Epidemiological studies provide strong evidence of the beneficial health effects of dietary measures, leading scientists to actively investigate which foods and which specific agents in foods can prevent disease.Public health workers and medical professionals should collaborate in designing disease prevention diets for nutritional interventions.Among promising functional food sources and attractive chemopreventive diets, microalgae are gaining worldwide attention for their richness in high-value products, including carotenoids, proteins, vitamins, essential amino acids, omega-rich oils and, in general, anti-inflammatory and antioxidant compounds.Among the recent entries in the dietary supplement sector, microalgae have emerged as a nutraceutical element, endowed with beneficial effects of microalgae on human health and/or well-being in the future that could be useful in preventing or delaying the onset of cancer and cardiovascular disease.Marine microalgae have a high growth rate and interest in these microorganisms from a biotechnology perspective has grown rapidly in the last decade as a sustainable source of chemical compounds, proteins and metabolites.Some species, such as Chlamydomonas reinhardtii, are already recognized as possible industrial biotechnological platforms for the production of various bioactive compounds and are currently subject to genetic manipulation with the aim of enhancing their biotechnological applications.The term "nutraceutical" arose from the integration of "nutrition" and "pharmaceutical" and refers to substances related to nutrition, endowed with physiological benefits associated with the prevention of chronic disease.Nutraceuticals include pure mixtures and compounds isolated from plants, as well as food derivatives, modified foods such as cereals, spices, herbs and beverages with beneficial effects on health.Nutraceuticals are similar to diet medications, they can be used to promote health, prevent chronic disease, increase life expectancy, and provide structural support to the body.The role of microalgae as a nutraceutical additive has been around for thousands of years.The Chinese population used cyanophyteNostoc 2000 years ago to survive during a famine.Other cyanophytes, such as spirulina harvested from lakes, were used by the Aztecs in the sixteenth century.Spirulina is a symbol of the use of microalgae to increase human benefits and help human survival or health, because of its high protein content with a balanced content of essential amino acids.To date, few microalgae are used as sources of additives for human or animal food, and among them, the greater contribution comes from Chlorella vulgaris and Spirulina pacific.The particular niche occupied by spirulina in biotechnology has also been invaded in recent years by other species (Chlorella, Haematococcus, Dunaliella, Tetraselmis), and the production of microalgal biomass has been reconsidered for various biotechnological applications.