Sustainable diets aim to balance planetary and human health; they are defined as nutrient-rich, affordable, accessible, and culturally acceptable, as well as having a relatively low environmental impact.

To ensure a diet is sustainable, the entire food system – including production, processing, distribution, consumption, and disposal – must be considered. Within this context, scientific models show that dairy products, including yogurt, may have a role to play in sustainable diets and food systems.

The characteristics of food systems should allow human impact to stay within planetary boundaries. These boundaries represent the systems that are crucial for regulating and maintaining the stability of our planet. Together, they define global limits within which humanity should operate to ensure a stable and resilient environment. Local, regional, and global food systems should operate within these planetary boundaries to produce foods that contribute to sustainable diets worldwide.
Today’s food systems are one of the biggest reasons why we exceed planetary boundaries, responsible for up to 35% of greenhouse gas emissions (GHGEs), 48% of cropland use, and 70% of freshwater use, with high impacts on forests and loss of biodiversity.

The 2019 report of the EAT-Lancet Commission,196 along with recent global events such as United Nations (UN) Climate Change Conferences and Food Systems Summits, have all called for a switch to diets that are made up of foods produced through sustainable food systems – which incorporate environmental improvements in food production, processing and distribution and reduced food loss and waste.

Sustainable diets must balance health, environmental, social, and economic impacts

However, a sustainable diet is more than just a dietary pattern with a low environmental impact. A sustainable diet represents an acceptable compromise between health, environmental, social, and economic factors, described by the UN’s Food and Agriculture Organization (FAO) and the World Health Organization (WHO).
Scientists have demonstrated that the best balance between these dimensions of a sustainable diet can be achieved by adopting varied, plant-based diets, such as flexitarian, planetarian, or territorial diets:

• Flexitarian and planetarian diets – designed to be healthy for both people and planet – combine a large number of plant-based foods with low levels of red meat and moderate amounts of poultry, fish, eggs, and dairy.
• Territorial diets, such as the Mediterranean diet, are region-specific flexitarian diets composed mainly of seasonal, locally sourced foods.

“Dairy foods, including yogurt, play a key role in sustainable flexitarian diets. They provide an affordable source of high-quality protein, are definitely the lowest cost source of calcium and other bone-building nutrients, and havea much lower carbon cost than meat.” -Professor Adam Drewnowski

Dairy products can be part of sustainable diets

Scientists use dietary models to predict how individual food changes will affect the overall nutritional quality and environmental impact of a particular diet. Several diet-modelling studies have found that dairy products can be part of theoretical sustainable diets in adults with a Western-style diet. For such adults, the dietary changes that most effectively reduce environmental impact while remaining consistent with dietary guidelines for health are:

1. To eat fewer calories overall
2. To eat less meat especially red and processed meats
3. To introduce pulses, legumes, nuts, and seeds
4. To eat more fruits, vegetables, and wholegrains.

Within this framework, maintaining nutrient-dense dairy foods as part of a sustainable diet can help individuals to satisfy their nutritional needs while consuming less meat and more plant-based foods. Fortified plant-based dairy-like products may also play a role in sustainable diets alongside dairy products.
In a diet modelled to reduce dietary carbon footprint by 30% while improving nutritional intakes and staying as close as possible to the diet of French adults, eating fortified plant-based dairy-like products – such as calcium-enriched soya drinks and yogurt-alternatives – alongside traditional dairy products helped to improve diet sustainability, especially in women with low energy intakes.

Recent public health guidance for sustainable diets includes a role for dairy products

The role of dairy products – including yogurt – as part of a plant-based, low-meat flexitarian diet is supported by global, regional, and local recommendations for sustainable diets:

• A moderate dairy intake of around 250 g (~9 ounces) per day that respects nutritional recommendations can form part of a sustainable diet, according to global recommendations published by FAO/WHO and the EAT-Lancet Commission.
• Modelling studies in regions including France, Nordic countries, and the UK have adapted a global flexitarian diet, including the role of dairy products, to be consistent with local dietary guidelines, cultural considerations, and food systems.

The role of dairy products as part of a flexitarian diet may vary depending on location, due to geographic differences in methods of production, local patterns
of consumption, and population-specific nutritional needs.

