HomeHealthcareOrganic food and the immune system, scientific evidence

Organic food and the immune system, scientific evidence

A varied and balanced diet, as seen, can favorably affect the microbiome and stimulate the immune system. Of particular attention, in the Covid era. However, the nutritional quality of individual foods varies, within the same product categories, due to the agronomic practices and production methods adopted. And organic foods have better characteristics. Brief scientific review.

Organic, environment and health

Organic is better, without ifs and buts. For the environment and society, like science shows, but also for health. There are two essential reasons:

- absence of pesticide residues and agrotoxic. Which, as seen, can alter the microbiome. Particularly reducing the presence of bacteria 'allies' of health and the immune defenses,

- greater bioavailability qualitative and quantitative nutrients and a greater variety of microorganisms with a probiotic effect (4,6). As well as demonstrated in previous scientific studies we have already made recall.

Bio food, microbiome and immune system

Polyphenols they play a crucial role in reducing oxidative stress in the body and therefore also stimulate the immune defenses, as we have seen. (1) Organic vegetables are distinguished - with respect to homologous products obtained through conventional agriculture, albeitplanet'- for the higher contents of polyphenols and other antioxidants (eg carotenoids). And their concentration, in organic vegetables, is directly associated with microbiome health. (5)

The logic is simple, plants not treated with agrochemistry are forced to organize themselves 'according to nature' to protect themselves. And they provide for it by metabolizing phytonutrients such as polyphenols. Which then perform a protective function also in the consumer of the related products. (2) The microbial composition of the soil is in turn linked to the fertilizers used. Where the use of organic fertilizers increases microbiodiversity and the presence of microorganisms useful for the quality and healthiness of food. (6)

The intestinal microbiota - which affects the immune system - is indeed strongly influenced by the diet, positively and negatively. And from the inappropriate use of drugs (like antibiotics). And the influence of the microbiota on immunological diseases such as obesity, type 2 diabetes, cardiovascular diseases is known. (3)

Organic food, among other things, it can help maintain an optimal intestinal flora thanks to the probiotics that are present in fresh organic foods such as vegetables. (4)

Nutrients and antioxidants, the bio-added value

Numerous scientific studies demonstrate a more marked biological activity, in organic foods, than conventional ones. In plant and animal production, with rare exceptions. (8) Proteins - in products of plant and animal origin - tend to be lower in quantity but better in quality and composition. Meats, milk and cheeses have a more balanced profile of fatty acids (Omega 6 / Omega 3), thanks to the quality of the forage fed and taken on the pasture, as well as a higher content of polyunsaturated fatty acids and conjugated forms (10,11,12) .

The greatest antioxidant capacity of organic food products has been experimentally verified - with an effect on the reduction of oxidant activity in the organism - thanks to a better metabolic and cellular energy state. (18)

Figure 1. Difference in antioxidant activity of conventional and organic foods. To observe the value of the medians. A higher number indicates a food with greater antioxidant action (De Lorenzo et al., 2009)

Organic spinach showed higher levels of polyphenols and flavonoids (+ 15%, on average) compared to conventional products (13). Tomatoes and processed products contain more polyphenols, carotenoids, flavonols and vitamin C. (14) Blueberries are richer in sugars, organic acids, phenolics and others phytochemicals with antioxidant action. (15) Even the olive from organic oil has a higher content of polyphenols, without recording differences in terms of fruit size and oil content. (16) Organic cauliflowers have in turn shown, in the Italian variety Velox, a higher content of polyphenols and carotenoids (+21 and + 13%. Respectively). (17)

Environmental pollutants and intestinal microbiota

Environmental pollutants - the residues of which are more frequent in conventional agriculture, for various reasons linked to the use of agrochemicals - instead determine an imbalance on the intestinal microbiota. Thus, they reduce the efficiency of the immune system and the absorption of nutrients, as well as contribute to other metabolic imbalances. (7) Among the various pollutants, nitrogen also deserves a mention - especially in the form of nitrates, toxic to health - which in soils and organic products is present in lower quantities than conventional counterparts. (9)

Figure 2. Different influence of organic and conventional feeding on the intestinal microbiota (Hurtado-Barroso et al., 2017)

Organic Mediterranean diet, prevention and protection in the Covid-19 era

The Mediterranean diet has millenary roots in the culture of its peoples. It is recognized as one of the optimal diets to promote the duration and quality of life, thanks to the miraculous balance of the foods that compose it. The immune system is certainly positively influenced by this type of diet, thanks to the higher concentration of soluble and insoluble dietary fiber, vitamins and minerals, polyphenols and other precious substances in fighting oxidative processes. Many vegetables help to have quicker immunological responses, especially against viruses and bacteria. (19) Fiber and reduced saturated fat content help maintain a better weight and decrease the risk of contracting infections such as pneumonia (the most common complication of Covid-19 infections). (20)

Some vitaminsamong other things, they play an important role in strengthening the immune system. Vitamin D has been pointed out by many - from the Academy of Medicine of Turin, as well as in a recent study published in Nutrients (21) - as a powerful ally in the prevention of infectious attacks, especially if related to respiratory tract infection. Vitamins A, C and E are in turn important to fight free radicals and increase the body's defenses. As well as zinc, a mineral present in nuts and legumes, useful for increasing the presence of white blood cells in the body. (22)

The biological system, in agri-food production, is aimed at guaranteeing the continuity of a tradition based on Respect for nature and the seasons, ecosystems and people. They operate in this area almost 80 thousand companies in Italy, mostly small and microscopic. Which bring to the territories, through 'short chain' models, value and health. Science and current events show us how this system can affect the protection of the environment and populations.

