My mother in law blamed vomiting and a 3day hospital stay on my cooking with too much garlic, and eating Weinersnitchel that day with my husband and the Coffemate was blamed as well so I know why you might be wondering about this.
It is easy to get paranoid about what you cook/provide as a caregiver after they cannot do the shopping.
I think you will have the best success with Acai juice, pomegranate juice and my personal favorite Kombucha if you want to try something special. Of course all of them cost an arm and a leg but are available at your local Whole Paycheck, I mean Whole Foods or mom and pop health food store. Best of luck to you!