EHS doctoral students summarize SPH Symposium presentations

An inborn epigenetic defect causing cancer
Dr. David I.K. Martin, research scientist at Children's Hospital Oakland Research Institute
Synopsis by Rosana Weldon, Ph.D. student

Epigenetics refers to all modifications to genes other than changes in the DNA sequence itself. Epigenetic modifications include addition of molecules, like methyl groups, to the histone tails of the DNA. Cytosine methylation can be used as a marker of the epigenetic silent state (the gene is turned off or not expressed). Genes that are not necessary for a cell’s function are rightfully permanently silenced, but sometimes abnormal silencing, called epimutations, occur. Dr. Martin’s presentation posed the question of whether epimutations may cause cancer to develop. Using the tumor suppressor genes and 2-hit hypothesis as a framework, Dr. Martin argued that epimutations could occur in the first allele and then some other stochastic insult could compromise the second allele which would produce a phenotype that would lead to disregulated growth of the particular cell type and ultimately cancer. His research group looked for evidence of epimutations in 94 patients who had been diagnosed with Hereditary Non-Polyposis Colorectal Cancer (HNPCC) and 2 were identified. One of the identified patients had three children. Of these three children, one daughter had no epimutations, but had an affected allele. The identified patient’s sperm was also analyzed and it was determined that the epimutation remained in 2% of his sperm. This evidence led to the conclusion that there is the potential for inheritance in a non-mendelian pattern and that it is possible that people are born with epimutations in a small number of somatic cells that predispose them to cancer.

The Politics of Obesity: Public Health Implications
Dr. Marion Nestle, Visiting professor of public policy, public health, and journalism
Synopsis by Rosana Weldon, Ph.D. student

Dr. Nestle describes her research as very low-tech. She observes, describes and makes inferences. In this presentation, she emphasizes how Americans are living in a gorge-yourself environment and how we are surrounded by food, food advertisements and mis-information regarding food. Dr. Nestle discussed specific media messages, cartoons, and advertisements in her presentation. Just last week, the New York Times (NYT) printed an article stating that the low-fat diet has no effect on Coronary Heart Disease. This conclusion was based on the recently published Women’s Health Initiative study results. Dr. Nestle pointed out the flaws of this study including the fact that approximately 500 calories/day were missing from the participating women’s diets. These critical explanations were missing from the NYT article, leaving the general public to believe that the low-fat diet is useless. This type of media negligence, misleading labels and food advertisements confuse the public about what is a healthy diet. One example of misleading product labeling is the presence of the American Heart Association (AHA) logo on a junk food cereal such as Cookie Crisp. This cereal clearly has very little nutritional value, high amounts of sugar and low amounts of fiber, but retains this AHA logo because the parent company, General Mills, pays the AHA for its use. Interestingly, Post cereals are not allowed to use the AHA logo because their parent company is the cigarette giant, Phillip Morris.

Companies are starting to realize that there may soon be a backlash against unhealthful products so they are starting to take measures to make their products genuinely healthier or at least seemingly healthier. PepsiCo has begun placing a “smart spot” on products that are healthier choices than some of their sodas. This spot does not claim that the product, such as Gatorade, is health food, but it is a better option. In recent years Cocoa Puffs have changed from pure junk food to whole grain junk food (with only 1 g fiber) to a product with 75% less sugar (but the same amount of calories and the addition of Splenda). Sponge Bob is now appearing on baby carrots as well as several junk food products. Lastly, McDonalds is now wrapping their products in paper that contains a food label with nutritional values, but you learn this important information only after you have bought the product.

Often our government is more interested in the food industry interests than the public’s health. This is one reason that food companies have been allowed to market directly to children. Marketing directly to children benefits the food industry in three major ways: 1) kids recognize brands, 2) kids know how to pester their parents enough to buy these products, and 3) kids start to believe that they require special foods that are different from adult food. This issue may soon be played out in the courts as there is currently an impending lawsuit against Kelloggs for marketing to children. Our government covers its bases on food issues by providing the food pyramid, which doesn’t actually tell you what to eat and emphasizes activity over food choices.

In closing, Dr. Nestle discussed how the public would like simplicity in their food choices and she mentioned her forthcoming book entitled, “What to Eat”.

China’s Tobacco Control Policy at the Crossroads
Dr. Teh-Wei Hu, Professor Emeritus of Public Health
Synopsis by Lesliam Quirós, Ph.D. student

Dr. Hu’s talk on tobacco control in China raises many important issues. One such issue is the role of government in implementing public health initiatives. As public health professionals we make recommendations which we believe will improve the quality of life of individuals, however, we sometimes fail to consider the challenges in implementing our recommendations such as financial burdens involved, which populations will be negatively affected by public health programs and the role of other parties, such as government, in implementing these initiatives.

