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Spotlight Fall 2010 on nutrition issues What’s Inside Did you know? p. 2, 8 In brief p. 5 Q&A p. 7 What’s new? p. 10 Authors Veronica Streeter, MAN, RD, is a recent graduate of the Master of Applied Nutrition program at the University of Guelph. Veronica also holds a Bachelor of Arts degree in kinesiology from the University of Western Ontario and a Bachelor of Science degree with a specialization in food and nutrition from Brescia University College. She has particular interests in nutrition education and health promotion and aims to work as a Registered Dietitian in a community setting. Vanessa Nagy is completing her Master of Public Health degree in community nutrition at the University of Toronto and is on a work placement in the Nutrition Department at Dairy Farmers of Canada. She has a particular interest in school and child nutrition and looks forward to working as a Registered Dietitian in a community or public health setting. Acknowledgement Our special thanks go to Dr. Stuart Phillips for providing an expert review of this issue of Spotlight. Dr. Phillips is a Professor and the Associate Chair of Graduate Studies in the Department of Kinesiology at McMaster University and is a Fellow of the American College of Sports Medicine and the American College of Nutrition. His research focuses on factors that maintain, increase or decrease skeletal muscle mass. Dr. Phillips has published over 140 research manuscripts in the areas of nutrition, exercise and body composition; we thank him for sharing his knowledge and expertise. Protein Power: Protein’s Contribution to the Reduction of Chronic Disease Risk Synopsis Diet and lifestyle modifications remain the cornerstone of chronic disease prevention and management. A growing body of evidence suggests that a balanced diet that includes adequate protein – characterized as protein intake above the Recommended Dietary Allowance of 0.8 grams of protein per kilogram of body weight, but well within the Acceptable Macronutrient Distribution Range for protein of 10% to 35% of total dietary energy – contributes to overall health and reduces the risk of some chronic diseases. Research also points to milk products in the reduction of risk for some common chronic diseases, likely as a result of the multiple nutrient components present in milk, including high-quality protein. Specifically, moderate consumption of milk protein may reduce risk factors for heart disease by improving an individual’s blood lipid profile and reducing blood pressure. Individuals at risk of or diagnosed with type 2 diabetes may also benefit from this macronutrient via improved glycemic regulation. Finally, milk protein consumption has advantages for body composition, which is beneficial for individuals trying to maintain a healthy body weight, or elderly individuals trying to prevent age-related muscle loss. These findings support the promotion of dietary protein within the recommended Dietary Reference Intakes, and are consistent with eating at least two, and up to four, daily servings of Milk and Alternatives, as recommended in Eating Well with Canada’s Food Guide. Given the aging Canadian population, the rising prevalence of obesity and the fact that heart disease and type 2 diabetes are two of the most significant causes of morbidity and mortality in Canada, optimizing protein intake, including adequate consumption of milk products, is not only relevant to, but also timely for, improving the health of the Canadian population. Introduction Chronic diseases are the major cause of death and disability worldwide.1 In Canada, chronic diseases are estimated to account for approximately 89% of all deaths.1 The economic impact of premature deaths due to heart disease, stroke and diabetes is substantial: in 2005 it was estimated that Canada lost approximately $500 million in national income as a result of premature deaths from chronic diseases.2 However, at least 80% of these premature deaths could be prevented by modifying individual lifestyle behaviours to include a healthy, balanced diet and regular physical activity.1 The promotion of behaviours that benefit health, such as improved diet and increased physical activity, is a cost-effective intervention that could slow the spiralling cost of chronic disease in Canada. Scientific research suggests that moderate consumption of protein, within the Acceptable Macronutrient Distribution Range (AMDR), can provide nutritional and metabolic advantages that may prevent and manage chronic diseases. The chronic diseases and conditions discussed in this issue of Spotlight are cardiovascular disease, type 2 diabetes, sarcopenia and obesity. Emerging evidence suggests that adequate consumption of highquality milk protein reduces the risk of these common chronic diseases. Additionally, dairy products are important contributors to higher-protein