Johanna Budwig (30 September 1908 – 19 May 2003) was a German biochemist and author. Budwig was a pharmacist and held doctorate degrees in physics and chemistry. Based on her research on fatty acids she developed a diet that she believed was useful in the treatment of cancer. There is no evidence that this or other “anti-cancer” diets are effective, and the Budwig diet may be actively harmful.
While working as a researcher at the German Federal Health Office she noted many cancer drugs being evaluated in the 1950s contained sulphydryl groups. Budwig believed sulphydryl compounds were important to cellular metabolism and cellular respiration. Budwig researched the theory that a low oxygen environment would develop in the absence of sulphydryl groups and/or fatty acid partners that would encourage the proliferation of cancerous cells. With H.P. Kaufmann she developed paper chromatography techniques to identify and quantify fatty acids. Budwig used these techniques to compare the fatty acid profiles of sick and healthy individuals. This made her one of the first scientists to consider the health implications of fat consumption, according to Mannion et al. in a 2010 paper in the journal Nutrients.
In 1952 she described a diet which she claimed had anti-cancer effects. She called it the “Budwig protocol”. The focus of this diet is on modifying the intake of dietary fats. It is rich in flaxseed oil, mixed with cottage cheese and meals high in fruits, vegetables, and fiber and avoids sugar, animal fats, salad oil, meats, butter, and especially margarine.
There is no reliable evidence supporting the claims of efficiency against cancer, or that this diet helps people with cancer in any meaningful way.  There is no indication for using anti cancer diets and they can cause adverse effects including malnutrition, stomach ache, flatulence, and allergic reactions.
People with cancer who delay or forgo effective treatments as a result of using diets such as the Budwig Diet might suffer relapse, experience unnecessary disease progression, and experience continuing cancer-related symptoms.