The linked article doesn't say that. The sentence actually reads:
Cardiovascular diseases are the leading cause of death in the world according to the Global Burden of Disease study, with 18.6 million annual deaths in 2019, of which around 7.9 are attributable to diet.
You are right, The line you quote is definitely the first line in the actual article. The first line in the introductory description “Cardiovascular diseases are the leading cause of death in the ratchet.” definitely does NOT appear anywhere in the article.