the full article: Health Risks of High-Protein Diets: Misunderstandings and Deceptive Statements

[Guest guest]

>

>Health Risks of High-Protein Diets

>Jan 23, 2004 10:33 PST

>

>Misunderstandings and Deceptive Statements

>Health Risks of High-Protein Diets

>

>Colorectal cancer, cardiovascular risk, renal disease, osteoporosis,

>and particular risks to individuals with diabetes

>Deceptive statements commonly cited in press

>

>

>Recent media reports have publicized the short-term weight loss that

>sometimes occurs with the use of very-high-protein weight-loss

>diets. Some of these reports have distorted medical facts and have

>ignored the potential risks of such diets. Based on past experience

>with the fen-phen drug combination and other weight-loss regimens,

>you may expect that some patients will disregard even serious long-

>term health risks in hopes of short-term weight loss.

>

>This advisory is intended to notify you of (1) risks from the long-

>term use of high-protein diets, (2) currently circulating

>misunderstandings and deceptive statements made in support of such

>diets, (3) the establishment of a registry for patients who have

>followed such diets, and (4) possible legal liability.

>

>

>home

>

>Health Risks

>Despite press accounts of seemingly dramatic weight loss, the effect

>of high-protein diets on body weight is similar to that of other

>weight-reduction diets. Three recent studies (one at Duke

>University1, a second at the University of Pennsylvania2, and a

>third at a Philadelphia medical center3) suggest that mean weight

>loss with high-protein diets during the first six months of use is

>approximately 20 pounds. While this weight loss is greater than that

>which occurs from diets not designed for weight loss (e.g., diets

>based on the Food Guide Pyramid or National Cholesterol Education

>Program guidelines), it is not demonstrably greater than that which

>occurs with other weight-loss regimens or with low-fat, vegetarian

>diets prescribed without energy restrictions.4 A recent review of

>107 research studies on high-protein, low-carbohydrate weight-loss

>diets found that the amount of carbohydrate in the diet had no

>effect on the degree of weight loss, although those individuals

>following their diets for longer periods had greater weight loss.5

>

>High-protein, very-low-carbohydrate weight-loss diets are designed

>to induce ketosis, a state that also occurs in uncontrolled diabetes

>mellitus and starvation. When carbohydrate intake or utilization is

>insufficient to provide glucose to the cells that rely on it as an

>energy source, ketone bodies are formed from fatty acids. An

>increase in circulating ketones can disturb the body's acid-base

>balance, causing metabolic acidosis. Even mild acidosis can have

>potentially deleterious consequences over the long run, including

>hypophosphatemia, resorption of calcium from bone, increased risk of

>osteoporosis, and an increased propensity to form kidney stones.6

>

>High-protein diets typically skew nutritional intake toward higher-

>than-recommended amounts of dietary cholesterol, fat, saturated fat,

>and protein and very low levels of fiber and some other protective

>dietary constituents. The Nutrition Committee of the Council on

>Nutrition, Physical Activity, and Metabolism of the American Heart

>Association states, " High-protein diets are not recommended because

>they restrict healthful foods that provide essential nutrients and

>do not provide the variety of foods needed to adequately meet

>nutritional needs. Individuals who follow these diets are therefore

>at risk for compromised vitamin and mineral intake, as well as

>potential cardiac, renal, bone, and liver abnormalities overall. " 7

>

>

>home

>

>A nutrient analysis of the sample menus for the three stages of the

>Atkins diet as described in Dr. Atkins' New Diet Revolution (pp. 257­

>

>259), using Nutritionist V, Version 2.0, for Windows 98 (First

>DataBank Inc., Hearst Corporation, San Bruno, CA) is presented

>below. The menus analyzed were as follows:

>

>Typical Induction Menu

>Breakfast

>Bacon slices, 4 slices

>Coffee, decaf, 8 ounces

>Scrambled eggs, 2

>

>Lunch

>Bacon cheeseburger, no bun:

>Bacon, 2 slices

>American cheese, 1 ounce

>Ground beef patty, 6 ounces

>Small tossed salad, no dressing

>Seltzer water

>

>Dinner

>Shrimp cocktail, 3 ounces

>Mustard, 1 teaspoon

>Mayonnaise, 1 tablespoon

>Clear consommé, 1 cup

>T-bone steak, 6 ounces

>Tossed salad

>Russian dressing

>Sugar-free Jell-O, 1 cup

>Whipped cream, 1 tablespoon

>

>Typical Ongoing Weight Loss Menu

>Breakfast

>Western Omelet:

