The Dairy Connection
Have you seen the advertisements promoting dairy foods to lose weight? Did they make you curious? Did you wonder what the “catch” was and whether or not it is a marketing gimmick? You are not alone! I have to admit I wondered the same thing. I tried looking for the fine print on the television with a disclaimer like you see on many supplement commercials, which usually refer to following a low calorie diet and exercise plan in addition to taking a supplement.
So, I began reviewing the research behind the advertising claims and found great news about calcium, dairy and weight loss. The relationship between adequate calcium intake and osteoporosis has been well established for decades, but calcium and/or dairy products reduce the risks for many other diseases including Hypertension (High Blood Pressure), Coronary Heart Disease and Stroke, Cancer, Dental Health, and now Obesity and Overweight.
Osteoporosis
Osteoporosis is a weakening of the bones. Bone health is vital to everyone and an adequate intake of calcium and/or calcium rich foods is needed to build strong bones. Research has shown that many of the components of dairy products (not just calcium) are very important to bone health. Phosphorus, Vitamin D (in fortified products), Protein and Magnesium all play a role in maximizing peak bone mass. We all reach our peak bone mass around the age of 30, and after that it decreases. As we get older, calcium becomes the single most important nutrient for building bone mass and preventing osteoporosis, according to the National Institute of Health.
Studies have shown that children that do not get enough calcium have lower bone mineral density and are at greater risk for fractures. So it is important to get enough of these nutrients at all ages. There is support for better bone health from actual dairy products instead of just calcium supplementation in research studies.
Hypertension, Coronary Artery Disease and Stroke
Numerous agencies collaborated on an important blood pressure-reducing study, called DASH – the Dietary Approaches to Stop Hypertension. The DASH Diet is a low-fat, calcium rich diet consisting of fresh fruits and vegetables, whole grains, lean meats and low fat dairy foods. Calcium, Potassium and Magnesium are nutrients that have been shown to reduce blood pressure and are all found in dairy products. Researchers suggest that Americans could lower their blood pressure by following the DASH diet plan just as well as with medication.
Lowering blood pressure also plays a role in heart disease, and the DASH diet can also help lower LDL cholesterol, and homocysteine levels. Homocysteine is an amino acid that has been linked to heart disease and stroke. Experts suggest that following the DASH diet could lower atherosclerosis (hardening of the arteries) heart disease and stroke through all of the above mechanisms.
Cancer
Increasing your intake of dairy foods and/or calcium may lower your risk for certain cancers. Colon cancer has been studied and it was discovered that adding dairy products and/or calcium supplementation reduced the growth of abnormal cells that occurs before cancer starts. There may also be a link between dairy products and a reduced risk of breast cancer in women.
Obesity and Overweight – Diabetes and Insulin Resistance
Can eating dairy foods really help you lose weight? The evidence is showing that this is the case. Dairy foods are often thought of as high fat foods to avoid, especially cheese. How can this make sense? There are actually some biochemical processes that occur in our bodies that affect the way our food is metabolized, how fat is burned and stored when dairy products and/or calcium is included.
Early research suggested a connection between dietary calcium and body weight, especially body fat regulation. Researchers from the National Institutes of Health (NIH) published a review of previous research to support the notion that dietary calcium plays a role in weight loss and/or maintenance. Highlights of the review findings include:
• Americans with the lowest calcium intakes tended to have the highest body weights
• An inverse association between calcium intake and body weight
• An inverse association between the relative risk of obesity and calcium intake
• Weight change negatively related to calcium intake
An inverse relationship describes an opposite relationship, so a high calcium intake was associated with a lower body weight and lower risk of obesity.
For many of you, these highlights alone may be a good enough reason to start adding calcium and/or dairy products to your diet, but some of you may be wondering how it works. There is a great deal of science and biochemistry behind these statements!
Intracellular Calcium is the Calcium that is present within a cell which is different than the calcium that is in blood. Calcium is an ion, and the balance of intracellular and extracellular calcium is complex. Calcium regulates numerous enzyme systems, including those associated with obesity, hypertension and insulin resistance. Higher concentrations of intracellular calcium stimulate fat production (lipogenesis), suppress fat breakdown (lipolysis) and increase lipid (fat) accumulation. Obese individuals have higher concentrations of intracellular Calcium than non-obese individuals of the same age and sex.
So, circumstances that trigger a higher concentration of intercellular calcium will in turn lead to more fat production, less fat breakdown and more fat accumulation. One circumstance that can cause a higher concentration of intracellular calcium (via a long cascade of hormones) is a low level of dietary calcium.
Another mechanism that was reviewed was the relationship between dietary calcium and dietary fat absorption. Calcium fortification has been shown to increase the percentage of dietary saturated fat that is excreted, which also resulted in improved cholesterol levels.
Michael Zemel, from the University of Tennessee, has conducted numerous studies looking at the relationship of calcium and dairy products and body weight. His recent research is the basis for most of the commercials and promotion of dairy products for losing weight.
A 2003 study supports the aforementioned processes, and looks at the difference between supplemental calcium, calcium fortified products and actual dairy products. It appears that more significant results are seen with dairy products, which may be attributed to the whey fraction of milk and/or the presence of protein in dairy foods.
A 12-week study on obese individuals eating 500 fewer calories per day were split in two groups; one group with a low Calcium intake (400–500 mg/day) or one group eating three servings of low-fat yogurt as part of their reduced calorie diet (1100 mg/day). Both groups lost weight; however the yogurt group lost more fat, especially around the mid-section (trunk).
The most recent study (April 2004) was similar, but was a 24-week study and the participants were divided into three groups. All were on reduced calorie diets (500 calorie/day deficit). Group 1 was a standard diet (400-500 mg Calcium/day), Group 2 was a High Calcium Diet (standard diet plus a calcium supplement; 400-500 mg/day + 800 mg Calcium supplement), and Group 3 was a High-dairy diet (1200-1300 mg calcium/day). Participants were able to choose from fat-free, low-fat and regular fat dairy foods.
All of the groups lost weight, however significantly more weight was lost on the high-dairy diet. Group 1 lost 6.4% of their body weight, Group 2 lost 8.6% of their body weight and Group 3 lost 10.9% of their body weight. Fat loss and mid-section (trunk) fat loss were also higher for the High Calcium and High Dairy Diets, with the greatest losses in the High-dairy group.
In other words, if you weighed 200 pounds you would have lost 12.8 pounds in Group 1, 17.2 pounds in Group 2, and 21.8 pounds in Group 3. The rate of weight loss ranges from .5 lb/week to about 1 pound per week in Group 3. (Aside from the look at how dairy and calcium play a role, you can see how much weight you may lose by only changing your diet. Just think of how much better your results can be if you also add exercise!) Although the research clearly supports dairy products preferentially to calcium supplementation or fortification, adequate calcium, even as a supplement, is still better than too little. Most Americans do not get enough calcium, even at young ages, and as you can see there are numerous ways that calcium prevents chronic diseases. Three servings of dairy products per day are recommended, or 1000-1300 mg/day.
