Cardiometabolic Health

Cardiometabolic health is a relatively new term that encompasses cardiovascular and metabolic diseases, including type 2 diabetes and metabolic syndrome. Collectively, such conditions are the leading cause of preventable death worldwide. They all share similar risk factors (e.g., overweight/obesity, elevated blood pressure) which can be modified by diet and lifestyle choices. The available evidence indicates that eggs, when consumed as part of an overall healthy diet pattern, do not affect risk factors for cardiometabolic disease. Recent recommendations from the American Heart Association, American College of Cardiology and American Diabetes Association do not limit egg or cholesterol intake, a change from earlier guidance from these organizations. In fact, several global health organizations, including Health Canada, the Canadian Heart and Stroke Foundation, the Australian Heart Foundation and the Irish Heart Foundation, promote eggs as part of a heart-healthy diet.

Given the public health significance of understanding cardiometabolic diseases, research on risk reduction remains an active area of pursuit. For example:

  • A randomized controlled study in people with metabolic syndrome showed that those consuming three whole eggs per day as part of a reduced carbohydrate diet experienced favorable changes in HDL-cholesterol, insulin sensitivity, and other aspects of the lipoprotein lipid profile
  • A randomized controlled weight loss trial in people with diagnosed type 2 diabetes showed improved lipid and glucose markers following consumption of 2 eggs per day for 12 weeks.
  • An egg-based breakfast, rich in protein (35% energy; 26.1 g egg protein), promoted glycemic control in people with type 2 diabetes and pre-diabetes relative to a high-carbohydrate breakfast.

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Eggs: A Nutrition Counselor’s Perspective

In honor of National Cholesterol Education Month, today’s blog post comes from Mary Donkersloot, a registered dietitian and nutrition consultant with a private nutrition practice in Beverly Hills, California. Donkersloot has helped individuals dealing with diabetes, heart disease, weight management, and eating disorders for more than 20 years. She is also one of ENC’s Health Professional Advisors.

When I was a child, eggs were considered a perfect food, and my mother felt she was doing a good thing by making them for us before she rushed us off to school.  The discovery of cholesterol and its link with heart disease has put that reputation into question.  With 180 milligrams of cholesterol in each egg yolk – nearly at the daily dietary recommendation of 300 milligrams for healthy Americans – we began to eat eggs sparingly, often feeling guilty when eating them.

But are the dangers of eggs all they are cracked up to be?  New research may indicate that they are not.  Studies have shown that adding an extra 200 milligrams of cholesterol a day to the diet increases blood cholesterol levels only slightly, with a minimal effect on heart disease risk.  I tell my clients that the benefits of eggs may outweigh that risk, since eggs are low in saturated fat and contain many other nutrients that are good for you – protein, folic acid, choline, lutein (good for eye health) and vitamin D.  So eggs effect on risk for heart disease can’t be understood only based on their cholesterol content.

Perhaps even more important, people respond in different ways to the cholesterol in their food.  Scientists sort people into two categories when it comes to cholesterol. The “responders” are those whose blood cholesterol goes up when they eat foods high in cholesterol and the “non-responders” are those who have little or no effect.

One of the favorite parts of my job as a registered dietitian is to help my clients sort out how to meet their individual dietary needs.  Based on any health concerns, weight and their current diet, I can help them map out a dietary approach that may involve decreasing refined carbohydrates, such as sugars and starches, rather than limiting eggs.  Many of my clients eat too many grains and/or sweets and not enough vegetables.  Perhaps they eat large portions, or consume too much saturated fat from meat or added fats.  These habits can lead to overweight and diseases linked to inflammation – diabetes, heart disease and certain kinds of cancer.  Current thinking is that inflammation may be caused by insulin, carbohydrate intake and excess body fat rather than saturated fat or dietary cholesterol.  This means, cutting out egg yolks does not solve the problem.

