Dairy Report One- Sided: Dairy Products Contribute to Cancer ... - NCBI

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excluded research showing that dairy products contribute to can- cer risk-especially prostate and ovarian cancer-and minimized the problems associated with.
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The opinions expressed here are not necessarily the opinions of the National MedicalAssociation.

Dairy Report OneSided: Dairy Products Contribute to Cancer Risks To the Editor: I read with interest your supplementary report "The Role of Dairy and Dairy Nutrients in the Diet of African Americans" (J Natl MedAssoc. 2004 (suppl);96: 5S-32S.). I was dismayed, however, to observe that the report excluded research showing that dairy products contribute to cancer risk-especially prostate and ovarian cancer-and minimized the problems associated with digesting dairy products. Since African-American men have the highest prostate cancer prevalence and death rates of any group in the United States, and since African-American women have lower overall age-adjusted cancer survival rates compared to whites, this omission does our patients a grave disservice. In addition, individuals with lactase nonpersistence experience very real discomfort. To downplay their level of discomfort works against empowering them to take a proactive role in their personal health. While adequate intake of many of the nutrients-most notably calcium-contained in dairy products and other foods is important, strong evidence suggests that dairy products should not be a recommended source for these nutrients, especially for African Americans. Let us consider the evidence in greater detail. For African-American men, prostate cancer is the second leading cause of cancer deaths and fourth leading cause of death from all causes. Given these sobering

statistics, it is important to note that at least 11 human population studies have linked dairy product consumption and prostate cancer, according to a review by the World Cancer Research Fund and the American Institute for Cancer Research. Additionally, in the Physician's Health Study, the relationship between dairy product consumption and prostate cancer was investigated among 1,012 men with prostate cancer after 11 years of follow-up. Compared with men consuming less than 0.5 daily servings of dairy products, men who consumed more than 2.5 servings per day had a 32% greater risk ofprostate cancer. SU

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As our research indicates, African-American women with advanced epithelial ovarian cancer have been found to receive less aggressive treatment, are more often diagnosed with advanced stage disease and have lower survival rates than white women. Since the prognosis of AfricanAmerican women with epithelial ovarian cancer is extremely poor and since recent studies have found a relationship between dairy consumption and epithelial ovarian cancer, African-American women would do well to avoid dairy products. In a prospective study looking at ovarian cancer

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risk in 80,326 women in the Nurses' Health Study, researchers found an increased risk for serous epithelial ovarian cancer among the highest lactose consumers. Skim and low-fat milk were the largest contributors of lactose to these women's diets. In another cohort study of 61,084 women in Sweden, researchers found that high intakes of lactose and dairy were associated with an increased risk of serous epithelial ovarian cancer. Women who consumed just two glasses of milk per day or at least four daily servings of dairy products had twice the risk of developing serous epithelial ovarian cancer compared to women who consumed fewer than two servings of dairy a day. These findings raise a red flag for dairy consumption since "serous" cancer is the most common histologic subtype of all the epithelial ovarian cancers diagnosed in women regardless ofrace or ethnicity. Lactase nonpersistence, the inability to digest lactose, is not merely a matter of cultural "food preferences and misconceptions," as the report suggests, but is wellestablished in the literature as a true physiological response to lactose. As the report notes, repeated studies have found that lactase nonpersistence occurs in a majority of African Americans. The report emphasizes that Suarez, et al. (1997), found that "lactose maldigesters can comfortably consume one cup of milk with breakfast or two cups of milk in divided doses." (p. 20S) However, it was not reported that in this dairy industry-sponsored study, only three of the subjects were African-American and close to half the original subjects would not go on to complete more than one lactose tolerance test. Furthermore, a double-blind randomized study found that symptoms of lactose maldigestion could occur VOL. 97, NO. 4, APRIL 2005

LETTERS TO THE EDITOR

after just a 12 g dose, which is the amount in one cup of milk. The report suggests that African Americans with lactase nonpersistence should build up a tolerance to dairy products. The majority of African Americans are lactose nondigesters. It is irresponsible to assume that they will eventually tolerate the digestive discomfort from lactose if they simply consume more lactose from dairy. This is especially problematic as the evidence mounts that dairy may contribute to cancer risk. To suggest that African Americans should spend more on products like Lactaid® and lactase supplements to ease dairy product consumption only imposes needless burdens on the public. Given the evidence on dairy for cancer risk and the difficulty digesting lactose among a majority ofAfrican Americans, dairy products are not a healthy choice or one that should be encouraged in this population. This is especially true since there are readily available, inexpensive and whole-foods sources of the nutrients found in milk. The most healthful calcium sources are green leafy vegetables and legumes. Broccoli, Brussels sprouts, collards, kale, mustard greens and a wide variety of legumes are loaded with highly absorbable calcium, fiber and a host of other healthful nutrients. These foods fit comfortably into AfricanAmerican culinary traditions and do not contain cholesterol or saturated fat, or cause digestive problems among individuals with lactase nonpersistence.

Sincerely, Groesbeck P Parham, MD Professor ofGynecologic Oncology and Preventive Medicine University ofAlabama at Birmingham OHB 538 619 19th St. S. Birmingham, AL 35249-7333 phone: (205) 975-5068 doctorparham@,uabmc. edu

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The authors (J NatlMedAssoc. 2005;97:41-45) make important observations on the presumably acquired echocardiographic features of systemic hypertension, noting in particular the changes in

diastolic LV function associated with blood pressure greater than 140/90 or treated hypertension. Given the sample size, the study would have greater utility if the patients and controls were age/sex-matched as well as matched for geographic area or tribal culture. Younger subjects are less likely to have concomitant additional risk factors undetected which might compromise efforts to record echocardiographic data that are reflective of the influence of hypertension only.

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management of perceived stress.' This strategy is supported by the role of silence in expressing the

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report in which pauses convey

Neurobiology of Managing Perceived Stress Tull et al.' hypothesize that a chronic defeat response to social or environmental stressors increases the likelihood of dysfunction of the hypothalamic-pituitary-adrenal axis with dysregulation of cortisol, accumulation of abdominal fat and development of glucose intolerance. This hypothesis is

JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION

supported by the association of passive dependency with coronary risk.2 Neurobiological features are suggested by studies linking dysregulation of coping behavior and mood, disruption of brainstem cardiovascular control and vasospasm with dopamine (DA) abnormalities lateralized to the right hemisphere. This hypothesis is supported by the association of the reduction of blood pressure with longer, less recurrent speech hesitation pauses of approximately two seconds. These responses are linked to the feeling of rhythmical and prefrontal cortical modulation of DA during the delayed alternation task.3 These findings prompt pharmacologic and/or behavioral intervention4 in the

meaning beyond words-the much-quoted: "Heard melodies are sweet, but those unheard are sweeter" (John Keats)','-and reports that auditory training induces asymmetrical changes in

cortical neuronal activity' and improves neural timing in the human brainstem.y

REFERENCES raism.n Nthed in lowplevelsointeurnale

1. lull ES, Sheu Y-T, Butler C, et al. Relationships between perceived stress, coping behavior and cortisol secretion in women with high and

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