diets, which further prevent and manage chronic disease risk. Did you know? Milk Proteins Cow’s milk represents a unique source of nutrients that can act both independently and synergistically with one another. Milk contains two types of protein: whey (20%) and casein (80%). Both are high-quality proteins, according to science-based rating scales, and both contain all essential amino acids in amounts sufficient to support the multiple roles of protein in the body.3,4 According to the Protein Digestibility-Corrected Amino Acid Score (PDCAAS), a method of measuring protein quality based on availability of essential amino acids as well as digestibility, milk provides higher-quality protein than beef, soy or wheat.5 Because of its high quality, cow’s milk protein is used as a standard reference protein to evaluate the nutritive value of food proteins.6 Individual milk proteins have been shown to exhibit a wide range of beneficial functions that may play a role in the prevention and management of chronic disease. 2 Spotlight Fall 2010 Cardiovascular Disease The term cardiovascular disease describes a cluster of diseases of the circulatory system; it is currently the leading cause of death in adult Canadians.14 Ischemic heart disease, or heart attack, is the most common type of cardiovascular disease and affects both men and women.15 The majority of cases of cardiovascular disease stem from modifiable risk factors, including lack of physical activity, poor diet, smoking, high blood cholesterol, hypertension and, potentially, stress.15 Healthy eating, which includes sufficient dietary protein consumption, assists in the reduction of cardiovascular disease risk. In particular, some components of milk proteins have been demonstrated to reduce blood pressure, which can contribute to lowering total estimated cardiovascular risk.16 The Evidence: Dietary Protein and Cardiovascular Disease An abnormal blood lipid profile consists of elevated levels of low-density lipoprotein (LDL) cholesterol, low levels of high-density lipoprotein (HDL) cholesterol, and high levels of triglycerides, a type of fat found in the blood.14 The Canadian Cardiovascular Society recommends a diet reduced in simple sugars and refined carbohydrates for the prevention of cardiovascular disease in adults.17 Subsequent evidence suggests that replacing simple carbohydrates with other macronutrients, such as protein from lean meats, poultry and dairy products, produces beneficial metabolic effects. Increasing protein intake can reduce simple carbohydrate consumption and contribute to weight loss. In one study, the comparison of three types of diets – high carbohydrate, high unsaturated fat and high protein – revealed favourable changes from baseline lipoproteins in all but the high-carbohydrate diet.18 However, the high-protein diet also significantly reduced the triglyceride concentration compared with the other two diets.18 The authors proposed that this further reduction in triglycerides by the high-protein diet reveals that protein possesses a triglyceridelowering effect, beyond the result of its replacing carbohydrates in the diet.18 Additional research supports the improvement of individuals’ blood lipid profiles with a moderate increase in protein intake, within the recommended AMDR, by decreasing triglyceride concentration,19–22 increasing HDL cholesterol22 and reducing LDL cholesterol.19,22 Finally, further scientific evidence suggests that a moderate increase in protein consumption, within the AMDR, results in a decreased risk of coronary heart disease18 and reduced estimated 10-year coronary heart disease risk.2 Hypertension, another modifiable risk factor, plays a role in cardiovascular disease prevention and management. The longitudinal CARDIA Study concluded that protein intake was inversely associated with average blood pressure in multiethnic groups during seven years of follow-up.23 A meta-analysis confirms this association.24 Emerging evidence suggests that the protein component of milk has hypotensive effects.16 Specifically, milk protein–derived peptides can inhibit angiotensin-1 converting enzyme (ACE) activity, a mechanism similar to the action of many antihypertensive medications.16 Furthermore, the addition of whey protein, a protein found in dairy products, to the diet has also demonstrated significant blood pressure–decreasing effects when compared to glucose controls. 