Are Eggs Good For You?

Written by Dr. Steve Chaney on . Posted in Eggs and Health

Do Eggs Reduce Heart Disease Risk?

Author: Dr. Stephen Chaney

Are eggs good for you?

are eggs good for youIf you are like most Americans, you are probably confused about whether you should eat eggs or not. It’s no wonder. The story about eggs keeps changing.

Just a few years ago we were told that eggs were full of cholesterol. They would increase our risk of heart disease. We should avoid them. If we did eat eggs, it should just be the egg whites because all the cholesterol was in the yolk.

Then we were told that the latest science showed that dietary cholesterol didn’t have much of an effect on serum cholesterol levels. It was saturated fats, trans fats, and obesity that raised serum cholesterol levels. Several major studies found that eggs didn’t increase heart disease risk. But we were told not to overdo it. Two to three eggs a week were probably OK, but more might be risky.

Now the headlines proclaim that eggs are good for our heart. They decrease heart disease risk. You can eat an egg every day and actually reduce your risk of heart disease. What is the truth? Let’s start by looking at the study (C. Qin et al, Heart, doi: 10.1136/heartjnl-2017-312651 ).

How Was The Study Done?

are eggs good for you and your heartThe study was performed in China. 500,000 adults (aged 30-79 years) from 10 diverse sites in China were enrolled in the study between 2004 and 2008. At the beginning of the study, the participants were asked about the frequency of egg consumption. A subset of the participants was asked about egg consumption at regular intervals during the first year to assess whether egg consumption was constant. The participants were followed for 8.9 years and cardiovascular incidents were determined from multiple health registries in China.

In terms of egg consumption:

  • 9% of the population never consumed eggs or consumed them very infrequently.
  • 20% of the population consumed eggs 1-3 days/month.
  • 47% of the population consumed eggs 1-3 days/week.
  • 11% of the population consumed eggs 4-6 days/week.
  • 13% of the population consumed eggs daily (average = 0.76 eggs/day).

 

Are Eggs Good For You?

 

are eggs good for you and reduce heart diseaseWhen the scientists conducting the study compared participants reporting daily egg consumption with those who never or rarely consumed eggs:

  • Overall risk of cardiovascular disease was lowered by 11%
  • Risk of heart attacks was lowered by 12%
  • Risk of major cardiovascular events was lowered by 12%.
  • Risk of hemorrhagic stroke (stroke caused by bleeding in the brain) was lowered by 26%
  • Risk of ischemic stroke (stroke caused by a blood clot) was lowered by 10%.

In addition, daily egg consumers lowered their risk of:

  • Cardiovascular death by 18%.
  • Hemorrhagic stroke death by 28%.

The reduction in hemorrhagic stroke risk is particularly significant for the Chinese. In China stroke is the leading cause of death and disability. The reasons for the high stroke risk in China are not well understood. However, the smoking rate and the incidence of high blood pressure are both higher in China than in the United States.

 

What Does This Study Mean For You?

There are some weaknesses to this study. For example, participants reporting daily egg consumption had a higher level of education and household income, were more likely to take a multivitamin supplement, and less likely to have high blood pressure than participants reporting little or no egg consumption. The authors did their best to compensate for these differences statistically, but there is always the concern that they might have introduced bias into the conclusions.

More to the point, diet and lifestyle are very different in China than in the United States. That also could have influenced the results. Thus, it is, perhaps, premature to claim the eggs reduce the risk of heart disease. However, several major studies performed in the United States have shown that eggs do not increase heart disease risk. That means eggs can be part of a heart healthy diet. According to the Mayo Clinic : “Most healthy adults can eat up to seven eggs a week with no increase in their risk of heart disease.”

