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Open Access Publications from the University of California

Nutrition Bytes

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The Effect of Beta-Carotene Intake on Lung Cancer Development

Lung cancer remains the leading cause of cancer death in the United States, comprising nearly 30% of all cancer-related mortality. Investigation into nutritional supplementation with beta-carotene as a means of reducing lung cancer incidence remains an active and intriguing area of research. The present review summarizes the salient findings in the literature to date. Although a number of observational studies have suggested an association between carotenoid consumption and reduced lung cancer incidence, two major double-blind, randomized, placebo-controlled trials have not yielded similar results. Not only did these studies fail to demonstrate a protective effect of beta-carotene in lung carcinogenesis, they indicated that beta-carotene supplementation may increase one’s risk of developing lung cancer. Potential reasons for such discrepancies between observational studies and these randomized trials are explored, along with hypotheses concerning the potential carcinogenic risk of beta-carotene. However, such theories remain unsubstantiated at present and therefore no recommendations may currently be made regarding beta-carotene intake for the purpose of reducing lung cancer incidence. Until such contradictions within the literature are resolved from basic science and epidemiologic perspectives, the optimal lung cancer prevention strategy shall remain the traditional triad of smoking cessation, smoking prevention, and avoidance of carcinogenic environmental insults such as asbestos.

Use of Opuntia Cactus as a Hypoglycemic Agent in Managing Type 2 Diabetes Mellitus among Mexican American Patients

The consumption of Opuntia cactus is a popular herbal remedy among Mexican American patients in their management of type 2 diabetes mellitus. Animal and human studies have demonstrated the hypoglycemic properties of the Opuntia (prickly pear) cactus that are likely attributable to both its fiber content and specific hypoglycemic molecular agents. Reduction in serum glucose levels are best observed when the cactus cladodes are consumed in cooked form, alluding to heating as a necessary step in attaining its hypoglycemic properties. Additional health benefits include its ability to reduce hypercholesterolemia, optimize platelet function, and decrease oxidative tissue damage. Health care professionals should inquire about and support the use of this complementary therapy among Mexican American patients in their management of type 2 diabetes mellitus.

The Diet-Heart Hypothesis: a critical appraisal of the relationship between diet and coronary artery disease

Abstract: The role of proper diet in cardiovascular health is one which has been heavily debated over the last century. In 1908, Ignatowski produced atherosclerotic lesions in rabbits with a diet high in cholesterol and saturated fat. He subsequently fed the rabbits cholesterol alone, which produced identical lesions (1). During the early 1950s, controlled feeding studies showed that saturated fatty acids and, to a smaller extent, dietary cholesterol increased serum cholesterol in human subjects (2). Later, epidemiologic studies found that increases in serum cholesterol predicted increased risk of coronary artery disease (CAD) in humans. These findings led to the development of the ‘diet-heart hypothesis’, which assumes a primary role of dietary saturated fat and cholesterol in the causation of atherosclerosis and CAD. Currently, the relationship between high serum cholesterol and CAD is well established, however, the role of diet in both the prevention and treatment of CAD remains controversial. Utilizing the medical literature, 3 dietary tenets have been established which are strongly associated with decreased risk of coronary artery disease: Consumption of good fatty acids (polyunsaturated fats, omega-3 fatty acids), multiple fruits and vegetables, and non-refined whole grains.

Are formula-fed infants of different ethnicities more likely to become overweight children?

A number of health risks are associated with being overweight in childhood. Because early experiences with food shape later eating habits and metabolism, investigators have hypothesized that the type of infant feeding would have a great impact on later development of obesity. Based on a series of conflicting studies that have examined the link between bottle-feeding and childhood overweight, there seems to be a minor protective effect of breastfeeding, but it is unlikely that bottle-feeding plays an important role in an infant’s risk of developing into an overweight child.