To summarize,
Similar decreases in risk of CHD mortality were observed when vegetable protein was substituted for either carbohydrate and animal protein.
This suggests that both animal protein & carbohydrate may have similar potentially adverse effects on CHD mortality compared to vegetable protein.
Although animal protein, per se, was not associated with any outcome when substituted for CHO, a composite of red & processed meat servings, in place of CHO food servings, was associated with a 44% increased risk of CHD mortality, and a similar increase in risk was observed for dairy food servings. (RR=1.41)
A modest increased risk of red & processed meat servings in place of CHO foods was also observed with all cause mortality (RR=1.16)
The apparent discrepancy between the animal protein and food group analyses may be from the inability to differentiate among the effects of proteins derived from different animal sources when using the nutrient value, suggesting that protein sources may differ in their metabolic effects.
A modest increased risk of legume servings in place of CHO foods was observed with cancer mortality (RR=1.23). This finding is inconsistent with our results for CHD mortality, where an inverse trend was observed for legumes, and may be a spurious association.
No significant associations were observed with cancer incidence.