Dairy Products benefit and risks, does milk increase mucus production?
July 6 2016 by
Ray Sahelian, M.D.

Dairy products are normally defined as foodstuffs produced from milk. Milk used for processing dairy products generally comes from cows, but at times from other mammals such as goats, sheep, or water buffalo. Some people shun dairy products due to misconcieved ideas about its adverse health benefits, but the Mediterranean diet does include some amounts of such foods and is considered a healthy diet.

Milk, dairy products, and excess mucus production
Many people believe that consumption of milk or dairy products increases mucus production in the lungs. At this time, in my opinion, only a small portion of the population, perhaps those who have excessive respiratory tract mucus production, find that many of their symptoms, including asthma, improve on a dairy elimination diet. However I will search for more studies on this topic.

Cow's milk protein allergy may occur more often among U.S. infants than the pediatric literature suggests.

Benefit of dairy products
Almost all milk fat is closed inside fat globules possessing envelope of phospholipids, glycosphingolipids, cholesterols and proteins. Phospholipids of milk are composed of phosphatidylcholine (lecithin), phosphatidylethanolamine (kefalin), sphingomyelin, also phosphatidylinositol, phosphatidylserine and lizophosphatidylcholine (lizolecithin) and make 30% of the milk fat globule membrane. Phospholipids regulate brain activity, improve memory and resistance to stress, reduce depression risk, Alzheimer and Parkinson diseases. Due to participation in molecular transport, they influence cell growth and development, speed up organism regeneration after great physical effort. They limit cholesterol absorption from gastrointestinal tract, are effective in liver therapy (steatosis, alcohol intoxication). Moreover, they are inhibitors of proinflammation factors, pathogens of alimentary canal and cancers (e.g. of colon and adenoma). Alkiloglycerphospholipids - unique component of milk fat - stimulate immune system and protect tissues against toxic action of hydroxyl radicals that is generated during radiotherapy.

Dairy Sci Technol. 2014. Health-promoting properties of bioactive peptides derived from milk proteins in infant food: a review. Milk proteins have attracted extensive interest in terms of their bioavailability following ingestion. Enzymatic digestion of dairy products generates numerous peptides with various biological activities. Both human milk and infant formulas based on cow's milk are potential sources of bioactive peptides. This review aims to present current knowledge on the formation and fate of bioactive peptides from milk feeds intended for infants. Emphasis is placed on the source of the bioactive peptides with the nutritional impact of human milk and cow milk-based formulas on infant health being critically discussed from that perspective. Furthermore, the effect of processing and in vitro or in vivo digestion on the release and availability of peptides with bioactive sequences is evaluated. Considerable differences with respect to bioavailability and metabolic effects between the biologically active fragments generated following ingestion of human milk and infant formulas are documented. Peptides from milk protein of bovine origin could be a valuable supplement to human milk as multiple health-promoting properties are attributed to peptide fractions identified in standard cow milk-based infant formulas.

Diabetes or blood sugar control
Dairy Foods and Dairy Proteins in the Management of Type 2 Diabetes: A Systematic Review of the Clinical Evidence. Type 2 diabetes mellitus (T2DM) is a growing public health concern affecting hundreds of millions of people worldwide and costing the global economy hundreds of billions of dollars annually. This chronic disease damages the blood vessels and increases the risk of other cardiometabolic ailments such as cardiovascular disease and stroke. If left unmanaged it can also lead to nerve damage, kidney damage, blindness, and amputation. For the most part, many of these symptoms can be prevented or reduced through simple dietary modifications and proper nutrition. Therefore, identifying relatively inexpensive and easily implementable dietary modifications for the prevention and management of T2DM is of considerable value to human health and healthcare modalities around the globe. Protein-rich dairy products have consistently been shown in epidemiologic studies to be beneficial for reducing the risk of developing type 2 diabetes mellitus. Advanced Nutrition, 2015.

Benefit with less risk
Buy low-fat varieties of milk, and make sure it is organic.
Eat yogurt as a milk alternative. It offers plenty of calcium and protein and probiotics or active cultures.
Nutrient-rich cheeses can make great additions to your snacks and meals.
Reduce your intake of butter, sour cream and other regular spreads which tend to be lower in nutrients and higher in fat.

