A core function of PHS is to stimulate, facilitate, and conduct research on social determinants of health. Below you will find past and current research projects supported by PHS. Contact us for more information about any of the projects or to be connected with the investigators.

Effects Of Alternative Food Voucher Delivery Strategies On Nutrition Among Low-Income Adults

Nutrition assistance programs are the subject of ongoing policy debates. Two proposals remain uninformed by existing evidence: whether restricting benefits to allow only fruit and vegetable purchases improves overall dietary intake, and whether more frequent distribution of benefits (weekly versus monthly) induces more fruit and vegetable consumption and less purchasing of calorie-dense foods. In a community-based trial, we randomly assigned participants to receive food vouchers that differed in what foods could be purchased (fruit and vegetables only or any foods) and in distribution schedule (in weekly or monthly installments, holding total monthly value constant). The use of vouchers for fruit and vegetables only did not yield significantly greater improvements than the unrestricted voucher did in terms of fruit and vegetable consumption or Healthy Eating Index (HEI) score. Weekly vouchers also failed to yield significantly greater improvements than monthly vouchers did. Proposed policies to make assistance more restricted or more frequent, while holding benefit value constant, might not improve nutrition among low-income Americans.  Access the journal article here.  For more information contact Linda Walker.

Health Effects of Minimum Wage Ordinances

There is international consensus that income is a determinant of health, shaping access to basic needs and social determinants of health such as housing, education, and job opportunities. Women and people of color—many of whom provide for families—are more likely to earn low wages and therefore disproportionately experience the adverse health effects of poverty. However, the minimum wage varies between and within states, and the current federal minimum does not keep pace with the costs of basic living needs. Furthermore, current metrics for setting minimum wages inadequately capture the basic necessities for living in full health. Therefore, APHA recommends actions at three levels of governance in support of ensuring livable wages. For example, the federal government should raise the federal minimum wage to allow a four-person household with a single wage earner to live above the poverty line, and individual states and municipalities should consider increasing the minimum wage and indexing it to inflation and the cost of living. In addition, all levels of government should ensure that minimum wage policies benefit the historically underserved populations disproportionately represented among minimum-wage earners, predominantly women and people of color.

This study will explore the health effects of local minimum wage ordinances. Some neighboring cities in the Bay Area, such as Mountain View, have agreed to raise their minimum wages, while others have not. The 3-year study will examine before-and-after effects among workers in cities experiencing the minimum wage increase, as compared to control groups in cities not experiencing the increase, prior to longer-term wage policies slated to take effect statewide.

Earn-Health Trial: Exploring the Health Effects of Poverty Relief Programs

The EARN-Health Trial is a randomized trial of the health effects of poverty relief programs. The trial will specifically study participants in the program, which creates incentives to generate long-term financial savings and pay down debts among low-wage workers. The EARN program is an individual development account (IDA), one of a series of measures found to successfully reduce poverty and debt in the United States, and is hypothesized to reduce debt-related mental health and substance abuse conditions. The trial will compare participants in the program to a wait-listed control group.  Access the journal article here. For more information, please contact Linda Walker.

Early Life Social and Environmental Determinants of DNA Methylation: A Population Based Study

The goal of this proposed study is to examine the social, economic, behavioral and environmental predictors of site-specific DNA methylation in a young population that is not yet experiencing chronic disease. The study rationale is that socioeconomically related exposures that are detrimental to health may already early in life be associated with site-specific differential DNA methylation. The significance of testing this hypothesis for sociodemographic factors and associated behavioral and environmental pathways is that this could give insight into biological pathways of disease pathogenesis that have relevance in human populations, and in to mechanisms of how early life exposures may impact disease later in life. The underlying hypothesis is that healthy, young people living under more adverse social circumstances will have quantitatively and qualitatively different patterns of DNA methylation in specific gene expression related regions as compared to people from higher socioeconomic backgrounds.