>Eggs, 2

>Cheddar cheese, 2 ounces

>Bell peppers, 1 tablespoon

>Onion, 1 tablespoon

>Ham bits, 1/10 cup

>Butter, 1 tablespoon

>Tomato juice, 3 ounces

>Crispbread, 2 carbo grams (1/4 slice)

>Tea, decaf, 8 ounces

>

>Lunch

>Chef's salad with ham, cheese, and egg with zero-carb dressing

>Iced herbal tea, 8 ounces

>

>Dinner

>Subway seafood salad, 1 item

>Poached salmon, 6 ounces

>Boiled cabbage, 2/3 cup

>Strawberries, 1 cup with 4 tablespoons cream

>

>

>Typical Maintenance Menu

>Breakfast

>Gruyere and spinach omelet:

>Eggs, 2

>Gruyere cheese, 2 ounces

>Spinach, 1/4 cup cooked

>Butter, 1 tablespoon

>1 cantaloupe

>Crispbread, 4 carbo grams, 1 slice

>Coffee, decaf, 8 ounces

>

>Lunch

>Roast chicken, 6 ounces

>Broccoli, 2/3 cup, steamed

>Green salad Creamy garlic dressing

>Club soda

>

>Dinner

>French onion soup, 1 cup

>Salad with tomato, onion, carrots

>Oil and vinegar dressing

>Asparagus, 1 cup

>Baked potato, 1 small with sour cream (2 tablespoons) and chives

>Veal chops, 1 serving

>Fruit compote, 1+ cups (generous cup)

>Wine spritzer, 16 ounces

>

>

>home

>

>Nutrient Analysis of Atkins Sample Diets

>Atkins Induction Atkins Weight Loss Atkins Maintenance

>Energy, kcal 1759

>1505

>2173

>Protein, g (% energy) 143 (33%) 120 (32%) 135 (25%)

>Carbohydrate, g (% energy) 15 (3%) 36 (10%) 116 (22%)

>Fat, g (% energy) 125 (64%) 97 (58%) 110 (45%)

>Alcohol, g (% energy) 0

>0 26 (8%)

>Saturated fat, g 42 45 38

>Cholesterol, mg 886 885 834

>Fiber, g 2 7 18

>Calcium, mg (% DV) 373 (37%) 952 (95%) 1019 (102%)

>Iron, mg (% DV) 15 (86%) 10 (54%) 13 (70%)

>Vitamin C (% DV) 20 (33%) 140 (234%) 242 (404%)

>Vitamin A, RE (% DV) 799 (80%) 1525 (153%) 2521 (252%)

>Folate, µg (% DV) 143 (36%) 268 (67%) 584 (146%)

>Vitamin B-12, 5g (% DV) 11 (191%) 8 (132%) 5 (80%)

>Thiamin, mg (% DV) 0.7 (48%) 1.1 (76%) 1.0 (64%)

>

>The nutritional analysis shows that the sample menus do not meet

>recommended dietary intakes for macronutrients. In addition to very

>high protein content and low carbohydrate content, the menus at all

>three stages are very high in saturated fat (Daily Value is < 20 g)

>and cholesterol (DV < 200 mg) and very low in fiber (DV > 25 g). In

>addition, these sample menus do not reach daily values for iron. The

>Induction menu does not meet the daily values for calcium, vitamin

>C, vitamin A, folate, and thiamin. The Weight Loss menu is low on

>calcium, folate, and thiamin.

>

>

>home

>

>High-protein, high-fat dietary patterns, when followed over the long

>term, are associated with increased risk of the following

>conditions:

>

>1. Colorectal cancer. Colorectal cancer is one of the most common

>forms of cancer and is among the leading causes of cancer-related

>mortality. Long-term high intake of meat, particularly red meat, is

>associated with significantly increased risk of colorectal cancer.