25,26 Additionally, whey protein has produced significant improvements in inflammatory markers and individual vascular function.26 Therefore, milk, as a whole food, has the potential to decrease blood pressure and should be considered an essential component of the treatment of hypertension.16 The Spring 2010 issue of Spotlight, “Dietary Factors in the Prevention and Management of Hypertension,” described the role of dairy products in the Dietary Approaches to Stop Hypertension (DASH) Diet, a highly advocated strategy for the prevention and management of hypertension. Type 2 Diabetes Mellitus Type 2 diabetes is a chronic disease that develops in stages. The onset is defined as insulin resistance, which is the decreased ability of insulin to stimulate muscle to clear glucose from the blood.27 In the later stages of diabetes, the pancreas loses the ability to secrete extra insulin in response to elevated levels of blood glucose.27 Currently, more than three million Canadians are living with diabetes; this number is expected to grow to 3.7 million by 2020.28 The number of people diagnosed with type 2 diabetes is increasing as a result of the aging of the population, rising rates of obesity and decreasing levels of physical activity.28 It is estimated that by 2020, the annual cost of diabetes to the Canadian health-care system will be approximately $16.9 billion.28 Lifestyle modifications, including adequate physical activity, a balanced diet and achieving or maintaining a healthy body weight, can prevent or delay the onset of type 2 diabetes and help those already diagnosed manage the disease. For example, a protein-rich diet can reduce hyperglycemia after meals, improve overall glucose control and decrease glycated hemoglobin (a blood marker used to identify the average plasma glucose over the previous three months). Additionally, there is considerable evidence that adequate consumption of milk products is associated with a reduced risk of developing type 2 diabetes.29,30 Several components of milk products may be responsible for reducing this risk. Recent evidence supports the role of milk protein in improving glycemic control and contributing to weight management. The Bottom Line: Substantial evidence supports the theory that replacing dietary carbohydrates with protein, within the AMDR, lowers LDL cholesterol and triglycerides, improves HDL cholesterol and reduces blood pressure. In particular, the bioactive peptides found in milk proteins have the potential to significantly lower blood pressure; therefore, milk products should be emphasized as part of a healthy balanced diet to help lower cardiovascular disease risk. Fall 2010 Spotlight 3 The Evidence: Dietary Protein and Type 2 Diabetes Mellitus Achieving optimal glycemic control is fundamental to the management of diabetes. Both fasting and post-prandial plasma glucose levels correlate with the risk of complications and contribute to the measured glycated hemoglobin value. 31 Emerging evidence indicates that a short-term increase in dietary protein consumption dramatically lowers glycated hemoglobin concentration, which indicates improved glycemic control.32,33 However, longer-term studies are required to understand whether an increase in dietary protein consumption also improves long-term glucose control and decreases the glycated hemoglobin value. The 2008 Canadian Diabetes Association Clinical Practice Guidelines recommend a diet reduced in simple sugars and refined carbohydrates, as do the Canadian Cardiovascular Society Guidelines.17,34 The guidelines do not provide suggestions as to which macronutrients should replace refined carbohydrates, but there are only two options: protein and fat. Recent studies have compared the effects of replacing simple carbohydrates with protein-rich foods in the diets of individuals with type 2 diabetes and found less variation in plasma glucose and plasma insulin with this altered macronutrient intake. 32–34 Additionally, strong evidence has established that dietary protein intake improves post-prandial glycemic control in healthy35–38 and insulin-resistant individuals,20 as well as in individuals with type 2 diabetes.33,39 Milk proteins are associated with reduced postprandial glycemia.38 Specific mechanisms for these metabolic outcomes are still being unravelled, but evidence suggests that the ingestion of food protein results in a significant increase in plasma insulin.40 Therefore, the replacement of refined carbohydrates with protein-rich foods will result in a reduced glucose response, not only because of the increased insulin response from the protein source, but also owing to the decreased ingestion of simple carbohydrates. 4 Spotlight Fall 2010 Food proteins differ in their capacity to stimulate insulin release.41 In one study, whey protein, a fraction of milk protein, demonstrated insulinotropic properties above those demonstrated by other food sources, such as cod and wheat gluten.41 These results indicate that consumption of milk protein may stimulate insulin activity and, therefore, that regularly consuming milk with meals may reduce post-prandial glycemia. A full review of the role of milk products in the prevention and management of type 2 diabetes can be found in the Spring 2009 issue of Spotlight, “Preventing and Managing Type 2 Diabetes.” The Bottom Line: Protein consumption, within the AMDR, has been shown to increase glucose control and