As long as they are gambling it wouldn't lessen those bad habits it wouldn't matter if they are gambling through online or in real life.
Yes it has no difference because there's a money involve. If we lose it can affect our mental health on thinking about our worries of losing the money in gambling. Sometimes to be able to temporarily forget those problem drinking and smoking are the solution to calm.
Going back, gambling and health has been a broad issue even before, but the main thing I could think of as a solution is proper control of time, funds, and emotion that we are giving off when gambling.
Indeed we need discipline when we gamble. If we can control ourselves and not eager to win or to chase back the losses then we wont face worst problem after.