In 1977 an advertising campaign was launched featuring the first American commercials produced in the Soviet Union. The ads depicted older individuals from Soviet Georgia, several of whom were over 100 years old, eating yogurt. One scene showed an 89-year-old man eating yogurt. Beside him was his 114-year-old mother who was looking quite pleased with his dietary choice. The obvious implication is that yogurt was responsible for the spectacular longevity in these Georgians. The ads were quite memorable and very successful, launching a little known yogurt company to prominence and starting the yogurt consumption craze in the US.
Dairy products are a good source for essential vitamins (A and B12), minerals (such as calcium and potassium) and high quality protein. On the other hand, dairy products are a leading source of saturated fat, cholesterol and sodium, all of which are detrimental to heart health. The American Heart Association/American College of Cardiology, the DASH (Dietary Approach to Stop Hypertension) Diet and Mediterranean Diet all recommend avoiding full fat dairy products and substituting fat free or low fat sources of dairy. What is the recent data on milk, yogurt and cheese and heart disease?
The PURE study evaluated 136,000 people from 21 countries and five continents. The study showed that those who consumed 2 or more dairy products (milk, yogurt and cheese) per day had a lower risk for dying and lower risk for cardiovascular death than those who did not eat dairy. Even in those who consumed only high fat dairy, there was a lower risk for dying, which seemingly contradicts all of the previous dietary recommendations. Another large analysis of several dairy trials confirmed these findings concluding that high fat milk did not increase heart disease or mortality. So it seems that dairy fat may not increase the risk for heart disease and death. The lesson from theses studies is the importance of evaluating dairy products not just on their fat content, but on their total nutritional value.
What about yogurt, can it prevent heart disease? One study evaluated 1900 middle-aged men without heart disease and followed them for 20 years. The study found that consuming yogurt cut the risk for heart attack in these men. It has also been shown that higher intake of yogurt decreases the risk for type 2 diabetes. In choosing a yogurt, it is important to choose a sugar free or low sugar product as many yogurts have added sugar.
Next up is cheese. Can eating a small amount of cheese every day benefit heart health? A major study of 200,000 participants sought to answer this question. The enrollees were monitored for 10 years and most did not have heart disease. The study showed that eating around 1.4 ounces of cheese every day lowered the risk for heart disease, heart deaths and stroke. However, not all cheeses are equal. For example, feta cheese is a low fat low calorie cheese favored in the Mediterranean diet. One ounce of feta is lower in fat (6 grams) and calories (74) than one ounce of cheddar or parmesan cheese (110 calories and 7 grams of fat). Skim mozzarella is another low calorie cheese (72). High calorie cheeses include gouda (101), swiss (111) provolone (98) and brie (95).
One thing to keep in mind is that the research supplying all of this data is not the strongest. Many of the studies are observational (they can observe an effect but not prove cause and effect) and many are sponsored by the dairy industry (so bias cannot be excluded). Despite this, a couple of things are clear. One is that eating a yogurt a day will not guarantee that you will live to one hundred. The other is that, in general, dairy is quite healthy. Dairy products provide significant nutritional value and may reduce the risk for cardiovascular disease and dying. It seems prudent to follow the guidelines of the Mediterranean diet and consume two servings of low fat dairy per day. This should come mostly from low fat or fat free milk, low fat yogurt and cheese. Low fat cheese should be limited to 3 servings per week, but choose your cheese carefully!
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