That said, for my patients who have diabetes or heart disease and struggle with dyslipidemia, elevated cholesterol or high triglycerides, we may have to take the step of limiting or eliminating egg yolks.  But for healthy people who want to stay healthy, the right balance of vegetable, fruits, whole grains, lean meat and dairy and lean protein – including eggs – is the best approach.  In fact, limiting eggs in order to lower cholesterol is not going to help most people achieve greater health.  Rather, for many, it will deprive them of a convenient and inexpensive source of nutrients.

It has been said that strong recommendations about cholesterol and eggs have been made based on very weak data.  It may have been the best information we had at the time, but current information suggests we consider the bigger picture and make sensible adjustments according to individual dietary and health need. So thanks, Mom, you were right on this one after all.

“What’s For Dinner?” Wednesday: What Eggs And Avocados Have In Common

Baked eggs in avocado

This week’s recipe pairs eggs with a trendy fruit, the avocado (indeed- it’s a fruit, not a vegetable). Avocados, also known as “alligator pears” due to their pear shape and bumpy, green skin, have gained much popularity the past several years. Grocery stores, restaurants and food manufacturers are all embracing the healthy benefits of avocados, which are frequently offered as a side of guacamole or a sandwich topping, but also go well with eggs.

Avocados are touted for their high content of heart healthy monounsaturated fatty acids (MUFAs), but what many health professionals may be surprised to learn is that approximately 23% of egg’s calories are from MUFAs. According to the American Heart Association, when replacing saturated fats in the diet, “monounsaturated fats can help reduce bad cholesterol levels in your blood and lower your risk of heart disease and stroke.”

Interestingly, foods high in MUFAs, such as eggs and avocados, are typically sources of vitamin E as well, a powerful antioxidant which may help prevent or slow chronic diseases by reducing damage from free radicals. Vitamin E can be found in egg yolks along with many other beneficial nutrients.

Enjoy this week’s recipe, Tomato and Avocado Egg Salad, a delicious meal which delivers 9g of monounsaturated fat and 10% Daily Value of vitamin E per serving and is also an excellent source of fiber, folate and choline.

2 avocados, chopped
1 cup chopped tomato
½ cup chopped red onion
¼ cup chopped fresh parsley OR cilantro
Spinach OR lettuce leaves

2 Tbsp. mayonnaise
2 Tbsp. sour cream
1 Tbsp. fresh lemon juice
½ tsp. salt
¼ tsp. hot pepper sauce

MIX dressing ingredients in small bowl. RESERVE and refrigerate 6 center slices from eggs for garnish. CHOP remaining eggs. COMBINE chopped eggs, avocados, tomato, onion and parsley in large bowl; toss gently to mix. ADD dressing; stir gently just until ingredients are evenly coated with dressing. REFRIGERATE at least 1 hour to blend flavors. SERVE on spinach leaves, garnished with reserved egg slices.

Nutrition Information:
Calories: 218, total fat: 17g, saturated fat: 4g, polyunsaturated fat: 3g, monounsaturated fat: 9g, cholesterol: 189mg, sodium: 316mg, carbohydrates: 10g, dietary fiber: 5g, protein: 8g, vitamin A: 867.9IU, vitamin D: 41.8IU, vitamin E: 3.2IU, folate: 89.6mcg, calcium: 51.0mg, iron: 1.5mg, choline: 139.8mg

Health Experts Share Insights on Recent Egg Research

As discussed in a previous post, the recent study on egg consumption published in Atherosclerosis was surprising and contradicts more than 40 years of research demonstrating that healthy adults can enjoy eggs without significantly impacting their risk of heart disease. As we continued watching news on the topic unfold, we saw that many health professionals had independently reviewed the study and voiced their interpretations of the study’s results on news, health and social media websites.