insulin sensitivity in both healthy individuals and those with insulin resistance or type 2 diabetes. Additionally, it appears that milk protein has the potential to reduce post-prandial glycemia and therefore that adequate consumption of milk products should be encouraged. In brief Dietary Reference Intakes The Dietary Reference Intakes are nutrient reference guidelines that aim to ensure that Canadians and Americans consume healthy, balanced diets.7 These guidelines consist of standard recommendations, including the Recommended Dietary Allowance (RDA) and the Acceptable Macronutrient Distribution Range (AMDR).7 The RDA is an estimate of the minimum amount of a nutrient required to prevent deficiency in most healthy people in a specific life stage and gender group.7 The RDA for protein for adults is 0.8 grams of protein per kilogram of body weight per day.8 Some researchers have suggested that the RDA, while useful for micronutrients, is not suitable for macronutrients.9,10 Emerging scientific evidence suggests that the optimal dietary protein intake is greater than the RDA, particularly for the prevention of chronic disease. This evidence further indicates that this standard may be inappropriate for the Canadian population.11,12 In contrast, the AMDR, expressed as a percentage of total energy intake, is a range of intakes determined to meet nutrient requirements and that is also associated with a reduced risk of chronic disease.8 Proponents of the latter are encouraging clinicians to abandon the RDA – the minimum daily requirement – and adopt the AMDR as the standard for macronutrient consumption.9,10 The AMDR for protein is 10% to 35% of total daily energy intake.8 Currently, Canadians consume an average of 17% of their daily calories from protein, or approximately 85 grams of protein per day.13 According to the AMDR, Canadians can safely increase their protein intake to as much as 35% of daily calories, or approximately 175 grams of protein per day for an average man or 130 grams per day for an average woman. Sarcopenia Sarcopenia is the process by which the body’s lean muscle mass declines with age over time.42 Sarcopenia affects more men than women.42,43 Its prevalence ranges from 20% to 30% in those over 60 years old and reaches 50% in those over 80.42 The prevalence of sarcopenia will continue to increase as the population ages. As sarcopenia increases, and muscle strength decreases, it is reasonable to suspect that the incidence of falls will increase, concordant with a decrease in quality of life and reduced functional independence, which can ultimately result in institutionalization.44 Sarcopenia is not a chronic disease in itself; however, it can be a catalyst for the development of chronic diseases and conditions, including cardiovascular disease, diabetes and obesity, owing to muscle’s capacity for lipid oxidation, glucose uptake and glucose storage.45 Behaviours associated with the development of sarcopenia include inadequate consumption of dietary protein and a sedentary lifestyle.46 Given that muscle mass is harder to build among the elderly because of a blunted cellular response to strength training and dietary protein, the role of high-quality, nutrient-dense sources of dietary protein is especially important.47 The Evidence: The Role of Dietary Protein in Preventing Sarcopenia The importance of adequate protein consumption in the prevention of sarcopenia is illustrated by a longitudinal study that examined this association in older, community-dwelling men and women. This study found that individuals in the highest quintile of protein intake (1.2 grams per kilogram of body weight per day, 50% greater than the RDA) lost 40% less lean mass than did individuals in the lowest quintile of protein intake (0.8 g/kg/d, the protein RDA).48 These results suggest that low protein intake may be a modifiable risk factor for sarcopenia among older adults.48 Fall 2010 Spotlight 5 Currently, many individuals aged 71 and older have inadequate dietary protein intake.49 No difference has been found between younger and older individuals’ protein digestion and absorption, but there is some disagreement over whether older people can mount a robust increase in muscle protein synthesis in response to a meal.50–52 This finding indicates that, besides their blunted cellular response to muscle hypertrophy and feeding, elderly individuals may not be consuming enough dietary protein or, more specifically, enough high-quality protein, such as milk-based proteins that contain leucine. Leucine is a branched-chain amino acid that has been shown to be critically important in stimulating muscle protein synthesis53 and is required in larger amounts in older persons.54,55 As individuals age, their energy consumption decreases. Moreover, recent research reports that dietary protein requirements are inversely proportional to energy intake,56 indicating that elderly