>The 1997 report of the World Cancer Research Fund and American

>Institute for Cancer Research, Food, Nutrition, and the Prevention

>of Cancer, reported that, based on available evidence, diets high in

>red meat were considered probable contributors to colorectal cancer

>risk. Proposed mechanisms for the observed association include the

>effect of dietary fat on bile acid secretion, the action of

>cholesterol metabolites within the colonic lumen, and the

>carcinogenic action of heterocyclic amines produced during the

>cooking process, among others. In addition, high-protein diets are

>typically low in dietary fiber. Fiber facilitates the movement of

>wastes, including intralumenal carcinogens, out of the digestive

>tract, and promotes a biochemical environment within the colon that

>appears to be protective against cancer.8

>

>2. Cardiovascular disease. Typical high-protein diets are extremely

>high in dietary cholesterol and saturated fat. The effect of such

>diets on serum cholesterol concentrations is a matter of ongoing

>research. In a small study, individuals following high-protein diets

>against medical advice showed increases in fibrinogen, lipoprotein

>(a), and C-reactive protein, and demonstrable progression of

>coronary artery disease, suggesting that high-protein diets may

>precipitate progression of CAD through increases in lipid deposition

>and inflammatory and coagulation pathways.9 However, such diets pose

>additional cardiovascular risks, including increased risk for

>cardiovascular events immediately following a meal. Evidence

>indicates that meals high in saturated fat impair arterial

>compliance, increasing the risk of cardiovascular events in the

>postprandial period. A recent study showed that the consumption of a

>high-fat meal (ham-and-cheese sandwich, whole milk, and ice cream)

>reduced systemic arterial compliance by 25 percent at 3 hours and 27

>percent at 6 hours.9

>

>3. Impaired renal function. High-protein diets are associated with

>impairments in renal function. Over time, individuals who consume

>large amounts of protein, particularly animal protein, risk

>permanent loss of kidney function. Harvard researchers reported

>recently that high-protein diets were associated with a significant

>decline in kidney function, based on observations in 1,624 women

>participating in the Nurses' Health Study. The damage was found only

>in those who already had reduced kidney function at the study's

>outset; however, as many as one in four adults in the United States

>may already have reduced kidney function. Many patients who have

>renal problems may be unaware of this fact and do not realize that

>high-protein diets may put them at risk for further deterioration.

>The kidney-damaging effect was seen only with animal protein. Plant

>protein had no harmful effect.10

>

>The American Academy of Family Physicians notes that high animal

>protein intake is largely responsible for the high prevalence of

>kidney stones in the United States and other developed countries and

>recommends protein restriction for the prevention of recurrent

>nephrolithiasis.11 In part, this is because protein ingestion

>increases renal acid secretion and calcium resorption from bone and

>reduces renal calcium resorption. In addition, animal protein is a

>major dietary source of purines, the major precursors of uric acid,

>an important factor in some stone formers. When uric acid builds up,

>especially in an acid environment, it can precipitate in uric acid

>stone formers, and decrease the solubility of calcium oxalate, a

>problem for calcium stone formers.12

>

>4. Osteoporosis. Elevated protein intake is known to encourage

>urinary calcium losses and has been shown to increase risk of

>fracture in cross-cultural and prospective studies.9,10 When

>carbohydrate is limited and a ketotic state is induced, this effect

>is magnified by the metabolic acidosis produced.3 In a 2002 study of

>10 healthy individuals who were put on a low-carbohydrate, high-

>protein diet for six weeks under controlled conditions, urinary

>calcium losses increased 55 percent (from 160 to 248 mg/d, P <

>0.01).13 The researchers concluded that the diet presents a marked

>acid load to the kidney, increases the risk for kidney stones, and

>may increase the risk for bone loss.

>

>5. Complications of diabetes. In diabetes, renal impairment and

>cardiovascular disease are particularly common. The use of diets

>that may further tax the kidneys and may reduce arterial compliance

>is not recommended. Furthermore, contrary to some news reports,

>diets high in complex carbohydrates and low in fat do not impair

>glucose tolerance; in fact, most evidence indicates that such diets

>improve insulin sensitivity.

>

>In individuals with diabetes, the principal strategies for

>preventing or slowing impairment of renal function include

>controlling blood glucose levels, blood pressure, and

>hyperlipidemia, and decreasing protein intake to low normal levels.

>The beneficial effect of low-protein diets in diabetic nephropathy

>has been confirmed in two recent meta-analyses, with no adverse

>effects on the glycemic control.14

>

>While high-protein diets may carry potential health risks for anyone

>if maintained for more than a few weeks, they are clearly

>contraindicated for individuals with recurrent kidney stones, kidney

>disease, diabetes, osteoporosis, colon cancer, or heart disease.

