What is the fine-grained topic of the following text: For more, let’s search a bit closer at such studies published in the medical periodical The Lancet, in which investigates from McMaster University in Canada looked at a whopping 130,000 parties from 21 two countries, all of whom were between 35 and 70 years old. Only return the topic.
Medical studies published in The Lancet by researchers from McMaster University in Canada.