Lemon juice, coconut oil and stopping all sugar intake won’t cure cancer

This Facebook post suggesting dietary ways to cure cancer has been widely shared on Facebook.

The post makes three claims: that if you stop all sugar intake any cancer cells in your body will die, that if you drink a cup of hot water and a whole blended lemon for one to three months (the post doesn’t say how often over the one to three months this should be done) your cancer will “disappear”, and that three spoonfuls of organic coconut oil morning and night will also result in your cancer disappearing.

It's similar to other posts which have reportedly been circulating, with the health claims attributed to various different doctors.

There is no evidence to suggest that doing any of these things will cure cancer and experts have warned that alternative therapies like these can cause other side effects, or prevent a patient’s conventional treatment from working effectively. They also warn that taking these alternative therapies instead of conventional treatment could prevent your cancer from being controlled or cured.

Let’s start with the sugar claim

Sugar, in and of itself, isn’t necessarily bad for you—you need it to live.

The NHS says that “carbohydrates should be the body's main source of energy in a healthy, balanced diet”. In order to be absorbed into the bloodstream and provide our bodies’ cells with energy, carbohydrates are broken down into the sugar glucose.

Cancer Research UK says that the idea sugar fuels cancer comes from the fact that cancer cells grow quickly so need more sugar and other nutrients than non-cancerous cells. It says “There’s no evidence that following a “sugar-free” diet lowers the risk of getting cancer, or boosts the chances of surviving if you are diagnosed.” 

The type of sugars we’re warned not to eat too much of for health reasons are called ‘free sugars’. These are mostly the sugars added to food and drink to make them sweet—fizzy drinks, cereals, sweets—and some that occur naturally like those in fruit juice and syrups. Cancer Research UK says there is an indirect link between sugar and getting cancer, as obesity is associated with an increased risk of some cancers.

And the lemon juice?

Contrary to the claims made in the post drinking lemon juice for several months will not make cancer “disappear” and it isn’t “1000 times better than chemotherapy”.

Cancer Research UK says “there’s no scientific evidence to show that lemon juice can cure cancer”. In response to similar online claims the National Centre for Health Research, a US-based health think tank, also says that “Lemons are not a “proven remedy against cancers of all types,” and no studies have ever been done that would compare the effectiveness of a lemon to chemotherapy.”

The University of Arkansas for Medical Sciences says: “There is some truth involved in the creation of this myth, based on a few recent studies. These studies indicate that citrus fruits, including lemons, contains compounds that may be beneficial in preventing or combating some types of cancer.”

“However, the myth significantly exaggerates the potential of lemons and lemon juice as a cancer remedy. The beneficial compounds in lemon juice have shown promise in recent studies, but the levels found in foods may only enhance the body’s ability to fight off cancer. In the end, there is no proven scientific replacement for radiation therapy or chemotherapy.”

So what about the coconut oil?

We’ve seen no evidence that coconut oil, in its natural form, has any cancer curing properties.

It’s unclear exactly where the claim came from. It may be from this 2017 study into the effects of lauric acid (found in coconut oil) on certain types of cancer cells. The study found that lauric acid could inhibit cancer cells’ growth or lead to their destruction, but it also said “further experimental evidence are warranted to better define the action of [lauric acid] alone or in the context of coconut oil consumption on tumor development as claimed by a current newsworthy debate.”

Experts urge caution on alternative therapies

Cancer Research UK says that the dangers with alternative therapies—such as those the Facebook image suggests—is that they may be unsafe, cause harmful side effects, or interact with a patient’s conventional treatment and prevent it from working as effectively. It also warns that giving up conventional treatment and replacing it with unproven alternative therapies unsupported by scientific evidence could reduce a patient’s “chance of curing or controlling [their] cancer”.