Cooperative Extension Specialist
About Susana Matias
Dr. Matias is a Cooperative Extension Specialist in the Department of Nutritional Sciences and Toxicology (NST) at the University of California, Berkeley. She has several years of experience in public health nutrition and a training profile that blends nutrition, epidemiology and psychology. Her research interests include maternal and child nutrition, immigrant health, food security, obesity and diabetes prevention, nutritional and behavioral interventions, implementation science and evaluation research. Prior to joining NST, Dr. Matias was an Assistant Project Scientist in the Department of Nutrition at the University of California, Davis.
My research centers on topics that promote health through nutrition and prevent nutrition related illness, with a focus in the mother-child dyad and other vulnerable populations.
Breastfeeding has many benefits, both for infants and for women. However, some mother-child dyads experience difficulties establishing breastfeeding, which can increase the risk of early breastfeeding discontinuation. Understanding the risk factors for early breastfeeding problems could assist targeting efforts to provide extra lactation support early on. We conducted research in a low-income community in Lima, Peru to determine the prevalence of early lactation problems (i.e. delayed lactogenesis, excessive newborn weight loss and sub-optimal breastfeeding behavior), and their association with later optimal breastfeeding practices (i.e. exclusive breastfeeding). We found that early breastfeeding problems were less prevalent in this setting, compared to the US, which may relate to the differences in childbirth practices between these two countries. Interestingly, we did not observe an association between early lactation problems and early discontinuation of exclusive breastfeeding, as has been observed in the US. This finding highlights the importance of cultural/environmental support towards breastfeeding.
In Northern California, we studied the risk factors for delayed lactogenesis (i.e. arrival of milk after 72 h postpartum) among women who had been diagnosed with gestational diabetes mellitus (GDM). In this population, obesity, severity of GDM and suboptimal breastfeeding performance were risk factors for delayed lactogenesis. Information on these potentially modifiable risk factors is usually available in clinical settings, making these findings potentially useful for screening GDM women at higher risk of delayed lactogenesis and consequently of early breastfeeding discontinuation.
Latinos experience higher rates of obesity than Whites, and these rates are higher in rural areas. Rural populations face unique environmental conditions because of its rural and isolated location, and the limited infrastructure and resources available. Using data from a cohort of Latino farmworkers in the Central Valley, we assessed the association between acculturation and dietary patterns in this generally low acculturated population. Despite their low acculturated levels, several of the acculturation indicators we measured were associated with fruit/vegetable consumption and fat intake, all except one in the anticipated direction (i.e., low acculturation, healthier dietary patterns). So, acculturation is an important factor to be taken into account when designing culturally tailored interventions in this population. Another interesting result from this study was the association between attendance to school in the US and having a child at home with higher fat intake in this adult population. These findings could assist targeting efforts when planning nutrition education interventions for Latino farmworkers.
Next, we moved from understanding the Latino population dietary practices to promoting behavioral change. In an unprecedented partnership with the largest berry producer in California, we implemented a randomized pilot intervention targeting Latino farmworkers in the areas of Oxnard and Watsonville. This intervention aimed to reduce obesity and prevent diabetes and was implemented in collaboration with the farmworkers’ employer organization. In addition to nutritional education this pilot intervention included a strong component on physical activity. This pilot intervention increased consumption of water and fruits and vegetables servings and the time spent in moderate physical activity in the overall sample, and reduced weight, body mass index and waist circumference among females.
My research program also includes impact and process evaluation research. In particular, I have evaluated the effectiveness of a novel nutritional product, lipid-based nutrient supplements (LNS). LNS products provide key macronutrients, including essential fatty acids, and several micronutrients in amounts appropriate for the needs of specific population groups (women and infants) and are added to a regular meal as they are considered home fortification products. This product has arisen as a promising alternative to prevent stunting and potentially anemia in low-income settings.
