High Quality Protein Promotes Optimal Health

By John W. Freitag
Thursday, November 6, 2008 2:35 PM CST

In May of 2007, 52 leading protein researchers from around the globe convened for a “Protein Summit” that was partially funded by The Beef Checkoff to evaluate and discuss the collective body of evidence of the impact of high-quality protein on optimal health. The emerging research that they reviewed and discussed suggested that high-quality protein plays an increasing role in weight management, muscle development and maintenance and disease prevention, including sarcopenia and diabetes.

With the obesity epidemic growing and baby boomers aging, the benefits of high quality protein have never been more critical. Rethinking the current dietary recommendations for high quality protein and focusing on achieving a level of protein intake to promote optimal health, not to simply meet needs to prevent protein deficiency was the essence of the discussion. In the 2008 May edition of the American Journal of Clinical Nutrition there were six comprehensive reviews representing a compilation of research specific to several chronic diseases and aging that the attendees of the “Protein Summit” thought warranted individual consideration.

Scientific evidence suggests that moderately increasing the proportion of protein in the diet may improve body composition, facilitate weight loss and improve weight maintenance following weight loss.

Additional research has shown that moderately increasing daily protein intake beyond the Recommended Daily Allowance (RDA) enhances muscle development and maintenance and reduces progressive muscle mass with age (sarcopenia). Diets with increased protein and reduced carbohydrates have shown positive effects in treating Type 2 diabetes and reducing risk factors for coronary heart disease. Dietary protein recommendations have traditionally been based on preventing deficiency (i.e., the RDA) as opposed to promoting optimal health, muscle development and maintenance and disease prevention.

Weight management, satiety

“Protein, Weight Management and Satiety” found elevated protein intake, in combination with controlled energy intake, to be an effective and practical weight loss strategy. The research attributed protein’s affect on weight loss to increased satiety (feeling of fullness), increased thermogenesis (metabolism), increased or maintained fat-free body mass and enhanced glycemic control.

Importantly, studies have shown higher-protein diets limit weight regain after weight loss. Research has shown high protein meals increase thermogenesis and energy expenditure and animal protein had a greater effect than plant proteins.

Muscle maintenance

There are compelling data to support the ability of dietary protein to stimulate muscle protein synthesis and reduce muscle loss in aging individuals. However, “Role of Dietary Protein in Sarcopenia of Aging” reported that 15 percent to 38 percent of adult men and 27 percent to 41 percent of adult women have dietary protein intakes below current recommended levels.

This is particular concerning as sarcopenia, or the progressive loss of muscle mass with age, is associated with a three-to-four-fold increased likelihood of disability. The most practical means of increasing skeletal muscle protein for the majority of older adults is to include a moderate serving of high-quality protein in each meal. Recent data suggests a moderate 113 gram (4 ounce) serving of intact protein such as lean meat contains sufficient amino acids to acutely increase muscle protein synthesis by approximately 50 percent without exercise.

High Quality protein also plays a positive role in bone health, heart disease and Type 2 diabetes. I don’t have the space to go into these areas at this time, but the research suggests that dietary proteins are as essential as calcium and vitamin D for bone health and osteoporosis prevention.

The study also reported that diets with increased protein and reduced carbohydrates reduce the risk factors for coronary heart disease by increasing the high density lipoprotein (HDL, the good cholesterol), and reducing blood pressure. It also documents that diets with increased protein and reduced carbohydrates have also been investigated for treatment of type 2 diabetes with positive effects on glycemic regulation.

The research report found protein quality is as important as adequate quantity to achieve optimal health. Animal protein foods such as beef, pork, eggs, fish, poultry and dairy products are essential sources of high-quality protein. When choosing proteins, it’s important to realize that all proteins are not created equal.

High-quality or complete proteins contain all the indispensable amino acids in the appropriate amounts needed by humans. The quality of a protein is also regulated to its digestibility, and animal proteins are highly digestible. For example, meat and cheese have a digestibility of 95 percent, whereas cooked split peas are about 70 percent digestible.

Beef, milk, yogurt, pork, eggs, cheese, fish and poultry are complete high quality proteins that are highly digestible and contain all the essential amino acids your body needs to build and maintain muscle mass and manage weight, sarcopenia, osteoporosis/osteopenia, cardiovascular disease and Type 2 diabetes. These animal proteins are nutrient powerhouses, providing the essential vitamins and minerals your body needs to be healthy.

Protein has a significant role in achieving and maintaining optimal health. Future dietary guidance should go beyond simply meeting needs to prevent protein deficiency and should focus on recommending a level of protein intake that promotes optimal health.

What is the optimal level of protein intake? Although the optimal level of protein intake is still undetermined, researches have concluded it is greater than the RDA and in fact, intake can increase to double the current RDA without adverse responses.

When scientifically determining the optimal level of protein, parameters related to muscle mass, strength and metabolic function should be considered and when it is, beef checkoff dollars will have helped provide some of the information necessary to make those decisions. BEEF. IT’S WHAT’S FOR DINNER!

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