Table 3.
Mean differences in rates of cognitive decline over four years of follow up, across quintiles of total flavonoid intake 1,2
| Quintiles of total flavonoid intake | ||||||
|---|---|---|---|---|---|---|
| Quintile 1 | Quintile 2 | Quintile 3 | Quintile 4 | Quintile 5 | p-trend | |
| Median flavonoid intake, milligrams/d | 145.4 | 220.5 | 297.7 | 412.0 | 684.1 | |
| Global composite score | ||||||
| Model 1 3 | 0.00 | 0.01 −0.02, 0.05 |
0.01 −0.02, 0.05 |
0.02 −0.01, 0.05 |
0.04 0.00, 0.07 |
0.029 |
| Model 2 4 | 0.00 | 0.01 −0.02, 0.04 |
0.01 −0.02 0.04 |
0.02 −0.02, 0.05 |
0.03 0.00, 0.07 |
0.053 |
| Verbal memory composite score | ||||||
| Model 1 3 | 0.00 | 0.03 −0.02, 0.07 |
0.04 −0.01, 0.08 |
0.04 0.00, 0.09 |
0.05 0.01, 0.09 |
0.028 |
| Model 2 4 | 0.00 | 0.02 −0.02, 0.07 |
0.03 −0.01, 0.08 |
0.04 0.00, 0.08 |
0.05 0.00, 0.09 |
0.040 |
| Telephone Interview of Cognitive Status | ||||||
| Model 1 3 | 0.00 | 0.08 −0.08, 0.24 |
0.02 −0.14, 0.18 |
0.04 −0.11, 0.20 |
0.18 0.02, 0.33 |
0.041 |
| Model 2 4 | 0.00 | 0.06 −0.09, 0.22 |
0.00 −0.16, 0.16 |
0.03 −0.13, 0.19 |
0.15 −0.01, 0.31 |
0.072 |
To help interpret these mean differences, we find that one year of age is associated with a mean decline of 0.02 standard units on the global score, 0.02 standard units on the verbal memory score, and 0.10 points on the Telephone Interview of Cognitive Status; thus, the mean differences that we observe for extreme quintiles of total flavonoid intake were equivalent to approximately 1.5 to 2.5 years of aging.
The global score is calculated by standardizing scores (using z-scores) on all six cognitive tests in our battery, and averaging them together. The verbal memory score is calculated similarly, but using only four tests of verbal memory. The telephone Interview of Cognitive Status is scored from 0–41 points.
Adjusted for age and education.
Adjusted for age, education, physical activity, body-mass index, total caloric intake, and annual household income.