One factor to consider is long term exposure. At 60-70-80-90 years old our body reflects the long term exposure.

Our longevity has changed with the addition of sanitation, medicine, advanced surgery, etc such that we can now see the effects of what we thought was good...... foods that may not be good for every one.

I'm not ready to give up my beef, but I sure think about my genetic and how the foods of my immediate ancestors affects what is better for this body.

Eggs. Not for everyone. Dairy. Not for everyone. A lifetime to figure it out.lol

I do know bread and wheat makes me feel terrible when I fill up.