Can 'alternative' cancer diets help

‘Alternative’ Cancer Diets

Key points:

  • After a cancer diagnosis, overall diet quality and choosing particular foods can be very helpful for supporting health and resilience. These choices can also contribute to other aspects of your health and wellbeing.
  • So-called ‘alternative cancer diets’ such as the Gerson and Breuss juice diets, the Budwig protocol, the alkaline diet and ketogenic diets, may be promoted as cancer treatments or even cures.
  • Some elements of ‘alternative’ diets may have some healthful properties.
  • Choosing an ‘alternative’ dietary regime in place of proper treatment is dangerous as firstly  the diet itself may have inherent risks
  • More importantly, choosing alternative ‘treatments’ misses the opportunity for evidence-based treatment that has been researched and tested carefully to treat cancer effectively.
  • People living with and beyond cancer should discuss alternative diets and therapies they may be considering with their medical team.

After a cancer diagnosis, people may ask if there are special diets or cancer-fighting foods that can help them. They may have heard of ‘alternative cancer diets’ such as the Gerson diet, the Breuss Cure, the Budwig protocol, the alkaline diet, or the ketogenic diet, and wondered about claims that diets can be used to treat or even cure cancer. In this article we’ll look at some of the diets that are claimed to treat cancer. We’ll see that the evidence for these ‘alternative diets’ should be considered very carefully before they are followed. You may also find our articles on Cancer Diets, Foods that Fight Cancer and Carcinogens helpful, as they discuss the evidence for eating well before, during and after treatment.

More than a third of us can expect to develop cancer during our lifetime, so most of us will experience cancer personally or in a close family member. Making healthful choices of diet and lifestyle can help to prevent cancers, and be very helpful and supportive during and after cancer treatment. For people living with and beyond cancer, eating well, staying physically active and maintaining a healthy body weight may impact on progression of some cancers1-6. Eating well can help your body at all stages of the cancer journey from diagnosis, through treatment and recovery, and for people living with and beyond cancer. At Curve we consider food to be a key element in your armory against cancer following diagnosis, whatever your stage. This is not to replace treatment, but to support you to get the most out of your treatment, to boost your resilience and do as well as you possibly can for someone in your position.

Cancer diet cure?

Choosing to follow an ‘alternative diet’ instead of treatment is sometimes considered, especially with the plethora of online (mis)information about cancer and nutrition. However, online information is of hugely variable quality and reliability – there’s plenty of ‘fake news’ in the online world of health information.  Treatment choices should always be discussed with your doctor. There are some potentially healthy elements in ‘alternative cancer diets’, such as in the Budwig protocol, that can be incorporated into a healthy diet to complement treatment. For example, flaxseed oil used in the Budwig protocol may have healthful properties. Also the so-called alkaline diet includes lots of vegetables, which can be a healthy choice – although the alkaline diet may not be suitable for some people with kidney problems (discussed below).

Man making juice in a blender

Can “alternative” diets treat cancer

Let’s look at some of the alternative diets that are claimed to treat cancer.

Juice diets such as Gerson7 and Breuss8 regimes

Since the early 20th century, the use of vegetable and fruit juices has been proposed as a way to cure degenerative conditions, including cancer7. In some therapies, such as Gerson and Breuss protocols, juices are combined with other non-dietary interventions such as enemas. Although some practitioners claim to have cured cancer with juices, there are no published studies showing that juice diets alone can treat cancer. Having a vegetable juice can be an occasional inclusion in a varied healthful diet. However, juices made from fruit and some root vegetables have a high natural sugar content, so these foods are best consumed as a food, rather than a juice, to consume all of the fiber. A varied intake of vegetables and fruit help the body to fight cancer9-11 and the fiber helps support the growth of beneficial microbes in the intestines.

A particular note of caution about juice diets for people with reduced kidney function. Some vegetables and juices made from them are very high in potassium, for example the Gerson protocol intentionally depletes the levels of sodium in the body and raises potassium intake7. The Breuss protocol for some cancers includes raw potato juice which is extremely high in potassium. These protocols present a particularly serious risk for people with high blood potassium levels due to poor potassium clearance. Specialist medical advice must always be sought for any dietary changes when kidney function is affected.

