Previous studies have shown that heart health at 50 predicts brain health at 75.

This study is interesting in that it quantifies the benefit as 12.5 extra dementia-free years. People with 0 risk factors had 30 years of dementia-free survival, vs 17.5 years for people with all 3 risk factors measured.

The risk factors in this specific study are blood pressure, diabetes (HbA1c), and smoking. You could reasonably also include cholesterol/ApoB, inflammation (hs-CRP), and perhaps Lp(a) as potential risk factors.

Yes. The time to fix your health is now. Any unhealthy habits put time on the biological clock, and they'll just get harder to undo later. This is true if you're 20, 40, or 60. Plaque literally starts building up on your arteries even if you're a healthy teenager. It all adds up.

But don't read this and panic or beat yourself up, that's a waste of energy. That's choosing the punishment instead of the fix.

Instead, quietly start doing one small healthy habit. If you stop, don't beat yourself up, just quietly start doing it again. Stubbornly persist until you've won.