Yogurt dates back to the Neolithic period, approximately 5,000 years ago. Still, our ancestors’ yogurt looked far different from today’s colorful, flavored, and neatly packaged varieties, and the processing procedures have undergone similarly considerable changes. Fundamentally though, this beloved creamy snack is a fermented product, one of the reasons it is deemed healthful, but is also derived from milk, whose health benefits are questionable. So, is yogurt truly the health panacea it has been characterized to be? Only a comprehensive examination of both yogurt and dairy research will tell.
What Really Is Yogurt?
How Is Yogurt Made?
Before fermentation, manufacturers pasteurize (heat above 185°F for approximately thirty minutes to kill bacteria) milk as mandated by the Food and Drug Administration. Pasteurization denatures milk’s whey proteins to create a more consistent and smooth yogurt texture. Once cooled, manufacturers introduce the bacterial cultures Streptococcus thermophilus and Lactobacillus bulgaricus and incubate the product around 105°F for approximately five hours. During this time, the bacteria digest lactose, milk’s natural sugar, to create lactic acid (the acid producing yogurt’s tart flavor). As the mixture’s acidity increases, the milk’s casein proteins separate and then reassemble into different arrangements, producing yogurt’s semi-solid consistency. The resultant product grows tarter the longer producers incubate this mixture.
Is Yogurt Different from Milk?
While this creamy treat certainly provides a different flavor, texture, and nutritional profile, its principal ingredient, milk, still remains. At the molecular level, heat and fermentation alter milk’s major components such as lactose (milk’s natural sugar) and casein and whey (milk’s natural proteins), but not sufficiently to warrant yogurt a non-milk product. For example, individuals with milk intolerances, which are generally lactose-attributed, or milk allergies, typically triggered by casein or whey, cannot consume this snack liberally. Yogurt fermentation does partially digest milk’s lactose though, so those who exhibit lactose intolerance may experience slightly less gastric distress eating this milk-derived food as opposed to drinking milk itself. Nevertheless, 65% of the human population displays partial or full lactose intolerance. This reality more than justifies questioning all milk products, including this trendy treat.
Yogurt: Examining the Science
Yogurt represents only a small portion of total dairy consumption. Consequently, studies examining this snack food are far less prevalent than milk or total dairy research, and their reliability is somewhat dubious. Organizations invested in yogurt consumption often oversee study design and publication. Moreover, much research claiming yogurt’s positive health benefits utilizes unequal comparison groups, such as juxtaposing yogurt with another potentially less wholesome ingredient, or emphasizes probiotics, which various supplements and arguably foods more salubrious that yogurt can provide. And some studies unearth that this popular refreshment does not necessarily bolster gastrointestinal or metabolic health at all.
Yogurt and Gut Health
One of yogurt’s biggest claims to fame is its ability to promote gut health. Research suggests, however, that probiotics, rather than yogurt itself, confer the positive effects. A large Nutrition Reviews systematic review concluded that probiotic-rich dairy products improved digestive complaints as well as irritable bowel syndrome symptoms. The American Journal of Clinical Nutrition published a similar study, asserting that substantial evidence exists supporting yogurt’s role in inflammatory bowel disease and colon cancer prevention and treatment, as well as in eradicating gut pathogens such as H. pylori. Still, these reviews are misleading. They make comparisons between probiotic-containing and probiotic-absent dairy products; hence, the research actually examines probiotics, not yogurt. Therefore claiming that yogurt itself creates the observed health benefits, such as disease and cancer prevention, is impossible. Also meriting scrutiny, Danone and the National Dairy Council funded the research. The authors also held Danone advisory board positions or received an honorarium from the National Dairy Council.
Yogurt and Brain Function
Researchers at UCLA fed three groups of women a probiotic yogurt, a probiotic-free yogurt, or nothing at all, respectively. They found that daily probiotic-rich yogurt consumption improved brain function and sensory processing more than eating probiotic-free yogurt and nothing. While the researchers concluded that the dairy snack likely enhances brain health and function, the study results suggest that probiotics actually produce the positive effects. Note as well that Danone, one of the world’s largest yogurt producers, funded the research and employed three of the study’s authors.
