The unique nutrition of the Arctic Indigenous Peoples is associated with their increased endurance, health, and adaptability to the harsh climate. Reindeer meat, blood, and liver are the most critical elements of this traditional nutrition enriched with minerals. Reindeer consumption is a crucial factor of successful adaptation to the cold stress, as well as a component of national culture, food, and economic security and sovereignty, affecting the well-being and health of the Indigenous population in the Arctic.
1. Introduction
The unique nutrition of the Arctic Indigenous Peoples is associated with their increased endurance, health, and adaptability to the harsh climate
[1]. Reindeer meat, blood, and liver are the most critical elements of this traditional nutrition enriched with minerals
[2,3][2][3]. Reindeer consumption is a crucial factor of successful adaptation to the cold stress, as well as a component of national culture, food, and economic security and sovereignty, affecting the well-being and health of the Indigenous population in the Arctic
[4,5,6,7,8,9][4][5][6][7][8][9].
The reindeer (
Rangifer tarandus) habitat covers territories in Eurasia and North America between 50- and 81-degrees north latitude
[10] and includes continental and island territories, tundra, taiga, and mountainous areas close to them in vegetation composition and climatic conditions
[11]. Reindeer live in Russia, the USA, Norway, Sweden, Finland, Denmark, Iceland, Canada, Mongolia, Great Britain, and China
[10]. The largest populations of wild reindeer (
Rangifer tarandus caribou) are in Russia (952.9 thousand; 2015) and Canada (1300 thousand; 2016)
[11]. The world’s largest livestock of domesticated reindeer is in Russia (1620.8 thousand reindeer in 2021)
[12]. In Russia, the largest population of wild reindeer is in the Krasnoyarsky Krai, the Chukotka Autonomous Okrug, the Republic of Sakha (Yakutia), and domesticated reindeer are in the Yamal-Nenets Autonomous Okrug
[13]. Such various reindeer habitats make pre-conditions for the different chemical compositions of reindeer products in different northern regions.
The macro- and microelement composition of reindeer meat is impacted by significant differences in the species and mineral composition of forages (plants and lichens), the duration of grazing seasons on winter and summer pastures, the proportion in the diet of green fodder, shrubs, lichens, mushrooms, eggs of birds, and rodents, the macro- and microelement composition of soil and water, pollution, availability of salty seawater, and the cutting of velvet antlers
[14,15][14][15]. A specific feature of the northern reindeer is its seasonal migration to areas with different forage resources: Summer pastures with a predominance of herbaceous plants and shrubs and winter pastures rich in lichens
[16].
The study of the macro- and microelement composition of reindeer meat started in the second half of the 20th century. In the 1970s, in Canada, O. Schaefer (1977) and K. Hoppner (1978) confirmed the high nutritional value of reindeer meat due to high protein and low fat content
[17,18][17][18]. Two decades later, H.V. Kuhnlein (1992; 1996; 2000; 2002) conducted a study of micronutrient composition of reindeer products
[19,20,21,22][19][20][21][22] and developed recommendations for the use of venison by patients with atherosclerosis, vitamin deficiency, diabetes mellitus, and for the prevention of heart, liver, and stomach diseases
[23,24,25][23][24][25]. In the 1990s, in Alaska, the USA, the chemical composition of traditional products, including venison, was studied
[26]. Currently, a national database includes the data on the complete quantitative and qualitative chemical composition of reindeer meat in Alaska
[27]. In Russia, studies conducted in Yamal-Nenets Autonomous Okrug
[28[28][29],
29], Nenets Autonomous Okrug
[30[30][31][32],
31,32], Taimyr
[33[33][34][35],
34,35], the Republic of Yakutia
[36], and on the Kola Peninsula
[37,38,39][37][38][39] confirmed the nutritional and biological value of reindeer meat. Furthermore, they proved the need to include this product in a healthy diet.
