Most know that “low-carb” diets are out. With concerns over a higher risk of damaged arteries and heart attacks that could accompany certain low-carb diets, their popularity has waned so much that Atkins Nutritionals Inc. experienced financial difficulty back in mid-2005. However, research continues to show substantial clinical support for including higher amounts of protein, especially from plant sources, into the diet. Additionally, 41% of consumers are seeking foods high in protein, according to the Natural Marketing Institute’s (NMI) 2005 Health & Wellness Database. (See chart “Protein Profiles.”)
An increase in new healthful product introductions realistically promoting protein for weight loss would be predicted to follow suit. Beyond the diet category, new developments in how proteins affect sports performance and heart health are opening new product opportunities for functional foods. According to NMI’s 2005 Health & Wellness Database, the top three health benefits that consumers associate with protein, however, are weight management, bone health and skin health. Despite the low-carb sales, nutritional products with proteins have held fairly steady. (See chart “Sales in Protein Consumer Products.”)
One of the latest theories of how high-protein diets may help combat obesity and promote weight loss comes from new understanding of the role of the gut hormone called peptide YY (PYY). PYY is an important appetite suppressor that apparently leads to a reduction in body weight.
In 2002, the journal Nature published a paper (Batterham RL, et al. 2002. Nature, 418:650) that explained how PYY physiologically inhibits food intake. Since this date, the research on PYY has been steadily increasing. In 2006, another paper (Batterham RL, et al. 2006. Cell Metab., 4:223) was again published on PYY reporting that dietary protein enhances satiety and promotes weight loss, “but (that) the mechanisms by which appetite is affected remain unclear.”
One clinical study that showed high-protein diets increase levels of PYY involved 20 participants. In the trial, 10 men of normal weight and 10 obese males were given isocaloric meals that were high in either protein, fat or carbohydrates, and their blood samples were analyzed. The high-protein diet resulted in the highest reduction in appetite in both the normal weight and obese participants (and the highest PYY levels). To determine if PYY was involved in mediating appetite, a mouse model was created that lacked the PYY protein. The mice fed any of the diets lacked control of appetite and became obese. When PYY was supplemented to the mice, their appetite and weight both became reduced to normal levels, and when PYY was taken out of their diets, they gained weight again.
Could this lead to the development of functional foods or dietary supplements that could supplement PYY? The answer appears to be no, as PYY is a protein which will be broken down by the body if delivered orally; therefore, it would need to be delivered by intravenous, subcutaneous, transdermal or nasally in order to get the benefits of supplementation of exogenous PYY. However, it appears that endogenous PYY can be altered in humans through the alteration of dietary constituents, such as a high-protein diet, lending credence once again to eating higher levels of protein. Batterham has not advocated the Atkins diet. She says that the low-carb approach does not necessarily mean high protein, but that many people increase fat when they cut out carbs.
What kind of products can take advantage of this research? There are a large number of new product introductions that focus on protein. Protein powders are coming from many different sources, such as hemp and goat milk. For example, Manitoba Harvest’s Organic Hemp Protein Powder notes that it is made of 100% raw, cold-milled hemp protein powder and is said to be rich in complete protein (38%), branched-chain amino acids, omega-6 and 3 essential fatty acids (EFAs) and has “healthy dietary fiber, 46%.” Goat protein powder from Garden of Life is claimed to contain all the essential amino acids and be easier to digest and less likely to be allergenic (because it is from goat’s milk) than cow’s milk. Its Goatein Ig claims to be the only protein supplement on the market containing fermented protein with immunoglobulin G. It notes that IgG is a class of naturally occurring immune proteins, commonly called gamma globulins, that act as antibodies and play a role in immunity.
Protica claims to have introduced the world’s first capsulized ready-to-drink protein beverage. Each vial-shaped container has 2.7oz of drink that delivers 25g of protein with no carbs and no fat and 50% of the recommended daily allowance of B vitamins, as well as aspartame.
Even noni producers are tapping in on the protein drink market, as Tahitian Noni International has introduced four high-protein drinks. These drinks contain a protein complex consisting of soy protein, total milk protein isolate, whey protein isolate, egg white protein and noni fruit protein concentrate.
However, many of the most popular uses for protein-based ingredients remain a bit more pedestrian. (See chart “Protein Utilization.”) The categories of “snack bars” and “meals and entrées” remain the most popular application for proteins such as those from whey, soy and egg.
