Breaking Anti-Cancer News: Ditch the Peanuts and Spread the Word

peanuts are not an anti-cancer food

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The first study to examine the effects of certain compounds in peanuts on the spread of cancer is about to be published–and the results show serious consequences for your anti-cancer diet, especially if you have metastatic cancer.

Certain proteins in peanuts, called peanut agglutinin (PNA), fuel the spread of tumors, says a research team from the University of Liverpool. PNA is a type of lectin, proteins that stick to different molecules of carbohydrates, and the molecules that PNA targets are present in most human cancer cells.  

“Previous studies have shown that PNA is highly resistant to cooking and digestion and rapidly enters the human blood circulation after peanut ingestion,” say the authors. There it binds to cancer cells that have spread to the blood, helping them to form clusters and to stick to the lining of blood vessels, explained Dr. Lugang Yu, one of the study’s authors.  As you probably already know, most cancers spread–or metastasize– to distant organs by travelling through the bloodstream.

 “As metastasis accounts for the majority of cancer-associated fatality, regular consumption of peanuts by cancer patients would therefore be expected to have an adverse effect on cancer survival,” the authors conclude. 

The journal “Carcinogenesis” has just published the abstract and will soon be publishing the full study. The work was done in cell cultures and animal models and focused on cancer cells that originate in the epithelial tissues that cover organs and line body cavities. Epithelial cancers account for 85 – 90% of human cancers. (Here’s more information on which types of cancer may be affected and why.)  

“More studies will be needed to test if peanut agglutinin will affect metastasis in cancer that is not of epithelial origin,” Yu said.   


Kudos to the American Institute of Cancer Research for funding this groundbreaking work. 



19 thoughts on “Breaking Anti-Cancer News: Ditch the Peanuts and Spread the Word

    • Oil is pure fat– so there should be no problem with lectins, which are proteins that bind to carb molecules. Peanut oil is around 32 percent polyunsaturated fatty acids (PUFAs), 17 percent saturated fats (SFAs) and 46 percent monounsaturated (MUFAs). As I’m sure you know, all oils have different combos of these fats.

      PUFAs go rancid quite easily when exposed to light and heat. That’s a problem when cooking with peanut oil and/or purchasing those clear bottles that get transported at who knows what temperatures and stay on shelves for who knows how long. (Saturated fats are the most stable in heat; monounsaturated are next.)

      Plus, peanut oil has a substantial amount of omega 6 fatty acids (a type of PUFA)–and to fight inflammation, you want to increase omega 3s (another PUFA–and even more sensitive to light and heat than 6s) relative to 6s.

      Did your doctor talk about extra virgin olive oil? It’s primarily composed of MUFAs (oleic acid, often called omega 9), which are more stable than PUFAs and neutral in their effect on inflammation. It’s also filled with healthy polyphenols, which have a host of anti-inflammatory properties. Heat will destroy some polyphenols, but olive oil is still a good choice as long as you use low to moderate temperatures and don’t let it smoke.

      Of course, if you’re looking for anti-inflammatory fats, then whole foods are a better choice than oils because the foods protect the oils/fats inside. Plant sources of omega 3s include English walnuts and chia (and the red or black seeds are higher in polyphenols than the white). Omega 3 oils, on the other hand, go rancid really quickly.

      Sorry to be so long-winded, Janice. Thanks for your question.


    • That’s a good question, Janice, and I think your assumption is correct. I will ask an expert, however, to be absolutely certain. As a sister survivor, I believe in the precautionary principle– and weigh the likelihood as well as gravity of each and every risk. Truth is never absolute. As one scientist at the recent AICR conference so wisely said, “we only know what we observe under certain conditions.” (a paraphrase) We’re just at the beginning of understanding how foods affect cancer risk and likely will be long gone before that understanding is complete. That’s why I choose to tell people about preliminary evidence–especially studies like this one, with such grave consequences. In fact, considering the gravity, I doubt we’ll ever get to human trials of peanuts on metastases. Would they even be ethical?


  1. From The China Study, there’s mention of peanuts acting as a potent carcinogen if they were consumed with a diet high in animal protein. The data came from an animal study conducted in India. For those rats who consumed a plant based, low protein diet, cancer didn’t occur. This was also observed by Dr. Campbell when looking at liver cancer rates in children under the age of 10 in the Philippines, where peanuts are commonly used in cooking. It turns out that the children from wealthier families who were eating a meat heavy diet were the ones who were sadly being afflicted with liver cancer. Some were as young as 4 years old. It was rare to see liver cancer in poor children who ate very little animal foods.


    • It’s the quality of the lectin in peanuts that’s important. It survives cooking and digestion, gets into the blood and sticks to carbohydrate compounds that are common in cancer cells. Many foods have lectins but they don’t necessarily survive cooking and digestion and/or don’t have an affinity for those particularly carbohydrates.

      Again, as I say in the article, the consequences are very important for cancer patients.


  2. The traditional chinese physician who was treating my sister for breast cancer also told my sister to avoid peanuts,chillies, egg yolk. dairy foods, deep fried,pan fried or charred foods,shellfish and other toxins.


  3. What is you don’t have metastatic cancer yet? I was diagnosed with Stage 1 IDC in January, had BMX, did not need rads or chemo, I am on tamoxifen. I’ve been eating 2 tablespoons of organic peanut butter every morning since January, to get more good fats. Could this have caused my cancer to spread?


    • Jane,

      I’m not a medical doctor but if it were me, I think I’d stick to the precautionary principle and avoid peanut butter. How about eating some tree nuts–walnuts and pecans, for example–and Hass avocados for those good fats? Beans and seeds (chia, pumpkin, flax, hemp) and olive oil and green olives are also healthy choices. Do any of those options interest you?


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