Drinking Organic Milk Healthier for Heart Than Drinking Regular Milk, Study Says
Omega-3 fatty acids, believed to be beneficial for heart health, are found in higher levels in organic milk than in regular milk, according to a study published on Dec. 9, 2013 in the peer-reviewed online journal PLOS One.
The study’s lead author, Charles Benbrook, PhD, a program leader at Washington State University’s Center for Sustaining Agriculture and Natural Resources (CSANR), stated that consuming whole (full-fat) organic dairy products “will certainly lessen the risk factor for cardiovascular disease.”
Organic milk was found to have lower levels of omega-6 fatty acids and higher levels of omega-3 fatty acids than regular milk. According to the authors, a high ratio of omega-6 fatty acids to omega-3 fatty acids has been linked to heart disease and problems related to the health of the brain, eyes, and other tissues. Conventional milk was found to have an average omega-6 to omega-3 ratio of 5.8, whereas the ratio in organic milk was found to be 2.3. The organic milk contained 62% more omega-3 fatty acids than the regular milk and 25% less omega-6 fatty acids.
To gain the maximum benefit from the omega-3 fatty acids in organic milk, Benbrook said that whole milk would be preferable to low-fat or skim milk, since reducing the fat also reduces the omega-3s. Health authorities have often warned against consuming too much whole milk due to its high saturated fat content (the American Heart Association, for example, recommends replacing whole milk with fat-free or low-fat milk), but Benbrook said that “Consumers are going to get the full measure of this benefit in organic milk if they buy whole milk. [The study] provides consumers with some pretty powerful evidence that choosing full-fat dairy products is going to help bring about a greater degree of balance” in their omega-6 to omega-3 ratio.
The reason for organic milk’s higher omega-3 content can be traced to the composition of the cows’ diet, the study reported. Cows producing milk for the US National Organic Program (NOP) are required to consume at least 30% of their daily “dry matter intake” (DMI) from pasture grasses and legumes, which have a high omega-3 content. Cows producing milk for nonorganic dairies eat mostly corn, which is low in omega-3s and high in omega-6s.
The 18-month, countrywide study was partially funded by organic dairy cooperative Organic Valley, but the organization had no role in the design of the study or its analysis, according to National Public Radio. Joseph Hibbeln, MD, a nutrition neuroscientist at the National Institutes of Health, said “I think this is a very good piece of work.”
However, Walter Willett, Chair of the Department of Nutrition at the Harvard School of Public Health, was less convinced of the study’s conclusions. Willett said the results were based on a “false assumption” that omega-6 fatty acids were detrimental, and that omega-6s were actually linked with a lower risk of heart disease. Willett also questioned the conventional wisdom that milk is an essential part of a healthy diet. “We don’t know all the long-term consequences, so I think the best strategy given current knowledge is to keep intake low to moderate (as in the Mediterranean diet) if it is consumed at all,” Willett told the New York Times in an email, pointing out that adults in many countries consume little to no milk.
Allison Aubrey and Melissa Block, “Study: Organic Milk Contains More Healthy Fatty Acids,” npr. org, Dec. 10, 2013
Charles M. Benbrook, et al., “Organic Production Enhances Milk Nutritional Quality by Shifting Fatty Acid Composition: A United States–Wide, 18-Month Study,” plosone.org, Dec. 9, 2013
Kenneth Chang, “More Helpful Fatty Acids Found in Organic Milk,” nytimes.com, Dec. 9, 2013
Bahar Gholipour, “Healthier Fatty Acids Found in Organic Milk,” livescience.com, Dec. 9, 2013
Mary MacVean, “Organic Whole Milk Provides Best Heart-Health Benefits, Study Says,” latimes.com, Dec. 10, 2013
“Milk Products,” American Heart Association website, Jan. 28, 2013