nginx processes

Hey guys, So after editing /etc/nginx/nginx.conf and adding the line
worker_processes 1
I did a service nginx restart
But I still get 5 nginx processes. Does anyone know how I can fix this? It's taking up too much ram.

23905 root 20 0 29240 860 144 S 0.0 0.3 0:00.00 nginx 23906 www-data 22 0 29244 1156 428 S 0.0 0.4 0:00.00 nginx 23907 www-data 18 0 29244 1184 456 S 0.0 0.5 0:00.00 nginx 23908 www-data 18 0 29244 1284 464 S 0.0 0.5 0:00.00 nginx 23909 www-data 20 0 29244 1236 416 S 0.0 0.5 0:00.00 nginx