The Role of Lifestyle Behaviors on 20-Year Cognitive Decline
Table 2
Regression coefficients (95% confidence intervals) representing rate of decline in verbal memory from 43 to 60+ years per level increase in each health behavior at 36 and 43 years and per cumulative and change in health behavior scores.
(%)
Verbal memory decline 43 to 60+ (95% CI)
Model 1
Model 2
Smoking at age:
36 y
Non-smoking
780 (76.6)
0.00
0.00
1–20 c/day
200 (19.6)
−0.16 (−0.85, 0.53)
−0.12 (−0.81, 0.57)
20+ cig/day
38 (3.7)
−0.22 (−1.67, 1.22)
−0.17 (−1.62, 1.28)
value
0.610
0.701
43 y
Non-smoking
816 (80.1)
0.00
0.00
1–20 c/day
159 (15.6)
−0.08 (−0.83, 0.67)
−0.07 (−0.83, 0.69)
20+ cig/day
43 (4.2)
−1.38 (−2.75, −0.01)
−1.24 (−2.61, 0.11)
value
0.124
0.165
Midlife score:
Non-smoker
744 (73.0)
0.00
0.00
Moderate smoker
252 (24.7)
−0.20 (−0.83, 0.43)
−0.12 (−0.76, 0.51)
Heavy smokers
22 (2.1)
−0.22 (−2.10, 1.66)
−0.01 (−1.90, 1.87)
value
0.535
0.750
Change in smoking:
Non-smoker
744 (73.0)
0.00
0.00
Increase
55 (5.4)
−1.11 (−2.32, 0.09)
−1.00 (−2.21, 0.21)
Decrease
79 (7.7)
0.10 (−0.91, 1.12)
0.09 (−0.92, 1.11)
Constant med/heavy
140 (13.7)
−0.03 (−0.83, 0.77)
0.04 (−0.78, 0.86)
value
0.363
0.473
Physical activity at age:
36 y
Inactive
324 (31.8)
0.00
0.00
Moderately active
275 (27.0)
−0.06 (−0.76, 0.64)
−0.07 (−0.78, 0.63)
Most active
419 (41.1)
0.21 (−0.42, 0.86)
0.17 (−0.47, 0.82)
value
0.484
0.571
43 y
Inactive
475 (46.6)
0.00
0.00
Moderately active
251 (24.6)
0.06 (−0.61, 0.75)
0.02 (−0.65, 0.71)
Most active
292 (28.6)
−0.06 (−0.72, 0.59)
−0.12 (−0.79, 0.54)
value
0.878
0.731
Midlife score:
Inactive
221 (21.7)
0.00
0.00
Moderate
608 (59.7)
−0.13 (−0.82, 0.54)
−0.23 (−0.91, 0.45)
Most active
189 (18.5)
−0.16 (−1.05, 0.71)
−0.31 (−1.20, 0.56)
value
0.697
0.472
Change in activity:
Inactive
221 (21.7)
0.00
0.00
Increase
164 (16.1)
−0.35 (−1.25, 0.54)
−0.47 (−1.37, 0.43)
Decrease
354 (34.7)
−0.10 (−0.84, 0.63)
−0.18 (−0.92, 0.55)
Constant mod/active
279 (27.4)
−0.06 (−0.87, 0.73)
−0.17 (−0.98, 0.63)
value
0.871
0.768
Diet at age:
36 y
Low-quality diet
564 (55.4)
0.00
0.00
High-quality diet
454 (44.6)
0.38 (−0.17, 0.93)
0.35 (−0.20, 0.91)
value
0.176
0.212
43 y
Low-quality diet
521 (51.1)
0.00
0.00
High-quality diet
497 (48.8)
0.20 (−0.34, 0.75)
0.17 (−0.38, 0.73)
value
0.468
0.549
Midlife score:
Low-quality diet
234 (22.9)
0.00
0.00
High-quality diet
784 (77.0)
0.71 (0.04, 1.38)
0.70 (0.02, 1.38)
value
0.037
0.043
Change in diet:
Low-quality
234 (22.9)
0.00
0.00
Increase in quality
330 (32.4)
0.65 (−0.08, 1.40)
0.65 (−0.10, 1.41)
Decrease in quality
94 (9.2)
0.95 (−0.09, 2.00)
0.91 (−0.14, 1.97)
Constant high-quality
360 (35.3)
0.78 (0.02, 1.53)
0.76 (0.00, 1.54)
value
0.146
0.180
Model 1: model adjusted for sex, childhood social class, childhood cognition at age 8, SEP (own occupation and education), and depression. Model 2: model 1 plus other lifestyle behaviors.
