Science - August 31, 2017

Eat your way to health

Text:
Tessa Louwerens

Dietary recommendations are mainly used to prevent disease, and seldom to treat it. They do have curative potential, but the Dutch healthcare system is not geared to that. ‘It is cheaper to prescribe pills than to supervise patients over a long period in changing their eating habits and lifestyles.’

Text Tessa Louwerens illustration Shutterstock/Paul Gerlach

In future, lifestyle and diet should play a bigger role in the treatment of chronic diseases. This is the drift of a report published this summer by a team of experts from Wageningen University & Research, their colleagues from other universities, and the National Institute for Public Health and the Environment (RIVM). ‘Recently we have been seeing a revival of interest in nutrition and lifestyle interventions,’ says project leader Renger Witkamp, professor of Nutrition and Pharmacology in Wageningen. 'In this report we summarized the potential of nutrition and looked at what it would take to exploit it better.’

The biggest benefits, say the experts, can be gained in the treatment of cardiovascular diseases and diabetes type 2, which tends to affect the elderly. But dietary changes can also benefit patients with certain types of cancer, kidney disease or lung conditions. ‘A healthy diet not only supports the treatment but also improves the patient’s general health, giving it a unique advantage over drugs,’ says Witkamp.

High costs

And the general health of the Dutch is not exactly blooming at the moment. Almost half of all adults are overweight and one third suffer from one or more chronic diseases, show surveys by the RIVM. ‘These patients take a lot of medicines, with all the side effects and high costs that that entails,’ explains GP Tamara de Weijer, chair of the Doctors and Nutrition Association. According to the Central Bureau for Statistics, the Dutch spent almost 95 billion euros on healthcare in 2015. Overweight and unhealthy lifestyles are responsible for about 14 percent of this healthcare burden.

The incidence of chronic diseases, with all the costs they entail, could be significantly reduced, believes De Weijer. ‘A healthy diet works on several fronts at the same time. Weight loss in patients with diabetes, high blood pressure and raised cholesterol not only enables them to stop their insulin injections but also to reduce their doses of drugs for lowering cholesterol and blood pressure.’

Directing patients to the greengrocer will become completely normal

Perverse incentives

But nutrition and lifestyle interventions are still not being applied much in practice. According to Witkamp, this is partly to do with the way healthcare is funded. ‘The current healthcare system works mainly with short-term models. It is cheaper to prescribe pills, the effect of which you see immediately, than to supervise patients over a longer period in changing their eating habits and lifestyles.’

This sounds familiar to De Weijer. ‘As a GP you are exposed to perverse incentives. A doctor earns more if a chronically ill patient keeps coming to the surgery and having drugs prescribed. Health insurance companies cover operations and pills but rarely lifestyle interventions.’

According to De Weijer, this is one of the reasons why GPs pay too little attention to diet and lifestyle. ‘Whereas at least three quarters of the medical problems we see are directly related to these things. Take diabetes, high blood pressure and cardiovascular diseases. In these cases, the drugs are not really treatments; they only keep the disease in check.’

There are a few diseases, however, for which the treatment protocol used by doctors does include discussing lifestyle interventions. But, says Witkamp, little is known about the extent to which doctors actually comply with these guidelines. From talking to colleagues, De Weijer’s impression is that they do not often follow through on them. ‘They find it difficult. It is time-consuming, or they do not think it is their responsibility.’

An added factor is that doctors do not learn much about nutrition during their training. In six years of training, medical students get an average of 29 hours of teaching on nutrition and 30 hours on lifestyle, says a recent report commissioned by the ministry of Health, Welfare and Sport.

No placebo fries

A further obstacle is the difficulty of obtaining scientific evidence in nutritional studies. Witkamp: ‘In drug research you can carry out studies in which one group is given a pill and the other a placebo (a fake pill). But in nutrition research it is not easy to conduct these kinds of studies: there is no such thing as placebo fries.’ And, adds Witkamp, nutrition studies often lack a clear-cut end point. ‘Maybe you want to know how many people in the study have a heart attack. But you usually only see the results of dietary interventions decades later, which makes this kind of study extremely expensive and well-nigh unworkable.’

In the report, therefore, the experts argue for alternative research methods which take into account knowledge based on the practical experience of healthcare workers and patients. Witkamp: ‘We are thinking in terms of things like eHealth programmes. People can monitor their blood sugars at home, for instance, using continuous glucose monitors, and send in their data. The advantage of this is that you can collect data from a lot of people over an extended period, and in a natural situation. It is important, though, that these data are processed and interpreted by experts.’

New curriculum

For the healthcare system to make better use of the potential of diet, several things need to change, says Witkamp. He thinks doctors and policymakers could make better use of the expertise of health professionals such as dieticians and lifestyle coaches. And more attention should also be paid to the importance of diet and lifestyle in the training of doctors, nurses and other healthcare workers. ‘In response to this report, a committee is being formed in collaboration with the ministry of Health, Welfare and Sport and the medical faculties, which will be tasked with developing a new curriculum for medical students, with more emphasis on diet.’

De Weijer is pleased with this initiative. ‘Directing patients to the greengrocer instead of the pharmacy might take some getting used to now but in a few years we shall consider it completely normal. If lifestyle adjustments do not work well or fast enough, drugs are plan B.’ Witkamp agrees. ‘This requires more investment in the short term, but in the long term it will probably pay back when we have a healthier society.’


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