Potatoes are not Paleo- TK is the reason.

June 7, 2015

Dear Friends,

There is some confusion about the humble potato, and whether or not it is Paleo. My view is that it is best avoided, and I encourage you to eat other roots. In recipes consider substituting cassava which you can purchase from various Pacific Island, Indian, Pakistani, Philippine, Indonesian and even Western stores. The potato lectin is unique in that it activates Tyrosine Kinase (TK) receptors. TK is involved in a great variety of diseases.

On the Pro side, potato is a tuber, and humans have eaten tubers for 2 million years or so, so we should be somewhat acclimatised to them from an evolutionary view.

On the Against side, we have a few lines of evidence:
1. The potato was only eaten in South America from human arrival around 7,000 years ago, and in Europe, Africa and Asia, only after the Conquistadors brought back the potato (and many other staple foods) 500 years or so ago. This makes the potato a “New World” food and subject to question as we have not had sufficient time to acclimatise to it.
2. The potato is high in antinutrients, and some of them (the glycoalkaloid saponins) are not destroyed by cooking. The potato is probably the most marginal food in the western diet, in terms of being close to inedible (followed by the soybean).

However, there is another really really powerful reason why you should avoid potatoes!

The roots which humans have eaten for 2 millions years come from completely different plant families to the potato. The potato lectin is unique in that it activates Tyrosine Kinase (TK) receptors. TK is involved in a great variety of diseases. I am not aware of any research where a potato free diet has been given to people with TK related diseases, but it would be very wise for such research to be done. There are a plethora of new drugs that block TK- see here and here. There probably won’t be any studies on the restriction of potatoes in the same diseases, even though that would be a logical step. The humble potato has flown under the radar.

The link between the potato and TK was pointed out early on in the leading (and to my knowledge, the only) textbook of Paleo Medicine, Food and Western Disease by Prof Staffan Lindeberg, who along with Prof Loren Cordain, has established much of the modern understanding of the Paleo Diet.

Why has the humble potato flown under the radar?
Wheat is the food that has taken all the flack, and if not wheat then all forms of gluten. There is a sensible historical context behind this as wheat/gluten was connected to coeliac disease in the 1940’s and gluten in the 1950’s. There has been a lot of research around this medically important disease. In recent years, the entity of non-celiac gluten-intolerance (gluten intolerance without celiac disease) has been recognised in several major studies and it appears that it affects around 7% of the population. So wheat is “dead in the water”. From listening to podcasts I get the impression that the vast majority of natural and alternative health therapists recommend everyone give up wheat, and sugar. It would possibly be the most common thing they would agree on.

The potato however has a charmed life, but perhaps this is only because there is no recognised subgroup of the populaton who have a severe disease like celiac disease, but given the importance of TK in so many diseases, I feel it is likely that one day a link will be made. In the meantime, please rest assured that potatoes are not Paleo.

An excellent substitute for potatoes in recipes is the cassava, which is very similar in texture, and has a pleasant taste, and is low in allergens. It is similar if boiled, or cooked in soups and stews. It is eaten peeled. When roasted it is not as tasty as a roast potato but my culinary skills are not my strong point! So maybe some chefs can roast it nicely (But the skin is removed!).

Here’s what Professor Lindeberg says about the potato:

“The question of root vegetables is even more complex. As outlined in Section 3.1, humans may be highly adapted to a high intake of root vegetables. Such an adaptation would mainly pertain to the particular phytochemicals that are present in African roots, including those found in some species of Dioscorea or Ipomoea. However, the potato, which originates from South America, may contain bioactive substances that are too foreign for us to cope with. For example, the potato lectin (Solanum tuberosum agglutinin or Solarium tuberosum lectin) activates tyrosine kinase receptors not necessarily affected by lectins from more distantly related plant tubers 558. Considering the amounts of potato consumed in Western countries, a higher degree of adaptation would have been preferable.” Food and Western Disease: Health and Nutrition from an Evolutionary Perspective p 7

Here’s what Professor Loren Cordain has to say about the potato: http://thepaleodiet.com/?s=potato

Additionally, potatoes are a stem tuber that is close to the surface, whereas other tubers are root tubers, deeper down.