Nutrition Science

Nutrition research is the underpinning of our programs and outreach. ENC is dedicated to providing accurate and up-to-date information on eggs, nutrition and health. Below is a collection of both ENC-funded research and relevant studies.

To learn more about our competitive research program, click here.

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Applying the Latest Research: Increasing Protein to Benefit Blood Pressure

Data from the NHANES 2005-2008 surveys shows that more than 30% of adult Americans have high blood pressure (HBP).1 It led to 330,000 deaths among Americans in 20072 and is responsible for more than 7 million deaths annually worldwide.1 In 2010, the healthcare costs and productivity losses related to HBP in the US were estimated to be $76.6 billion.1

Blood pressure is affected by many complex factors, and diet plays a key, but, modifiable role in its development. Therefore, it is important that we identify the impact of specific foods and nutrients on blood pressure in order to formulate effective population-based strategies for HBP prevention.  Dietary patterns, such as the Dietary Approaches to Stop Hypertension (DASH) that is characterized by higher intakes of fruits and vegetables and low-fat dairy, have been shown to have blood pressure-lowering effects in clinical trial settings. 3

Evidence from recent reviews4;5 and meta-analyses6;7 suggests that dietary protein consumption may benefit blood pressure, although questions remain regarding the effects of different types of protein. In fact, there are few observational studies (and no clinical trials) that have addressed the differential long-term effects of animal and plant proteins on blood pressure, and the results of the studies are conflicting.8-10
AJH-Logo-300x44In our current study, we used blood pressure data from 11 years in the Framingham Offspring Study to quantify the long-term effects of different amounts and types of protein on blood pressure, as well as the risk of high blood pressure. We used statistical modeling to account for other factors, such as physical activity or smoking habits, in our analyses. After adjusting for these factors, we saw that higher intake of total protein as well as both animal and plant proteins led to lower systolic and diastolic blood pressures at the follow-up exams. And this was true for both normal-weight and overweight (BMI ≥ 25 kg/m2) middle-aged adults.

We also observed that increased intakes of both animal and plant proteins led to about 30-50% reductions in the risk of HBP. Participants in the highest protein intake category (consuming about 103 g/day) had a 40% lower risk of developing HBP over the next 10 or so years. When people who had higher protein diets also consumed more dietary fiber, there was an even greater benefit – they had a 51% lower risk of HBP.

There are relatively few long-term studies of protein and blood pressure. Overall, we found that there was no adverse effect of either animal or plant protein on HBP risk among these middle-aged adults. In fact, those consuming more protein had significant reductions in high blood pressure risk. Thus, if you’re concerned about your clients’ risk of HBP, we found no reason for you to recommend that they avoid foods containing protein. Finally, since there are many different pathways in the body that lead to HBP, and since different foods and nutrients act on different pathways, we think that it is probably important to consume protein from a variety of sources (e.g., eggs, nuts, dairy, poultry, legumes, soy, meat, fish, etc.).



