Written by Dr. Sanjana V.B Bhms,dbrm,cdn

Founder & medical director of siahmsr wellness.in

All rights reserved with siahmsr digital healthcare[siahmsr wellness]

Reviewed by SIAHMSR medical team.

Yogurt 

   Yogurt is a dairy product, which is made by blending fermented milk with bacterial cultures and various ingredients that provide flavor and color. Yogurt can be commercially produced with substantial variety in composition, flavors, and additives.

History

  Yogurt is used as a food since ancient times and exact date of origin is not yet known. It is believed that yogurt was first formed accidently in Mesopotamia thousands of years ago. Archaeological evidences point out that Mesopotamians domesticated goats and sheep around 5000 B.C. The milk gathered from these animals was stored in gourds, and in the warm climate it naturally formed a curd. This curd was the primitive form of yogurt. Eventually, they started developing yogurt for commercial purposes from milk. In a similar way yogurt production started in various other parts of the globe.

   The oldest writings mentioning yogurt are attributed to Pliny Elder, who remarked that certain "barbarous nations" knew how "to thicken the milk into a substance with an agreeable acidity".

   Historical accounts states that yogurt was used by many emperors around the world as a food. However, yogurt was introduced as a common food since 1900s. Later the awareness about its nutritive value made it popular and many dairy industries started producing yogurt in different flavors and adding nutritious ingredients like nuts, seeds etc.

    Cow's milk is most commonly used to make yogurt. However, milk from water buffalo, goats, ewes, mares, camels, and yaks are also used to produce yogurt.  Pasteurized or raw milk may be used in the process of yogurt making. Each type of milk produces substantially different outcomes.

   The bacteria used to make yogurt are known as yogurt cultures. Yogurt may be produced using a culture of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophiles. Fermentation of sugars in the milk by these bacteria produces lactic acid, which acts on milk protein to give yogurt its texture and characteristic tart flavor.

Traditional yogurt is thick and creamy. Yogurt (plain yogurt from whole milk) contains 81% water, 9% protein, 5% fat, and 4% carbohydrates.

Preparation

 Yogurt is prepared by warming milk to a temperature (30–45 °C (86–113 °F)) that will not kill the live microorganisms that turn the milk into yogurt & inoculating certain bacteria (starter culture), usually Streptococcus thermophilus and Lactobacillus bulgaricus, into the milk, and finally keeping it warm for several hours (4-12 hours).

 Milk with a higher concentration of solids than normal milk may be used in some yogurt preparations; the higher solids content produces a firmer yogurt. Solids can be increased by adding dried milk powder.

Safety

 The yogurt-making process involves the risk of growth of harmful microorganism .Heat and low PH or acidity provides safety in using yogurt to a great extent preventing growth of microorganisms. However, contaminations are possible in traditionally formed yogurts or if packaging is not properly done in proper manner by the dairy industry producing yogurt.

  Yogurt made with raw milk can be contaminated with bacteria  such as Listeria, Cryptosporidium, Campylobacter, Brucella, Escherichia coli and Salmonella. Yogurts can also be contaminated with aflatoxin-producing Aspergillus flavus, Aspergillus parasiticus and Aspergillus nomius.

  Under US Food and Drug Administration regulations, milk must be pasteurized before it is cultured, and may optionally be heat treated after culturing to increase shelf life. Most commercial yogurts are not heat treated after culturing, and contain live cultures.

  Yogurt with live cultures is more beneficial than pasteurized yogurt for people with lactose malabsorption. Lactose intolerance is a condition in which people have digestive problems due to the decreased ability to digest lactose, a sugar found in dairy products.

In 2010, the European Food Safety Authority (EFSA) found that lactose intolerance can be managed by ingesting live yogurt cultures (lactobacilli) that are capable of digesting the lactose in other dairy products.

Types of yogurts

  Various types of yogurt are available in the market. These include whole-milk yogurt, low-fat, or non-fat forms; plain or flavored;

 Addition of natural or artificial sweeteners into yogurt is common to make it more palatable. Some yogurts are fortified with vitamin D.

Greek yogurt or labneh [strained yoghurt]

Strained yogurt has been strained through a filter, traditionally made of muslin and more recently of paper or non-muslin cloth.

 Straining the fermented milk after coagulation removes the liquid whey as well as some of the lactose, creating a richer consistency. This removes the whey and makes it thicker in consistency. Strained yogurt is made at home, especially if using skimmed milk which results in a thinner consistency. Strained yogurt is known as Labneh in Middle Eastern countries.

It is strained to decrease its water content and to help delay spoilage. Strained yogurt is a traditional component of Mediterranean, Middle Eastern, and South Asian cuisines.

In North America, strained yogurt is commonly called "Greek yogurt". Powdered milk is sometimes added into yogurt while making, to achieve thickness. In Britain it is known as as "Greek-style yogurt"

The process of straining can lead to the loss of certain micronutrients, particularly the water-soluble vitamins.

Yogurt probiotic drink is a drinkable yogurt pasteurized to kill bacteria, with Lactobacillus added before packaging.

Health benefits of yogurt

· Rich source of calcium, magnesium, zinc, potassium and phosphorus.

 Yogurt consumption helps your bones, boosts immunity and nerves and blood vessels’ health.

Calcium and phosphorus support bone and teeth health. Potassium and magnesium improve heart health.  Zinc has an important role in improving your immunity. The concentrations of these minerals are higher in yogurt compared with milk by nearly 50%.

· A good source of selenium

 Selenium is good for health of thyroid; It is also a powerful antioxidant and helps to prevent cancers and heart diseases.

