Professor of Nutrition Epidemiology
Alicja Wolk's research program primarily involves the investigation of diet, use of dietary supplements, physical activity and other lifestyle factors in relation to the etiology and prevention of major chronic diseases such as cancer, cardiovascular disease, osteoporosis and fractures, age-related cataracts, other important conditions as well as mortality.
She has devoted substantial ongoing effort to the development and refinement of standardized dietary and physical activity questionnaires that are relatively easy to use and can be completed repeatedly by subjects with a varying level of education. The questionnaires have been demonstrated to provide reasonably accurate assessments of a wide spectrum of nutrients and other food-related factors (e.g. food contaminants).
She continues to work on the development and evaluation of biological markers of dietary intake, using plasma and adipose tissue samples. These biological indicators are primarily utilized in validation studies of accuracy of the questionnaire-based dietary estimates.
The conducted studies involve large population-based prospective longitudinal cohorts of women and men from central Sweden (Dr.Wolk is the Principal Investigator and Director of the cohorts):
- The Swedish Mammography Cohort (SMC) including over 60,000 women born 1914-48
- The Swedish Mammography Cohort - Clinical (SMC-C) a sub-cohort including over 5,000 women with several clinical measurements and biological samples
- The Cohort of Swedish Men (COSM), a cohort of nearly 50,000 men born 1918-52
- The Cohort of Swedish Men-Clinical (COSM-C), a sub-cohort of 5,000 men with several clinical measurements and biological samples
- The COSM+SMC Biobank including material from nearly 50,000 participants
Dietary and lifestyle data have been collected from all of these populations (repeated measures). Ascertainment of incidence of chronic diseases and cause of death in the cohorts are annually updated by linkage with several nation-wide Swedish disease registers (In-patient-, Out-patient-, Cancer-, Cause-of-Death-, Prescription-register, etc.) with high validity and completeness.
The research based on the SMC and COSM cohort has resulted in nearly 400 scientific reports.
Novel findings include adverse associations between retinol intake and bone mineral density (Ann Intern Med 1998), that was later confirmed by others (N Engl J Med, 2004); between long-term dietary cadmium exposure (a recently proposed endocrine disruptor) and increased risk of endometrial (Cancer Res 2008), breast (Cancer Res 2012) and prostate cancer (Br J Cance 2012).
Protective associations, on the other hand, were observed between dietary folate intake and risk of cancer of the ovaries (J Natl Cancer Inst, 2004) and pancreas (J Natl Cancer Inst, 2006); between magnesium intake and colorectal cancer risk (JAMA, 2005); between vitamin B6 intake and risk of colorectal (J Natl Cancer Inst , 2005) and pancreatic (Gastroenterology 2007) cancer; and between consumption of fatty fish and risk of kidney cancer (JAMA 2006).
Other new observations include an interaction between alcohol and hormone replacement therapy for the risk of estrogen/progesterone receptor positive (ER+/PR+) breast cancer (J Natl Cancer Inst, 2005); association of diabetes with increased risk of colorectal cancer (J Natl Cancer Inst, 2005) and of metabolic syndrome with increased risk of cataracts (Ophthalmology, 2008).
A novel finding of increased IGF 1 in prostate cancer patients (J Natl Cancer Inst, 1998) has been followed by further reports (The Lancet 2000 and 2001). The SMC data show that about 77% myocardial infarctions in Swedish women may be preventable by healthy diet and lifestyle (Arch Intern Med 2007). In addition to these etiological studies, the group was the first to assess the validity of questionnaire-based estimates of glycemic load (Am J Clin Nutr 2006) and total antioxidant capacity of consumed foods (Am J Clin Nutr2008).
Alicja Wolk and her research group, in addition to investigations regarding specific nutritional factors, also examine food-contaminants, dietary patterns and other lifestyle factors in relation to occurrence of important diseases. Her current research is expanding to investigate complex interactions between nutrition and genetic factors as well as micro-flora in the development of major chronic diseases.
Alicja Wolk is also collaborating with researchers from other Swedish universities and from Harvard Medical School, Harvard School of Public Health and National Cancer Institute (USA), researchers from Oxford and Cambridge Universities (UK) and others.
Five selected publications
Insulin-like growth factor 1 and prostate cancer - a population-based case-control study.
J Natl Cancer Inst 1998; 90:911-5
Long-term intake of dietary fiber and decreased risk of coronary heart disease among women.
Can measurements of IGF-1 and IGFBP-3 improve the sensitivity of prostate-cancer screening?
Lancet 2000; 356:1902-3
Fatty fish consumption and risk of prostate cancer.
Long-term fatty fish consumption and renal cell carcinoma incidence in a population-based prospective cohort of women.
JAMA 2006; 296:1-6