Several characteristics of yogurt support its contribution to sustainable diets and food systems

1) Health and nutrition: Yogurt is a nutrient-rich food with health benefits

Eating yogurt daily is an effective way of meeting nutritional requirements with a balanced energy intake – yogurt contains high-quality proteins and essential
nutrients including calcium, potassium, magnesium, iron, zinc, and numerous vitamins.

Yogurt also contains lactic acid bacteria, which have been shown to benefit gut health and digestion. Eating yogurt has been associated with a variety of additional
health benefits, including improvements in weight management and reductions in risk of Type 2 diabetes, metabolic syndrome, and cardiovascular disease.

2) Environment: Yogurt has a smaller footprint than some other animal foods

Within the range of animal-based foods, scientists recommend eating less meat – especially beef – to achieve the greatest environmental and health benefits. One study found that reducing the consumption of red meat has an environmental benefit around five times greater than reducing the consumption of dairy products, when considering GHGEs, land use, water footprint, and soil pollution.

The environmental footprint of individual foods should be weighed against the nutrient content they provide.
Life-cycle assessments show large differences in both nutrient density and environmental impact among foods. In such analyses, yogurt scores above average for nutrient density and slightly below average for climate impact.

Carbon footprint (GHGEs)
Greenhouse gasses are released at every stage of the food production and consumption cycle – from farming and agricultural practices to packaging, transport and storage in the supermarket and the home, as well as during waste management. Beef and lamb consumption generates around ten times the GHGEs per serving as pork, poultry, and dairy products, which have around ten times the GHGEs of plant-based foods, such as grains, fruits, and vegetables.
Some studies have found that yogurt compares favourably with many other animal foods in terms of GHGEs for the level of nutrition it provides.
These studies estimated that yogurt production has a smaller carbon footprint than that of red meat, poultry, and cheese production, similar to that of milk.

Water footprint, land use, and biodiversity
Animal-sourced foods generally have a higher impact on land and water use than plant-based foods, with particularly large impacts for the production of red meat. Some studies have found that yogurt production might have a relatively lower impact on biodiversity loss, land use and fresh water use, compared with other animal products such as cheese and meat.

Regenerative dairy farming practices
Scientists estimate that current land and water use for farming is 52–60% above the targets set for limiting biodiversity loss and freshwater withdrawals.216 Recent improvements in the production and processing of dairy products have helped strengthen their role in sustainable food systems and may help to address this imbalance. Regenerative farming practices improve land use and farming techniques to help enhance soil health and biodiversity, reduce water use and food loss, increase carbon storage and reduce GHGEs, reducing the impact of dairy products on the environment.

Studies show that regenerative dairy farming practices can compensate for up to 28% of GHGEs through soil carbon sequestration.222 Improvements to livestock management through feeding changes, selective breeding, and manure management can also help to reduce methane emissions from dairy herds by up to 15–20%.

3) Society: Yogurt is part of local cultures in many regions

Dietary choices are often driven by the customs, religion, and culture of specific countries and regions. Fermented dairy products such as yogurt can be found in many geographies worldwide and are already staple foods in many cultures, with different types including:

• Amasi and Maas (Africa)
• Dahi and Lassi (Bangladesh, India and Pakistan)
• Chal and Kumia (Central Asia)
• Kefir, Smetana, and Ayran (Europe)
• Labneh, Laban, and Kushk (Middle East)
• Yogurt and Curd (Worldwide)

4) Economy: Yogurt can be affordable and contribute to local economic welfare

Food profiling studies show that yogurt is an affordable source of high-quality proteins and other essential nutrients in many countries and is one of the most affordable sources of calcium. When comparing the costs of different foods per calorie, dairy products including yogurt cost less than meat, poultry, and fish, and are more comparable with the per-calorie cost for beans and eggs.
The affordability of dairy products enables a variety of uses and their incorporation into various dietary patterns and food traditions in different countries and cultures.46 The production of fermented foods, such as yogurt, is a natural and simple process that provides access to safe and healthy food, creates demand for local produce, and provides employment and income opportunities.Fermentation can also be a good way of producing more sustainable food sources by reducing agricultural and food processing wastage.