Expounding on Sports
New protein advances also have been made in the sports area. Four studies by the company PacificHealth Laboratories for its Accelerade brand found that the optimum protein to carbohydrate ratio is 1:4; if protein is too high while exercising, then performance slows and rehydration decreases (see website www.enduroxr4.com/pages/ studies.html). However, too little protein brings no benefits. The four studies were presented at the American College of Sports Medicine. Compared to carbohydrate-only drinks like Gatorade, its competitor, Accelerade was said to have increased exercise performance, muscle function, exercise endurance and decreased muscle fatigue, muscle damage and soreness. One independent study found Accelerade increased endurance 29% and decreased muscle damage by 83%. Accelerade is available as both a ready-to-mix powder and also a sports gel. The brand, first introduced some five years ago, added a lemon-flavored product to its line in 2006, according to Mintel.
Another new study showed that ingesting whey protein and creatine monohydrate supplements before muscle-building exercise improves the muscle gain potential. In the study, men were divided into groups and given supplements either right before exercise (resistance training) or at other times of the day. The authors of the study see this advancement as good information not just for body-builders but for the general population who should try building muscle as part of healthy aging (Cribb P and Hayes A, 2006. Medicine & Science in Sports & Exercise. 38:1918). Cribb, the lead author on the study, is also director of research for AST Sports Science, a company that offers creatine and whey supplements. He writes a blog on the company’s website.
Soy for heart health is old news; however, a new study reiterates that soy protein (not isoflavones) is responsible for lowering blood lipids and (potentially) the heart-healthy benefits. In this study, soy protein, independent of isoflavone content, produced serum lipid changes consistent with lowering cardiovascular risk. Three different soy extracts (milk protein isolates) were tested in the study: one with 32g of protein and no isoflavones; another was a low-isoflavone soy protein isolate with 32g of protein; and a third with 32g of protein and 62g of isoflavones. The trio was tested, and blood lipid levels were measured. In both isoflavone-containing groups, the blood ratios were not as favorable as the group with just straight milk protein, and because blood lipid ratios are considered a better way to predict cardiovascular health, the authors suggested further research should be conducted to determine the effects of processing on the composition of soy protein and how this affects lipid levels (McVeigh BL, et al. 2006. Am J Clin Nutr. 83:244).
Another study (Appel LJ, et al. 2005. JAMA, 16;294:2455-64) found that substituting about 10% of calories from carbohydrate to protein-rich sources (mostly from vegetable proteins) or to monounsaturated fats (like those contained in olive and canola oil) had more heart-healthy benefits than a carbohydrate-rich diet, like the Dietary Approaches to Stop Hypertension (DASH). (See chart “DASH Goals.”)
Again, the benefits of vegetable vs. animal protein were highlighted when a study followed 4,680 people in China, Japan, the U.S. and the U.K. and found that a five-a-day diet produced results consistent with the World Health Organization’s advice of following this diet for lowering the incidence of heart disease. However, this study found that vegetable protein, not animal protein, produced lower blood pressure (Elliot P, et al., 2006. Arch Intern Med. 166:79).
New technologies involving proteins are affecting both food and ingredient developments. A team of food scientists have created and been awarded a patent for a new kind of tortilla that is low-fat, low-carb and soy-free. This high-protein tortilla has less than 0.5g of fat per 50g and 70% animal protein content from poultry, beef or fish. According to the researchers, this tortilla will have a longer shelflife due to the high protein content, and will be more durable with less tearing when rolled or folded. The brand name for these tortillas is Flaquitas, marketed by the U.S. company Aspirion.
In the ingredient area, proteins are hot for many functions. One new use of proteins is that certain milk proteins form nanotubes that may become a new food technology for gelling and encapsulation (Graveland-Bikker and C. de Kruif, 2006. Trends Food Sci Technol,17:196). One soy protein supplier has announced the introduction of an ingredient that may reduce the cost of formulating nutrition bars and increase shelflife. It does this by delivering at least 50% of the protein in nutritional bars without affecting sensory qualities, and it has the secondary benefit of increasing shelflife. Another supplier has launched a new textured soy protein said to have a texture closer to whole- muscle meat than what is now on the market.
We may be seeing only the beginning of new product development involving proteins. Science is showing that innovations in food technology, as well as advances in our understanding of the role of proteins, are opening a whole new approach to human dieting and consumption. NS