Dairy has been subject of multiple health debates in recent years. Although dairy products are present in almost all dietary guidelines, their benefits, including the benefits of yogurt, have been questioned and some claim that they pose risks to our health. As a dietiTian it is my responsibility to review the evidence, draw conclusions (clear and not misleading), and share relevant information in favor of health. Regarding dairy, I can assure you that during the last couple of years more research has come up and the results are quite interesting.
First of all, not all dairy products are the same. The process that milk goes through in order to produce butter, cheese, kefir, or yogurt creates enormous differences in nutrient composition and other organoleptic characteristics that may impact our health. Calcium content, bioactive lipids, satiating and bioactive peptides, and nutrient density have all been related to weight and adiposity control, bone health, and cardiovascular health. Yogurt, a fermented dairy product, has been subject of more research due to its content of live cultures and its impact gut health.
Benefits of Yogurt as part of a healthy diet and lifestyle
Recently, I had the opportunity to attend the fourth Yogurt in Nutrition Summit (San Diego, California) and the Second YINI Summit on the Health effects of Yogurt in Mexico Initiative towards a Correct Diet: Health Effects of Yogurt. Both events were wonderful, with researchers from all over the world and Mexico, presenting data on how yogurt has been associated with healthy lifestyles, healthier nutritional status, and diabetes prevention.
It is important to note that yogurt consumers tend to have healthier lifestyles. According to Dr. Angelo Tremblay, several observational cohort studies of Europe and North America describe yogurt consumers to have better diet quality; for example, in the FRAMINGHAM cohort it was associated with higher intake of nutrients like calcium, zinc, magnesium, potassium, protein, and some vitamins. In the Canadian study Infogene, yogurt consumption was associated with a prudent diet (higher intake of vegetables, fruits, and nuts); these results are similar to those described in the most recent (2012) Mexican National Health and Nutrition Survey (ENSNAUT) in which yogurt consumers tend to eat more vegetables and fruits and less sugar-sweetened-beverages.
In the SUN Cohort, according to Dr. Carmen Sayon, yogurt consumption has been associated with less weight gain. It is to note that this effect was enhanced, when yogurt was mixed with fruit—a traditional dessert of the Mediterrean diet—, suggesting that the symbiosis of live cultures in yogurt with prebiotics and other non-nutritional compounds of fruit may boost the benefits.
Dr. Sayon also showed the PREDIMED cohort (which includes elder adults with high cardiovascular risk) findings in which higher yogurt consumption was associated with reduced risk of metabolic syndrome. Dr. Simin Meydani made it clear that there are a few observational studies of yogurt and older adults, however, they tend to suggest that this dairy product may not only improve nutritional status but enhance the immune system, thus, contributing to healthy aging.
Decreased risk of developing Type 2 Diabetes
One the well-known benefits of yogurt is linked to diabetes prevention. Several epidemiological studies have suggested a risk reduction in people with higher yogurt consumption. Dr. Jordi Salas presented evidence that fermented dairy products, like yogurt, were linked to better glucose metabolism; some studies even demonstrated 17% lower diabetes risk with 3 or more servings of yogurt a day.
The mechanisms through which yogurt help prevent type 2 diabetes are not quite clear. Dr. Salas presented two hypothesis:
- Yogurt affects satiety and contributes to lower adiposity, thus diabetes risk is lowered: Mechanisms related to this hypothesis are calcium content on yogurt, satiating protein, and live culture effects on health
- Yogurt increases insulin sensitivity and/or diminishes pancreatic secretion: Once again, calcium may play an important role (it favors insulin secretion and glucose uptake), bioactive peptides could affect incretin hormones, and bioactive fatty acids (odd chain fatty acids have been related to diabetes protection)
Taking into account the evidence on lower diabetes risk due to the benefits of yogurt and its consumption, Dr. Andrew Prentice simulated what would the impact be on UK’s health care expenditure if yogurt consumption increased from 4 teaspoons to one pot a day. His conservative estimations reached up to £2.3 billion savings over 25 years and, moreover, life quality would increase significantly. Thus, promotion of yogurt consumption might be a target for public health in order to diminish health costs associated to type 2 diabetes.
Finally, but not least, yogurt consumption may become part of our everyday diet. Constance Brown-Riggs RD, Azmina Govinji RD, and Megrette Fletcher helped us understand how yogurt may be a key food towards healthy life-styles and, along with mindful eating, contribute in our fight towards the obesity and diabetes epidemic. Right now, our concern is sugar content on several “healthy” products. Dr. Thomas Wolver proved to us that yogurt is a low glycemic index food, no matter if it is plain or sweetened. Therefore, yogurt benefits can be enjoyed without sacrificing taste.
What to remember?
As a conclusion, dairy products do not pose risk to our health. On the contrary dairy have many benefits, among which benefits of yogurt are being extensively studied. Dietary recommendations should include dairy regularly; yogurt, along with other fermented products, may be needing a special category in the future, due to the beneficial effects of live cultures in our diets. It is a fact that more studies, especially randomized double-blind controlled trials, are needed to deeply understand the mechanisms of yogurt in health and to be able to give more accurate recommendations. Meanwhile, one yogurt a day seems just perfect to everyone.