There is no official definition of superfood, but it is considered to be a marketing term used to describe foods that are supposed to offer particular health benefits. The Macmillan Dictionary defines "superfood" as a beneficial food for health, which can help even in pathological conditions. The corresponding definition in the Oxford Dictionary is "a nutrient-rich food that is considered particularly beneficial to health and well-being." The UK Cancer Research Group defines "superfood" as "a marketing tool with little scientific basis", while another source defines it as a "non-medical term that has spread in the media and refers to foods with properties promoting health, such as reducing the risk of an illness or improving any aspect of physical or mental health. " Since 2007, the European Union has banned the marketing of products as "superfoods" unless accompanied by specific medical recommendations based on substantiated scientific research.