Life Extension Magazine December 2012
YOGURT: A Spoonful of Powerful Nutritional Value
By William Gamonski
While yogurt is widely known for its healthy probiotics, it also boasts an impressive nutritional profile that makes it a frontrunner for the ultimate super food. Yogurt's health-promoting properties ward off a variety of health conditions, from gastrointestinal disorders to obesity to gum disease.
The origin of yogurt remains uncertain, but it was documented as a favorite food of the conqueror Genghis Khan and his army in the 13th century. While yogurt has been a dietary mainstay across the Middle East, Asia, Russia, and Bulgaria for thousands of years, its health benefits only became apparent during the 20th century, due to the research performed by Dr. Elie Metchnikoff on lactic acid bacteria. Yogurt is becoming increasingly popular around the world, particularly in the United States, as well as Turkey, India, and Greece, where it's being used for culinary purposes.1
Supporting Gastrointestinal Health
Yogurt is produced by fermenting milk with bacterial starter cultures Lactobacillus bulgaricus and Streptococcus thermophilus. Other live cultures such as Lactobacillus casei and Lactobacillus acidophilus are often added during the process.1 These beneficial bacteria, known as probiotics, might improve digestion and prevent common gastrointestinal disorders.
Lactose intolerance refers to the inability to digest the sugar lactose in dairy products due to a deficiency in the enzyme lactase. Yogurt shows promise as an alternative to milk for individuals suffering from this condition, according to research reported in the New England Journal of Medicine.2 Scientists found that lactose intolerant subjects consuming 18 grams of lactose from yogurt digested and absorbed the lactose more efficiently than those who received the same amount of lactose from milk. This improved toleration resulted in less diarrhea and other gastrointestinal symptoms in the yogurt group.
Scientists believe that probiotics in yogurt boost the release of beta-galactosidase, an enzyme that enhances lactose digestion.3
It is estimated that one out of every four people experience antibiotic-associated diarrhea.4 Scientists at Indiana University School of Medicine investigated whether the healthy bacteria in yogurt would help prevent the condition. A group of 202 hospitalized patients receiving oral or intravenous antibiotics were randomly selected for 8 ounces of yogurt, or no yogurt, for eight days. The frequency of diarrhea was assessed during that time period. The results showed a 24% reduction in the incidence of diarrhea in the yogurt group, compared with a 12% decrease in the control group.5
Numerous studies have demonstrated the obesity fighting potential of yogurt. In animal research, scientists found that mice supplemented with yogurt powder while on a moderate-fat diet had significantly lower weight gain than control mice. This was attributed to increased lipid levels in the feces of the supplemented group, suggesting that yogurt works by reducing fat absorption in the small intestine.6
These favorable effects extend to humans as well. Individuals with the highest intake of dairy foods, such as yogurt, lowered their risk of weight gain by 67% over a 10-year period compared to those with the lowest intakes, according to research published in the Journal of the American Medical Association.7 Furthermore, researchers at Harvard School of Public Health studied the relationship between specific foods and long-term weight gain in more than 120,000 men and women.8 After analyzing data from the 20 year follow-up, researchers concluded that yogurt was the food most associated with keeping weight off, even more so than fruits, vegetables, and whole grains.
To determine whether yogurt consumption can enhance weight loss in humans, researchers at the University of Tennessee randomly assigned 34 healthy obese participants 18 ounces of fat-free yogurt or one serving of dairy daily for 12 weeks.9 Both groups adhered to a similar calorie-reduced diet. At the end of the study, the yogurt group experienced an average weight loss of 14 pounds, compared to 11 pounds in the control group. Additionally, those who consumed yogurt retained 31% more muscle mass and lost 81% more abdominal fat, which was reflected in a reduction of over 1.5 inches from the waist. By comparison, the control group lost 0.23 inches. This improvement is noteworthy since visceral fat accumulation has been associated with increased risk for cardiovascular disease and type II diabetes.10
Existing data indicates that calcium is the main component in yogurt responsible for its anti-obesity benefits. Although calcium may operate through multiple mechanisms, one mode of action relates to its ability to suppress the release of the hormone calcitriol, thereby halting fat storage and promoting fat break down.11
Emerging evidence reveals that the addition of yogurt to your diet can protect against the development of several types of cancer, including those of the colon, bladder, and breast. In a study published in the International Journal of Cancer, a 35% colon cancer reduction risk was found in those consuming the highest amount of yogurt compared to those with the lowest amount in more than 45,000 men and women over a 12-year period.12
Swedish scientists uncovered a strong association between yogurt intake and bladder cancer risk among 80,000 men and women. After 9-years of follow-up, findings showed a 38% lower risk of the disease in those who regularly consumed yogurt versus those who ate little or none.13
In another study, researchers evaluated the intake of fermented dairy products in 133 breast cancer patients and 289 controls. They discovered that yogurt had a protective effect against breast cancer, as the highest intake was associated with a 37% reduction risk.14
Combating Heart Disease
Other research has shown that yogurt offers powerful cardiovascular support. In a study involving more than 1,000 women aged 70 and older, those with the highest yogurt intake not only had higher HDL cholesterol levels, but also significantly lower carotid artery thickness, a measurement of atherosclerosis, than those with the lowest intake.15
A study published in the European Journal of Clinical Nutrition further confirmed the HDL raising effects of yogurt in human volunteers. After consuming 10.5 ounces of full-fat yogurt daily for 21 weeks, participants experienced an increase of nearly 12 mg/dL in HDL cholesterol levels without any change in LDL levels. This in turn favorably altered their LDL/HDL cholesterol ratio by over 23%.16
Fight Gum Disease
The chronic growth of bacteria in the mouth leads to inflammation and damages the gums and bones that support the teeth. This condition, known as periodontal disease or gum disease, has been associated with stroke and heart disease.17 Japanese researchers found that a daily intake of at least 2 ounces of yogurt among men and women was linked with a decreased risk of developing deep probing depth by 60% and clinical attachment loss by 50%, both periodontal disease parameters.18
Incorporating yogurt into your diet offers healthy probiotics and other nutrients that may help protect against gastrointestinal disorders, cancer, cardiovascular disease, obesity, and gum disease. Please remember that yogurt is not a dietary supplement, and should be used to replace constituents of your diet that may be less healthy such as ice cream. If one intentionally added yogurt without removing another food, then the excess calories might counteract the beneficial effects of the yogurt.
If you have any questions on the scientific content of this article, please call a Life Extension® Health Advisor at 1-866-864-3027.
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16. Kiessling G, Schneider J, Jahreis G. Long-term consumption of fermented dairy products over 6 months increases HDL cholesterol. Eur J Clin Nutr. 2002 Sep;56(9):843-9.
17. Pihlstrom BL, Michalowicz BS, Johnson NW. Periodontal diseases. Lancet. 2005 Nov;366(9499):1809-20.
18. Shimazaki Y, Shirota T, Uchida K, et al. Intake of dairy products and periodontal disease: the Hisayama Study. J Periodontol. 2008 Jan;79(1):131-7.