In the case of China, implementing tobacco control policy is a challenge since the government controls all tobacco leaf production and pricing. Tobacco is also the main revenue source for many provinces in this country. Thus, a ban on tobacco production may not be a feasible means by which to reduce exposure to ETS and improve health. As public health professionals we must work collectively with other researchers, health organizations, local and state government officials, policy analysts, and economists to arrive at feasible solutions that will improve public health and be acceptable to all of the major party players involved as they will be instrumental in the success or failure of the public health initiatives. Balancing short term economic loss against long term health effects of tobacco is a challenge much like other emerging issues in public health. As public health officials we need to focus not only on the solutions to problems affecting public health but also on the implications of these initiatives on a larger scale.

The Politics of Obesity: Public Health Implications
Marion Nestle, Visiting professor of public policy, public health, and journalism
Synopsis by Lesliam Quirós, Ph.D. student

Dr. Nestle’s talk gives rise to many conflicting opinions on the topic of obesity. In the last few years, obesity in America seems to be a topic of great public health interest. As a graduate student, it is true that fast food chains around the corner are more economically feasible. Could buying habits of fast food chains lead to a more obese me? Well, it is up to me what I do to remain in good physical health. Even if a gym is not affordable, there are parks or malls in which I could walk or jog to get some exercise. However, what about people who are economically disadvantaged and may not have the means to get to a park or a facility to exercise and whose neighborhoods are unsafe to walk in and practice physical activity? Would providing exercise facilities in “bad” neighborhoods aid in physical health? Would better safety in these neighborhoods help? We may be quick in trying to blame others, such as industry, for our physical state, however, I do not believe that the problem is rooted in industry, but in our personal environments.

What makes someone obese and what could lead someone to reach a state that jeopardizes ones health and, to many, is not aesthetically pleasing? There are many factors that may lead to this condition such as social and cultural support (i.e. did we grow up in an environment where physical activity was encouraged? does our present environment and lifestyle facilitate physical activity?), as well as psychosocial factors like stress related with the demands of work and school as well as family life.   Obesity is a complex, multi-factorial chronic disease involving environmental (social and cultural), genetic, physiologic, metabolic, behavioral and psychological components. We should focus on these factors first, before blaming industry for our state of health.

China’s Tobacco Control Policy at the Crossroads
Dr. Teh-Wei Hu, Professor Emeritus of Public Health
Synopsis by Quan Gan, Ph.D. student

During the School of Public Health Research Symposium on Feb. 14 th 2006, Dr. Teh-wei Hu from the Division of Health policy and Management presented the research findings of the Chinese Tobacco Control project, which has been a joint effort between researchers from both U.S. and China. One of the focuses of the project is to evaluate the situation of tobacco farming in China. In a survey conducted between 2002 and 2004 within three provinces where tobacco farming was dominant, they found that tobacco leaf was the least profitable farm product (i.e. associated with the least return/cost rate of only 99%) for farmers compared to other farm products such as fruit, grain and vegetable oil. In other words, very little profit and incentive is expected for farmers to invest in tobacco leaf. On the other hand, both the central and local governments’ revenue rely heavily on tobacco tax. For instance, more than 7% of the central government’s revenue came from tobacco in 2003, only dropped from 11% in 1996. Dr. Hu’s team showed that raising cigarette tax in China would not only be a solution to problem of the nation’s tobacco epidemic, as consumption will go down as a result of increased tax, but also encourage tobacco farmers to invest in other more profitable farm products. While at the same time the revenue for the governments will increase as well.

Other findings Dr. Hu presented at the research symposium included a physicians’ smoking survey, which has found not only significant smoking rates among Chinese physicians (37%), but also that a significant number of physicians smoke in front of their patients. The survey also revealed worrisome knowledge gap of smoking related diseases among Chinese physicians. Hu pointed out the necessity of helping physicians quit and change their behavior in counseling patients as the public thinks of physicians as role models for health behaviors.

One ongoing project Dr. Hu presented was the evaluation of a smoke-free campaign in health care facilities in China. Directors from major Chinese central and local CDCs, medical universities and hospitals signed a smoke-free memorandum in May 2005. An environmental tobacco smoke (ETS) sampling project in undergoing to evaluate the effectiveness of the campaign.

In the end of the presentation, Dr. Hu pointed out both the challenges and the opportunities China is facing in curbing the nation’s tobacco epidemic.