Milk - The Nutrition Source

Milk is the liquid produced by the mammary glands of mammals, including humans. Breast milk is the preferred food for infants, as it is well-tolerated while their digestive tracts develop and mature. Dairy milk may be introduced at later ages if tolerated well. Although dairy milk may come from any mammal, cows, goats, buffalo, and sheep are common producers. This section will focus on dairy milk from cows, and briefly discuss non-dairy plant milk alternatives. Whole cow’s milk contains about 87% water. The remaining 13% contains protein, fat, carbohydrates, vitamins, and minerals. Processing techniques remove fat to produce lower fat varieties: “reduced fat” contains 2% milkfat, “lowfat” contains 1% milkfat, and “nonfat” or “skim” has virtually no milkfat. Cows are often pregnant while they are milked, so dairy milk contains hormones like insulin-like growth factor-1 (IGF-1), estrogens, and progestins. Some cows are given additional hormones to increase milk production. Source Of Calcium Protein Vitamin B2 (riboflavin) Vitamin B12 Potassium Phosphorus Vitamin A and Vitamin D (added during processing) Milk and Health The Dietary Guidelines for Americans recommends including three 8-ounce servings of milk daily (or equal portions of other dairy foods like cheese or yogurt), which is justified to increase calcium intake and reduce the risk of osteoporosis and fractures. Marketing efforts such as the iconic “Got Milk?” campaign with celebrities donning milk mustaches spread this message as well. However, research has not shown a consistent benefit on bone health with high intakes of milk, and furthermore has suggested potential harm with certain conditions like prostate cancer. [1] Research on milk often produces contrary findings. Some reasons may be the wide range of different nutritional qualities in milk and how milk intake is measured, as seen in the following factors: The amount of milk that is considered a “high” or “low” intake can vary among populations studied. For example, people from Japan tend to drink about less than half of the milk consumed in Western countries [2] Are different classifications of milk included, or just one type? Whole, reduced-fat, fat-free, or organic? The composition of milk (fat, protein from varying amino acids) may differ depending on the breed and feed of the cows. Are other factors in the diet considered, such as if the participants are eating plenty of fruits and vegetables, or large amounts of processed meat or refined carbohydrates, which can confound the true health effects of milk? Different forms of dairy foods, such as cheese, or yogurt, may have health effects different than milk. Cardiovascular disease Bone health Weight Diabetes Cancer Bottom line: The health benefits of milk appear to be stronger for fermented types like yogurt, which play a role in the gut microbiome. Milk possesses several individual nutrients that can affect blood pressure and bone health, but some of their health-promoting effects may be weakened by whole milk’s high saturated fat content. Although popular media articles have speculated that whole milk is not less healthful than skim milk, research has not supported this statement in regards to diabetes and heart disease, and a high intake of any type of milk can lead to weight gain due to the extra calories. What is A2 milk? Is raw milk safe to drink? For Your Health and the Planet’s Health icon of a globe with a fork and spoon on the sides of itThe production of dairy foods places considerable demand on land, water, and other natural resources, and dairy-producing ruminant animals like cattle, sheep, and goats generate methane—a powerful greenhouse gas. In identifying a dietary pattern both healthy for people and sustainable for the planet, the “planetary health diet” sets the target for dairy foods at 250 grams per day (with a range of 0 to 500 grams per day), which is about one (8-ounce) cup of milk.