Hello. Usage of 有助于 is correct, but 提高 is used in a wrong way. 有助于 means sth is helpful to sth/sb, e.g.: morning jog is helpful to your health. The word 提高 is used on the words that have degree such like level, score, rate and so on, all these words can have high or low degree. Therefore, a correct form of your sentence should be 有助于提高人们的健康水平。