The Role of Lifestyle Behaviors on 20-Year Cognitive Decline

Table 1

Characteristics and mean scores for memory and search speed at age 60+ years, by lifestyle behaviour profiles and dichotomous covariates.

Variable	𝑁	Memory at age 60+ years	𝑃	Search speed at age 60+ years	𝑃
Smoking at age:
36 years
Non-smoker	780	25.00 (5.88)	<0.001	273.47 (73.13)	0.002
1–20 c/day	200	24.18 (6.37)		266.7 (69.88)
20+ cig/day	38	21.23 (7.33)		233.26 (59.33)
43 years
Non-smoker	816	25.05 (5.95)	<0.001	274.45 (72.55)	0.001
1–20 c/day	159	23.99 (6.05)		258.60 (68.67)
20+ cig/day	43	20.72 (7.05)		242.83 (73.49)
Midlife score:
Non-smoker	744	25.05 (5.90)	<0.001	274.51 (73.69)	<0.001
Moderate smoker	252	24.07 (6.30)		263.48 (67.50)
Heavy smoker	22	20.18 (7.25)		221.81 (59.74)
Change in smoking:
Non-smoker	744	25.05 (5.90)	0.005	274.51 (73.69)	0.011
Increase	55	22.89 (5.91)		254.63 (65.05)
Decrease	79	24.77 (6.51)		272.29 (60.10)
Constant med/heavy	140	23.52 (6.60)		255.44 (72.33)
Physical activity at age:
36 years
Inactive	324	23.82 (5.83)	<0.001	264.87 (72.81)	0.138
Moderate active	275	24.61 (5.98)		270.04 (68.14)
Most active	419	25.44 (6.24)		275.49 (74.58)
43 years
Inactive	475	23.85 (6.13)	<0.001	263.83 (69.38)	<0.001
Moderate active	251	25.15 (6.05)		267.10 (69.13)
Most active	292	25.69 (5.84)		284.76 (78.01)
Midlife score:
Inactive	221	23.37 (6.01)	<0.001	259.08 (74.61)	0.003
Moderate active	608	24.81 (5.98)		270.87 (68.78)
Most active	189	25.90 (6.20)		283.43 (79.00)
Change in physical activity:
Inactive	221	23.37 (6.01)	<0.001	259.08 (74.61)	0.003
Increase	164	25.03 (5.35)		282.39 (74.40)
Decrease	354	24.61 (6.30)		266.84 (66.91)
Constant active	279	25.68 (6.08)		277.72 (74.71)
Diet at age:
36 years
Low quality	564	24.01 (6.19)	<0.001	267.26 (69.12)	0.096
High quality	454	25.55 (5.84)		274.85 (76.14)
43 years
Low quality	521	23.72 (6.13)	<0.001	267.24 (69.30)	0.124
High quality	497	25.72 (5.86)		274.21 (75.41)
Midlife score:
Low quality	234	22.51 (5.90)	<0.001	260.02 (67.96)	0.010
High quality	784	25.34 (5.99)		273.81 (73.41)
Change in diet:
Constant low quality	234	22.55 (5.90)	<0.001	260.02 (67.96)	0.022
Increase	330	25.06 (6.18)		272.39 (69.57)
Decrease	94	23.98 (5.44)		263.80 (71.44)
Constant high	360	25.96 (5.88)		277.73 (77.16)
Sex:
Male	490	23.72 (5.94)	<0.001	265.36 (71.84)	0.024
Female	528	25.61 (6.07)		275.54 (72.63)
Father social class
Non-manual	507	26.28 (5.90)	<0.001	278.69 (75.64)	<0.001
Manual	511	23.12 (5.84)		262.66 (68.16)
Education:
<advanced	567	22.77 (5.66)	<0.001	263.03 (70.09)	<0.001
≥advanced	451	27.12 (5.71)		280.21 (74.17)
Midlife social class at age:
36 years
Non-manual	617	26.24 (5.79)	<0.001	280.36 (71.29)	<0.001
Manual	401	22.33 (5.75)		255.69 (71.62)
43 years
Non-manual	696	26.08 (5.79)	<0.001	276.31 (71.73)	<0.001
Manual	322	21.72 (5.60)		258.38 (72.42)
Depression at age:
43 years
No symptoms	966	24.80 (6.05)	0.036	271.08 (72.92)	0.403
Depressive symptoms	52	22.98 (6.47)		262.46 (61.78)
60+ years
No symptoms	805	24.85 (6.09)	0.194	270.03 (73.61)	0.531
Depressive symptoms	171	24.19 (5.74)		273.87 (69.23)