individuals likely need to consume larger amounts of dietary protein to compensate for their decreased energy intake. Additionally, recent scientific evidence suggests that elderly people may actually have a protein requirement that is higher than the current RDA,11,12,43,46 providing further support for the theory that many elderly individuals consume inadequate amounts of protein and are at high risk of becoming sarcopenic. Research has established the optimum quantity of dietary protein per meal to be 25 to 30 grams, as this amount is sufficient to optimize protein synthesis.57,58 In one study, consumption of more than 30 grams of protein per meal did not result in an increase in protein synthesis beyond what was observed with consumption of 30 grams. 57 This finding was confirmed in a study comparing younger and older participants, indicating that this recommendation is not only practical for elderly individuals, but also for the younger population.57 The quality of ingested protein should also be considered in dietary recommendations.59 It has been suggested that as a result of inadequate dietary protein intake, the elderly should consume highquality protein sources, such as dairy proteins. 6 Spotlight Fall 2010 As mentioned, the Protein Digestibility-Corrected Amino Acid Score (PDCAAS) is used to determine protein quality.5 Milk-based products are a source of high-quality protein, and have a PDCAAS of 121% (values higher than 100% are truncated at 100%).5 More importantly, milk proteins also have a high content of the amino acid leucine, which plays a large role in stimulating muscle protein synthesis in aging muscle.53–55 Eating Well with Canada’s Food Guide recommends that adults over age 50 consume three servings of Milk and Alternatives per day. However, currently fewer than 30% of men and women in this age group consume the recommended number of servings.13,60 Adequate milk product consumption in the elderly is recommended not only for the high-quality protein these foods contain, but also for their large amounts of whey protein.46,59 This particular dairy component is digested and absorbed more quickly than soy protein and also stimulates muscle protein synthesis better than soy protein. 3 The proteins in milk, including casein and whey, also promote the maintenance of lean muscle mass, another important factor in the prevention of sarcopenia, which can alleviate the risk of developing other chronic diseases.3,61 Therefore, adequate consumption of Milk and Alternatives by adults over age 50 is important because these foods may play a role in decreasing the risk of sarcopenia in this population.62 The Bottom Line: Currently, many older individuals do not consume enough dietary protein or milk products. Inadequate consumption of protein may contribute to the decrease in muscle mass and the increase in risk of chronic disease experienced by older adults. Adequate consumption of milk protein is particularly important owing to its high content of both leucine and whey, both of which play large roles in muscle protein synthesis in the elderly. Health professionals can encourage sufficient protein consumption in this population by stressing the importance of consuming approximately 25 to 30 grams of high-quality protein at each meal and three servings of Milk and Alternatives per day. Q&A Q: D oes high dietary protein consumption have a negative effect on bone health? Q: Are higher-protein diets considered safe? A: A: Despite this widely held belief, research strongly suggests that individuals with high protein intakes – up to approximately 2 grams per kilogram of body weight – actually have better bone quality when calcium intake is adequate (i.e., 1000 to 1200 milligrams per day).63 This is true throughout the life cycle: adequate protein intake is associated with high bone mineral density in teenaged girls and in premenopausal women,64 and high dietary protein consumption has been correlated with reduced risk of hip fracture in both elderly men and women.65 The misconception that high dietary protein intakes lead to poor bone health came from early studies that identified a correlation between increased protein intake and increased urinary calcium excretion.66,67 For example, the acid-ash hypothesis theorizes that the consumption of protein increases the acid load of the diet and brings about the release of calcium from the skeleton, leading to increased urine calcium and, eventually, osteoporosis.68 However, current research does not support the principles of the acid-ash hypothesis and suggests that dietary protein actually increases intestinal absorption of calcium. Therefore, excretion of calcium in the urine may result from increased gastrointestinal calcium absorption that results in adequate calcium balance.66–68 Research completed to date shows negative calcium balance depends on dietary calcium intake, not protein intake.69 Moreover, Heaney