Association Between Consumption of Ultraprocessed Foods and Cognitive Decline

> Results A total of 15 105 individuals were recruited and 4330 were excluded, leaving 10 775 participants whose data were analyzed. The mean (SD) age at the baseline was 51.6 (8.9) years, 5880 participants (54.6%) were women, 5723 (53.1%) were White, and 6106 (56.6%) had at least a college degree. During a median (range) follow-up of 8 (6-10) years, individuals with ultraprocessed food consumption above the first quartile showed a 28% faster rate of global cognitive decline (β = −0.004; 95% CI, −0.006 to −0.001; P = .003) and a 25% faster rate of executive function decline (β = −0.003, 95% CI, −0.005 to 0.000; P = .01) compared with those in the first quartile.

I'd expect those who eat healthy to also be more likely to exercise. If so, it could be exercise slowing cognitive decline rather than diet.

Or sleep. Or income. Point being, there are a lot of variables correlated with "not eating junk food" that would more intuitively predict slowed cognitive decline.