We conducted two randomized effectiveness trials to evaluate the effectiveness of LNS on reducing stunting and anemia and improving child development: 1) a longitudinal, cluster- randomized trial with four arms involving women and children in Bangladesh (n=4,011), and 2) a randomized trial with two arms allocating infants (n=422) to receive either LNS or the standard of care in Peru. Because LNS was a novel approach and not produced locally we also conducted a process evaluation and a cost analysis study. This type of information is needed for advancing public health decisions and policy.
Both of these LNS interventions were added into existing programs, thus the implementation of these trials relied on successful partnerships beyond academia. In Bangladesh, we collaborated with a non-profit organization already implementing a community-based program in the study area. In Peru, collaboration between academia, a humanitarian non-profit organization and the government sector was fundamental for implementing the trial using the platform of a national program delivered in health centers targeting infants and young children. These types of collaborations are critical for conducting community-based interventions and testing the feasibility of scaling up successful nutrition interventions.
Kathryn Dewey, Susana Matias, Malay Mridha, Charles Arnold. Nutrient supplementation during the first 1000 days and growth of infants born to pregnant adolescents. Annals of the New York Academy of Sciences 2019 Aug 4. doi: 10.1111/nyas.14191. [Epub ahead of print].
Md Barkat Ullah, Malay K Mridha, Charles D Arnold, Susana L Matias, Md Showkat A Khan, Zakia Siddiqui, Mokbul Hossain, Rina R Paul, Kathryn G Dewey. Newborn physical condition and breastfeeding behaviors: secondary outcomes of a cluster-randomized trial of prenatal lipid-based nutrient supplements in Bangladesh. Maternal and Child Nutrition 2019; 149(7):1271-1281. doi: 10.1093/jn/nxz059.
Md Barkat Ullah, Malay K Mridha, Charles D Arnold, Susana L Matias, Md Showkat A Khan, Zakia Siddiqui, Mokbul Hossain, Kathryn G Dewey. Provision of pre- and postnatal nutritional supplements generally did not increase or decrease common childhood illnesses in Bangladesh: a cluster-randomized effectiveness trial. Journal of Nutrition 2019 Jun 4. pii: nxz059. doi: 10.1093/jn/nxz059. [Epub ahead of print].
Gilberto Kac, Charles D. Arnold, Susana L. Matias, Malay K. Mridha, Kathryn G. Dewey. Gestational weight gain and newborn anthropometric outcomes in rural Bangladesh. Maternal and Child Nutrition 2019 Mar 23:e12816. doi:10.1111/mcn.12816. [Epub ahead of print].
Susana L Matias, Malay K Mridha, Rebecca T Young, Sohrab Hussain, Kathryn G Dewey. Daily Maternal Lipid-Based Nutrient Supplementation with 20 mg Iron, Compared with Iron and Folic Acid with 60 mg Iron, Resulted in Lower Iron Status in Late Pregnancy but Not at 6 Months Postpartum in Either the Mothers or Their Infants in Bangladesh. Journal of Nutrition 2018; 148(10):1615-1624. doi:10.1093/jn/nxy161.
Susana L Matias, Malay K Mridha, Rebecca T Young, Md. Showkat A Khan, Zakia Siddiqui, Md. Barkat Ullah, Stephen A Vosti, and Kathryn G Dewey. Prenatal and postnatal supplementation with lipid-based nutrient supplements reduces anemia and iron deficiency in 18-month-old Bangladeshi children: a cluster-randomized effectiveness trial. Journal of Nutrition 2018; 148(7):1167-1176. doi: 10.1093/jn/nxy078.