A high intake of juices such as in the Gerson protocol can also cause bowel disturbances and lead to weight loss if juices are used instead of eating regular foods. Extreme juice diets that exclude all solid food for prolonged periods, such as the Breuss protocol which involves 42 days on juices and teas with no other foods for some types of cancer8, can lead to severe weight loss12.

The bottom line on juice diets is that they aren’t supported by evidence as alternative treatments for cancer. Enjoying vegetable juices in moderation can be an enjoyable addition to a healthful diet, but following ‘alternative’ cancer protocols such as Gerson7, Breuss and others using high juice intakes carry risks especially that can be especially serious for people with high potassium and compromised kidney function.

Flaxseed oil and cancer: The Budwig Protocol

In the 1950’s Johanna Budwig developed a protocol that she claimed would correct cell abnormalities. Dr Budwig was a pharmacist and biochemist who researched fatty acids. Budwig proposed mixing together two specific foods: flaxseed (linseed) oil and quark, a fresh cheese that is similar to curd cheese or cottage cheese. The proportions were defined and Budwig’s theory behind the mixture was that these two foods produce specific compounds that normalize abnormal cells13. Other dietary restrictions were also recommended by Budwig; vegetables were increased, and meat and processed fats were avoided in the Budwig protocol.

Whole and ground flaxseed

However, since the original work by Budwig, knowledge of cell biology in general, and cancer in particular, has developed exponentially. The current understanding of cancer cell behavior does not fit with the proposed mechanisms that Budwig based her theory on, and there is no documented evidence for the Budwig protocol as an alternative treatment for cancer.

On the other hand, Budwig’s protocol does contain some elements that in themselves may be beneficial, not because Budwig’s theory was correct, but because we now know that flaxseed (linseed) oil and fermented cheese may contain healthy elements that can be suitable to include in the diet.

Firstly, studies suggests that omega-3 fats from foods like flaxseed oil and oily fish, can help to reduce inflammation in the body. So this element of the Budwig ‘mixture’ may have merit in a varied diet. Some studies have observed that an increased intake of omega-3 fats including from linseed, may be linked to lower rates of cancer14-17 and laboratory studies have linked flaxseed oil components with suppression of cancer cell growth in the laboratory18.

Secondly, the ‘quark’ that Budwig proposed is a typical fresh fermented cheese widely consumed in Germany, Scandinavia and many other parts of Europe. It may have two potentially healthful properties unrelated to the proposed mechanism that Budwig described. The calcium present may have some protective affect against colorectal cancer. Several studies have reported that consumption of calcium from dairy and non-dairy sources may be linked to a lower risk of colorectal cancer19, although high consumption of high fat-dairy foods may increase risks of other cancers.  Budwig may not have anticipated another possible benefit of eating fermented dairy foods like quark – the healthful microbes from the live cultures20. Traditionally made quark such as from Budwig’s region uses cultures, although commercially made product often simply use a coagulant like rennet. So if you choose to include quark or similar fresh dairy products in your diet, the traditionally cultured varieties may be a better choice than those made simply using rennet. Yoghurt is also a source of calcium and beneficial cultures, and widely available.

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Budwig advised the use of flaxseed oil, but the flaxseed itself also contains some beneficial fiber. So another take on this would be to use flaxseeds rather than the oil, to enjoy additional nutrients beyond those that Dr Budwig identified.

So Budwig’s protocol of flaxseed oil and fresh cultured cheese may have some helpful elements, and moderate consumption of them may be healthful for some people. Budwig’s advice to avoid processed fats and increase consumption of vegetables was also healthful. However, the Budwig protocol as an ‘alternative cancer diet’ is not supported by evidence that it can treat cancer, and there are inherent risks of using it as a substitute for conventional treatments.

Keto diet and cancer21-25

Cancer is a complex group of diseases, and the metabolism of cancer cells is an area of active research. It’s known that cancer cells adapt to rapidly use some nutrients to fuel growth, and researchers are looking for ways to block these pathways in cancer cells21. Some new medical treatments may emerge from these explorations of cancer cell metabolism.