That is fortunate because eggs are a very healthy food. According to the authors of this study:

  • Studies have shown that egg protein results in better blood sugar control, better satiety (feeling of fullness), and reduced subsequent food intake in healthy and overweight individuals. In layman’s terms that means egg protein can help you achieve and maintain a healthy weight.
  • Egg yolks are a good source of lutein and zeaxanthin. We think of lutein and zeaxanthin as good for eye health. But, they also play an important role in protecting against oxidation, inflammation, and atherosclerosis.
  • Egg yolks also contain choline. We think of choline as good for brain and nerves. But, choline and other phospholipids in the yolk also raise HDL levels and enhance HDL function.
  • Eggs are a good source of vitamin A, vitamin D, vitamin B12, riboflavin, selenium and iron.
  • Eggs contain almost twice as much monounsaturated and polyunsaturated fats as saturated fats.

are eggs good for you but not sausage and baconThere is one other possible takeaway from this study. Let’s return to the differences between the Chinese study and US studies. There is one other major study showing that daily egg consumption reduces heart disease risk, and it was performed in Japan. What is different between Japan, China, and the United States you might ask. The answer is simple. They consume primarily plant-based diets.

That suggests eggs may be healthier as part of a primarily plant-based diet than they are as part of the typical American diet. In short, eggs are healthy. It’s the sausage, bacon, ham, breakfast muffin, and biscuits that are the problem.

Are eggs good for you? Yes.

For more information on heart healthy diets, read my book “Slaying The Food Myths.”

 

The Bottom Line:

A recent study looked at the effect of egg consumption on heart disease risk in China. It found that people who consumed one egg per day had significantly lower risk of heart disease risk than people who seldom or never consumed eggs.

This study has some shortcomings and may not be directly applicable to those of us in the United States. However, several major studies in the United States have concluded that egg consumption does not increase heart disease risk. That means eggs can be part of a heart healthy diet. According to the Mayo Clinic: “Most healthy adults can eat up to seven eggs a week with no increase in their risk of heart disease.” That is fortunate because eggs are a very healthy food.

There is one other major study showing that daily egg consumption reduces heart disease risk, and it was performed in Japan. What is different between Japan, China, and the United States you might ask. The answer is simple. They consume primarily plant-based diets.

That suggests eggs may be healthier as part of a primarily plant-based diet than they are as part of the typical American diet. Are eggs good for you? Yes, eggs are healthy. It’s the sausage, bacon, ham, breakfast muffin, and biscuits that are the problem.

For more information on heart healthy diets, read my book “Slaying The Food Myths.”

For more details on this study, read the article above:

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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Latest Article

A Low Carb Diet and Weight Loss

Posted January 15, 2019 by Dr. Steve Chaney

Do Low-Carb Diets Help Maintain Weight Loss?

Author: Dr. Stephen Chaney

 

low carb dietTraditional diets have been based on counting calories, but are all calories equal? Low-carb enthusiasts have long claimed that diets high in sugar and refined carbs cause obesity. Their hypothesis is based on the fact that high blood sugar levels cause a spike in insulin levels, and insulin promotes fat storage.

The problem is that there has been scant evidence to support that hypothesis. In fact, a recent meta-analysis of 32 published clinical studies (KD Hall and J Guo, Gastroenterology, 152: 1718-1727, 2017 ) concluded that low-fat diets resulted in a higher metabolic rate and greater fat loss than isocaloric low-carbohydrate diets.

However, low-carb enthusiasts persisted. They argued that the studies included in the meta-analysis were too short to adequately measure the metabolic effects of a low-carb diet. Recently, a study has been published in the British Medical Journal (CB Ebbeling et al, BMJ 2018, 363:k4583 ) that appears to vindicate their position.

Are low carb diets best for long term weight loss?

Low-carb enthusiasts claim the study conclusively shows that low-carb diets are best for losing weight and for keeping it off once you have lost it. They are saying that it is time to shift away from counting calories and from promoting low-fat diets and focus on low-carb diets instead if we wish to solve the obesity epidemic. In this article I will focus on three issues:

  • How good was the study?
  • What were its limitations?
  • Are the claims justified?

 

How Was The Study Designed?

low carb diet studyThe investigators started with 234 overweight adults (30% male, 78% white, average age 40, BMI 32) recruited from the campus of Framingham State University in Massachusetts. All participants were put on a diet that restricted calories to 60% of estimated needs for 10 weeks. The diet consisted of 45% of calories from carbohydrate, 30% from fat, and 25% from protein. [So much for the claim that the study showed low-carb diets were more effective for weight loss. The diet used for the weight loss portion of the diet was not low-carb.]

