Scientific Conference on Preventive Nutrition
To the Editor:
The summary of a scientific conference on preventive nutrition1 represents a step in the right direction, but the summary does not incorporate the latest information on dietary causes of chronic disease. Thus, it stops short of making recommendations that will significantly reduce the risk of chronic disease, especially in the elderly. For example, ≥5 case-control and cohort studies have found that the nonfat portion of milk has the highest association with prostate cancer. This result is supported by an ecological study involving 41 countries.2 Although there is still debate on how calcium in milk causes the association, the epidemiological evidence linking skim milk consumption to prostate cancer is very strong.
More importantly, the recommendation of keeping total fat to just 30% of total calories is too high to protect many persons from a number of chronic diseases given the total caloric intake in the typical diet and lipid profile in the United States. The prevalence of Alzheimer’s disease in the United States, which is slightly >5% among those aged ≥65 years, seems to be proportional to dietary fat in grams per day at the time of incidence and inversely related to fish oils and, likely, other omega-3 oils.3 The probable mechanism of this association is inflammation, which cuts off blood flow to parts of the brain and results in the death of those parts of the brain. Genetics also plays a role, but it seems to be secondary to diet on the basis of a comparison of international prevalence.3 Breast cancer is likely related to dietary fat early in life. An ecological study found that dietary fat supply 10 to 15 years before breast cancer mortality gave the best statistical results.4 An energy-rich diet in childhood leads to earlier menarche and, thus, to an increased lifetime dose of estrogen, which is a risk factor for breast cancer. Colon cancer is related to a diet high in animal fat and animal products, which are uncommon in developing countries.5
Despite some of the weaknesses of the summary, it is useful in many respects and should help move forward the debate on nutrition and health.
- Copyright © 2000 by American Heart Association
Deckelbaum RJ, Fisher EA, Winston M, et al. Summary of a scientific conference on preventive nutrition: pediatrics to geriatrics. Circulation. 1999;100:450–456.
Grant WB. An ecologic study of dietary links to prostate cancer. Altern Med Rev. 1999;4:162–169. Available at http://www.thorne.com/altmedrev/.fulltext/4/3/162.html
Grant WB. Dietary links to Alzheimer’s disease. Alz Dis Rev. 1997;2:42–55. Available at http://www.coa.uky.edu/ADReview/contents.htm
Sasaki S, Horacsek M, Kestellot H. An ecological study of the relationship between dietary fat intake and breast cancer mortality. Prev Med. 1993;22:187–202.
O’Keefe SJ, Kidd M, Espitalier-Noel G, et al. Rarity of colon cancer in Africans is associated with low animal product consumption, not fiber. Am J Gastroenterol. 1999;94:1373–1380.