Proteins are probably the most important class of biochemical molecules essential for life, perhaps only behind water. They are the foundation of human tissue and cell reproduction. Most diets are believed to be protein deficient. The Institute of Medicine (IOM) at the National Academy of Sciences has established the recommended intake of quality protein. If you exercise regularly these levels may be insufficient for optimal health. CLICK HERE FOR AN INTERACTIVE POST DISCUSSING TOP PROTEIN SOURCES and concern about vegetarian and vegan diets for those people whose body type needs animal source protein for optimal healthy longevity.
The Dietary Reference Intake (DRI) for healthy adults is:
0.37 grams of quality protein per pound of body weight per day. This computes to:
- 45 grams of quality protein per day for a 125 pound person
- 91 grams of quality protein per day for a 250 pound person
SO HOW DO YOU GET THAT MUCH PROTEIN WITHOUT BEING OVERWEIGHT?
An egg contains about 7 grams of protein. Milk contains 8 grams of protein per 8 ounce cup and an increasing amount of health professionals are not impressed with the nutrient value or protein quality in pasteurized milk. To get 64 grams of protein from eggs, you would need to eat 9 eggs each day.
Proteins consist of amino acidunits. There are 20 recognized amino acids your body needs daily, 8 or 9 of which are deemed “essential” and can only come from a food sources. Good dietary protein must provide all essential amino acids that participate in the body’s metabolic and physiologic systems including the intestine, skeletal muscle, and the cardiovascular, nervous, and immune systems. Protein turnover in these body systems is continuous and supplementation with quality products is a good way to assure steady supply of the fuel needed for cell health and life extension.
Recent analyses of the dietary protein needs of people suggest that age and activity level influences protein requirement for optimum health. For example, elderly adults may have a significantly higher protein requirement than that of young adults and may be deficient due to reduced appetite and poor diet. This requirement may be as high as 1.0 g protein per kg body weight per day, or 25% more than that suggested for a young adult. This higher requirement may derive from a lower efficiency of protein utilization in advancing age. Some scientists also suggest increased protein synthesis needs following exercise. Athletes competing in body building or endurance sports may require significantly more protein than normal.
All Proteins are not alike
Some of the protein you eat contains all the amino acids needed to build new proteins. This kind is called complete protein. Animal sources of protein tend to be complete but getting only high quality toxin free animal food sources is difficult and expensive today. Also it is not uncommon for people to over-eat animal source proteins which contributes to other health problems. Other protein sources lack one or more “essential” amino acids—that is, amino acids that the body can’t make from scratch or create by modifying another amino acid. Called incomplete proteins, these usually come from fruits, vegetables, grains, and nuts.
Vegetarians need to be aware of this - CLICK HERE FOR AN INTERACTIVE POST DISCUSSING TOP PROTEIN SOURCES.
Watch this interesting video of Dr. Terry Shintani – President, Hawaii Health Foundation; Associate Chair, Dept of Complementary and Alternative Medicine, University of Hawaii School of Medicine where he concludes you can get all the protein you need from a plant based diet.
Protein Products Today
Protein supplements are one of the more popular product categories today. Plant proteins (examples are brown rice, hemp, and pea), whey proteins, egg proteins and others are emerging. They are not, however, well understood and easy comparisons are not available. Goat milk derived protein supplements are expensive but more bio-available than whey according to recent research.
Our favorite protein supplement sources are Meal Replacement Products that have a variety of protein sources combined with fruits, vegetables, enzymes, probiotics and other nutrient sources in combination as opposed to pure protein supplemental products popular with many athletes and body builders.
Common Protein Food Sources
Protein can help you shed pounds and keep your belly full. The following list is a summary of WebMD’s advice on protein. WebMD is good to reference but hardly comprehensive or leading edge information source relating to natural health and nutritional science:
- Seafood (one of the best sources low in fat), such as salmon
- White meat poultry (excellent, lean protein. Dark meat is higher in fat. The skin is loaded with saturated fat, so remove skin before cooking)
- Milk, Cheese and Yogurt (dairy foods are excellent sources of protein with valuable calcium)
- Eggs (one of the least expensive forms of protein – normal healthy adults can safely enjoy an egg a day – organic cage free eggs are superior)
- Beans (One-half cup of beans contains as much protein as three ounces of broiled steak and are loaded with fiber to keep you feeling full)
- Other Lean Animal Meats (Pork and lean beef are examples of versatile meat wit zinc, iron and B12)
- Soy (See caution below regarding soy protein supplements)
- Meal replacement drinks, protein bars, and most energy bars now contain useful protein. Make sure they are low in sugar and fat and have at least 30% protein by weight.
