Dr. Howard D. Sesso is an Associate Epidemiologist at Brigham and Women’s Hospital (BWH) and Assistant Professor of Medicine at Harvard Medical School. He received his BA in Human Biology from Stanford University, an MPH in Epidemiology from The George Washington University, and a ScD in Epidemiology from the Harvard School of Public Health. Dr. Sesso specializes in the epidemiology and prevention of cardiovascular disease (CVD), especially hypertension, physical activity, obesity, and dietary factors such as antioxidant vitamins, lycopene, flavonoids, and alcohol, as well as the role of novel biomarkers that underlie these associations.
Dr. Sesso is Co-Director of Hypertension Research and Director of Nutrition Research at the Division of Preventive Medicine. Dr. Sesso is also interested in the design, methodology, and conduct of epidemiologic studies and randomized clinical trials. He leads the Physicians’ Health Study II, a randomized trial that has tested whether common supplemental doses of vitamin E, vitamin C. and a multivitamin have any effect on cardiovascular disease, cancer, and other chronic diseases in 14,641 men initially aged ≥ 50 years. He has also recently initiated a 1-year clinical trial testing a lycopene supplement in more than 200 subjects with coronary heart disease for the progression of carotid atherosclerosis and changes in coronary biomarkers.
Berry Intake and Cardiovascular Health Through Epidemiologic and Clinical Studies
There are promising, albeit limited, epidemiologic data on the intake of berries and a lower risk of cardiovascular disease (CVD). The types of berries most frequently examined in relation to either coronary risk factors or the risk of developing CVD have been strawberries and blueberries. Based on limited longitudinal dietary data, berry intake has either remained steady or modestly increased over time. Limited studies have examined the determinants of berry intake, and have largely focused more broadly on fruit and vegetable intake. Perceived health benefits are an important motivator; less understood is the impact of pre-existing or newly developed medical conditions. Given the continued increases in the prevalence of obesity and its associated health effects, berries offer a viable option as part of a healthy dietary pattern to positively influence cardiovascular health.
Most of the research on berry intake and CVD has been confined to basic research studies, cross-sectional studies, and shorter-term intervention trials. These studies have provided a number of plausible cardiovascular mechanisms through which berry intake may lead to improvements in coronary risk factors, including insulin resistance, diabetes, hypertension, hypercholesterolemia, metabolic syndrome, and other intermediate vascular endpoints. Whether these promising short-term effects lead to long-term reductions in incident CVD remains to be seen. This is especially important given the increasing validity of findings from cross-sectional studies, case-control studies, prospective cohort studies, and clinical trials.
Large epidemiologic studies of berry intake and CVD have particular advantages, including excellent statistical power, dietary data typically collected long before the development of CVD, and the ability to generate hypotheses for targeted clinical trials. Disadvantages of large epidemiologic studies include the potential for measurement error, confounding by the ‘healthy user’ effect of other associated factors on berries and CVD, and the lower levels of berry intake in the population at large versus doses tested in clinical trials. Food frequency questionnaires typically used in large cohort studies only ask about strawberry and blueberry intake, without differentiation between fresh and frozen berries. Yet this dietary assessment tool still adequately differentiates between high and low levels of berry intake.