Nutrition Bytes

Adequate protein intake is an important concern for many athletes who are undergoing strength-training programs. Many athletes choose to take a protein supplement, such as whey protein, in order to help them build lean muscle mass more efficiently. But the benefit of very high levels of dietary protein in resistance training remains questionable. This paper examines the effectiveness of whey protein, and other forms of protein supplements, in helping athletes augment their muscle mass. A comparison is also made between whey and other forms of protein with respect to efficacy and other potential benefits besides muscle gain. Review of the current literature seems to indicate that protein supplementation can induce significant gains in muscle mass, and that whey protein can provide these gains but may lack other benefits for overall health. Nevertheless, protein supplementation is not essential if adequate protein intake can be achieved from dietary sources.

Coronary heart disease (CHD) is the leading cause of death in the United States as well as in many developing and developed countries. However, several studies studying the epidemiology of CHD across the world have found that there is a significantly lower incidence in Japan and Mediterranean Southern Europe, a difference which was found to be independent of serum cholesterol levels. The traditional Mediterranean diet consists of a high intake of olive oil as an important fat source, resulting in a high intake of monounsaturated fatty acids (MUFA) and a low intake of saturated fatty acids (SFA). Studies have shown that MUFA or PUFA, as opposed to SFAs, decrease plasma total cholesterol levels as well as low density lipoprotein (LDL) cholesterol concentrations. In addition, MUFAs, because they only have one double bond, are more resistant to oxidative modification and entrance into the oxLDL atherogenic pathway. Recent studies on the Mediterranean diet show that adherence to the diet is associated with a 33-39% lower mortality rate from CHD as well as drops in inflammatory markers of endothelial function. This data supports the Mediterranean diet tangible lifestyle modification patients can make in order to lower their risk of coronary artery disease.

Coronary heart disease (CHD) continues to be the leading cause of death in the United States today. As research continues to implicate increased levels of serum low-density lipoprotein cholesterol (LDL-C) as a major cause of CHD, many therapies have been designed to specifically lower LDL-C, in hopes of preventing CHD. In 2001, the National Cholesterol Education Program (NCEP) Adult Treatment Panel (ATP III) recommended that first line therapy for primary prevention of CHD should involve dietary and behavioral modifications, otherwise referred to as therapeutic lifestyle changes (TLC). In order to evaluate both primary and secondary prevention strategies, currently available options are described below, including dietary modifications, pharmacotherapy, and high-density lipoprotein cholesterol (HDL-C) therapies. Finally, critical evaluation of recent studies provides further support for the guidelines established by the NCEP ATP III, which strongly recommends therapeutic lifestyle changes (TLC) as first-line therapy for primary prevention of CHD.

Coenzyme Q-10 (CoQ10) has been used as an adjunctive therapy for various cardiovascular disorders for over three decades. As a powerful anti-oxidant and free radical scavenger, CoQ10 protects cells against DNA damage and oxidative stress. Its primary function in the body is as a key component of the electron transport chain, an essential element of ATP synthesis. This paper provides a brief overview of some of the indirect and direct evidence available on the effects of CoQ10 on cardiovascular health. In general, CoQ10 is a safe and well-tolerated nutritional supplement that has been shown to improve cardiovascular function in both experimental and clinical studies. However, more studies are needed to attain a clear recommendation on the use of CoQ10 as supplemental therapy in cardiovascular disease.

The new noncaloric sweetener Splenda has recently gained incredible popularity. Splenda’s sweetness comes from the compound sucralose, a tri-chlorinated version of sucrose that is about 600 times sweeter. Sucralose has many advantages over older noncaloric sweeteners, such as saccharin, cyclamate, and aspartame. It has a taste profile very similar to sugar, and its stability at high temperatures allows for its use in industrial food processing and home baking. In spite of numerous experiments in both model systems and human subjects, the safety of sucralose consumption has not been adequately assessed. We know that sucralose is largely unmetabolized in the human body and is well tolerated in both healthy and diabetic people. Currently, there is no direct clinical evidence that sucralose consumption is unsafe. Since sucralose is such a new product, there have been no long-term studies on the safety of its consumption. Due to the continuously increasing presence of Splenda-containing products, a long-term assessment of safety is imperative. As with any other food additive or nutritional supplement, the sweetness of Splenda can still be enjoyed safely in moderate quantities.

Obesity is an increasingly common health issue in developed and developing countries. There is a growing body of evidence linking high dietary calcium and dairy products with low adiposity. In the CARDIA study, Pereira et al. compared the lowest to highest quintile of calcium consumption and found the incidence of obesity reduced by 18.7% (P<0.001). Other researchers have found comparable results. Controlled trials of high calcium diets have had mixed results. In a longitudinal study of young girls, Phillips et al. found no relationship between dietary calcium or dairy products and BMI. Other studies by Zemel have found significant benefits in weight loss from diets high in calcium and in dairy. In a study of 32 obese women on an energy deficient diet, those in the high calcium and high dairy groups lost 38% and 64% more fat, and specifically more truncal fat than did women in the low calcium diet. Calcium’s modulation of adiposity appears to act through down regulating PTH and Vitamin D which have been shown to be lipogenic. Certain dangers are associated with high levels of calcium. However, most people in the US are not getting sufficient calcium, and therapeutic levels of calcium do not approach the upper limit of safety. Physicians should feel comfortable recommending that a patient increase his or her consumption of a low-fat dairy product, or use supplements to achieve the AI of calcium to reduce the risk of osteoporosis, and to enhance the weight loss achieved with a low-calorie diet and exercise.

Obesity and overweight are serious health problems in the U.S., with an estimated 65% of adults either obese or overweight as of 2002, and among children and adolescents the prevalence of overweight has nearly tripled over the past two decades to 16 %. Modest weight loss and body fat reduction can reduce the risks of obesity. Recent laboratory studies have described potential cellular mechanisms for calcium and its role in lipid metabolism, and several observational studies have suggested a possible relationship between dairy/dietary calcium and weight loss or body fat reduction. However, randomized studies have mixed results as to whether dairy product or calcium supplementation significantly correlates with decreased weight or body fat when compared to controls. Despite promising findings, further studies are needed regarding this issue.