Relationship among Plasma Homocysteine, Folate, Vitamin B₁₂and Nutrient Intake and Neurocognitive Function in the Elderly

Abstract

This study examined the relationship among plasma homocysteine, folate, and vitamin B12 levels and neurocognitive function in 118 community-dwelling elderly subjects (mean age, 75.1 ± 6.7 years). The Mini-Mental State Examination (MMSE-KC) was used to screen and assess neurocognitive function in the participants. Dietary intake data including the use of dietary supplements were obtained using the 24-hour recall method by well-trained interviewers. Plasma folate and vitamin B12 concentrations were analyzed by radioimmunoassay, and homocysteine was assessed by a high performance liquid chromatography-fluorescence method. The proportions of participants with suboptimal levels of plasma folate (＜ 3 ng/mL), vitamin B12 (＜ 221 pmol/mL), and homocysteine ( ＞ 15 μmol/L) were 16.1%, 5.9%, and 21.2%, respectively. A multiple regression analysis showed that plasma homocysteine was negatively associated with plasma folate and vitamin B12 levels. The MMSE-KC test scores were significantly associated with plasma homocysteine and folate, but not with vitamin B12, after adjusting for age, gender, body mass index, living with spouse, education, current smoking, energy intake, and chronic diseases such as hypertension, diabetes, thyroid disease, dyslipidemia, stroke, and cardiovascular disease. A general linear model adjusted for covariates revealed that MMSE-KC test scores increased from the lowest to the highest quartiles of vitamin B1, vitamin B2, vitamin B6, vitamin B12, and vitamin C intake (p for trend = 0.012, 0.039, 0.014, 0.046, 0.026, respectively). These results indicate that the problem of folate inadequacy and hyperhomocysteinemia are highly prevalent among community-dwelling elderly people and that dietary intake of the B vitamins and vitamin C is positively associated with cognitive function scores. (Korean J Nutr 2011; 44(6): 498 ~ 506)

Folate food source, usual intake, and folate status in Korean adults

“…van der Griend et al [ 32 ] reported that plasma folate levels were significantly lower in men than in women after an 8-week trial with 500 µg/day of folic acid. In this study, folate intake of men was significantly higher than that of women, whereas plasma folate concentration was significantly lower in men than in women, which has also been reported by other studies [ 16 33 34 ]. Therefore, men may require more folate intake to improve folate status and to reduce risk of cardiovascular disease.…”

“…One-way ANOVA followed by Duncan's multiple range test was used determine differences in intake and plasma concentrations of folate among age groups. Pearson's partial correlation coefficient was calculated to determine possible relationships among folate intakes and plasma folate level after controlling for age, gender, body mass index, and energy intake [ 16 ]. Statistically significant differences were considered at P values < 0.05.…”

“…Although the dietary folate intake status of Koreans has been recently reported, current population-based studies on the current folate status of Korean adults including biochemical index are limited. Prior studies conducted in Korea have reported the folate status of non-pregnant women of childbearing age [ 11 ], pregnant or lactating women [ 12 13 14 ], university students [ 5 15 ], and the elderly [ 16 ]. The latest study regarding the folate status of Korean healthy adults including men was reported in 2001, and 13% of Koreans indicated folate deficiency based on plasma folate concentration [ 17 ].…”

Association of Nutrient Intakes with Cognitive Function in Koreans Aged 50 years and Older

“…Such circumstances around dementia continuously increase the national and socioeconomic burden. So the effective strategies for early prevention of dementia and delaying the onset of dementia are needed [ 2 3 ].…”

Physiological Characteristics and Production of Folic Acid of Lactobacillus plantarum JA71 Isolated from Jeotgal, a Traditional Korean Fermented Seafood

“…Known as folate in its natural form, folic acid belongs to the B group of vitamins, and is a very important substance in maintaining the functions of the central nervous system in human beings along with certain other B-group vitamins such as vitamin B 2 , vitamin B 6 , and vitamin B 12 (Duthie et al ., 2002) . A deficient intake of the B vitamins involved in the single-carbon metabolism can lead to the development of hyperhomocysteinemia; and an increased level of homocysteine has been reported not only to be a risk factor with regard to vascular diseases but also to cause DNA damage to the central nervous system (Kim et al ., 2011 ; Kruman et al ., 2000) . In addition to the relationship between the intake and blood level of B-group vitamins (including folic acid) and the cognitive functions, it has been also reported that a decrease in homocysteine in the blood caused by vitamin B group supplementation improved the cognitive functions (Dangour et al ., 2010 ; McMahon et al ., 2006 ; Morris et al ., 2005 ; Riggs et al ., 1996) .…”