Fermented milk products
Am J Infect Control. 2013. Decreased duration of acute upper respiratory tract infections with daily intake of fermented milk: A multicenter, double-blinded, randomized comparative study in users of day care facilities for the elderly population.

Are kids drinking too much milk?
Even though dairy products have some benefits, too much is a cause for concern, "This recommendation to drink three cups a day of milk – it’s perhaps the most prevailing advice given to the American public about diet in the last half century,” says David Ludwig, who wrote the editorial published online in 2013 in the journal JAMA Pediatrics. Ludwig is the director of the New Balance Foundation Obesity Prevention Center at Boston Children’s Hospital. “As a result, Americans are consuming billions of gallons of milk a year, presumably under the assumption that their bones would crumble without them.”

Heart health
Dairy foods are a major source of saturated fat in the diet, which has been associated with heart disease. Dr. Eva Warensjo of Uppsala University measured blood levels of two biomarkers of milk fat in 444 heart attack patients and 556 healthy controls. The substances, pentadecanoic acid and heptadecanoic acid, indicate how much dairy fat a person has been eating. Dr. Eva Warensjo found that people with the highest levels of milk fat biomarkers, suggesting they consumed the most dairy fat, were actually at lower risk of heart attack. Dairy foods contain a number of potentially beneficial substances, such as calcium, vitamin D, and potassium. The study was funded in part by the National Dairy Council / Dairy Management Inc., a trade group for the US dairy industry. Dr. Eva Warensjo has been a paid speaker for the Swedish Dairy Association and the International Dairy Federation. American Journal of Clinical Nutrition, 2010.
    Comments: I know many people who shun dairy products but I think small amounts in the diet are acceptable and may provide health benefits.

Diabetes
Q. I recently attended a seminar conducted by leading doctors and nutritionists and also a video talk by Dr. Neal Barnard, where I learnt that milk and milk products and animal foods are harmful for diabetics (insulin resistance) and general health. I cross checked with another dietitian here in the city and they disagreed with this fact, and went on to tell me that milk and milk products are essential source of protein and calcium and that they are good especially for diabetics because they need to be on proteins and low on carbs. I having learnt the same thing in my study books having studied nutrition but it just contradicts the latest findings after attending the seminar. Could you please help me understand and have the correct knowledge of the query above and its effects and facts and proofs of your opinion?
   A. The key is moderation. These are of benefit as long as they are consumed in moderation.

Dairy and prostate cancer
Dr. Giovannucci is a professor in the departments of Nutrition and Epidemiology at the Harvard School of Public Health. He was awarded the 2005 DeWitt-Goodman Award for excellence in cancer research from the American Association for Cancer Research. At the symposium, Dr. Giovannucci spoke about evidence linking dairy products with risk for aggressive prostate cancer. Dr. Giovannucci’s research in the Harvard Health Professionals Follow-Up Study, which followed more than 47,000 men for 16 years, found a twofold increased risk for high-grade prostate cancer in men with high calcium intake, mainly from dairy products, compared with those with low calcium intake. Some researchers believed the high-fat dairy products were to blame for this increased risk, but new evidence shows that low-fat dairy products might increase the risk for prostate cancer even more than high-fat products.

Am J Clin Nutr. 2015. Dairy products, calcium, and prostate cancer risk: a systematic review and meta-analysis of cohort studies. High intakes of dairy products, milk, low-fat milk, cheese, and total, dietary, and dairy calcium, but not supplemental or nondairy calcium, may increase total prostate cancer risk. The diverging results for types of dairy products and sources of calcium suggest that other components of dairy rather than fat and calcium may increase prostate cancer risk. 

