[Show abstract][Hide abstract] ABSTRACT: Contributions of fish and other foods to variance of selenium and mercury status were studied in British adults.
Plasma and red-cell selenium and whole-blood mercury concentrations were measured during the National Diet and Nutrition Survey of Adults aged 19-64 years in mainland Britain, 2000-2001 (n = 1216). Food intake was weighed for seven consecutive days, and foods were combined in groups for data analysis. Four subsidiary groups characterised fish intakes: fried white fish, 'other' white fish, shellfish and oily fish.
Geometric means and 5-95% ranges were: for whole-blood mercury, 5.61 (1.30-22.2) nmol l(-1); for plasma selenium, 1.09 (0.83-1.43) micromol l(-1); for red-cell selenium, 1.64 (1.14-2.40) micromol l(-1). Twenty-eight per cent had no fish intake recorded during 7 days; the remaining 72% had a median intake of 237 g over the 7-day period, 5-95% range 45-780 g. Total fish intake was strongly and directly correlated with blood mercury, and moderately with red-cell and plasma selenium. Thus, sqrt(total fish intake) was correlated with: loge(blood Hg), t = +19.7; loge(plasma Se), t = +9.8; and loge(red-cell Se), t = +9.6, all P < 0.0001. All three biochemical (mercury and selenium) indices were strongly correlated with oily fish intake, and moderately correlated with shellfish and 'other' ( = non-fried) white fish, but none was significantly correlated with fried white fish. Blood mercury was strongly and directly correlated with red-cell and plasma selenium, and both increased with age.
Dietary fish, especially oily fish, is a strong predictor of blood mercury and selenium in British adults.
Preview · Article · May 2007 · Public Health Nutrition
[Show abstract][Hide abstract] ABSTRACT: Relationships between Se and Hg in erythrocytes, and between these indices and intakes of fish and other foods, were studied as an adjunct to the British National Diet and Nutrition Survey (NDNS) of young people aged 4-18 years. Hg was measured in 965 packed erythrocyte samples by inductively coupled plasma mass spectrometry. Fe measurements permitted the calculation of whole-blood Hg. Erythrocyte and plasma Se, and 7 d weighed dietary intake estimates, were available. Erythrocyte Hg was positively skewed, normalised by log-transformation. It was 20 % higher in girls than boys (3.17 v. 2.65 nmol/l, P=0.004), and increased with age in boys but not girls. It was directly and strongly correlated with erythrocyte or plasma Se. Hg and Se concentrations were directly correlated with fish intake. Certain other food groups were also directly correlated with Se and Hg concentrations, but less strongly than for fish. The strength and consistency of the relationship between erythrocyte Hg and Se suggests an important chemical link. Previous studies suggest that Se protects against the toxicity of Hg, and that fish is an important source of both. No toxic levels of Hg were found, which is reassuring because of the known health benefits of fish consumption, especially oily fish. Hg intakes need to be monitored, especially in women of child-bearing age, to ensure that Food Standards Agency guidelines are met.
Preview · Article · Oct 2006 · British Journal Of Nutrition