- Visit our superfood section in the member store for some 60% protein by weight excellent wide array food concentrate powders
- Hemp, Spirulina, Brown Rice, Nopal Cactus and other gluten free plant protein sources should increasingly be considered for daily use.
How much protein do I need each day?
There is no one-size-fits-all answer to that question. The Institute of Medicine recommends that adults get a minimum of 0.8 grams of protein for every kilogram of body weight per day—that’s about 64 grams for a 160 pound adult. In the U.S., adults get an average of 15 percent of their calories from protein; for a person who requires a 2,000-calorie-per-day-diet, that’s about 75 grams of protein. In healthy people, increasing protein intake to 20 to 25 percent of calories can reduce the risk of heart disease, if the extra protein replaces refined carbohydrates, such as white bread, white rice, or sugary drinks. Higher protein diets can also be beneficial for weight loss, in conjunction with a reduced calorie diet, although long-term evidence of their effectiveness is controversial and lacking.
The clear trend is toward increased personalized protocols- both diet, exercise and medications – based on more knowledge about the world and improved testing and evaluation to understand your personal characteristics.
As general rules, for people in good health:
- consuming 20 to 25 percent of calories from protein should not harm the kidneys
- for people with diabetes or early-stage kidney disease, however, the American Diabetes Association recommends limiting protein intake to 0.8 to 1.0 gram of protein per kilogram of body weight (roughly 10 percent of energy intake), since this may help improve kidney function;
- in later stage kidney disease, sticking to the 0.8 grams per kilogram minimum is advisable.
Are high-protein diets bad for the heart?
One concern about the high-protein diet craze has been that eating diets high in protein and fat, and low in carbohydrate, would harm the heart. Recent research provides reassurance that eating a lot of protein doesn’t harm the heart. In fact, it is possible that eating more protein, especially vegetable protein, while cutting back on easily digested carbohydrates may benefit the heart. A 20-year prospective study of 82,802 women found that those who ate low-carbohydrate diets that were high in vegetable sources of fat or protein had a 30 percent lower risk of heart disease, compared with women who ate high-carbohydrate, low-fat diets. But women who ate low-carbohydrate diets that were high in animal fats or proteins did not have a reduced risk of heart disease.
So if you are going on a lower carbohydrate diet, do your heart a favor by choosing vegetable fats and protein sources. And to reduce the risk of colon cancer, limit red meat to no more than 18 ounces per week, and avoid processed meats. See our articles, Top Five Cancer Causing Foods, on cancer to learn about the growing direct link between processed meats and food and cancer and other chronic illnesses.
Protein and Chronic Disease
The most solid connection between protein and health has to do with allergies. Proteins in food and the environment are responsible for these overreactions of the immune system. Beyond that, relatively little evidence has been gathered regarding the effect of protein on the development of chronic diseases.
Cardiovascular disease: One concern about the high-protein diet craze has been that eating diets high in protein and fat, and low in carbohydrate, would harm the heart. Recent research provides reassurance that eating a lot of protein doesn’t harm the heart.
In fact, it is possible that eating more protein, especially vegetable protein, while cutting back on easily digested carbohydrates may benefit the heart. A 20-year prospective study of 82,802 women found that those who ate low-carbohydrate diets that were high in vegetable sources of fat or protein had a 30 percent lower risk of heart disease, compared to women who ate high-carbohydrate, low-fat diets. (4) But women who ate low-carbohydrate diets that were high in animal fats or proteins did not have a reduced risk of heart disease.
Diabetes: Although proteins found in cow’s milk have been implicated in the development of type 1 diabetes (formerly called juvenile or insulin-dependent diabetes), ongoing research has yielded inconsistent results. (5) The amount of protein in the diet doesn’t seem to adversely affect the development of type 2 diabetes (formerly called adult-onset diabetes), although research in this area is ongoing. A recent 20-year prospective study in women suggests that eating a low-carbohydrate diet that is high in vegetable sources of fat and protein may modestly reduce the risk of type 2 diabetes.(26)
Cancer: There’s no good evidence that eating a little protein or a lot of it influences cancer risk. Eating a lot of red meat is linked to an increased risk of colon cancer, however, as is eating processed meat. (3)
Osteoporosis: Digesting protein releases acids that the body usually neutralizes with calcium and other buffering agents in the blood. Eating lots of protein, such as the amounts recommended in the so-called low-carb or no-carb diets, takes lots of calcium. Some of this may be pulled from bone. Following a high-protein diet for a few weeks probably won’t have much effect on bone strength. Doing it for a long time, though, could weaken bone. In the Nurses’ Health Study, for example, women who ate more than 95 grams of protein a day were 20 percent more likely to have broken a wrist over a 12-year period when compared with those who ate an average amount of protein (less than 68 grams a day). (6) But this area of research is still controversial, and findings have not been consistent. Some studies suggest increasing protein increases risk of fractures; others associate high-protein diets with increased bone -mineral density. The evidence is inconclusive, and more research is needed.