  1. Vital signs: prevalence, treatment, and control of hypertension–United States, 1999-2002 and 2005-2008. MMWR Morb Mortal Wkly Rep 2011;60:103-108.
  2. Ezzati M, Lopez AD, Rodgers A, Vander HS, Murray CJ. Selected major risk factors and global and regional burden of disease. Lancet 2002;360:1347-1360.
  3. Appel LJ, Moore TJ, Obarzanek E, Vollmer WM, Svetkey LP, Sacks FM, Bray GA, Vogt TM, Cutler JA, Windhauser MM, Lin PH, Karanja N. A clinical trial of the effects of dietary patterns on blood pressure. DASH Collaborative Research Group. N Engl J Med 1997;336:1117-1124.
  4. Altorf-van der Kuil W, Engberink MF, Brink EJ, van Baak MA, Bakker SJ, Navis G, van ‘t V, Geleijnse JM. Dietary protein and blood pressure: a systematic review. PLoS One 2010;5:e12102.
  5. Teunissen-Beekman KF, van Baak MA. The role of dietary protein in blood pressure regulation.Curr Opin Lipidol 2013;24:65-70.
  6. Tielemans SM, Altorf-van der Kuil W, Engberink MF, Brink EJ, van Baak MA, Bakker SJ, Geleijnse JM. Intake of total protein, plant protein and animal protein in relation to blood pressure: a meta-analysis of observational and intervention studies. J Hum Hypertens 2013;27:564-571.
  7. Rebholz CM, Friedman EE, Powers LJ, Arroyave WD, He J, Kelly TN. Dietary protein intake and blood pressure: a meta-analysis of randomized controlled trials. Am J Epidemiol 2012;176 Suppl 7:S27-S43.
  8. Alonso A, Beunza JJ, Bes-Rastrollo M, Pajares RM, Martinez-Gonzalez MA. Vegetable protein and fiber from cereal are inversely associated with the risk of hypertension in a Spanish cohort. Arch Med Res 2006;37:778-786.
  9. Liu K, Ruth KJ, Flack JM, Jones-Webb R, Burke G, Savage PJ, Hulley SB. Blood pressure in young blacks and whites: relevance of obesity and lifestyle factors in determining differences. The CARDIA Study. Coronary Artery Risk Development in Young Adults. Circulation 1996;93:60-66.
  10. Stamler J, Liu K, Ruth KJ, Pryer J, Greenland P. Eight-year blood pressure change in middle-aged men: relationship to multiple nutrients. Hypertension 2002;39:1000-1006.

The Multi-Functional Egg

Chef eggs

NawalToday’s blog post is written by Nawal Al-Nouri, ENC’s Dietetic Intern. Nawal studies Nutrition and Dietetics at the University of Illinois at Chicago, and will be eligible to sit for the RD exam in December of 2013. She maintains a balanced lifestyle by staying active and exposing herself to new ideas, and enjoys cooking and experimenting with different food genres and flavors.

It may be interesting to learn that Columbus’ ships are believed to have carried the first of the chickens related to egg production in America today. It may also surprise you that eggs have several additional functions other than eating them scrambled, fried, poached, baked, in the shell, or as omelets.

Few foods are entirely as versatile as the egg. It has been stated that each of the one-hundred pleats on a chef’s toque represents a different way use eggs, and within each pleat are countless variations. Indisputably, there are other foods or products that can be used to perform similar functions as eggs in a certain setting, however no other food is known to match all properties of the egg. Below are a few unique purposes of the multi-functional egg:

Leaven- Eggs serve as a leavener to increase volume and add lightness to food due to their excellent ability to foam. Eggs, especially the whites, function to leaven soufflés, meringues, angel food cakes and more.


Emulsify- Emulsions may be oil droplets in water, such as mayonnaise or water droplets in fat, such as butter. Egg yolks are considered chemical
emulsifiers, so they have one end that dissolve in water and one dissolved in oil, which helps combine two otherwise immiscible liquids.

Bind & thicken- Eggs act as “glue” and bind ingredients in foods such as meatloaves and casseroles to keep them from crumbling, as well as thicken puddings and sauces.

Impede crystallization- If crystals in candies, frostings, or ice creams form too quickly, they will be small in number but large in size, resulting in an unpleasant grainy texture. Egg whites in particular are introduced as an interfering agent, slowing down the crystallization process to form many fine crystals, bringing about a smooth overall texture.

salmon-150x117Color- The proteins in the eggs influence the browning reactions of foods while the alkaline nature of eggs will help improve browning of acidic products by lowering their acidity. Eggs are responsible for the rich golden glow in custards, egg noodles and béarnaise sauce.

Moisturize & Dry- The fat in the yolk of the egg helps moisturize baked goods, while the white helps give that desired crisp dryness in baked goods such as cream puffs.

The functions of egg whites, egg yolks, and whole eggs are diverse—contributing to its resourcefulness. Adding eggs to your food items provide a wide variety of nutrients, increasing the quantity of essential nutrients specifically in desserts and sauces which may otherwise not provide adequate nutrient value. Check out the American Egg Board’s Eggcyclopedia for a more in depth look at the versatility of eggs.