and Layman suggest that optimal protein intakes for bone health are likely higher than currently recommended intakes, particularly in the elderly.63 Research strongly supports adequate amounts of both protein and calcium, two key components of milk, for healthy bones. he Dietary Reference Intakes report no T identifiable health risks associated with protein consumption up to 35% of total energy intake in healthy individuals.8,70 However, caution is advised for individuals with renal disease as protein consumption at the higher end of the AMDR is contraindicated in such cases.71 Renal function decreases with age; therefore, assessment of renal function is recommended before older individuals adopt a higher-protein diet.72 Q: S hould I recommend protein supplements to my clients to enhance their protein intakes? A: eople can easily meet their protein requirements P by consuming whole foods such as milk products, eggs, nuts, legumes, lean meats, fish and poultry. Consuming protein supplements may cause adverse effects such as diarrhea and bloating.73 A balanced diet, including whole, protein-rich foods, is a healthier, less expensive and sufficient way to meet individual protein requirements.74 ormation nutrition inf Fall 2010 Spotlight 7 Weight Management: A Key to Preventing Chronic Disease Excess body weight is a major risk factor for chronic diseases, such as cardiovascular disease, type 2 diabetes and metabolic syndrome.15,17,77,78 Maintaining optimal energy balance, which includes both physical activity and healthy eating, is a key prevention strategy.15,17,41,77,78 Adequate protein consumption may enhance the benefits of resistance-based physical activity, such as weight lifting, by promoting accretion of lean muscle mass47,79–81; it also plays an important role in healthy eating through its effects on appetite. Physical Activity It is important for health professionals to motivate clients to engage in regular exercise. Ideally, adults should aim for 30 to 60 minutes of moderate physical activity most days of the week, incorporating a mixture of endurance, flexibility and weight-bearing activities.82 Regular exercise is beneficial not only for weight loss, but also to assist with favourable body composition changes, including the development and maintenance of muscle mass.47 Additionally, the consumption of protein, including milk protein, immediately after resistance exercise may assist with protein synthesis and contribute to the accretion of lean muscle mass.47,79–81 Lower-fat milk has proven to be an effective drink to support favourable body composition outcomes during resistance training by stimulating muscle protein synthesis in men83,84 and promoting lean-mass gain and fat-mass loss in women.85 Weight loss is also often associated with bone loss. In one study, consumption of a high-protein diet and three daily servings of Milk and Alternatives during a period of weight loss attenuated participants’ bone mineral loss.86 Encouraging the consumption of milk products after periods of physical activity and during weight loss endeavours promotes the maintenance of lean muscle mass and bone mass, thereby promoting weight loss primarily of adipose tissue.61,86 Healthy Eating In Your Practice The 2006 Canadian Clinical Practice Guidelines for the management and prevention of obesity conclude that a moderate increase in protein consumption, within the AMDR, may be advantageous for weight loss.87 Dietary protein plays a role in body weight regulation, partially through its effects on appetite. Protein as a macronutrient has proven to be significantly superior to both fat and carbohydrate in producing satiety.88 Additionally, milk protein has been demonstrated to be more effective than soy protein at decreasing hunger.71,89 Timing of protein intake is important; scientific research suggests that protein consumption at breakfast decreases hunger and appetite throughout the rest of the day.90,91 According to one study, the consumption of protein-rich snacks, such as cheese, should not promote weight gain because energy intake appears to be regulated during subsequent meals.92 In summary, milk protein’s ability to reduce hunger 93,94 and increase satiety71,89 can produce substantial decreases in caloric intake, resulting in successful weight management.61 Nutrition therapy, including optimizing intake of high-quality protein, can play an integral role in reducing the risk of chronic disease. Protein-rich foods are typically found in the Meat and Alternatives and Milk and Alternatives food groups of Canada’s Food Guide and include lean meats, fish, poultry, eggs, cheese, yogurt, legumes and nuts (see Table 1).62,95 Milk in particular is an excellent source of highquality complete protein in a nutrient-rich package.5 In fact, given the nutrient density of milk, which contains protein, calcium and vitamins D, B12 and A, it is surprising that Canadians’ average consumption of milk products is below recommendations13,60 ; this food source of protein should be particularly encouraged. The evidence-based AMDR recommends 10% to 35% of caloric intake from protein. 