What is nutrition?
According to the World Health Organization, nutrition is the intake of food, considered in relation to the body’s dietary needs. Despite a wild variation in their visual representation, nutritional guidelines around the globe are quite homogeneous when translating the nutritional needs – in terms of nutrients – into foods and food groups required to meet a balanced diet. These guidelines take into account cultural differences, and also food safety aspects and use very similar methods in presenting their concepts of the “ideal” dietary pattern to give consumers a selection of recommended food groups. A healthy diet helps to preserve or even enhance overall health. A healthy diet complies with the dietary guidelines regarding the macro and micronutrient contents. But even in a society with an abundant supply of food, a large proportion of the population does not meet the Dietary Reference Intake (DRI) for several vitamins and minerals.
The 2015 Dietary Guidelines for Americans defined “nutrients of concern” as those nutrients that may pose a substantial public health concern. The Committee determined that calcium, potassium, vitamin D, and fibre are under-consumed and may pose a public health concern. Dairy foods, including yogurt, are major dietary contributors of three of the four nutrients of concern. Milk provides nine essential nutrients important for optimal health: calcium, potassium, phosphorus, protein, vitamins A, D and B12, riboflavin, and niacin (niacin equivalents). The nutrient composition of milk and yogurt are similar; however, yogurt represents a more concentrated source of riboflavin, vitamin B12, calcium, magnesium, zinc, and potassium. Hence, the dairy food group is a substantial contributor of many of the above nutrients (e.g., calcium, phosphorus, vitamin A, vitamin D, and protein), all of which should work towards promoting health.
National and international organizations, such as the Food and Agriculture Organization of the United Nations, and the US Dietary guidelines, recommend the daily consumption of dairy products, such as yogurt. And several scientific studies have reported that regular consumers of yogurt have a better overall diet quality, a more diverse and balanced diet that respects the dietary guidelines regarding nutrient intake, than non-consumers.
Yogurt intake is associated with healthier eating
In a regular diet, yogurt appears particularly interesting due to added active bacterial cultures, high protein content, and vitamins and minerals such as vitamins A and D, calcium, magnesium, potassium and phosphorus(1).
A US study(2) showed that yogurt is a key contributor to the Prudent dietary pattern and healthy eating. The Prudent diet is indeed characterized by higher intakes of vegetables, fruits, nuts, non-hydrogenated fats, yogurt, fish and seafood. Moreover, yogurt consumption was associated with lower body weight, waist-to-hip ratio, and waist circumference and tended to be associated with a lower BMI.
A similar analysis(3), based on the dietary records of 986 adults in France, showed that the higher scores of diet quality and better compliance with the French dietary recommendations were observed with increasing fresh dairy products consumption. Indeed, high fresh dairy products consumers eat more fruits, fish, legumes, nuts, water and fibers, and less alcohol. Moreover, they have better intakes in 11 micronutrients, including some that are not highly present in fresh dairy products such as vitamin C and vitamin B9.
Focus on Calcium and Vitamin D
Calcium is a key bone healthy nutrient and a major building block for the skeleton. 99% of the calcium found in our body is residing in our bones and it contributes to preserve calcium levels in the blood for nerves and muscles functions. Calcium is needed at all ages, but teenagers in particular need high levels; yogurt contains also proteins and vitamin D, which contribute to their growth. A review of evidence has evaluated associations between milk or dairy product intake and health outcomes in children and adolescents. Results suggest that dairy products are important for linear growth and bone health during childhood. Consumption of dairy products, particularly cheese and yogurt, is also associated with reduced dental caries in children.
A balanced diet and daily physical activity are key in stimulating bone health throughout life and preventing the risk for osteoporosis. A bone-healthy diet will help children and adolescents to build bone mass at a maximum level. Adults need to maintain healthy bones and avoid bone loss. For seniors it is crucial to sustain mobility and independence. Yogurt consumption is recommended to fuel adequate intake of calcium and vitamin D. People who suffer from lactose maldigestion or intolerance avoid dairy foods in general, which increases the risk of calcium deficiency and osteoporosis. Yogurt is the perfect alternative, as it contains live culture and is well tolerated.