Many cancer cells become highly dependent on certain components of protein (amino acids) especially L-glutamine and L-methionine. Most cancer cells use glucose in large amounts for cell growth. Based on these characteristics of cancer cell biology, there is some interest in using diets such as the ketogenic diet that attempt to ‘starve’ cancer cells by reducing access to glucose and other nutrients.

Diets where the main fuel is fat are termed ketogenic diets because fats are broken down to produce ketones. In the ketogenic diet these ketones act as an alternative fuel to glucose, healthy cells can burn ketones in the absence of glucose but some cancer cells may be less able to burn ketones. So the interest in using ketogenic diets in cancer is based on the theory of reducing the level of glucose in the body and therefore reducing the fuel for cancer cells.

There are different versions of the ketogenic diet. In the early 1900’s the ketogenic diet was ‘discovered’ almost by accident, in children with epilepsy. Doctors observed that children with severe intractable epilepsy – status epilepticus -stopped having fits when they had been without food for long periods, and the fits returned more frequently if foods high in sugar and starch were eaten. By a process of trial diets, they identified that eating foods like meat and cheese kept seizure rates lower than starchy foods. Thus the ketogenic diet was established, based on fats and protein foods.

The earliest ‘classical’ ketogenic diets were high in saturated animal fats, which may have disadvantages for many people. Ketogenic diet studies have established different models of ketogenic diets, using different types and proportions of fat and protein. The Atkins Diet is a ketogenic diet but is also high in animal protein. Ketogenic diets are also popular amongst some weight loss influencers, because ketogenic diets may help people lose weight rapidly in a short time. That’s partly because ketogenic diets may help people to burn body fat, but ketogenic diets exclude sugar and starch, so people following a ketogenic diet are avoiding all those cookies, cakes and confectionary that carry lots of calories.

A plate of cheese

How effective is it?

It’s still a very hotly debated question about whether ketogenic diets may help people after a cancer diagnosis. Some well-respected research groups are studying whether ketogenic diets can improve outcomes and complement treatment in advanced cancers22-25. The debates surrounding the ketogenic diet include how well it can cut off cancer’s access to glucose. When carbohydrates are removed from the diet the body can still make glucose in the liver, but this produces a lower level of glucose than someone eating a typical Western industrialized diet, of refined starchy foods and sugar.

Another question about the ketogenic diet arises from knowledge of the nature of cancer, as it’s known that cancers may adapt to use different nutrients in the body. Some lab studies of a ketogenic diet have shown that some cancers can adapt to burn ketones if they are starved of glucose. In the lab, some sub-types of melanoma and colorectal cancer were found to actively thrive on a model of the ketogenic diet, because they had genetic changes that enable them to feed on the ketones generated in the ketogenic diet23. So for some people, it’s possible the ketogenic diet may enhance cancer cell growth. Also some types of ketogenic diet that are high in animal protein may increase inflammation in the body, and increase a growth factor, IGF-1.

It’s also likely that switching to a ketogenic diet that is high in animal fat and low in vegetables will have an adverse effect on the balance of microbes in the intestine26.

However, a few researchers working with people with brain cancers identified that ketogenic diets may reduce the number of seizures that people suffered, which goes back to the origins of the ketogenic diet. From there, some case studies looked at whether ketogenic diets can be supportive of people affected by some brain cancer cells, especially the very aggressive glioblastoma cancers. Trials of ketogenic diets to support treatments for brain cancers and some other advanced cancers are taking place in various places around the world24,25. Specialist medical advice should always be sought by those thinking about whether a restricted diet may be right for them, and ketogenic diets don’t replace cancer treatments.

One feature of a ketogenic diet is that it reduces the amount of insulin that the body is required to make. As insulin is a tumor promoter, reducing sugar and refined starchy foods in the diet is itself a healthful change to make, without having to embark on a ketogenic diet.