Malay K. Mridha, Susana L Matias, Charles D Arnold, Kathryn G Dewey. Factors associated with nutritional status and dietary practices of Bangladeshi adolescents in early pregnancy. Annals of the New York Academy of Sciences 2018 Feb 18. doi: 10.1111/nyas.13568. [Epub ahead of print]
Katherine P Adams, Emmanuel Ayifah, Thokozani E Phiri, Malay K Mridha, Seth Adu-Afarwuah, Mary Arimond, Charles D Arnold, Joseph Cummins, Sohrab Hussain, Chiza Kumwenda, Susana L Matias, Ulla Ashorn, Anna Lartey, Kenneth M Maleta, Stephen A Vosti, Kathryn G Dewey. Maternal and Child Supplementation with Lipid-Based Nutrient Supplements, but Not Child Supplementation Alone, Decreases Self-Reported Household Food Insecurity in Some Settings. Journal of Nutrition 2017; 147(12):2309-2318. doi: 10.3945/jn.117.257386.
Susana L Matias, Alejandro Vargas-Vásquez, Ricardo Bado Pérez, Lorena Alcázar Valdivia, Oscar Aquino Vivanco, Amelia Rodriguez Martín, Jose Pedro Novalbos Ruiz. Effects of lipid-based nutrient supplements versus micronutrient powders on nutritional and developmental outcomes among Peruvian infants. Public Health Nutrition 2017; 20(16):2998-3007. doi: 10.1017/S1368980017001811.
Kassandra L Harding, Susana L Matias, Malay K Mridha, Stephen A Vosti, Sohrab Hussain, Kathryn G Dewey, Christine P Stewart. Eating down or simply eating less? The diet and health implications of these practices during pregnancy and postpartum in rural Bangladesh. Public Health Nutrition 2017; 20(11):1928-1940. doi: 10.1017/S1368980017000672.
Susana L Matias, Malay K Mridha, Fahmida Tofail, Charles D Arnold, Md Showkat Ali Khan, Zakia Siddiqui, Md Barkat Ullah, Kathryn G Dewey. Home fortification during the first 1,000 days improves child development in Bangladesh: a cluster-randomized effectiveness trial. American Journal of Clinical Nutrition 2017; 105(4):958-969.
Kassandra L. Harding, Susana L. Matias, Malay K. Mridha, Md. Moniruzzaman, Stephen A. Vosti, Sohrab Hussain, Kathryn G. Dewey, Christine P. Stewart. Adherence to recommendations on lipid-based nutrient supplement and iron and folic acid tablet consumption among pregnant and lactating women participating in a community health programme in northwest Bangladesh. Maternal and Child Nutrition 2017; 13(1). doi:10.1111/mcn.12252.
Susana L Matias, Malay K Mridha, Rina R Paul, Sohrab Hussain, Stephen A Vosti, Charles D Arnold, Kathryn G Dewey. Prenatal lipid-based nutrient supplements affected maternal anthropometric indicators only in certain subgroups of rural Bangladeshi women. Journal of Nutrition 2016; 146: 1775-82.
Susana L. Matias, Kathryn G. Dewey, Charles P. Quesenberry, Jr., Erica P. Gunderson. Maternal pre-pregnancy obesity and insulin treatment during pregnancy are independently associated with delayed lactogenesis among women with recent gestational diabetes mellitus. American Journal of Clinical Nutrition 2014; 99: 115-121.
Susana L. Matias, Maria T. Stoecklin-Marois, Daniel J. Tancredi, Marc B. Schenker. Adherence to diet recommendations is associated with acculturation among Latino farm workers. Journal of Nutrition 2013; 143: 1451–1458.
Susana L. Matias, Laurie A. Nommsen-Rivers, Kathryn G. Dewey. Determinants of Exclusive Breastfeeding in a Cohort of Primiparous Peri-urban Peruvian Mothers. Journal of Human Lactation 2012; 28 (1): 45-54.
Susana L. Matias, Laurie A. Nommsen-Rivers, Hilary Creed-Kanashiro, Kathryn G. Dewey. Risk Factors for Early Lactation Problems among Peruvian Primiparous Mothers. Maternal and Child Nutrition 2010; 6:120-133.
Complete list of publications in PubMed: https://www.ncbi.nlm.nih.gov/pubmed/?term=Susana+L+Matias