Rangifer tarandus is highly adapted to Arctic conditions. The optimal work of enzymes that ensure adaptation to cold stress provides the accumulation of essential trace elements necessary for the practical work of enzymatic chains. The most crucial macronutrients are calcium (Ca), magnesium (Mg), phosphorus (P), potassium (K), and sodium (Na), among others, which activate enzymes, regulate the number of hormones, promote muscle and nervous activity, and therefore are essential components of the daily human diet
[40,41,42][40][41][42]. Thus, the consumption of reindeer meat can increase adaptation to the Arctic conditions, reduce the risk of heart diseases, and improve metabolism
[43,44,45][43][44][45].
Improving knowledge about the macro- and microelement composition of reindeer meat in different northern regions will contribute to the expansion of the use of reindeer products to prevent diseases and increase the adaptation of the Arctic population and shift workers in the circumpolar area, as well as develop effective medicinal and pharmaceutical products. Furthermore, studying the chemical composition of reindeer meat will also increase the value of exported reindeer meat, which is an important factor in promoting the economic sovereignty and well-being of the Indigenous Peoples in the Arctic.
2. Macro- and Microelement Composition in Reindeer Meat: Heterogeneity Analysis
2.1. Magnesium
The iron content in reindeer meat was available in 11 studies. The standardised mean differences ranged from 2.9107 to 11.0987; most ratings were positive (100%). The estimated standardised mean difference based on a random-effects model was 5.3972 (95% CI: 3.7340–7.0604). Thus, the mean value was significantly different from zero (z = 6.3602,
p < 0.0001) (
Table 21,
Figure 21).
Figure 21. Forest plot of the comparison of the content of magnesium in reindeer (Rangifer tarandus) meat by geographical regions.
Table 21. The content of macro- and microelements in reindeer (
Rangifer tarandus) meat: Heterogeneity analysis.) meat: Heterogeneity analysis.
Macro- and Microelements |
Random-Effects Model, k |
Estimate * |
se |
Z |
p |
CI Lower |
CI Upper |
Magnesium |
9 |
5.40 |
0.849 |
6.36 |
<0.001 |
3.734 |
7.060 |
Iron |
9 |
5.83 |
1.31 |
4.43 |
<0.001 |
3.250 |
8.404 |
Zinc |
9 |
0.51 |
0.149 |
3.45 |
<0.001 |
0.22 |
0.804 |
Calcium |
9 |
−2.12 |
2.45 |
−0.867 |
0.386 |
−6.918 |
2.674 |
Potassium |
10 |
24.3 |
25.4 |
0.96 |
0.34 |
−25.45 |
73.99 |
Sodium |
9 |
24.1 |
23.7 |
1.02 |
0.31 |
−22.31 |
70.5 |
Phosphorus |
9 |
14.5 |
19.0 |
0.76 |
0.45 |
−22.7 |
51.7 |
Heterogeneity Statistics |
Macro- and Microelements |
Tau |
Tau² |
I² |
H² |
df |
Q |
p |
Magnesium |
2.419 |
5.8524 (SE = 3.259) |
92.17% |
12.776 |
8.000 |
66.719 |
<0.001 |
Iron |
3.832 |
14.686 (SE = 7.81) |
97.04% |
33.77 |
8.000 |
269.34 |
<0.001 |
Zinc |
0.44 |
0.194 (SE = 0.0995) |
97.67% |
42.98 |
8.000 |
429.42 |
<0.001 |
Calcium |
7.292 |
53.1782 (SE = 26.9478) |
99.3% |
142.905 |
8.000 |
488.351 |
<0.001 |
Potassium |
79.87 |
6378.95 (SE = 3034.51) |
99.44% |
178.16 |
9.000 |
1970.58 |
<0.001 |
Sodium |
71.00 |
5041.41 (SE = 2522.57) |
99.94% |
1779.06 |
8.000 |
8955.84 |
<0.001 |
Phosphorus |
56.8 |
3227.16 (SE = 1621.7) |
99.54% |
216.18 |
8.000 |
2146.4 |
<0.001 |