Focus on Protein
Protein is an important building block of our organs and tissues and is needed to make enzymes, hormones and other chemicals in the body. Moreover there is a body of evidence that demonstrates that protein has a role in satiety and in hunger management. Satiety is the feeling of satisfaction we get after we have eaten a meal and has an important influence on how much we eat overall. If satiety lasts for a while, it can reduce how much food we eat at the next meal or snack. Foods that give satiation signals a helping hand could benefit people to manage their health and weight in our food-filled environment. As evidence supports energy (calories) from protein being more satiating than energy from carbohydrate or fat, potentially via an influence over appetite regulating hormones. Yogurt and more particularly protein-rich yogurt is a nutritious example of food that can create feelings of fullness, and its versatility lends itself well to breakfast, end of meal or snacking occasions.
The protein quantity and quality of foods, are contributing factors to their effects on glucose control. But foods are much more complex than a single nutrient, or even the sum of their individual nutrients. That’s why some types of protein-rich foods are better for us than others, and choosing the right source of proteins may be important in preventing diseases, including type 2 diabetes. A review pointed out that a higher intake of dairy products (such as milk, yogurt, cheese and whey proteins) consistently shows a beneficial relationship with glucose regulation and/or T2D risk reduction.
Prevention of obesity and type 2 diabetes is one of our biggest public health challenges of today. Eating foods that reduce appetite and lower the surge in blood glucose level that is seen after a meal could play an important role. Including yogurt and cheese in your meals is an effective way of reducing your appetite and controlling blood glucose. This in turn may help to protect you against obesity and type 2 diabetes.
Yogurt & fruits: the winning combination
Fruits consumption is part of numerous dietary guidelines worldwide. Their energy density is relatively low, they provide a variety of antioxidants and contain fibers (assimilated to prebiotics) which are beneficial for gut microbiota. Yogurt consumption, as well as fruit consumption, is associated with healthier dietary pattern. And they are both nutrient dense foods! The association of yogurt and fruits may confer combined health benefits on gut microbiota through potential prebiotic and probiotic effects. It can also be considered as a winning combination for substituting nutrient-poor and/or obesogenic foods.
The US 2015 Dietary Guidelines Advisory Committee concluded that “consumption of dairy foods provides numerous health benefits, including lower risk of diabetes, metabolic syndrome, cardiovascular disease and obesity”. Indeed, dietary guidelines around the world recommend yogurt and dairy foods as an integral food group. Yogurt possesses unique properties, including its nutritional composition (high nutrient density and relatively low energy density); lactic acid bacteria, which may affect gut microbiota and food matrix, which may have a role in appetite and glycemic control. And if yogurt consumption may have an interest in a balanced healthy diet, recent studies tend to show a surprising effect on behaviors and stress…even depression. The question may seem odd but the answer appears to be promising as two studies(4,5) have shown the probiotic component of yogurt may be associated with reducing depression symptoms.
The place of fermented food in nutrition
Fermented foods are not consistently represented in nutritional guidelines. However a lot of traditional foods are in fact made with fermentation. Fermented foods and beverages are lacto-fermented with natural bacteria or yeast creating lactic acid. The most popular include: yogurt, cheese, soya, beans, fish, meat, cabbages and sauerkraut. Moreover, recent studies on fermented foods support the possibility that the fermentation, and the contribution of microbes may provide additional properties beyond basic nutrition. One study found that fermented milk eased symptoms of irritable bowel syndrome, possibly due to beneficial changes in gut bacteria that such foods bring. Other fermented foods appear to relieve the diarrhea that people often suffer from after taking antibiotics. The live microorganisms present in these products are now considered responsible for many of these health benefits. The benefits of fermented foods are likely greater than the sum of their individual microbial, nutritive, or bioactive components:
- Fermented foods can be an important dietary source of live microorganisms.
- Fermentation can enhance or alter nutritive and health-modulating properties of food constituents.
- Microbes in fermented foods helps to digest, produce vitamins like B12 and K, introduce new compounds to the foods that are delivered to the gut
Murphy M et al, Daily intake of dairy products in Brazil and contributions to nutrient intakes: a cross-sectional study, Public Health Nutrition, 2015
Cormier H, Thifault E et al. Association between yogurt consumption, dietary patterns, and cardio-metabolic risk factors. Eur J Nutr, 2016, 55(2) : 577-87.http://dx.doi.org/10.1017/S1368980015001780
Lecerf, J.M. et al., Who are fresh dairy products consumers? Analysis of their dietary and nutritional profiles, Nutrition clinique et métabolisme, 2015, 1-29
Cornago AP et al. The Journal of Nutrition 2016
Marin, I. A. et al. Sciences Report 2017; 7, 43859; doi: 10.1038/srep43859