If you are interested in a detailed analysis of the study and what it means to you as a health professional, check out some of these insights from notable health and nutrition experts:

  • Sports dietitian Chris Mohr PhD, RD, explains on, “With this study there were a ton of controllable factors, which all can play a role in atherosclerosis, that weren’t examined.”
  • Further insights are provided by Sheah Rarback, MS, RD, in the Miami Herald. “Saturated and trans fatty acids are the primary culprits in raising blood cholesterol levels. Recent clinical studies on the effect of dietary cholesterol on plasma lipid levels have shown that it has a measurable — but mostly clinically insignificant — effect on plasma cholesterol levels.”
  • Dr. Briffa continues on, “Another fundamental problem with research of this nature as it relies on individuals reporting how much and/or often they eat of specific foods.”
  • Susan Dopart, MS, RD, CDE agrees with this position on “Research shows that when you have patients ‘recall’ what they ate, especially over many years like this study did, the accuracy is quite questionable.”
  • Taking a closer look at the data on Health Goes Strong, Robyn Flipse, MS, RD, points out, “What the research did show is that eating eggs improves the overall blood cholesterol profile, but that was nowhere to be found in the headline.”
  • When asked about the study by ABC News, Dr. Steve Nissen of the Cleveland Clinic cautioned, “It is extremely important to understand the differences between ‘association’ and ‘causation’.”
  • Putting things into perspective, Elizabeth Ward, MS, RD blogged on WebMD, “This is a single, observational study that does not prove cause and effect and does not change the fact that more than 40 years of research suggests that healthy people can eat eggs without having a significant impact on their risk for heart disease.”
  • Martha McKittrick, RD, CDN, CDE offers a good piece of advice for consumers on City Girl Bites, “The majority of studies have shown that eggs can fit into a healthy diet. The key is moderation. The effect of the cholesterol found in eggs on blood cholesterol will vary from individual to individual.”
  • Concluding her article in the Clarion Ledger, Kathy Warwick, RD, CDE states, “Eggs are a nutritious low-calorie, high protein food that provide 13 essential vitamins and minerals. As with all things dietary, eggs can be part of healthy balanced diet. Daily exercise and maintaining a healthy weight are crucial for preventing heart disease.”

Obviously, many health experts agree there are several limitations to the study and the results should be interpreted in light of the entire body of research on eggs, cholesterol and heart disease. We would like to thank the many health professionals who have shared their insights and continue to inform consumers about the nutritional benefits of eggs!

Egg Research Update: Atherosclerosis Study

A study published in the journal Atherosclerosis last week suggested that eating eggs can be almost as damaging to you heart as smoking cigarettes. Maybe you’ve seen the press coverage? It was all over the media last week and, needless to say, it kept us pretty busy at the Egg Nutrition Center. First thing we did was contact seven cardiovascular researchers for their perspectives on the study; three of the seven are among the leading epidemiology researchers in the country. All pointed out a number of flaws in the study design, ranging from:

  • “this was a cross sectional study and, as such, it is impossible to reach a case-and-effect conclusion”
  • “there didn’t appear to be any dietary control for other dietary constituents (besides eggs)—a fatal flaw”
  • “the failure (of the researchers) to adjust…for age is a major if not fatal flaw”
  • “the subjects were already sick…this is the classic setup for reporting bias that could lead to exactly the results that they found in that those who were sickest reported the highest egg intakes…”.

And on and on. Most of the researchers we queried wondered how the study was accepted for publication considering its flaws.
It should be noted that the lead researcher on this project has had issues with eggs before. A couple of years ago he was quoted as saying that an egg was worse for you than a Kentucky Fried Chicken Double Down sandwich (a breadless sandwich with three pieces of fried chicken; 540 kcals; almost 40 gms fat; 1400 mg sodium). A dubious statement, to say the least, but one that may help explain a pre-conception the author has about eggs that may have carried over into the recent study.

It is always a shame when studies of this nature garner so much media attention. While it would have been nice for reporters to have done their homework first and uncovered some of the flaws and biases associated with this study before running with it, I suppose that the headline (Eggs are as Bad as Cigarettes) was just too tantalizing to pass up.