· An excellent source of B vitamins, vitamin A and folates.

Yogurt contains riboflavin, niacin, vitamin B-6, and vitamin B-12.

 Yogurt is a rich source of vitamin B12, All these vitamins are very important for the functions of heart, brain and nervous system. Vitamin A improves vision or eyesight.

· A good source of protein

Yogurt is an excellent source of essential amino acids.

Proteins help various functions of the body in the form of enzymes, hormones. Protein helps body building and strengthens muscles of your body. The protein content of yogurt ranges from 3.5 to 5.3 g.

· Yogurt   is a good probiotic to help your gut health

Yogurt is considered a probiotic food as it contains beneficial live microorganisms which can provide various health benefits with consumption. Probiotics help to improve the gut health removing harmful microorganism from intestines.

Recent research studies also emphasize that your gut health determines your mental health. So healthy gut improves your mental health.

 Benefits of yogurt consumption in the ageing people

According to a study described by NIH, aging is associated with multiple nutritional deficiencies and health issues.

In ageing people both deprivations as well as excessive intake of various nutrients is associated with health complications.

 Ageing may lead to muscle weakness, decreasing bone mineral density and consequent osteoporosis, cardiovascular diseases such as heart attack and stroke, memory impairment, cognitive decline &weakening of immunity.

Research studies related to various health issues and role of yogurt consumption in mitigating them is very significant in nutritional or dietary management of health of ageing population. Yogurt consumption is a practical solution to many of the problems related to old age. Furthermore, yogurt is easily available and affordable to all.

In addition to the health benefits mentioned above, yogurt has vital role in maintaining the health of ageing population.

Yogurt consumption reduces the chance for nutrient deficiencies of B vitamins riboflavin, vitamin B-12, and minerals calcium, magnesium, and zinc in old people.

 

Potential benefits of yogurt on bone health

Deficiency of calcium is common in old age due to poor intake of calcium rich food. In addition to that low protein consumption accelerates the poor bone health and higher risk of osteoporosis, muscle weakening, falls, and fractures in the elderly.

 Many studies have shown that vitamin D and calcium supplementation have positive effects on bone health, including reduction in falls and fractures and better muscle strength.

Consumption of dairy products such as yogurt which are rich in calcium may protect adults against loss of bone mineral density.

 However, it has not yet been fully understood if calcium supplementation alone may help to improve bone health in the absence of vitamin D.

Vitamin D deficiency is common in the elderly because of the age-related decrease in vitamin D3 production by the skin, poor nutrition, and prolonged indoor activity. Therefore, ensure adequate vitamin D supplementation through food or sun exposure along with calcium from dairy products and vegetables.

 

Potential benefits of yogurt on musculoskeletal health 

 Yogurt is an important source of protein and calcium for the elderly, and yogurt may potentially improve bone and muscle health.

     According to NIH data base a study shows that greater BMD or bone mineral density observed in yogurt consuming groups in a few bone sites compared with no consumers. Yogurt consumption improved bone mineral density, although the increase was only significant at the trochanter in hip joint and it may potentially reduce fracture risk in hips.

   Menopause in elderly women is associated with decreased bone mineral density and enhanced risk of osteoporotic fracture due to declining oestrogens. The bone loss is happening through a process called bone resorption and various other factors within the body contribute to it.

 A study has found that yogurt consumption may potentially lower amounts of bone resorption. That means there is a potential for better bone health in postmenopausal women consuming yogurt due to the balancing that happens between bone formation and resorption. However, long-term studies are needed to evaluate the effect of yogurt consumption on bone and muscle health.

 

Role of yogurt consumption on muscle weakness and fat gain of old age

  Ageing is associated with loss of lean muscle tissue and consequent reduction in muscle function and mobility.  Studies indicate that dairy products, and in particular yogurt, have the potential to reduce the risk of obesity.

  Evidence from studies on overweight and obese individuals further indicates that dietary calcium, particularly when sourced from dairy, can promote weight loss [5].

 

Yogurt consumption helps mental health and cognition in the aged

 The numbers and diversity of protective bacteria species of gut may decline with ageing. The intestinal flora is affected by changes in diet, reduced intestinal motility, excessive and chronic use of antibiotics, changes in gastrointestinal architecture, and impairment of gut immunity.

  Yogurt is a good probiotic and helps to restore healthy intestinal flora and improves gut health. Recent research studies show that gut health and mental health are interconnected. An improvement in gut microbiota can improve mental health also. Thus, it improves cognition and memory in ageing people. Its anti-inflammatory property may be protective against cognitive impairment.

  Yogurt consumption may enhance immune response, thereby reducing infectious disease risk. The immunity boosting nutrients of yogurt include zinc, vitamin B-6, protein, and bacteria.

Probiotic consumption also has been associated with improving immunity.

Daily consumption of yogurt may help to resist respiratory infection, specifically colds, in the elderly.

References

1.    https://pubmed.ncbi.nlm.nih.gov/23351406/
2.    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6410895/
3.    https://pubmed.ncbi.nlm.nih.gov/19543765/
4.    https://pubmed.ncbi.nlm.nih.gov/15447921/
5.    https://pubmed.ncbi.nlm.nih.gov/15672113/
6.    O’Toole PW, Claesson MJ.. Gut microbiota: changes throughout the lifespan from infancy to elderly. Int Dairy J 2010;20:281–91. [Google Scholar]
7.    https://pubmed.ncbi.nlm.nih.gov/18183940/
8.    https://en.wikipedia.org/wiki/Yogurt
9.    https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=76&contentid=01117-1