Casein, along with other sources of lean and low-fat protein, can be a truly valuable aid for weight loss or muscle gain. The notion of “more is better” does not apply to casein supplements, however. Getting a little bit of extra protein might be nutritious and beneficial, but too much casein can put your health at serious risk.
The Talk About Curing Autism group describes casein as the protein found in all mammals’ milk. In addition to being a primary feature of milk, casein is also found in cream, sour cream, ice cream, yogurt, butter, cheese and some deli meats. You can also buy casein protein separately, in a powder or mix form, as a dietary supplement.
Regardless of whether you get most of your protein from casein or other sources, MayoClinic.com recommends that you consume no more than 35 percent of your daily calories from the nutrient, which equates to a maximum of 175 g per day for someone who follows a 2,000-calorie diet. Getting more protein than that, according to the American Council on Exercise scientist Cedric Bryant, might result in calcium loss that can increase the risk of osteoporosis. Katherine Zeratsky, dietitian for MayoClinic.com, also notes that too much protein can raise the risk of diverticulitis, liver and kidney problems, cancer or heart disease.
If you’re getting too much casein, you might experience several symptoms. One is dehydration, which Bryant notes is a common side effect of excess protein intake. Another is weight gain, whether intentional or unintentional effect because extra calories from casein will show up as fat or muscle gain on your body. If you’re lactose intolerant -- allergic to dairy -- or restricting carbohydrates in your diet, you might also experience constipation or digestive discomfort. The last symptom is particularly probable if you’re consuming casein at the expense of high-fiber foods, which tend to aid healthy and efficient digestion.
Casein protein can have notable advantages, so it’s not necessary to exclude it from your diet altogether if you feel it might further your individual health goals. However, as the President’s Council on Physical Fitness and Sports notes, most healthy adults get enough protein through the foods they eat to satisfy nutritional requirements, and they do not need to resort to protein supplements for that reason. Before you begin taking regular casein supplements or make any significant changes to the balance of your diet, get approval from your physician or a registered dietitian.