At the Egg Nutrition Center we’ll continue to study the effects of eggs on human health as we’ve always done, and we’ll let the chips fall where they may regarding the results of the projects we fund. We adhere to the Guidelines for Industry Funded Research and request that all investigators who work with us do the same. We realize that not every study will yield a positive result; that’s the nature of science. The key is to support well- designed, well-controlled studies so that you can feel good about the results, whatever they happen to be. In the case of the recent Atherosclerosis paper, I’m not so sure that’s what we got.

Advances in Protein Research

Is it just me or is there growing interest in understanding the importance of the long overlooked macronutrient protein? Protein has always seemed like the Cinderella of diet planning. Carbohydrates and fats always commanded much more attention in dietary guidance, including protein as only afterthought.

As the baby boomer generation enters their senior years there seems to be a growing concern about keeping healthy through diet and exercise. Baby boomers are seeing that the high carbohydrate/low fat meals they were advised to prepare left them perpetually hungry and often at risk of cardiovascular disease related to the unattractive spare tire around their abdomen.  It’s time to ask why have the last 20 years seen an epic growth of obesity, metabolic syndrome and little change in the cardiovascular disease rates despite this supposedly healthy dietary advice?

Enter the shocking success of the Atkins/South Beach diets that found followers experienced more sustained relief from hunger and improved cardiovascular risk factors resulting from a reduction in carbohydrates and an increase in both fat and protein intake. People who previously sacrificed their favorite full fat meat, cheese and chicken dishes found that they could eat these foods again if they gave up white rice, bagels and pasta and surprisingly, were rewarded with increased high density lipoprotein levels along with reduced triglycerides and body weight garnering praise from their physician.

Now the scientific community appears to be catching up with the success of the higher protein intake. Two published studies1,2 looked at the effect of high protein intake on diabetes control.  In the Why WAIT (Weight Achievement and Intensive Treatment) Program, developed at the Joslin Diabetes Center for diabetes weight management in clinical practice, a high protein-low carbohydrate (30% protein [1.5–2 g/kg] and 40% carbohydrates) energy–restricted diet was tried within a multidisciplinary diabetes weight management program for 12 weeks. The authors conclude that an intake of 1.0-1.5 gm/kg of protein is appropriate for diabetics, helping to improve many health risk factors including a lower HbA1c in addition to a reducing total serum cholesterol, LDL cholesterol, triglycerides, blood pressure and markers of inflammation. The researchers reported diabetic patients were less hungry after meals, which contributes to their lower calorie intake and subsequent reduced body weight while maintaining muscle mass. The authors do however make the point that a higher protein intake may be contra- indicated in patients with diabetes accompanied by chronic kidney disease.

More recently, a study published in Advances in Nutrition 3 suggests the brain’s control of appetite is greatly affected by protein intake. From both animal and human research the authors conclude that after protein consumption, peptide hormones are released from the gastrointestinal tract that communicates information about the peripheral energy status to the brain. These hormones control food intake by acting on brain regions involved in energy homeostasis such as the brainstem and the hypothalamus.  High-protein diets lead to greater activation than a normal-protein diet in the regions of the brain responsible for satiety. These areas are triggered particularly by leucine, a branched chain amino acid that influences the reward and motivation aspects of eating behavior and plays an important role in the reduced hedonic response associated with a high-protein intake.

1         Hamdy, O. Issues in Nutritional Treatment of Type 2 Diabetes Mellitus and Obesity, Current Diabetes Reports, April 2011, 11(2):75-6.

2         Hamdy, O. and Norton E.S. Protein Content in Diabetes Nutrition Plan, Current Diabetes Reports, April 2011, 11(2):111-9.

3         Journel, M. et. al. Brain Responses to High Protein Diets, Advances in Nutrition, 2012, 3:322-9.