Dairy

Bovine milk is globally the most commonly produced and consumed type of milk (85% of all milk types) (89). Because the consumption of other types of milk (such as sheep or goat’s milk in traditionally made feta cheese) in the Finnish food culture is so minor, ‘milk’ in this text only refers to cow’s milk.

Milk is a nutrient-dense fluid mixture of fats, proteins, carbohydrates, vitamins, and minerals (89,90). The composition varies, e.g., due to genetic, physiological, environmental, and nutritional factors of a cow (89). For the food industry, however, the fat and protein content of milk are mostly standardised (89). Milk contains all the essential vitamins and minerals, although some in low quantities (90). Milk is a good source of protein, vitamin B2 and B12, calcium, iodine, potassium, and phosphorus (89,90).

Since 2003, Finnish liquid dairy products have also been a good source of

vitamin D because of the vitamin D fortification recommendation (91).

Especially since 2010 they became a valuable source of vitamin D, when the fortification recommendations were doubled (91). Milk is also fortified in the US, but not in the United Kingdom (UK), for instance (90). Due to its nutritious nature, milk and milk products, i.e., dairy is thus considered as one of the main food groups (90).

Milk can be processed into many different products that vary due to traditional, social, religious, and dietary habits (92). The most common dairy products worldwide are cheeses and acid-fermented milks (e.g., yogurt) (93). The most popular milk products consumed in Finland are low-fat milk, skimmed milk, quark, cheese, yogurt, whole milk, sour milk, cream, curdled milk, sour cream, crème fraiche, farm milk, and milk powder (87).

Milk products can be categorized e.g., as fermented, heat desiccated, coagulated, clarified butter fat, frozen, and dried products (92).

For simplicity, in this thesis, milk products are categorized as non-fermented, such as plain milk, cream, and ice cream and fermented dairy.

Fermented dairy is “a milk product obtained by fermentation of milk”, initiated with the help of unknown microorganisms and in the food industry, with pure starter cultures, which may be different for different end products (94). The full list of non-fermented and fermented products in this thesis is published in Study III in Table 1.

Usually, the energy value of a fermented product and the

non-fermented raw material are somewhat the same (94). The nutritive value in the fermented product, however, may change due to the fermentation process and microbial growth in the product. It is thought that fermented dairy is more nutritious, and some of the nutrients in fermented dairy are easier to absorb compared to non-fermented dairy products (94). The nutrient content of some dairy products is displayed in Table 6.

Table 6. The nutrient content of dairy products per 100 ml or 100 g.

Formulated based on the information on Fineli, the National Food Composition Database in Finland (71).

Component Skimmed/

low-fat/

whole milk

Sour milk (fat-free)

Whipping cream

Quark Ripened cheese

Energy, kcal 34/46/63 30 356 59 277

Total fat, g 0.1/1.5/3.5 0.1 38.0 0.4 20.0

SAFA, g <0.1/1.0/2.2 <0.1 25.4 0.1 12.7

MUFA, g <0.1/0.4/0.7 <0.1 8.7 <0.1 4.9 PUFA, g <0.1/<0.1/<0.1 <0.1 0.9 <0.1 0.5 Cholesterol, mg 1.0/6.4/11.0 5.0 77.0 6.0 48.2

Carbohydrate, g 4.9/4.8/4.8 3.6 2.9 3.0 0.2

Protein, g 3.1/3.0/3.0 2.9 1.9 9.8 23.4

Calcium, mg 121.0/120.0/124.0 143.0 70.0 117.0 939.7 Iron, mg <0.1/<0.1/<0.1 <0.1 <0.1 <0.1 0.2

Iodine, μg 13.8/13.8/13.7 17.0 10.0 17.0 22.3

Potassium, mg 160.0/150.0/160.0 190.0 100.0 170.0 83.1 Magnesium, mg 12.0/11.0/11.0 14.0 7.0 12.0 29.4

Sodium, mg 44.0/41.0/44.0 56.0 28.0 99.1 565.6

Phosphorus, mg 90.0/90.0/90.0 120.0 62.0 180.0 511.0

Selenium, μg 2.8/2.8/2.9 2.8 1.9 3.9 20.6

Zinc, mg 0.4/0.4/0.4 0.5 0.3 0.6 4.0

Folate, μg 4.2/4.2/6.0 14.2 7.0 16.0 18.2

Vitamin B3, mg 0.9/0.8/0.8 0.9 0.5 2.8 5.9

Vitamin B6, mg 0.05/0.05/0.05 0.04 0.02 0.05 0.06 Vitamin B2, mg 0.19/0.18/0.18 0.18 0.17 0.23 0.35 Vitamin B₁, mg 0.03/0.04/0.03 0.03 0.02 0.05 0.03 Vitamin A, μg 0.8/12.9/28.6 5.1 330.5 1.5 155.2

Vitamin B12, μg 0.4/0.4/0.4 0.4 0.2 0.6 1.8

Vitamin C, mg 1.2/1.1/1.0 1.0 0.7 1.0 0

Vitamin D, μg 1.0/1.0/1.0¹ 1.0¹ 0.2 <0.1 0.2 Vitamin E, mg <0.1/<0.1/<0.1 <0.1 0.7 <0.1 0.3 Vitamin K, μg 0.16/0.33/0.81 0.16 11.40 0 18.88

1Before 2003, Finnish milk and yogurt did not contain significant amounts of vitamin D. Since 2003, it has been recommended to fortify milk with vitamin D (91).

