits of Heritage Potato

 If you could only grow one crop - Potato should be your choice!

On this page I'm reporting on the on-going studies of the health benefits of potato - particularly glycoalkaloids and antioxidants that have proven to be anticarcinogenic.

TGA in the potato skin and antioxidants in dark colored potato flesh. Plus, potatoes are a primary source of proteins, Vitamin C and Potassium.

This page is linked to the Kenosha Potato Catalog

Click here to review the catalog.

Please open my catalog page and search for keyword TGA (Total GlycoAlkaloids) to find the varieties reported to have high levels. To be safe Health Canada has established an upper limit of 20mg of TGA per 100g of fresh weight in potato tubers. Cultivars that show higher levels cannot be registered for commercial food production in Canada. It is legal to grow your own tubers - eating tubers with high level TGA in small quantity may be very beneficial. I do it! You have to evaluate your own risk!

Tested cultivars have shown a higher concentration in the skin. Perhaps we need to wait years to find out if the health benefits of the anticarcinogenic effects outweight the negative effects (like intestinal permeability).

I grow in my garden the varieties Haida, Cowhorn and Lenape. Especially Lenape has very high TGA and is reported to be fit for animal feed only. It is a very waxy cultivar - stores extremely well and is well suited for cooking in soups (does not fall apart).

Cowhorn has been grown in New York State since before 1853. While Haida is the name of the Native American tribe - it is reported that Spaniards have brought tubers from South America (Voyages of Discovery). Crews from some of these vessels used spuds as a trade item and showed some of the native peoples along the coast how to grow them. Indians liked the potatoes well enough to keep them going, saving this variety that is thought to be very old (a landrace tuber thought to be grown in South America before 1800). In the Queen Charlotte Islands, the Haidas grew potatoes that were about two or three inches long. The individual tubers vary in shape. Some are oblong. Others are egg shaped. Still others are nearly round. Many are knobby. They have medium brown skin, with a number of eyes. The flesh is waxy, and cream-colored. The high TGA levels have not bothered these folks for hundreds of years.

Very interesting is the report by Dr. Horia Groza (UW - retired) published in the Badger Common'Tater that shows how antioxidant levels in dark potato flesh are higher than in white flesh, and are enhanced with cooking!

In dark purple flesh the antioxidant levels may be ninety times higher than in white flesh. Obviously higher levels are found in fresh tubers (poor soil quality, bruising, storage would reduce the high oxidant levels). An other reason for growing your own garden potatoes! Most potato growers leave the tubers in the field, after the vines have been killed for a couple of weeks. The process makes the skin tougher - better for storage in huge piles. Your garden potatoes are harvested with thin skin and stored without bruising. Eat potato skins for maximum health benefits!

Potato as a primary source of Amino Acid to build Proteins -

Potatoes contain all 22 amino acids to form complete proteins after easy digesting. It makes for easier protein absorption than the digestive effort of breaking down the complete proteins in meat and dairy.

What follows is a study text that explains that all potato cultivars are rich as a source of protein. Looking for cultivars with higher protein content is a waste of time!

Samples of coagulable protein, from tubers of 34 varieties of Solanum tuberosum, were analysed for amino acids. The coagulable protein was rich in most of the essential amino acids. The essential amino acid index ranged from 86 to 93. Methionine was the first limiting essential amino acid. Its content in coagulable protein was considerably higher than values reported in literature. Lysine content was very high, which makes the protein a valuable component for mixed feed. Arginine was the second limiting amino acid. The varietal differences in amino acid composition were small. There was no correlation between protein content and content of most of the essential amino acids. Breeding for increased protein content in potato may be expected to have little effect on the nutritional value of the protein. Selection can be directed to content of coagulable protein.

Potato as a primary source of Vitamin C - Vitamin C is an antioxidant that increases the general resistance to diseases (diminishes the chance of strokes, excessive blood pressure, cataracts, some forms of cancer) and makes easier the movement of calcium in the body. Cultivars with high levels of Vitamin C include Ranger Russet, Yukon Gold and Shepody. In cooking a limited loss of Vitamin C is reported when baked or boiled unpeeled, while frying may cause up to 50% Vitamin loss. Shorter cooking and keeping the skin intact increases the Vitamin C content.

Potato as a primary source of Potassium - For every 100 gram increase (one medium potato = 150 grams) in total potato intake, there was a 2.6 unit drop in diastolic blood pressure! One medium potato with the skin contains 620 mg of potassium. That's 18% of your daily requirement and more than a banana! Potassium plays an essential role in the response of nerves to stimulation and in the contraction of muscles, including the heart muscle.

The Kenosha Potato Project provides pictures of all potato cultivars of our extensive "garden grown" tuber collection, including description of skin and flesh colors. A text search will lead you to the cultivars with different skin / flesh colors.

Wanted: Potato Gardeners

If you'd like to participate with the Kenosha Potato Project - here are your options:

  • If you live in Southeastern Wisconsin - please email me at
  • If you live somewhere else in the USA or Canada - are you a member of Seed Saver Exchange? We have a few gardener who participate with the Kenosha Potato Project within the Seed Saver Exchange.
  • We have members of our Global Potato Network in Europe and are always please to cooperate with any gardener / farmer. Sending seed abroad is restricted or difficult ... but we may find ways to cooperate.
  • Also, please visit our "Vertical Growth - 99 lbs in micro plot Challenge web pages"

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