>

>

>home

>

>Misunderstandings and Deceptive Statements

>Recent prominent news stories have encouraged the circulation of

>significant misunderstandings among members of the public, sometimes

>further encouraged by inaccurate information produced in the course

>of media interviews. Some patients may be confused or misled about

>important dietary issues based on the following inaccurate notions:

>

>1. " High-protein diets cause dramatic weight loss. "

>As noted above, the weight loss typically occurring with high-

>protein diets—approximately 20 pounds over the course of six months—

>is not demonstrably different from that seen with other weight-

>reduction regimens or with low-fat, vegetarian diets. Anecdotal

>accounts of greater weight loss are atypical and may represent the

>additional effects of exercise or other factors.

>

>2. " Fatty foods must not be fattening, because fat intake fell

>during the 1980s, just as America's obesity epidemic began. "

>Some news stories have encouraged the public to discount health

>warnings about dietary fat and saturated fat, suggesting that fat

>intake declined during the 1980s, an era during which obesity became

>more common. However, food surveys from the National Center for

>Health Statistics from 1980 to 1991 show that daily per capita fat

>intake did not drop during that period. For adults, fat intake

>averaged 81 grams in 1980 and was essentially unchanged in 1991.

>While the American public added sodas and other non-fat foods to the

>diet, forcing the percentage of calories from fat to decline

>slightly, the actual amount of fat in the American diet did not drop

>at all.

>

>A notable contributor to fat intake during that period was cheese

>consumption. Per capita cheese consumption rose from 15 pounds in

>1975 to more than 30 pounds in 1999. Typical cheeses derive

>approximately 70 percent of energy from fat and are a significant

>source of dietary cholesterol.

>

>3. " Fat and cholesterol have nothing to do with heart problems. "

>Abundant evidence has established the ability of dietary fat and

>cholesterol to increase cardiovascular disease risk. Nonetheless,

>some popular-press articles have suggested that evidence supporting

>this relationship is weak and inconsistent. In addition, widely

>circulated news reports of a cardiac arrest suffered by the late

>diet-book author Atkins have suggested that neither diet nor

>atherosclerosis played any role in the unfortunate event. The net

>result of such reporting may be to suggest that individuals may

>disregard well-established contributors to heart disease.

>

>4. " Meat doesn't boost insulin; only carbohydrates do, and that's

>why they make people fat. "

>Popular books and news stories have encouraged individuals to avoid

>carbohydrate-rich foods, suggesting that high-protein foods will not

>stimulate insulin release. However, contrary to this popular myth,

>proteins stimulate insulin release, just as carbohydrates do.

>Clinical studies indicate that beef and cheese cause a bigger

>insulin release than pasta, and fish produces a bigger insulin

>release than popcorn.13

>

>5. " People who eat the most carbohydrates tend to gain the most

>weight. "

>Popular diet books point out that a carbohydrate restriction may

>induce ketosis as well as a reduction in energy intake, resulting in

>temporary weight loss. This has been misinterpreted as suggesting

>that carbohydrate-rich foods are the cause of obesity. In

>epidemiological studies and clinical trials, the reverse has been

>shown to be true. Many people throughout Asia consume large amounts

>of carbohydrate in the form of rice, noodles, and vegetables, and

>they generally have lower body weights than Americans—including

>Asian Americans—who eat large amounts of meat, dairy products, and

>fried foods. Similarly, vegetarians, who generally follow diets rich

>in carbohydrates, typically have significantly lower body weights

>than omnivores.

>

>

>home

>

>Legal Liability

>Given the possibility of health risks that may occur with long-term

>use of high-protein diets, clinicians who prescribe such diets may

>put themselves into a position of potential legal liability.

>

>High-Protein Diet Registry Established

>In order to assist consumers and consulting clinicians, the

>Physicians Committee for Responsible Medicine has established a

>registry for individuals who have elected to follow high-protein

>diets or have been prescribed them by practitioners. Individuals

>signing onto the registry can report their experience with such

>diets and will find information on medical research and on legal

>issues that may relate to liability.

>

>

>home

>References:

>1. Westman EC, Yancy WS, Edman JS, Tomlin KF, Perkins CE. Effect of

>6-month adherence to a very low carbohydrate diet program. Am J Med

>2002;113:30­6.

>2. GD, et al. A randomized trial of a low-carb diet for

>obesity. N Engl J Med 2003;348:2082-90.