References:

• Drewnowski A. Measures and metrics of sustainable diets with a focus on milk, yogurt, and dairy products. Nutr Rev. 2018;76:21–8.
• Kok CR, Hutkins R. Yogurt and other fermented foods as sources of health-promoting bacteria. Nutr Rev. 2018;76(Suppl1):4–15.
• World Health Organization, Food and Agriculture Organization of the United Nations. Sustainable healthy diets: guiding principles. October 2019.
• EAT Forum. EAT-Lancet Commission Summary Report. July 2019.
• Steffen W, Richardson K, Rockström J, et al. Planetary boundaries: Guiding human development on a changing planet. Science. 2015;347:1259855.
• Moreno LA, Meyer R, Donovan SM, et al. Perspective: Striking a Balance between Planetary and Human Health-Is There a Path Forward? Adv Nutr. 2022;13:355-75.
• Colao A, Vetrani C, Muscogiuri G, et al. “Planeterranean” Diet: extending worldwide the health benefits of Mediterranean Diet based on nutritional properties of locally available foods. J Transl Med. 2022;20:232.
• Dussiot A, Fouillet H, Perraud E, et al. Nutritional issues and dietary levers during gradual meat reduction – A sequential diet optimization study to achieve progressively healthier diets. Clin Nutr. 2022;41:2597–606.
• Gazan R, Vieux F, Lluch A, et al. Individual Diet Optimization in French Adults Shows That Plant-Based “Dairy-like” Products May Complement Dairy in Sustainable Diets. Sustainability. 2022;14:2817.
• Perraud E, Wang J, Salomé M, et al. Dietary protein consumption profiles show contrasting impacts on environmental and health indicators. Sci Total Environ. 2023;856:159052.
• Rocabois A, Tompa O, Vieux F, et al. Diet Optimization for Sustainability: INDIGOO, an Innovative Multilevel Model Combining Individual and Population Objectives. Sustainability. 2022;14:12667.
• Mertens E, Kuijsten A, Kanellopoulos A, et al. Improving health and carbon footprints of European diets using a benchmarking approach. Public Health Nutr. 2020;24:565–75.
• Hess J, Rao G, Slavin J. The Nutrient Density of Snacks: A Comparison of Nutrient Profiles of Popular Snack Foods Using the Nutrient-Rich Foods Index. Glob Pediatr Health. 2017;4:2333794X17698525.
• Chalupa-Krebzdak S, Long CJ, Bohrer BM. Nutrient density and nutritional value of milk and plant-based milk alternatives. Int Dairy J. 2018;87:84e92. 207.
• Karlsson JO, Carlsson G, Lindberg M, et al. Designing a future food vision for the Nordics through a participatory modeling approach. Agron Sustain Dev. 2018;38:59.
• World Wildlife Foundation UK. Eating for 2 Degrees: New and Updated Livewell Plates. August 2017.
• World Wildlife Foundation France. Towards A Low-Carbon, Healthy and Affordable Diet. November 2017.
• Ridoutt BG, Baird D, Hendrie GA. The role of dairy foods in lower greenhouse gas emission and higher diet quality dietary patterns. Eur J Nutr. 2021;60:275–85.
• Comerford KB, Miller GD, Reinhardt Kapsak W, et al. The Complementary Roles for Plant-Source and Animal-Source Foods in Sustainable Healthy Diets. Nutrients. 2021;13:3469.
• Vieux F, Rémond D, Peyraud J-L, et al. Approximately Half of Total Protein Intake by Adults Must be Animal-Based to Meet Nonprotein, Nutrient-Based Recommendations, With Variations Due to Age and Sex. J Nutr. 2022;152:2514–25.
• Mertens E, Kuijsten A, van Zanten HHE, et al. Dietary choices and environmental impact in four European countries. J Clean Prod. 2019;237:117827.
• Clark MA, Springmann M, Hill J, et al. Multiple health and environmental impacts of foods. Proc Natl Acad Sci USA. 2019;116:23357–62.
• Strid A, Hallström E, Sonesson U, et al. Sustainability Indicators for Foods Benefiting Climate and Health. Sustainability. 2021;13:3621.
• Global Nutrition Report. 2021 Global Nutrition Report: The state of global nutrition. 2021.
• Clark M, Springmann M, Rayner M, et al. Estimating the environmental impacts of 57,000 food products. Proc Natl Acad Sci USA. 2022;119:e2120584119.
• Walker C, Gibney ER, Hellweg S. Comparison of Environmental Impact and Nutritional Quality among a European Sample Population – findings from the Food4Me study. Sci Rep. 2018;8:2330.
• International Dairy Federation. UN Food Systems Summit: Game changing solutions for dairy. March 2021.
• Climate and Clean Air Coalition, United Nations Environment Programme. Global Methane Assessment: Summary for Decision Makers. 2021.