Yogurt and Inflammation
Another randomized controlled trial, published in the Journal of Nutrition, erred similarly. Researchers found that pre-meal yogurt intake improved post-meal metabolism and decreased inflammation in healthy women. The scientists divided the women into two groups: one that received a low-fat yogurt and the other a soy-based pudding. The trouble is, however, that the soy-based pudding lacked any probiotics, and soy itself may create additional confounding health effects. This research, similar to the UCLA study, does not delineate whether the probiotics or yogurt itself generated the desirable results. Also notable, the National Dairy Council oversaw and funded this research.
Yogurt and Chronic Diseases
Research examining yogurt and disease is similarly disappointing. A large study investigating cardiovascular disease and mortality published in the European Journal of Epidemiology followed 938,465 participants over a fifteen year period and discovered that fermented dairy product consumption, including yogurt, inconsequentially affected mortality and cardiovascular disease risk. Further, drinking milk was actually linked to a 2% higher mortality rate. Additionally, BMC Public Health evaluated dairy intake and metabolic syndrome risk factors, such as abdominal fat, cholesterol levels, and blood pressure, among 15,909 participants for six years. The researchers did see a link between yogurt consumption and a 15% lower chance of excessive abdominal fat, the only metabolic risk factor that exhibited any significant association with yogurt intake. Therefore, study authors ultimately concluded that the research unearthed no noteworthy relationship between metabolic syndrome and the luscious milky treat.
Overall, the existing research fails to support yogurt’s reputation as a food that confers health benefits. While probiotics themselves likely bolster well-being, many foods besides yogurt contain these advantageous microorganisms. Thoroughly evaluating this dairy product requires digging even deeper and examining milk’s health risks.
Expanding the Investigation: Milk and Dairy Research
Broadening this analysis to include milk and other dairy products besides yogurt furnishes considerably more high-quality studies. Determining a final verdict regarding the familiar dairy item in question requires thorough examination of this research.
Dairy and Cancer
Considering the reality that cow milk’s truly functions to promote a calf’s rapid growth, connections between dairy and cancer are unsurprising. Markedly, research shows that dairy products increase IGF-1 levels in the body. IGF-1, a molecule that stimulates mammalian growth, has been linked to multiple cancers, particularly breast and prostate. Contrary to popular belief, organic dairy does not solve the problem. IGF-1 is generally lower in organic products, but not absent since this molecule occurs naturally in dairy.
A recent longitudinal study, published in the International Journal of Epidemiology, followed over 50,000 women for eight years. Results were striking: drinking only a third a cup of milk per day increased breast cancer risk 30%, while imbibing three cups daily elevated risk as high as 80% relative to women eschewing milk completely.
Other large reviews, such as this 2016 Nutrition Journal study including 778,929 participants, revealed inconclusive results upon examining dairy’s relationship with cancer mortality (the likelihood of dying from cancer after being diagnosed). This review’s authors specifically cite a connection between prostate cancer mortality and dairy, but state mixed conclusions regarding other cancers.
Dairy and Skin Health
A large Nutrients meta-analysis involved 78,529 children and adolescents aged 7-30 years old. Researchers determined that those with the highest dairy consumption, including yogurt and milk, experienced a significantly higher risk of developing acne. Individuals consuming the fewest dairy products exhibited the lowest acne risk.
Dairy affects skin health beyond adolescent acne, potentially provoking wrinkles as well. A Journal of the American College of Nutrition study compared dairy intake, including milk and milk-based products, and hand wrinkling in elderly subjects. Low dairy consumers developed significantly less skin wrinkling than high consumers. Of note—measuring hand rather than face wrinkles allowed the researchers to partially control for facial cosmetic and anti-aging product usage.
Dairy and Bone Health
If there is one most commonly touted dairy-attributed health benefit, it is strong bones. Surprisingly though, existing research cannot support this claim. A particularly large study, published in BMJ, followed more than 100,000 individuals for over twenty years. Regardless of low, moderate, or high milk intake, fracture prevalence was equal. Milk failed to strengthen bones. Beyond bone health, high milk consumption (3+ glasses per day) was even associated with 93 percent greater all-cause mortality compared to <1 glass per day. A JAMA Pediatrics study spanning twenty-two years echoed these findings. Ingesting milk during teenage years did not decrease hip fracture risk later in life. In fact, higher milk consumption among men was weakly associated with increased fracture risk.