>3. Samaha FF, et al. A low-carbohydrate as compared with a low-fat

>diet in severe obesity. N Engl J Med 2003;348:2074-81.

>4. Ornish D, Brown SE, Scherwitz LW, Billings JH, Armstrong WT,

>Ports TA. Can lifestyle changes reverse coronary heart disease?

>Lancet 1990;336:129­33.

>5. Bravata DM, L, Huang J, et al. Efficacy and safety of low-

>

>carbohydrate diets: a systematic review. JAMA 2003;289:1837-50.

>6. Wiederkehr M, Krapf R. Metabolic and endocrine effects of

>metabolic acidosis in humans. Swiss Med Wkly 2001;131:127­32.

>7. St Jeor ST, BV, Prewitt TE, Bovee V, Bazzarre T, Eckel RH;

>Nutrition Committee of the Council on Nutrition, Physical Activity,

>and Metabolism of the American Heart Association. Dietary protein

>and weight reduction: a statement for healthcare professionals from

>the Nutrition Committee of the Council on Nutrition, Physical

>Activity, and Metabolism of the American Heart Association.

>Circulation 2001;104:1869­74.

>8. World Cancer Research Fund/American Institute for Cancer

>Research. Food, Nutrition, and the Prevention of Cancer: a global

>perspective. World Cancer Research Fund/American Institute for

>Cancer Research, Washington, DC, 1997, pp. 216­51.

>9. Fleming RM. The effect of high-protein diets on coronary blood

>flow. Angiology 2000 Oct;51(10):817­26.

>10. Knight EL, Stampfer MJ, Hankinson SE, Spiegelman D, Curhan GC.

>The Impact of Protein Intake on Renal Function Decline in Women with

>Normal Renal Function or Mild Renal Insufficiency Ann Int Med

>2003;138:460-7.

>11. Nestel PJ, Shige H, Pomeroy S, Cehun M, Chin-g J. Post-

>prandial remnant lipids impair arterial compliance. J Am Coll

>Cardiol 2001;37:1929­35.

>12. Goldfarb DS, Coe FL. Prevention of Recurrent Nephrolithiasis. Am

>Fam Physician 1999;60:2269­76.

>13. Abelow BJ, Holford TR, Insogna KL. Cross-cultural association

>between dietary animal protein and hip fracture: a hypothesis.

>Calcif Tissue Int 1992;50:14­18.

>14. Feskanich D, Willett WC, Stampfer MJ, Colditz GA. Protein

>consumption and bone fractures in women. Am J Epidemiol 1996;143:472­

>

>9.

>15. Reddy ST, Wang CY, Sakhaee K, Brinkley L, Pak CY. Effect of low-

>carbohydrate high-protein diets on acid-base balance, stone-forming

>propensity, and calcium metabolism. Am J Kidney Dis 2002;40:265­74.

>16. Gin H, Rigalleau V, Aparicio M. Lipids, protein intake, and

>diabetic nephropathy. Diabetes Metab 2000 Jul;26 Suppl 4:45­53.

>17. Holt SHA, Brand JC, Petocz P. An insulin index of foods;

>the insulin demand generated by 1000-kJ portions of common foods. Am

>J Clin Nutr 1997;66:1264­76.

>

>http://www.atkinsdietalert.org/physician.html

>_________________

>

>JoAnn Guest

>mrsjoguest@...

>DietaryTipsForHBP

>http://www.geocities.com/mrsjoguest

>

>

>Community Newsletters.

>http://www.alternative-medicine-newsletter.info

>

>Community Message Boards.

>http://www.alternative-medicine-message-boards.info

>

> " Do not let either the medical authorities or the politicians mislead you.

>Find out what the facts are, and make your own decisions about how to live

>a happy life and how to work for a better world. " - Linus ing

>

>Getting well is done one step at a time, day by day, building health and

>well being.

>

> group.

>list or archives: Alternative_Medicine_Forum

>

>subscribe:........ Alternative_Medicine_Forum-subscribe

>post:............. alternative_Medicine_Forum

>digest form:...... Alternative_Medicine_Forum-digest

>individual emails: Alternative_Medicine_Forum-normal

>no email:......... Alternative_Medicine_Forum-nomail

>moderator:........ Alternative_Medicine_Forum-owner

>unsubscribe:...... Alternative_Medicine_Forum-unsubscribe

>

>

>

>

>

>

>