Dairy and weight loss
Adults who favor full-fat dairy gain less weight over time. Swedish researchers found that among more than 19,000 middle-aged women, those who had at least one serving of whole milk or cheese each day put on less weight over the next 9 years than women who consumed these foods less often. The potential role of dairy foods in weight control won much attention after some recent studies suggested that milk, yogurt and other dairy foods might help regulate body fat. However, the picture is far from clear, as other research has failed to find that dairy products benefit the waistline. The new findings, published in the American Journal of Clinical Nutrition, are unlikely to clear up the confusion. For one thing, only whole milk, and not low-fat milk, seemed to offer protection against weight gain. For another, the benefit was seen only among women who were normal-weight at the start of the study. American Journal of Clinical Nutrition, 2006.

Eur J Clin Nutr. 2013. Effect of a dairy- and calcium-rich diet on weight loss and appetite during energy restriction in overweight and obese adults: a randomized trial. A diet rich in dairy and calcium (Ca) has been variably associated with improvements in body composition and decreased risk of type 2 diabetes. Our objective was to determine if a dietary pattern high in dairy and Ca improves weight loss and subjective appetite to a greater extent than a low dairy/Ca diet during energy restriction in overweight and obese adults with metabolic syndrome. A total of 49 participants were randomized to one of two treatment groups: Control (low dairy, ≈ 700 mg/day Ca, -500 kcal/day) or Dairy/Ca (high dairy, ≈ 1400 mg/day Ca, -500 kcal/day) for 12 weeks. Body composition, subjective ratings of appetite, food intake, plasma satiety hormones, glycemic response and inflammatory cytokines were measured. Control (-2.2 ± 0.5 kg) and Dairy/Ca (-3.3 ± 0.6 kg) had similar weight loss. Based on self-reported energy intake, the percentage of expected weight loss achieved was higher with Dairy/Ca (82.1 ± 19.4%) than Control (32.2 ± 7.7%; P=0.03). Subjects in the Dairy/Ca group reported feeling more satisfied (P=0.01) and had lower dietary fat intake over 12 weeks compared with Control. Compared with Control, Dairy/Ca had higher plasma levels of peptide tyrosine tyrosine (PYY, P=0.01) during the meal tolerance test at week 12. Monocyte chemoattractant protein-1 was reduced at 30 min with Dairy/Ca compared with Control (P=0.04). In conclusion, a dairy- and Ca-rich diet was not associated with greater weight loss than control. Modest increases in plasma PYY concentrations with increased dairy/Ca intake, however, may contribute to enhanced sensations of satisfaction and reduced dietary fat intake during energy restriction.

Advertisement
U.S. dairy producers will have to stop promoting the idea that drinking more milk spurs weight loss, the Federal Trade Commission told a physician's advocacy group in May 2007. Calling it a "victory for consumers," the Physicians for Responsible Medicine said two national dairy advertising campaigns overseen by the U.S. Department of Agriculture will stop claiming that dairy products cause weight loss because "such claims are not supported by existing scientific research." Greg Miller, senior vice president for the National Dairy Council, said the industry stands "behind our weight loss messages and the science supporting those messages." "Milk and cheese are more likely to pack on pounds than help people slim down," said Dan Kinburn, Physicians for Responsible Medicine general counsel. "This case calls into question other advertising claims made by the industry, especially the notion that milk builds strong bones. Evidence shows it does nothing of the kind."

Farm milk versus pasteurized milk
Drinking farm milk appears to reduce the risk of asthma and allergy. Children drinking unpasteurized farm milk and eating other farm-related dairy products show the same level of protection against asthma and allergies, regardless of whether they are living on a farm or not. The benefits are greatest when consumption of farm milk begins during the first year of life. However, consumption of raw or unboiled milk is not recommended since raw milk may contain (disease-causing microbes) such as salmonella or Escherichia coli. Farm milk consumption is tied to reduced risks of asthma and allergy. Further studies are needed to identify the properties of farm milk that confer protection against asthma and allergy. Clinical and Experimental Allergy, 2007.

Raw milk risk
2007 - A survey of unpasteurized milk samples drawn from dairy farms across Wisconsin found a significant presence of Coxiella burnetii and Listeria monocytogenes, two different types of bacteria that can cause serious infection and even death in some people. These findings have particular relevance for consumers seeking raw milk products.