8 Currently, Canadians consume approximately Table 1. Protein Content of Various Foods and Beverages96 Food Group Meat and Alternatives The Bottom Line: Consuming milk after resistance exercise can stimulate muscle protein synthesis and promote fat loss. Additionally, adequate protein in the diet can contribute to body weight regulation by helping to control appetite. Did you know? It is commonly believed that recreational athletes have higher protein requirements than average Canadians; however, studies show no benefit to exercise or sport performance with consumption of dietary protein in excess of the Acceptable Macronutrient Distribution Range.75 Furthermore, adequate dietary protein consumption can be achieved with a balanced diet, without the use of protein supplements.74–76 17% of their daily energy from protein sources.13,60 Therefore, Canadians can safely increase their daily consumption of dietary protein; in fact, most Canadians could double their protein intake and still be safely within recommended guidelines. A diet reduced in refined carbohydrates has been recommended for individuals diagnosed with type 2 diabetes, obesity or cardiovascular disease.17,34,87 A wealth of research has demonstrated that replacing carbohydrates in the diet with protein may have a number of beneficial health effects. Consumption of approximately 25 to 30 grams of dietary protein at meals maximally stimulates protein synthesis.48 Encouraging your clients to consume a serving of Milk and Alternatives at each meal will help them meet the daily servings from this food group recommended by Eating Well with Canada’s Food Guide and will also ensure they are well on their way to consuming an adequate amount of protein at each meal. Milk and Alternatives Grain Products Vegetables and Fruit Food Protein Content, grams Beef sirloin steak, 75 g 26 Tofu, firm, raw, 75 g 21 Pork tenderloin, 75 g 21 Chicken, skinless breast, 75 g 20 Tuna, canned light, 75 g 19 Eggs, whole cooked, 2 large 13 Kidney beans, boiled, 175 mL (¾ cup) 12 Lentils, boiled, 175 mL (¾ cup) 13 Almonds, 60 mL (¼ cup) 8 Cottage cheese, 125 mL (½ cup) 15 Cheddar cheese, 50 g (1¾ oz) 12 Milk, 250 mL (1 cup) 8 Yogurt, 175 mL (¾ cup) 8 Whole-wheat pasta, cooked, 125 mL (½ cup) 4 Whole-wheat bread, 1 slice 3 Brown rice, cooked, 125 mL (½ cup) 3 Oatmeal, prepared, 175 mL (¾ cup) 3 Potato, with skin, cooked, 125 mL (½ cup) 5 Broccoli, cooked, 125 mL (½ cup) 2 Butternut squash, cooked, 125 mL (½ cup) 1 Banana, raw, 1 medium 1 Apple juice, bottled, 125 mL (½ cup) — Bolded foods indicate high-quality, complete protein sources. 8 Spotlight Fall 2010 Fall 2010 Spotlight 9 References What’s new? Protein for Active Canadians Be on the lookout in the new year for Protein for Active Canadians and Protein – A Current Reference for Fitness Professionals, a pair of resources being developed by the Canadian Society for Exercise Physiology and the Registered Dietitians at Dairy Farmers of Canada. These user-friendly resources ormation nutrition inf update fitness professionals on the most recent scientific evidence and consensus on protein for active Canadians. They also provide practical clientcentered tips and tools such as post-workout snack and meal suggestions with good sources of protein to support intakes adequate for good health and physical activity. Conclusion Evidence has shown that in addition to reducing the risk of obesity, adequate protein consumption, as part of a balanced diet, may also help prevent and manage other chronic diseases and conditions, such as cardiovascular disease, diabetes and sarcopenia. In particular, milk products are protein-rich foods that may promote optimal body composition and help prevent and manage chronic diseases. Healthy eating patterns can include a wide range of protein intakes – from 10% to 35% of total energy for adults.8 Health professionals should encourage two to four daily servings from the Milk and Alternatives 10 Spotlight Fall 2010 food group, depending on the client’s age, in addition to promoting consumption of other protein-rich foods, such as lean meats, beans, fish, eggs and poultry to replace simple sugars and refined carbohydrates, in accordance with the 2009 Cardiovascular Society Guidelines, the 2008 Canadian Diabetes Association Practice Guidelines and Eating Well with Canada’s Food Guide.17,34,62 These relevant and timely recommendations may help reduce the risk of common chronic diseases in the Canadian population. 1.World Health Organization. Facts related to chronic disease. http://www.who.int/dietphysicalactivity/publications/facts/chronic/en/. Accessed June 9, 2010. 