Countries recovering from war are at risk of being left to their own devices in tackling non communicable diseases, leaving an "open door" for exploitation by alcohol, tobacco and food companies, health experts warn.

Writing in the Bulletin of the World Health Organization, Bayard Roberts and Martin McKee, of the London School of Hygiene and Tropical Medicine, and Preeti Patel, of King's College London, argue that the post-conflict environment risks increases of mental health problems and other NCDs, such as high blood pressure, diabetes and cancer.

After exposure to violent and traumatic events, people may be prone to developing harmful health behaviours, such as excessive drinking and smoking, which exacerbate the problem of NCDs in the long-term.

This is why the lack of a strong will from the authorities to restore the health system leaves an open door for commercial ventures to influence health policy to their advantage.

The authors write: "This toxic combination of stress, harmful health behaviours and aggressive marketing by multinational companies in transitional settings requires an effective policy response but often the state has limited capacity to do this."

Afghanistan has no national policy or strategy towards NCDs and, apart from the European Commission, none of its partners has given priority to introduce and support them. High blood pressure is largely untreated in Iraq, three times as many people die prematurely from NCDs in Libya than from infectious diseases and similar patterns can be found in other countries recovering from conflict.

"This policy vacuum provides an open door for multinational companies to influence policies in ways that undermine efforts to control tobacco and alcohol use or improve unhealthy diets in transitional countries," the experts say.

Little attention is paid in reconstruction and humanitarian efforts to helping countries emerging from conflict deal with their present or future burden of NCDs - with the topic virtually ignored during the United Nations high-level meeting on NCDs in September 2011.

The authors argue that this gap must be filled, pointing out that the post-conflict period can provide an opportunity to completely rewrite strategies and undertake reforms to better address the health needs of a population and lay the foundations for a more efficient health system.

Dr Roberts, a lecturer in the European Centre on Health of Societies in Transition at LSHTM, says: "While great attention is rightly paid to infectious diseases, noncommunicable diseases should also be given attention - especially as the post-conflict environment can provide the perfect breeding ground for unhealthy activities like smoking, drinking and poor diet. We are making the argument that if the authorities do not step up to lead the way in developing policies which will benefit public health, then they leave the route clear for companies to step in and serve their own interests."