In conclusion, ketogenic diets are an interesting area of research. Some types of ketogenic diet may be unhealthy if they contain a lot of animal protein and saturated animal fats. Ketogenic diets are not suitable for everyone affected by cancer, their use requires a specialized opinion and advice. Importantly, ketogenic diets are not an alternative to cancer treatment.

Alkaline diet

A simple on-line search of ‘cancer diet’ will often turn up ‘alkaline diet’ as ‘alternative cancer diet’. The theory of the alkaline diet is that cancer cells love acid and so achieving alkaline conditions in the body will suppress cancer growth. Unfortunately cancer biology and human physiology are much more complex than this explanation for an alkaline diet.

‘Acid’ and ‘alkali’ are well known concepts on chemistry, but how they relate to body chemistry is often misunderstood. The body has systems to maintain an ideal pH, which is the scale of acid (low pH) to alkaline (high pH). Different parts of the body have different requirements for acid/alkaline balance. For example the contents of the stomach needs to be very acidic in order to digest food. On the other hand, saliva in the mouth tends to be alkaline and the enzymes in the mouth prefer alkaline conditions to start the process of digestion. Alkaline conditions in the mouth help to neutralize acid which erodes tooth enamel. So a healthy body will make acid where it’s needed, and alkali where it’s needed. Inside each cell and surrounding cells are compounds that keep the pH where it needs to be for optimum health. In the blood these ‘buffers’ keep the pH where it needs to be.

Leafy greens, cucumber, apples, ginger

Dietary intake has a part to play in the balance of acid and alkali in the body, although the role of ‘dietary acid load’ is still a nutritional controversy27. If the diet is very high in animal proteins, the end-products of metabolizing these proteins are acidic, and the body must compensate for this by moving minerals around. On the other hand, eating a lot of vegetables provide alkaline components like potassium that offset the acid produced from metabolizing proteins.

Alkaline diet for cancer patients

The theory often put forward for the alkaline diet is that eating a lot of vegetables will suppress cancer growth, as the alkaline components will stop cancer growth because cancer cells love an acidic environment. But this is a simplistic view of biochemistry. Cancer cells produce a lot of acid by the process of malignant cell growth, but eating a lot of ‘alkaline foods’ won’t stop the cancer cells producing more acid.

So the theory of the alkaline diet as an alternative cancer treatment misunderstands the relationship between cancer and acid. Similarly, alleged cancer ‘cures’ like taking baking soda because it’s alkaline are also misguided. Baking soda is alkaline, but when it’s swallowed, the acid in the stomach will neutralize it, producing carbon dioxide gas. So the alkalinity of the baking soda ends, literally, with a fizz, in the stomach.

As with other ‘alternative cancer diets’ we’ve looked at, such as the Budwig protocol, there are some potentially healthful elements of the alkaline diet. Firstly the ‘alkaline diet’ is high in vegetables. That’s good for most people concerned about cancer, because many plant foods provide good nutrients that are linked to better health1,4. Also the additional fibre provided by vegetables in the ‘alkaline diet’ help to support the beneficial bacteria in the intestines, they are important for immunity26. Additionally, the ‘alkaline diet’ tends to be lower in animal protein and processed foods, so again a healthful choice2,3.

However, for people with kidney problems, as with the juice diets, the alkaline diet is inherently high in potassium, which can be very risky people who have high blood potassium and reduced potassium clearance. So always seek specialist medical advice if you have kidney problems and you’re thinking about significantly changing your diet, especially the ‘alkaline diet’ as it increases the intake of potassium-rich vegetables.

The bottom line on the alkaline diet is that it isn’t a replacement for evidence-based medical treatment.


To summarize, we’ve discussed some ‘alternative cancer diets’ but claims that they treat cancer are not supported by proper studies. Some have elements that may have healthful properties when incorporated into a healthy balanced diet that is high in plant foods. For example, the two main components in the Budwig protocol, flaxseed oil and quark, may be healthful. Flaxseed can be a useful source of omega-3 fatty acids that may help reduce inflammation, and cultured dairy foods can provide beneficial cultures for the digestive system. Research into the ketogenic diet is genuinely interesting and ongoing.

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