2.Haydon E et al. Chronic disease in Ontario and Canada: determinants, risk factors and prevention priorities. Report prepared for the Ontario Chronic Disease Prevention Alliance and the Ontario Public Health Association, 2005. http://www.ocdpa.on.ca/rpt_ChronicDiseaseOntario.htm. Accessed May 25, 2010. 3.Phillips SM et al. The role of milk- and soy-based protein in support of muscle protein synthesis and muscle protein accretion in young and elderly persons. J Am Coll Nutr 2009;28(4):343–354. 4.Bos C et al. Nutritional and physiological criteria in the assessment of milk protein quality for humans. J Am Coll Nutr 2000;19(2):191S–205S. 5.Schaafsma G. The Protein Digestibility-Corrected Amino Acid Score. J Nutr 2000;130:1865S–1867S. 6.Miller GD et al. Handbook of dairy foods and nutrition, 3rd ed. Boca Raton, FL: CRC Press, 2007. 7.Barr SI. Introduction to Dietary Reference Intakes. Appl Physiol Nutr Metab 2006;31(1):61–65. 8.Institute of Medicine. Dietary Reference Intakes for energy, carbohydrates, fibre, fat, fatty acids, cholesterol, protein and amino acids (macronutrients). Washington, DC: National Academy Press, 2005. 9.Lomangino K. The RDA for protein: the minimum or optimal intake. Clin Nutr Insight 2008;34(10):4–5. 10.Wolfe RR and Miller SL. The Recommended Dietary Allowance of protein: a misunderstood concept. JAMA 2008;299:2891–2893. 11.Millward DJ. Macronutrient intakes as determinants of dietary protein and amino acid adequacy. J Nutr 2004;134:1588S–1596S. 12.Layman DK. Dietary guidelines should reflect new understanding about adult protein needs. Nutr Metab (Lond) 2009;6:12 doi:10.1186/1743-7075-6-12. 13.Garriguet D. Overview of Canadians’ eating habits. Health Rep 2007;18(2):17–32. http://www.statcan.gc.ca/pub/82-003-x/2006004/article/ habit/9609-eng.pdf. Accessed June 17, 2010. 14.Public Health Agency of Canada. Cardiovascular disease, 2009. http://www. phac-aspc.gc.ca/cd-mc/cvd-mcv/index-eng.php. Accessed May 27, 2010. 15.Public Health Agency of Canada. Minimizing the risk of cardiovascular disease, 2009. http://www.phac-aspc.gc.ca/cd-mc/cvd-mcv/risk-risqueseng.php. Accessed May 27, 2010. 16.FitzGerald RJ et al. Hypotensive peptides from milk proteins. J Nutr 2004;134:980S–988S. 17.Genest J et al. 2009 Canadian Cardiovascular Society/Canadian guidelines for the diagnosis and treatment of dyslipidemia and prevention of cardiovascular disease in adults – 2009 recommendations. Can J Cardiol 2009;25(10):567–579. 18.Furtado JD et al. Effect of protein, unsaturated fat, and carbohydrate intakes on plasma apolipoprotein B and VLDL and LDL containing apolipoprotein C-III: results from the OmniHeart Trial. Am J Clin Nutr 2008;87:1623–1630. 19.Appel LJ et al. 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Circulation 1996;93:60–66. 24.Liu L et al. Epidemiological evidence of the association between dietary protein intake and blood pressure: a meta-analysis of published data. Hypertens Res 2002;25:689–695. 25.Luhovyy BL et al. Whey proteins in the regulation of food intake and satiety. J Am Coll Nutr 2007;26(6):704S–712S. 26.Pal S and Ellis V. The chronic effects of whey proteins on blood pressure, vascular function, and inflammatory markers in overweight individuals. Obesity 2009;doi:10.1038/oby.2009.397. 27.Canadian Diabetes Association. Canadian Diabetes Association 2008 clinical practice guidelines for the prevention and management of diabetes in Canada: definition, classification and diagnosis of diabetes and other dysglycemic categories. Can J Diabetes 2008;32(Suppl 1):S10-S13. 28.Canadian Diabetes Association. The prevalence and cost of diabetes. http://www.diabetes.ca/documents/about-diabetes/PrevalanceandCost_09. pdf. Accessed May 27, 2010. 29.Pereira MA et al. 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Inadequate dietary protein increases hunger and desire to eat in younger and older men. J Nutr 2007;137:1478–1482. 94.Weigle DS et al. A high-protein diet induces sustained reductions in appetite, ad libitum caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and ghrelin concentrations. Am J Clin Nutr 2005;82:41–48. 95.Health Canada. Eating well with Canada’s food guide: a resource for educators and communicators, 2007. http://www.hc-sc.gc.ca/fn-an/pubs/ res-educat/res-educat-eng.php. Accessed June 17, 2010. 96.Health Canada. Canadian nutrient file, 2007. http://webprod.hc-sc.gc.ca/ cnf-fce/start-debuter.do?lang=eng. Accessed June 28, 2010. If you are interested in being on our mailing list please visit our health professional Web site: www.dairynutrition.ca (click on “newsletter” at upper right-hand corner of page to subscribe). For hard-copy subscriptions in Ontario call 1-866-392-9929 and in the Maritimes call 1-800-465-2697. Spotlight is a free newsletter written by Registered Dietitians for health professionals. It is available in French and English and covers current research on milk-related issues. A client-friendly fact sheet accompanies this newsletter. 12 Spotlight Fall 2010