AN IN-VIVO C-13 MAGNETIC-RESONANCE SPECTROSCOPIC STUDY OF THE RELATIONSHIP BETWEEN DIET AND ADIPOSE-TISSUE COMPOSITION

C-13 magnetic resonance spectroscopy (MRS) is a noninvasive technique used in the study of lipids. We applied C-13 MRS to assess the effects of long-term dietary variation on adipose tissue composition in human s. In vivo C-13 MRS was used to analyze the fatty acid composition of adipose tissue in 88 healthy volunteers with significantly different d iets (38 vegans, 11 vegetarians, and 39 omnivores) assessed by analysi s of dietary records. Results were compared with the serum lipid profi le. C-13 MRS revealed clear differences in the adipose tissue composit ion of vegans, which contained more unsaturated (P < 0.01) and fewer s aturated fatty acids (P < 0.01) compared with omnivores acid vegetaria ns. The vegan subjects had a significantly lower intake of saturated f atty acids and higher intake of polyunsaturated fatty acids than eithe r the omnivore or the vegetarian groups (P < 0.01). These findings wer e associated with significantly lower levels of serum total cholestero l and low density lipoprotein-cholesterol in the vegan group compared with the omnivores. Our results demonstrate the use of C-13 MRS for th e noninvasive study of adipose tissue composition and its application to the study of the interaction between long-term dietary and metaboli c risk factors in humans.