Table 2. Blood Omega-3 Fatty Acids and Cognitive Decline (8/10 Positive Studies).
| Study | Population | Methods | Findings | Other |
|---|---|---|---|---|
| Conquer et al. 2000 (79) | Canada, N=55 77-83 yrs | Plasma PL, Cog testing | Low plasma n-3 in AD and Cog-impaired aged | Higher n-6 and lower n-3/n-6 in AD or impaired |
| Heude et al., 2003 (80) | France-EVA, N=246 63-74 yrs baseline | RBC, 4 yrs follow-up, MMSE | High n-3 predicts reduced decline (OR=0.59) | High n-6, n-6/n-3 predicts more decline |
| Laurin et al., 2003 (81) | Canada, 65+ yrs | Plasma PL | Higher DHA in dementia cases | Unchanged n-3 in AD |
| Schaefer et al 2006 (11) | Framingham, N=899 unimpaired, Median 76 yrs, prospective | Plasma PL, 9.1 yr follow-up Dementia/AD | 99 /899 got dementia, 71 AD, high quartile DHA, RR=0.53 dementia 0.61 AD | 3 servings/ week in high DHA quartile |
| Dullemeijer et al., 2007 (82) | Holland FACIT (folic acid) trial, N=807, 50-70 yrs cross-section | Plasma PL, Cog testing | High n-3 predicts less decline in sensorimoter and complex speed over 3 yrs. | Plasma n-3 did not predict 3-yr changes in memory, information-processing speed, or word fluency. |
| Beydoun et al., 2007 (12, 83) | Minneapolis, (n=2251, 50-65 yrs) | Plasma PL/ chol. Esters. Cog testing, 6 yr follow-up | 140 decline, Higher n-3 reduces risk of decline in verbal fluency | Effects stronger w/ hypertension/ dyslipid-emia, important in middle age |
| Cherubini et al. 2007 (84) | Chianti, Italy, N=935, Mean age 75.6 | Plasma, MMSE | n-3 levels reduced with cognitive deficits | (low n-3/n-6 trend, p=0.09) |
| Tully et al., 2003 (85) | Dublin, N=148 AD (76.5 yrs), 45 (70 yrs) controls | Serum cholesterolester DHA | DHA significantly reduced in all AD | DHA levels reduced with dementia severity |
| Wang et al., 2008 (13) | Oregon, N=46, AD + controls | RBC DHA | MMSE directly correlates with RBC n-3 index | Lower DHA and antioxidants associate |
| Whalley et al., 2008 (14) | England, N=120, born in 1936, age 64-68 | RBC DHA | High RBC DHA associated w/ better cognitive function | Significant only in non-Apo E4 |
Abbreviations: cholesterol, chol; Cognitive, Cog; Etude sur le Vieillissement Arteriel, EVA; Folic Acid and Carotid Intima-Media Thickness, FACIT; phospholipids, PL; relative risk, RR; red blood cells, RBC.