Why Is Yogurt Such an Acclaimed Health Food in the First Place?
At First Glance, Yogurt Appears to Offer a Good Nutritional Profile
From a conventional nutrition standpoint, low-sugar or unsweetened yogurt, a low-fat, high-protein food containing few added ingredients, seems superficially healthy. Plus, manufacturers often fortify this snack food with additional calcium and vitamin D, further boosting its nutritional appeal. When placed alongside other convenient hunger busters, such as chips or candy bars, yogurt certainly wins. Further, yogurt’s reputation as nourishing fare means that those who eat it typically follow more highly nutritious diets, containing abundant fiber, micronutrients, and whole foods. Thus, other lifestyle factors may explain any findings that high yogurt consumption correlates with better health.
Today, “probiotics” is a buzzword, but few people fully understand its significance. Probiotics are bacterial organisms that live naturally within the human body, most significantly populating the gut. Healthcare professionals generally profess that probiotic species enhance human health, and scientific studies continue illuminating this phenomenon. Still, much research exploring these microorganisms utilizes either isolated pills or multiple other probiotic-rich foods besides yogurt, the consumption of which may not replicate positive research findings.
Industry Lobbying and Research Monopolies
It is no secret that the dairy industry is a major US superpower. In 2018 alone, dairy interest groups invested more than $7.4 million dollars lobbying governmental legislative bodies. Their efforts were successful, with results including federal support that ultimately boosted dairy sales among SNAP (food stamps) users and initiated new labeling obstacles that frustrate plant-based companies’ liberty to use terms such as “milk,” “yogurt,” and “cheese.”
Funding sources fueling most yogurt research also merit inspection. Major dairy companies, such as Danone, frequently sponsor scientific studies and even give researchers honorary company board positions, as noted earlier. Many will recall the sweeping Activia Yogurt campaign, which the United States Federal Trade Commission cited as deceptive and lacking substantiation for its health claims. Dannon, the Danone Company subsection responsible for Activia, ultimately paid $21 million to resolve additional investigations led by thirty-nine US state attorneys, and more money to reimburse consumers who had filed class action lawsuits.
Probiotic Options that Trump Yogurt
In light of dairy’s drawbacks, it is worthwhile to consider prioritizing the bountiful health-promoting foods that also contain probiotics in lieu of America’s favored dairy snack. The smooth-velvety texture and tangy-sweet taste yogurt offers can make abandoning it a challenge though. Either way, consider a few guidelines to make the most wholesome and informed choices.
Methods to Choose Fermented Foods
- Check whether the product specifically lists a live probiotic count. Foods may be heat-treated following fermentation, thus killing probiotic species and frequently denaturing healthful enzymes and other micronutrients.
- Read the nutrition and ingredient labels. Like most packaged foods, store bought fermented foods may contain excessive added ingredients. Major offenders include processed sugars and sodium. For example, the sugar content that many classic yogurt cups provide rivals that of a candy bar!
- Plant-based yogurt alternatives: These options generally include products derived from coconut, almond, or cashew milks. They also provide bonus nutritive benefits, such as more fiber than their dairy counterparts. Plus, research indicates that coconut’s specific fats increase HDL (good cholesterol) and possess antimicrobial properties.
- Non-yogurt options: Kimchi, kombucha, and sauerkraut are all traditional fermented foods that when prepared properly, provide probiotics as well as other micronutrients. Kimchi and sauerkraut are made from cruciferous vegetables, which naturally release multiple phytochemicals and antioxidants during the fermentation process. These molecules may exhibit protective effects against various cancers and cardiovascular diseases. Regarding kombucha, choose varieties made using green tea for increased antimicrobial activity and higher antioxidant concentrations.
The Bottom Line
Although yogurt may offer some probiotic-attributed nutritional benefits, at its core it is a milk product. Dairy’s largely adverse health profile soils this widely beloved snack food. Fortunately, plentiful alternatives exist for those aiming to consume more probiotic-rich fermented foods or who simply crave yogurt’s creamy texture, and these options also boast plentiful additional nutritive components.