Lauren Twigge, registered and licensed Dietitian, shared her reaction on this announcement with us.

 

 

Voir cette publication sur Instagram

 

Une publication partagée par Lauren Twigge || MCN, RDN, LD (@nutrition.at.its.roots)

The FDA announced that it is going to allow yogurt makers to include the qualified health claim that regular consumption of yogurt may reduce the risk of type 2 diabetes (1). This is a big announcement considering that 537 million adults live with Type 2 diabetes worldwide and that number is expected to increase (2).

Effects shown in many studies and reviews

Some of the studies that were used to support this claim including two reviews (3,4) show an inverse relationship between dairy consumption and type 2 diabetes. In fact, one of the reviews showed that a 50 g/day increase of yogurt consumption led to a 7% lower risk for developing type 2 diabetes.

This claim can be added to any yogurt brand, regardless of added sugar or fat content. It is always good to be mindful of limiting added sugar and being aware of the sugar content in the yogurt you are regularly consuming… especially if you aim for the 3 servings of yogurt per week recommendation.

This inverse relationship between yogurt and type 2 diabetes has not been attributed to one specific nutrient within yogurt but has been linked to the food as a whole.

A great example of dairy matrix

This is a great example of the dairy matrix which is a concept I discussed a while back in my profile reminding us us that foods, like yogurt, function as more than just one nutrient in our body. Plain yogurt is a low glycemic food that contains many healthful nutrients like probiotics, calcium, vitamin D, high-quality protein and many other bioactive components that work together to support our health and reduce risk for diseases like type 2 diabetes. With a large number of americans living with type 2 diabetes and potentially even more that are not diagnosed, it is a great news that FDA flags what foods we can include in the diet to help reduce this burden.

Yogurt is an incredibly diverse food that can be added to recipes like parfaits, smoothies, dressing, soups, and more. Next time you’re at the store, be sure to add yogurt to your cart!

Sources:

1. FDA Announces Qualified Health Claim for Yogurt and Reduced Risk of Type 2 Diabetes

2. IDF Diabetes Atlas Report

3. Feng Y, Zhao Y, Liu J, Huang Z, Yang X, Qin P, Chen C, Luo X, Li Y, Wu Y, Li X, Huang H, Hu F, Hu D, Liu Y, Zhang M. Consumption of Dairy Products and the Risk of Overweight or Obesity, Hypertension, and Type 2 Diabetes Mellitus: A Dose-Response Meta-Analysis and Systematic Review of Cohort Studies. Adv Nutr. 2022 Dec 22;13(6):2165-2179.

4. Aune D, Norat T, Romundstad P, Vatten LJ. Dairy products and the risk of type 2 diabetes: a systematic review and dose-response meta-analysis of cohort studies. Am J Clin Nutr. 2013 Oct;98(4):1066-83. 

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Lauren Twigge is a Dallas based registered and licensed Dietitian with a Master’s degree in Clinical Nutrition and a bachelor’s degree in Animal Science. Along with running her own nutrition company and working with private clients, Lauren works as social media dietitian, recipe developer, blogger, and brand ambassador. Lauren was born and raised in a family of farmers located in central California and is an outspoken supporter of the agricultural industry. Growing up on a dairy and being raised around farming her whole life has given Lauren a unique perspective on where our food comes from and her passion is to work at the crux of agriculture and human nutrition to fight misinformation and give consumers back their food confidence. Lauren is on Instagram @nutrition.at.its.roots and educates on a variety of health topics including the truth about the agricultural industry, education on where our food comes, and discussing the role that various agricultural products, like milk, can play in a healthy diet!

