Alternate Healthy Eating Index

98 Clinton Avenue Montclair, NJ 07042 E-mail: granddaddy3{at}msn.com

Dear Sir:

The use of the ratio of polyunsaturated to saturated fatty acids in the Alternate Healthy Eating Index of McCullough et al (1) seems surprising. In an international observational study, Keys et al (2) reported that death rates were "unrelated to dietary energy percentage from polyunsaturated fatty acids" but strikingly related to the ratio of monounsaturated to saturated fatty acids.

The Lyon Diet Heart Study (3) reported that ratios of polyunsaturated to saturated fatty acids at 1–4 y of follow-up did not differ significantly between the control subjects and the experimental subjects (0.69 and 0.65, respectively). In contrast, the concentrations of n-3 and n-6 fatty acids in the experimental subjects were 3 times and about two-thirds, respectively, those in the control subjects. In addition, the concentrations of saturated fatty acids and monounsaturated fatty acids in the experimental subjects were 29% lower and 25% higher, respectively, than those in the control subjects. The most striking comparison was for the ratio of n-6 to n-3 fatty acids (19.6 for the control subjects compared with 4.4 for the experimental subjects).

Other studies, most recently that of Albert et al (4), have pointed strongly to the merits of increasing the intake of n-3 fatty acids, at least for populations who consume a "Western diet." Thus, McCullough et al may have substantially underestimated the health, survival, and medical-cost benefits of prudent eating.

REFERENCES

1. McCullough ML, Feskanich D, Stampfer MJ, et al. Diet quality and major chronic disease risk in men and women: moving toward improved dietary guidance. Am J Clin Nutr 2002;76:1261–71.
2. Keys A, Menotti A, Karvonen MJ, et al. The diet and 15-year death rate in the Seven Countries Study. Am J Epidemiol 1986;124:903–15.
3. de Lorgeril M, Renaud S, Mamelle N, et al. Mediterranean alpha-linolenic acid-rich diet in secondary prevention of coronary heart disease. Lancet 1994;343:1454–9.
4. Albert CM, Campos H, Stampfer MJ, et al. Blood levels of long-chain n-3 fatty acids and the risk of sudden death. N Engl J Med 2002;346:1113–8.