Dario Dongo and Andrea Adelmo Della Penna


(1) Polyphenols and the immune system, see https://www.greatitalianfoodtrade.it/salute/polifenoli-e-salute-i-vegetali-amici-del-sistema-immunitario
(2) Barański et al. (2014). Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: A systematic literature review and meta-analyzes. Br. J. Nutr. 112: 794-811, doi: 10.1017 / S0007114514001366
(3) Miele et al. (2015) Impact of gut microbiota on obesity, diabetes and cardiovascular disease risk. Curr. Cardiol. Rep. 17: 120, doi: 10.1007 / s11886-015-0671-z
(4) Torjusen et al. (2014). Reduced risk of pre-eclampsia with organic vegetable consumption: Results from the perspective Norwegian Mother and Child Cohort Study. BMJ Open. 4e006143, doi: 10.1136 / bmjopen-2014-006143
(5) Ozdal et al. (2016). The reciprocal interactions between polyphenols and gut microbiota and effects on bioaccessibility. Nutrients 8:78, doi: 10.3390 / nu8020078
(6) Hartman et al. (2014). Distinct soil microbial diversity under long-term organic and conventional farming. ISME J. 9: 1177-1194, doi: 10.1038 / ismej.2014.210
(7) Jin et al. (2017). Effects of environmental pollutants on gut microbiota. Environ. Pollut. 222: 1-9, doi: 10.1016 / j.envpol.2016.11.045
(8) Hurtado-Barroso et al. (2017). Organic food and the impact on human health. Critical Reviews in Food Science and Nutrition. doi: 10.1080 / 10408398.2017.1394815
(9) Vallverdù-Queralt et al. (2016). Foodonomics: a new tool to differentiate between organic and conventional foods. Electrophoresis 37:1784-1794, https://doi.org/10.1002/elps.201500348
(10) Średnicka-Tober et al. (2016) Composition differences between organic and conventional meat: a systematic literature review and meta-analysis. Br. J. Nutr. 23: 1-18
(11) Średnicka-Tober et al. (2016) Higher PUFA and n-3 PUFA, conjugated linoleic acid, α-tocopherol and iron, but lower iodine and selenium concentrations in milk: a systematic literature review and meta- and redundancy analyzes. Br. J. Nutr. 115: 1043-1060, doi: 10.1017 / S0007114516000349
(12) Palupi et al. (2012). Comparison of nutritional quality between conventional and organic dairy products: a meta-analysis. J. Sci. Food Agric. 92: 2774-2781, doi: 10.1002 / jsfa.5639
(13) Koh et al. (2012). Effect of organic and conventional cropping systems on ascorbic acid, vitamin C, flavonoids, nitrate, and oxalate in 27 varieties of spinach (Spinacia oleracea L.). Agric. Food Chem. 60: 3144-50, doi: 10.1021 / jf300051f
(14) Vallverdù-Queralt et al. (2014). Differences in the carotenoid profile of commercially available organic and conventional tomato based products. J. Berry Res. 4: 69-77, doi: 10.3233 / JBR-140069
(15) Wang et al. (2008). Fruit quality, antioxidant capacity, and flavonoid content of organically and conventionally grown blueberries. J. Agric. Food Chem. 56: 5788-94, doi: 10.1021 / jf703775r
(16) Rosati et al. (2014). Effect of agronomic practices on carpology, fruit and oil composition, and oil sensory properties, in olives (Olea europaea L.). Food Chem. 159: 236-43, doi: 10.1016 / j.foodchem.2014.03.014
(17) Lo Scalzo et al. (2013). Variations in the pythochemical contents and antioxidant capacity of organically and conventionally grown Italian cauliflower (Brassica oleracea L. subsp. botrytis): results from a three-year field study. J. Agric. Food Chem. 61: 10335-44, doi: 10.1021 / jf4026844
(18) DeLorenzo et al. (2009). Role of the Organic Mediterranean Diet on the state of health.
(19) Craddock et al. (2019). Vegetarian-based dietary patterns and their relationship with inflammatory and immune biomarkers: a systematic review and meta-analysis. Adv. Nutr. 10: 433-451, doi: 10.1093 / advances / nmy103
(20) Alwarawrah et al. (2018). Changes in nutritional status impact immune cell metabolism and function. Front. Immunol. 9: 1055-1069, doi: 10.3389 / fimmu.2018.01055
(21)Grant et al. (2020). Evidence that vitamin D supplementation could reduce risk of influenza and COVID-19 infections and deaths. Nutrients 122: 988, doi: 10.3390 / nu12040988
(22) Barnard et al. (2019). Plant-based diets for cardiovascular safety and performance in endurance sports. Nutrients 11 (1): 130, doi: 10.3390 / nu11010130

Andrea Adelmo Della Penna

Graduated in Food Technologies and Biotechnologies, qualified food technologist, he follows the research and development area. With particular regard to European research projects (in Horizon 2020, PRIMA) where the FARE division of WIISE Srl, a benefit company, participates.

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