Protein and Weight Control
The notion that you could lose weight by cutting out carbohydrates and eating plenty of protein was once tut-tutted by the medical establishment, partly because such diets were based on little more than interesting ideas and speculation. In the past few years, head-to-head trials that pitted high-protein, low-carbohydrate diets against low-fat, high-carbohydrate diets have provided some evidence that a low-carbohydrate diet may help people lose weight more quickly than a low-fat diet, although so far, that evidence is short term.
In two short, head-to-head trials, low-carb approaches worked better than low-fat diets. (7, 8) A more-recent year-long study, published in 2007 in the Journal of the American Medical Association, showed the same thing. (9) In this study, overweight, premenopausal women went on one of four diets: Atkins, Zone, Ornish, or LEARN, a standard low-fat, moderately high-carbohydrate diet. The women in all four groups steadily lost weight for the first six months, with the most rapid weight loss occurring among the Atkins dieters. After that, most of the women started to regain weight. At the end of a year, it looked as though the women in the Atkins group had lost the most weight since the start of the study, about 10 pounds, compared with a loss of almost 6 pounds for the LEARN group, 5 pounds for the Ornish group, and 3½ pounds for the Zone group. Levels of harmful LDL, protective HDL, and other blood lipids were at least as good among women on the Atkins diet as those on the low-fat diet.
If you read the fine print of the study, though, it turns out that few of the women actually stuck with their assigned diets. Those on the Atkins diet were supposed to limit their carbohydrate intake to 50 grams a day, but they took in almost triple that amount. The Ornish dieters were supposed to limit their fat intake to under 10 percent of their daily calories, but they got about 30 percent from fat. There were similar deviations for the Zone and LEARN groups. What this and other diet comparisons tell us is that sticking with a diet is more important than the diet itself.
Why do high-protein, low-carb diets seem to work more quickly than low-fat, high-carbohydrate diets? First, chicken, beef, fish, beans, or other high-protein foods slow the movement of food from the stomach to the intestine. Slower stomach emptying means you feel full for longer and get hungrier later. Second, protein’s gentle, steady effect on blood sugar avoids the quick, steep rise in blood sugar and just as quick hunger-bell-ringing fall that occurs after eating a rapidly digested carbohydrate, like white bread or baked potato. Third, the body uses more energy to digest protein than it does to digest fat or carbohydrate. (10)
No one knows the long-term effects of eating high-protein diets with little or no carbohydrates. Equally worrisome is the inclusion of unhealthy fats in some of these diets. There’s no need to go overboard on protein and eat it to the exclusion of everything else. Avoiding fruits and whole grains means missing out on healthful fiber, vitamins, minerals, and other phytonutrients. It’s also important to pay attention to what accompanies protein. Choosing plant-based high-protein foods that are low in saturated fat will help the heart even as it helps the waistline. (4)
The Bottom Line: Recommendations for Protein Intake
- Get a good mix of proteins. Almost any reasonable diet will give you enough protein each day. Eating a variety of foods will ensure that you get all of the amino acids you need.
- Pay attention to the protein package. You rarely eat straight protein. Some protein comes packaged with healthful fiber and micronutrients, such as beans, nuts, and whole grains. Some protein comes packaged with lots of unhealthy fat, like when you eat marbled beef or drink whole milk. Fish and poultry are the best choices for meat eaters; if you are partial to red meat, such as beef, pork or lamb, steer yourself toward the leanest cuts, and make it only an occasional part of your diet. If you like dairy products, skim or low-fat versions are healthier choices.
- Balance carbohydrates and protein. Cutting back on highly processed carbohydrates and increasing protein intake improves levels of blood triglycerides and HDL, and so may reduce your chances of having a heart attack, stroke, or other form of cardiovascular disease. It may also make you feel full longer, and stave off hunger pangs.
- Eat soy in moderation. Soybeans, tofu, and other soy-based foods are an excellent alternative to red meat. But don’t go overboard. Two to four servings a week is a good target. And stay away from supplements that contain concentrated soy protein or soy extracts, such as isoflavones. Larger amounts of soy may soothe hot flashes and other menopause-associated problems, but the evidence for this is weak.
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