Dairy is considered a part of a healthy diet and thus, is part of most dietary guidelines (90). For example, in the US, children over 9 y and

healthy adults are recommended to consume three cups of dairy each day, which equals 7 deciliters per day. Cheese can also be consumed as part of dairy products; about 50 grams of cheese equals one cup (75). In the Finnish dietary guidelines, the recommendation is similar: from 5 to 6 deciliters of liquid dairy products plus from 2 to 3 slices of cheese per day (77). In both countries, it is recommended to choose fat-free or low-fat products and favor products that are low in sodium (75,77).

About 90 percent of the citizens of the US do not meet the dairy

recommendations (75). National dietary survey in Finland indicates that the dairy consumption may also be insufficient among some population

groups in Finland, such as among the youngest women (18‒44 y) (95). Their total liquid dairy consumption was 265 g/d and cheese 31 g/d (95), which is about half of the recommended daily dairy intake (77). However, the importance of low dairy consumption for health may depend on whether dairy products are substituted, e.g., with fortified vegan milks or not (77).

The consumption of total dairy did not differ between Finnish men and women, but women used more fermented dairy products and cheese than men (95). Among men, the cheese consumption was highest among the youngest age groups (<64 y). The consumption of yogurt, quark, and low-fat milk was lowest among the oldest (65‒74 y) men and women (95).

Considering quality, dairy choices need improvement towards low-fat and fat-free options (87,95).

Dairy plays globally an important role for meeting the energy, macro- and micronutrient needs in many populations (96). However, the

suboptimal fat quality in some dairy products and a high calcium content have raised concern about their impact on cardiovascular health (96). Even though low-fat and fat-free products are commonly recommended

(74,75,77), it seems that fat in dairy products may have a different effect from fat in other products and may not have adverse consequences on cardiovascular health (96). Also, dietary calcium seems not to have a major role in coronary calcification and may controversially have some health benefits (96). In addition, associations of dairy intake with several cancers

have been under study. The current evidence suggests that an association between cancer and dairy consumption does not exist, although prostate cancer may be an exception (96).

However, when considering the health impact of dairy, it should not be examined as a single category. As stated earlier, fermented dairy is thought to be superior to its non-fermented counterparts (94). Moreover, within fermented dairy, the products are not similar regarding their health effects, either. The health impact of a certain product depends on the food matrix, microorganisms in the fermentation, and the processing conditions (93).

For example, products that contain Lactobacillus, Streptococcus, or Bifidobacterium are thought to have probiotic effects (93), whereas over 1000 different types of cheeses (93) are so far a fairly unexplored area with potential prophylactic properties (94).

According to the statistics of FAO, the global average milk consumption per person was 90 kilograms in 2013 (84), which equals 250 grams of milk per day. However, the differences between countries are huge: in many African countries the average milk consumption was less than 10 kg per year, the lowest consumption was in Laos (2.9 kg), whereas in Finland the consumption was notably the highest, 431 kg (84). It has to be kept in mind, however, that to make one kilogram of cheese about 10 kilograms of milk is needed (97). Hence, the dairy intakes per person presented in FAO’s statistics are higher than the actual amounts of food consumed. Thus, according to Luke’s statistics, the consumption of liquid dairy products was about 144 kg per person and of cheese 25 kg in Finland in 2020 (87).

Dairy consumption has been globally steady during the past 50 years (Figure 5). Also, in the US, Europe, and Africa the dairy consumption has consistently stayed at a constant level. In Asia and South America, the dairy consumption has slowly increased over the years. In Finland, the

consumption has constantly been much higher than other regions, and more periodical fluctuation has been seen. However, the recent Finnish consumption trends of dairy are opposite in the statistics from the FAO and Luke for unknown reasons, even though they should mainly be based on the same information and principles. The main source of FAO’s statistics is the information provided by its member countries (84).

The main sources of Luke’s statistics are Finnish production and harvest statistics, farm surveys, and the foreign trade statistics of Finnish Customs (98). The food balance sheets by the FAO (84) and Luke (98) present the potentially available food for human consumption. They are calculated by adding the total quantity of domestic food produced and the total quantity of imported food. The values are adjusted by changes in stocks, such as exports, losses during storage, and non-food uses (84,98). The differences in statistics may be due to, e.g., which products are included from import and export data and which ratios are used to convert cheese into milk (Senior Specialist Erja Mikkola, Luke, personal communication, 19 August 2021). According to the statistics from the FAO, Finnish dairy consumption increased nearly 100 kilograms between the years 2004 and 2013 (Figure 5), whereas Luke reports that the total dairy consumption has decreased (Figure 6). In addition, the consumption trends between dairy subtypes have changed over the years in Finland.

Figure 5. Changes in the average milk consumption per person in Finland, the United States, Europe, South America, the world, Asia, and Africa in 50 years, between the years 1967–2017. The figure is based on the data from the United Nations Food and Agriculture Organization (84) and made by Our World in Data (88). The numbers are overestimations, as they do not consider any waste at the household level.

Figure 6. Changes in the average dairy consumption per person in Finland between the years 1967–2020 according to the statistics of the National Resources Institute Finland (87).