2021 PHHI Seminar Series: Bioavailability of Carotenoids - Focus on Dietary Divalent Minerals and Proteins

Dr. Torsten Bohn is a food chemist and nutritionist by training. He is currently heading the Nutrition and Health Group at the Luxembourg Institute of Health, at the Department of Population Health. He is also an adjunct associate professor at Luxembourg University, where he is teaching. He has been Editor-in-Chief of the International Journal for Vitamin and Nutrition Research since 2014. Other activities include his being part of the Nutri-Score Expert Panel and EFSA’s panel on Nutrition, Novel Foods and Food Allergens (NDA). His main research field is micronutrients and phytochemicals, their digestion, metabolism and relation to chronic diseases, especially those characterized by oxidative stress and inflammation.

Carotenoids are typically C-40, tetraterpenoid pigments produced by plants, fungi and bacteria. Their dietary intake and circulating concentrations have been associated in epidemiological studies with a number of health beneficial aspects, such as reduced risk of developing type 2 diabetes or cardiovascular diseases. Some carotenoids, such as beta-carotene, can also act as precursors for vitamin A, while others, such as lutein/zeaxanthin, have been related to the prevention of age-related macular degeneration. However, their bioavailability is typically low, presenting a challenge, especially for certain populations with low intake of pre-formed vitamin A, such as vegetarians. Dietary factors that can improve their absorption include a certain amount of fat, while dietary fiber may reduce their absorption.

Recent studies have also discussed far less scrutinized factors such as divalent minerals and proteins. While divalent minerals may result in the precipitation of fatty acids and bile salts, reducing the emulsification properties in the intestine (a requirement for carotenoid bioavailability), proteins may have positive and negative effects on carotenoid absorption, such as stabilizing lipid droplets during digestion, though also preventing enzymatic access and processing of these. In this presentation, dietary factors influencing carotenoid bioavailability will be highlighted, with a focus on recent findings from in vitro studies and human trials in the area of divalent minerals and protein interactions.

10.30-11.30: LECTURE

via Zoom