Can oats have negative health effects for healthy individuals that consume oats everyday for a long time in a well balanced diet?
If you have some sort of food allergy or intolerance to oats, you may run into negative health effects. In almost every other scenario, oats consumed in the scope of a balanced diet will be a net positive.
If you have carb intolerant Type 2 diabetes, you may find that oats, like any grain, may spike your blood glucose far far far, beyond what you’d expect just from the carb count.
That reaction is person specific, and not universal.
Not sure why they would cause an issue. For a year or so I’ve been eating oats almost every morning. I add walnuts and seeds (flax or hemp)as well as a touch of maple syrup. My cholesterol went down on blood work. I assume that had something to do with it. I was not trying to lower it.