How can my husband and I tell his parents they drink too much alcohol?

They stayed here 2 days recently. His mom drank 2 bottles of wine solo and his Dad almost a whole bottle of scotch. His mom keep knocking things down and got all emotional. His Dad got all grumpy and wanted all the food for himself. Sometimes they call us drunk from their house. I'm tired of it and I don't want my daughter over at their house alone with them anymore. They are 80 years old. How can we tell them politely to stop this excessive drinking? They don't exercise and both eat excessively and are overweight which doesn't help either. Should we talk to them about it? My husband is worried.