Talk:Behenic acid

Cholesterol?
The reference Nilo B. Cater and Margo A. Denke: "Behenic acid is a cholesterol-raising saturated fatty acid in humans" Am J Clin Nutr 2001 73 41-44 is cited to support the contention that behenic acid is a cholesterol-raising saturated fatty acid in humans. The reference is a paper covering a study of seven adult male humans. The cholesterol-raising conclusion was based on comparisons of total cholesterol and LDL cholesterol produced by a high-behanate diet compared to a high-oleate diet.

For total cholesterol, the high-behenate result was 5.87&plusmn;0.8 mmol/L, the high oleate result was 5.12&plusmn;0.5 mmol/L, according to Table 3, p. 43. The difference, 0.75&plusmn;0.94 is claimed to be significant at the 98.33% level, according to the Student's t test (subsection "Statistical analysis, also on page 43.) For seven measurements, the t value (average / standard deviation of average) must be no less than 2.365 to be significant at the 97.5% level, and no less than 2.998 to be significant at the  99% level.  The standard deviation of the average is the standard deviation divided by the square root of the number of subjects (seven in this case).  Thus, for the claimed level of significance, 0.75 divided by 0.356 (= 2.106) must be greater than 2.365.  It is not.

For LDL cholesterol, the published results were 4.40&plusmn;0.8 and 3.70&plusmn;0.6, yielding an average difference of 0.70, a standard deviation of the average difference of 0.380, and a t value of 1.84, which still is not greater than 2.365.

According to the data in the referenced paper, the significance claimed in the referenced paper based on the data is not there. Consequently, I have tagged the reference as unreliable. Jay L09 (talk) 14:05, 27 July 2009 (UTC)