From Spain, Joan is a board certiﬁed physician in internal medicine who moved to the U.S. to further train in Public Health Nutrition. He obtained the degree of Doctor of Public Health in Nutrition from Loma Linda University. He was an American Heart Association post doctoral fellow in the Preventive Medicine Department, then became an Assistant Professor in the Department of Epidemiology & Biostatistics and in the Department of Nutrition. Shortly after, he rose to Associate Professor. In 1998, he was named Chair of the Department of Nutrition while continuing his teaching commitments in epidemiology.
He served as principal investigator in a nutrition research study that directly linked the consumption of walnuts to signiﬁcant reductions in serum cholesterol. His ﬁndings were published in the New England Journal of Medicine in 1993 and received the attention of more than 400 media sources, both national and international. Bringing the research full circle Archives of Internal Medicine has recently published the ﬁndings of his pooled analysis of 25 intervention trials establishing the beneﬁts of nut consumption on blood lipid levels and lowering the risk of heart disease. Joan continues to research the relationship of almonds, pecans, and walnuts to heart disease risk factors. He has served as a co-investigator of the Adventist Health Study, a cohort study of nearly 60,000 Seventh-day Adventists and the relationships between their diets and various diseases and is currently a co-investigator of the Adventist Health Study-2, which enrolled 96,000 Seventh-day Adventists.
He has also conducted considerable research in the area of vegetarian nutrition, is editor of the book Vegetarian Nutrition published in 2001, and was the principal architect of the Vegetarian Food Guide Pyramid released in 1997 at the 3rd International Congress on Vegetarian Nutrition and redesigned in 2008. As co-chair of the 3rd International Congress on Vegetarian Nutrition in 1997, chair of the 4th congress in 2002, the 5th congress in 2008, and the 6th congress in 2013 he has been inﬂuential in helping establish the scientiﬁc evidence of the health beneﬁts of vegetarian diets.