This canard is endlessly repeated without substantiation.
More advanced in culture? Does that mean in political organization? I doubt it, since Europe had a much more advanced legal system (Roman law and the beginnings of British common law) and more complex and representative political structures (republics, constitutional monarchies, merchant city alliances, elective monarchies, cantons) than the primitive shariat and caliphate.
Does it mean music? I doubt it, since strict Islam outlawed all music beside muezzin chant - while Europeans were developing complex polyphonic music and theoretically advanced counterpoint for instruments.
Does it mean the plastic arts? Don't make me laugh. While Islam outlawed representative forms Europeans were perfecting perspectival painting, the incredible frescoes which adorn the churches of Europe, remarkably innovative and diverse architectural forms.
Does it mean literature or philosophical speculation? Preposterous. While Islam limited literary invention to devotional poems and philosophical research to parroting Aristotle or hippyesque Sufi mysticism Europe outgrew in one generation the recycled and mistranslated Aristotle that had obsessed Muslims for four centuries. Europe revived the ancient forms of epic, drama and lyric to add to their already superior devotional verse and created a variety of new literary forms to boot.
Islam was medically advanced? How so? Their medical knowledge never progressed beyong Galen - a Greek who died centuries before Muhammad's birth. While Italians and Englishmen were inventing modern physiology, pharmacology and biology Muslims were specializing in two forms of surgery: chopping off thieves' hands and adulterers' heads.
Technology? What technological breakthroughs did Islam create? No architectural ones. No medical ones. Nothing in terms of mechanics. Nothing in terms of physics. Nothing in terms of engineering. Everything they had was borrowed piecemeal from either the Copts they murdered, the Persians they murdered or the Greeks they murdered.
Islam is not a culture - it is a devourer of cultures.