The idea that certain foods have healing properties and can be used to treat disease is controversial.
We are willing to accept that the western diet is making us sick but there is scepticism about whether certain foods can heal the body after trouble sets in.
Ireland is more conservative than other countries when it comes to complementary therapies. The US/Mexico border is dotted with alternative clinics bearing names that drip optimism like The Oasis of Hope Hospital.
Most are set up by US citizens taking advantage of Mexico’s loose medical regulations to offer nutritional therapies for diseases like cancer.
Thousands of Americans travel every year, usually after they have been told conventional medicine can do no more for them, and are put on a regimen of vitamin therapy, daily enemas and large doses of nutritional supplements.
Miracle cures
There have been claims of miracle cures but just as many accusations of bogus treatments.
Debate about the clinics tends to erupt when someone prominent dies in them, such as Martin Luther King's widow Coretta Scott King back in 2006 following unsuccessful treatment for ovarian cancer.
When Steve Jobs was diagnosed with pancreatic cancer in 2003, he delayed surgery for nine months to explore nutritional and other alternative options. It was a decision he came to regret as the cancer had spread by the time he was willing to submit to conventional treatment.
It seems that when it comes to fighting killer diseases, putting your faith in food alone is not a good idea, but orthodox medicine can also be very one-dimensional.
Prescribing nutrition
Even when treating diseases associated with poor diet like heart disease or diabetes, the default is pharmaceutical drugs rather than reversing the condition with diet. So is it time for doctors to get more serious about prescribing nutrition?
If you have any doubts about the power of food, watch the documentary Fat, Sick and Nearly Dead. It tells the story of Joe Cross, a 310lb Australian who cured his chronic auto-immune condition urticaria with a medically supervised 60-day juice diet and was able to ditch the pills he had been on for nine years.
He also managed to persuade a morbidly obese Ohio trucker who suffered from the same condition to try the juice route, with an outcome that will leave you cheering at the screen.
There is a middle ground emerging in the form of “integrative nutrition” – the idea that food can be used alongside conventional medicine to support the body to heal itself.
Patricia Daly is a nutritional therapist whose speciality is working with cancer patients. She stresses that she never recommends nutritional therapy as an alternative to conventional medicine and that her job is to keep people as healthy as possible during treatment.
Her clients usually come to her during chemo or radiotherapy for help with combating side effects. “I don’t consider myself as alternative at all; what I do must be integrated with orthodox medicine,” says Daly.
“For emergencies, modern medicine is fantastic but for more chronic illnesses it is worth looking into integrating other therapies.”
She uses extensive lab testing to monitor how her clients react to her programme of dietary changes and to check for nutritional deficiencies and overloads. This ensures a more targeted approach.
“I need the support of lab testing. For example, with cancer I regularly use liver-function tests, and after treatments I like to monitor digestive health, hormone levels and other functions depending on the symptoms the client experiences.”
Toxic effects
Because of the toxic effects of chemotherapy, a big part of her work is maintaining the strength of the immune system so that treatment does not have to be interrupted because of infection.
“That is the challenge for me – trying to keep the immune system as well as possible during chemo. I use, for instance, medicinal mushrooms to support the immune system and educate clients on the effects of sugar and processed foods on tumours. Sugar feeds cancer cells and it is imperative that it is cut out of the diet.”
She values turmeric for its anti-inflammatory properties, papaya to aid digestion and ginger to combat the nausea associated with chemotherapy. The evidence that nutrients can be used in isolation as therapy is patchy. This could be because there is less incentive to carry out large studies. So long as there is little money to be made in using food as medicine, pharmaceutical companies will continue to push pills.
When medicinal claims are made about food, they are often couched in hedge betting language – X food is “thought to” be helpful in treating specific conditions; a low intake of B vitamin “could be” linked with depression; and liquorice “may be” a good cure for acid reflux.
It is this "thought to" aspect that poses difficulties for scientists like Maria O'Sullivan, associate professor in human nutrition at Trinity College Dublin. She says that for nutrition to be justifiably called a therapy you would need the same kind of hard evidence that you would expect from a clinical drug trial.
Actual therapy
"That is the quality of evidence you would need for scientists and medical professionals to take something like a nutrient seriously as an actual therapy, as opposed to something that has a nutritional effect.
“And that level of evidence is lacking for many of the things we think might have a therapeutic effect.”
She says that while people may find relief from symptoms with certain foods, that does not mean it is treating the core disease. However, she agrees that diet is very effective in managing certain chronic conditions.
“If you have a disease like coeliac disease, which is an inflammatory disease of the gut, the known and proven therapy for that is a gluten-free diet. There is emerging evidence for vitamin D as an anti-inflammatory but it is not yet proven.
“Turmeric has been shown to have an anti-inflammatory and maybe anti-cancer effect, but again it is not totally proven.
“I guess there is room for debate on it, and as scientists we are reasonably open minded and can but judge the current evidence which may change with time.”