A weather forecaster understands this dilemma, shrugging when we ask if it's going to rain tomorrow. I'd say an 80 percent chance. Because we can cover our bases by carrying an umbrella and a sun hat, we do not fret over the limitations of the weather report. Not so with medical studies. Too much is at stake and we need to feel in control of our health, so we act as though medical problems have more definite solutions than weather predictions.
Every week there's a new study with different recommendations.
I confess that it's beyond me how to determine what is the optimal combination of vitamins, minerals, herbal supplements and fat and fiber content. Even more confusing is the relationship of estrogen to memory. At least with breast cancer, one can construct studies in which there are objective endpoints such as tumor recurrence or death. Neuropsychologists act as though memory is an entity that can be quantified via testing. Down deep we all know differently.