• Instagram page: https://www.instagram.com/nutrition.at.its.roots/
• Website: https://www.laurentwiggenutrition.com
• Blog: https://www.laurentwiggenutrition.com/blog
• Tik Tok: https://www.tiktok.com/@nutrition.at.its.roots 

Dairy foods have long been hailed for their nutritional richness, although researchers are still debating over the metabolic effects of milk fats. Many dietary recommendations advocate fat-free or low-fat dairy options due to concerns over the possible adverse effects of saturated fatty acids (SFAs) on cholesterol levels. But now, a review of recent research has cast doubt on this conventional thinking.

A literature review conducted by researchers in Mexico compiles evidence on the metabolic effects of milk fatty acids from clinical and basic research studies, shedding light on their relationship with metabolic disorders and gut microbiota composition [1].

The evidence suggests that milk fatty acids aren’t directly linked to cardiometabolic risk, and calls into question whether dietary recommendations for low-fat dairy foods are indeed necessary for preventing obesity and cardiometabolic disease.

What are the fatty acids in milk and dairy foods?

• Milk fat is made up of saturated (62%), mono-unsaturated (29%) and poly-unsaturated (4%) fatty acids [2]
• Milk fats are mainly stored as fat globules surrounded by a membrane known as the milk fat globule membrane (MFGM) [2]
• The main components of the MFGM are triglycerides (95.8%), with lower proportions of free fatty acids, mono- and di-glycerides, phospholipids, and cholesterol [3]
• Milk triglycerides contain nearly 400 different fatty acids, which have a wide range of metabolic effects depending on their chain length and level of saturation [3]
• The main fatty acids present in milk and dairy foods include palmitic, stearic, oleic, and myristic acid.

Most dairy fats have effects that may help prevent adiposity

While some milk fatty acids are associated with increased adiposity, most exert anti-fat effects that may help to prevent weight gain, the research has revealed.

• Several clinical studies have shown that some medium- and long-chain fatty acids found in dairy foods are associated with reduced body fat accumulation.
• Pre-clinical studies suggest that some milk fatty acids may exert anti-fat effects through modifying lipid metabolism in adipose tissue [4].

The overall effect of milk fatty acids on weight gain may depend on the balance between them in different dairy foods. Further clinical research is needed to understand the possible mechanisms by which dairy fats may contribute to decreased adiposity, the researchers suggest.

Eating full-fat dairy foods may be associated with a reduced risk of diabetes

The researchers discovered that eating full-fat dairy foods has been associated with a reduced risk of type 2 diabetes (T2D) progression in some studies,  including a large multi-national study in which participants were followed for a median of 9 years [5] although not all studies have confirmed these findings.*

A large observational study suggested that dairy fat was associated with improved glucose tolerance via hepatic and systemic insulin sensitivity [6].

Pre-clinical studies also suggest that some short-chain fatty acids found in dairy foods can improve insulin sensitivity, increase β-cell function, and reduce inflammation.

Evidence suggests that even though some milk fatty acids are associated with insulin resistance, this does not lead to an increased risk of T2D when they are consumed within dairy foods.

Dairy foods may have neutral or beneficial effects on cardiovascular disease (CVD) risk

Concerns over the effects of full-fat dairy foods on CVD risk arose from historical data suggesting that saturated fatty acids are associated with increased cholesterol levels. However, researchers found that recent studies support the idea that dairy foods have a neutral or beneficial association with CVD outcomes.

Results of several randomised controlled trials show that consumption of SFAs from dairy foods can adversely increase low-density lipoprotein cholesterol (LDL-C).

But the literature suggests that LDL-C is not a good predictor or cause of CVD risk, raising doubt over the cautious approach taken towards dairy fats. [7].

Further analysis reveals that eating dairy foods high in SFAs can boost levels of high-density lipoprotein cholesterol (HDL-C) and has no adverse effects on other CVD markers including blood pressure, inflammation, and vascular function [8].

It appears that dairy fat as a whole, as well as individual fatty acids, have either neutral or mixed effects on atherogenesis, lipid profiles and inflammation, according to the researchers.

What about the role of the gut microbiota in metabolic health?

The researchers also examined the relationship between consumption of milk fatty acids and the gut microbiota. They found that eating dairy food is associated with beneficial changes to the composition of the gut microbiota.

