( ( ( The use ) ( of ( trans fats ) ) ) ( ( ( ( ( became popular ) ( in ( the ( late 1960s ) ) ) ) , ) ( after ( ( saturated fats ) ( ( were conclusively ) ( linked ( to ( ( an ( increased risk ) ) ( of ( heart disease ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (NN use)) (PP (IN of) (NP (JJ trans) (NNS fats)))) (VP (VBD became) (ADJP (JJ popular)) (PP (IN in) (NP (DT the) (JJ late) (NNS 1960s))) (, ,) (SBAR (IN after) (S (NP (JJ saturated) (NNS fats)) (VP (VBD were) (ADVP (RB conclusively)) (VP (VBN linked) (PP (TO to) (NP (NP (DT an) (VBN increased) (NN risk)) (PP (IN of) (NP (NN heart) (NN disease)))))))))) (. .)))
The use of trans fats became popular in the late 1960s, after saturated fats were conclusively linked to an increased risk of heart disease.
(ROOT (S (NP (NNP Trans) (NNP fat)) (VP (VBD added) (PP (TO to) (NP (JJ certain) (NNS foods))) (S (VP (TO to) (VP (VB keep) (S (NP (PRP them)) (ADJP (JJ fresher))) (ADVP (RBR longer)) (, ,) (S (NP (NP (NN increase)) (PRN (-LRB- -LRB-) (PRP s) (-RRB- -RRB-))) (NP (NP (DT the) (NN risk)) (PP (IN of) (NP (NN heart) (NN disease))))))))) (. .)))