By Dr. Gabe Merkin at http://www.drmirkin.com/
---------------------------------------------
A new study shows that yogurt, cheese and other fermented dairy products may help to prevent heart attacks (Journal of Agricultural and Food Chemistry, April 2015;63 (10):2830-9). People who ate a lot of cheese had very high levels of butyrate in their stool and urine and much lower levels of LDL (bad) cholesterol. This means that the fermented dairy products are being converted by bacteria in the intestines to butyrate that prevents food from forming the bad LDL cholesterol that is associated with increased heart attack risk. The authors believe that they have shown that fermented dairy products encourage the growth of healthful intestinal bacteria that may help to prevent heart attacks. Another study of 27,000 people, ages 45 to 74, shows that eating cheese and yogurt lowers risk of type-2 diabetes by 25%, while meat increases risk (Am J Clin Nutr, April 2015).
How can cheese and yogurt be beneficial when other studies show that milk is associated with increased risk for heart attacks? Yogurt, cheese and other fermented milk products have not been associated with increased risk for diabetes, heart attacks or bone loss (Am J Clin Nutr, 2014;99:1235S-42S), probably because they have very low levels of lactose and galactose (J Hum Nutr Diet, 2009;22:400-8). Fermenting milk breaks down the galactose so that almost no galactose is left in cheese or yogurt. Indeed, several studies have shown that cheese reduces blood levels of the "bad" LDL cholesterol when compared to butter with the same fat content.
Why Milk May Increase Risk for Diabetes and Heart Attacks
We know that D-galactose, a sugar found in milk, causes the same oxidative damage and chronic inflammation that is associated with diabetes, heart attacks, certain cancers and bone loss (Biogerontology, 2004;5:317-25). The people who drank milk had increased urine levels of 8-iso-PGF2a (a biomarker of oxidative stress) and serum interleukin 6 (a major inflammatory biomarker). Chronic exposure of mice, rats, and Drosophila flies to galactose caused their cells to develop signs associated with aging: shorter telomeres and DNA damage Journal of Neuroscience Research, 2006;84(3):647-654). Their cells had signs of aging: shorter telomeres and DNA damage.
A study from Sweden followed more than 60,000 women (aged 39-74) for 22 years and 45,000 men (aged 45-79) for 13 years (British Medical Journal, October 28, 2014; 349:g6015) and found that:
* Women who drank three or more glasses of milk daily had twice the death rate of those who drank less than a glass daily and also suffered increased risk for total body bone fractures and hip fractures.
* Men who drank three or more glasses daily had a ten percent increase in death rate over those who drank less than a glass daily.
* For every glass of milk, the death rate increased 15 percent in women and three percent in men. Neither the men or the women received any protection from fractures by drinking milk.
Another study showed that reducing milk consumption is associated with reduced heart attacks and heart attack deaths (Journal of Nutritional & Environmental Medicine, Sept 1, 2002).
Cheese May Explain the "French Paradox"
For more than 50 years the medical community has struggled to explain the "French Paradox" -- why people in southern France have a low rate of heart attacks, even though they eat a high-fat diet. Researchers tried to explain the apparent protection with the fact that these people drank a lot of wine. Several recent studies have questioned whether alcohol in any form offers any protection from heart attacks. The studies that show an association between drinking small amounts of alcohol and reduced risk for heart attacks all include former drinkers in the group of nondrinkers (BMJ, 2015 Feb 10;350:h384). Former drinkers include people who were forced to give up drinking because they have had heart attacks, strokes, liver disease, alcoholism, depression and other life-shortening and heart-attack provoking diseases. This means that the non-drinker groups were full of people who were already sick, so no really good data show that drinking alcohol at any level prevents heart attacks. Taking more than two drinks a day and binge drinking have both been shown to increase risk for heart attacks and heart failure (Journal of Cardiopulmonary Rehabilitation & Prevention, May/June 2014;34(3):159-171). I speculate that instead of wine, cheese may be the explanation for the "French Paradox". The traditional French diet includes plenty of cheese and very little milk.
All Sugared Drinks Can Harm
Sugared drinks, including milk, are associated with increased risk for obesity, diabetes, inflammatory-related pain, heart attacks, certain cancers, and premature death. Eating or drinking sugar can cause a high rise in blood sugar that can damage all of the cells in your body. Sugar in drinks causes a much higher rise in blood sugar levels than sugar in food. When food reaches your stomach, the pyloric sphincter muscle at the end of the stomach closes and only a liquid soup is allowed to pass into your intestines. Beverages pass very quickly into your intestines and then into your bloodstream, while solid foods stay a long time in your stomach. An 8-ounce glass of two percent low-fat milk contains:
* 122 calories, more than an 8-ounce glass of soda,
* more than three teaspoons of sugar, and
* more than the current daily recommendations for sugar for children.
Chocolate milk and other milk-based beverages often have even more sugar added to make them taste better.
Yogurt and other fermented dairy products do not need to be classified as sugared drinks because the fermentation process breaks down galactose (the main sugar in the milk from which they are made). However, check the labels to make sure that other sugars have not been added.
What These Studies Mean for You
These studies do not prove that milk causes diabetes or heart attacks, or that cheese and yogurt help to prevent them. However, they raise questions that suggest that you should limit the amount of milk that you drink, and that cheese and yogurt may be beneficial.