• Clinical studies show that dairy consumption promotes the abundance of healthy gut bacteria, such as Bifidobacterium, which are associated with anti-inflammatory properties and a lower risk of T2D.
• The gut microbiota can also modify milk fatty acids, producing metabolites that may benefit metabolic health.

It is important to consider the metabolic health effects of the entire food matrix from which milk fatty acids are consumed. For instance, interactions between the nutrients within dairy products can change the effects of individual fatty acids on the metabolism, altering their overall cardiometabolic risk profile [9].

“Fatty acids contained in dairy products have neutral, mixed or even positive effects on metabolic diseases (overweight, obesity, T2D, CVD and atherosclerosis) by modifying risk factors such as insulin resistance, and the expression of genes related to inflammation and dyslipidaemia.” – Muñoz-Alvarez KY, et al., 2024

Studies on the large-scale Prospective Urban Rural Epidemiology (PURE) add to the growing body of evidence pointing to the need to re-evaluate the guidelines that recommend avoiding whole fat dairy products.

It concludes that a diet comprising higher amounts of fruit, vegetables, nuts, legumes, fish, and whole-fat dairy is associated with lower CVD and mortality in all world regions (10).

Specifically, it concludes that higher intake of whole fat (but not low fat) dairy was associated with a lower prevalence of metabolic diseases and most of its component factors, and with a lower incidence of hypertension and diabetes (5).

*On March 1st, 2024, the U.S. Food and Drug Administration (FDA) has approved a qualified health claim regarding the consumption of yogurt and reduced risk of type 2 diabetes (T2D) : “Eating yogurt regularly, at least 2 cups (3 servings) per week, may reduce the risk of type 2 diabetes according to limited scientific evidence.”

Source: (1) Muñoz-Alvarez KY, Gutiérrez-Aguilar R, Frigolet ME. Metabolic effects of milk fatty acids: A literature review. Nutr Bull. 2024 Jan 16.

Additional references

(2) Fong, B.Y., Norris, C.S. & MacGibbon, A.K.H. (2007) Protein and lipid composition of bovine milk-fat-globule membrane. International Dairy Journal, 17(4), 275–288.

(3) Damodaran, S. & Parkin, K.L. (2017) Fennema’s food chemistry, 5th editio edition. Boca Raton, FL, USA: CRC Press, Taylor & Francis Group.

(4) Chávaro-Ortiz, L.I., Tapia, B.D., Rico-Hidalgo, M., Gutiérrez-Aguilar, R. & Frigolet, M.E. (2021) Trans-palmitoleic acid reduces adiposity via increased lipolysis in a rodent model of diet-induced obesity. British Journal of Nutrition, 2021, 1–9.

(5) Bhavadharini B, Dehghan M, Mente A, et al. Association of dairy consumption with metabolic syndrome, hypertension and diabetes in 147 812 individuals from 21 countries. BMJ Open Diabetes Res Care. 2020 Apr;8(1):e000826. doi: 10.1136/bmjdrc-2019-000826.

(6) Kratz, M., Marcovina, S., Nelson, J.E., Yeh, M.M., Kowdley, K.V., Callahan, H.S. et al. (2014) Dairy fat intake is associated with glucose tolerance, hepatic and systemic insulin sensitivity, and liver fat but not β-cell function in humans. The American Journal of Clinical Nutrition, 99(6), 1385–1396.

(7) Givens, D.I. (2022) Saturated fats, dairy foods and cardiovascular health: no longer a curious paradox? Nutrition Bulletin, 47(4), 407–422.

(8) Drouin-Chartier, J.P., Côté, J.A., Labonté, M.É., Brassard, D., Tessier-Grenier, M., Desroches, S. et al. (2016) Comprehensive review of the impact of dairy foods and dairy fat on Cardiometabolic risk. Advances in Nutrition (Bethesda, Md.), 7(6), 1041–1051.

(9) Astrup A, Geiker NRW, Magkos F. Effects of full-fat and fermented dairy products on cardiometabolic disease: food Is more than the sum of its parts. Adv Nutr. 2019;10(5):924S-930S.

(10) Mente A, Dehghan M, Rangarajan S, et al. Diet, cardiovascular disease, and mortality in 80 countries. Eur Heart J. 2023 Jul 21;44(28):2560-2579.