During the initial phase of the study 161 of the participants achieved 10% weight loss. These participants were randomly divided into 3 groups for the weight maintenance phase of the study.

  • The diet composition of the high-carb group was 60% carbohydrate, 20% fat, and 20% protein.
  • The diet composition of the moderate-carb group was 40% carbohydrate, 40% fat, and 20% protein.
  • The diet composition of the low-carb group was 20% carbohydrate, 60% fat, and 20% protein.

Other important characteristics of the study were:

  • The weight maintenance portion of the study lasted 5 months – much longer than any previous study.
  • All meals were designed by dietitians and prepared by a commercial food service. The meals were either served in a cafeteria or packaged to be taken home by the participants.
  • The caloric content of the meals was individually adjusted on a weekly basis so that weight was kept within a ± 4-pound range during the 5-month maintenance phase.
  • Sugar, saturated fat, and sodium were limited and kept relatively constant among the 3 diets.

120 participants made it through the 5-month maintenance phase.

 

Do Low-Carb Diets Help Maintain Weight Loss?

low carb diet maintain weight lossThe results were striking:

  • The low-carb group burned an additional 278 calories/day compared to the high-carb group and 131 calories/day more than the moderate-carbohydrate group.
  • These differences were even higher for those individuals with higher insulin secretion at the beginning of the maintenance phase of the study.
  • These differences lead the authors to hypothesize that low-carb diets might be more effective for weight maintenance than other diets.

 

What Are The Pros And Cons Of This Study?

low carb diet pros and consThis was a very well-done study. In fact, it is the most ambitious and well-controlled study of its kind. However, like any other clinical study, it has its limitations. It also needs to be repeated.

The pros of the study are obvious. It was a long study and the dietary intake of the participants was tightly controlled.

As for cons, here are the three limitations of the study listed by the authors:

#1: Potential Measurement Error: This section of the paper was a highly technical consideration of the method used to measure energy expenditure. Suffice it to say that the method they used to measure calories burned per day may overestimate calories burned in the low-carb group. That, of course, would invalidate the major findings of the study. It is unlikely, but it is why the study needs to be repeated using a different measure of energy expenditure.

#2: Compliance: Although the participants were provided with all their meals, there was no way of being sure they ate them. There was also no way of knowing whether they may have eaten other foods in addition to the food they were provided. Again, this is unlikely, but cannot be eliminated from consideration.

#3: Generalizability: This is simply an acknowledgement that the greatest strength of this study is also its greatest weakness. The authors acknowledged that their study was conducted in such a tightly controlled manner it is difficult to translate their findings to the real world. For example:

  • Sugar and saturated fat were restricted and were at very similar levels in all 3 diets. In the real world, people consuming a high-carb diet are likely to consume more sugar than people in the other diet groups. Similarly, people consuming the low-carb diet are likely to consume more saturated fat than people in the other diet groups.
  • Weight was kept constant in the weight maintenance phase by constantly adjusting caloric intake. Unfortunately, this seldom happens in the real world. Most people gain weight once they go off their diet – and this is just as true with low-carb diets as with other diets.
  • The participants had access to dietitian-designed prepared meals 3 times a day for 5 months. This almost never happens in the real world. The authors said “…these results [their data] must be reconciled with the long-term weight loss trials relying on nutrition education and behavioral counseling that find only a small advantage for low carbohydrate compared with low fat diets according to several recent meta-analyses.” [I would add that in the real world, people do not even have access to nutritional education and behavioral modification.]

 

low carb diet and youWhat Does This Study Mean For You?

  • This study shows that under very tightly controlled conditions (dietitian-prepared meals, sugar and saturated fat limited to healthy levels, calories continually adjusted so that weight remains constant) a low-carb diet burns more calories per day than a moderate-carb or high-carb diet. These findings show that it is theoretically possible to increase your metabolic weight and successfully maintain a healthy weight on a low-carb diet. These are the headlines you probably saw. However, a careful reading of the study provides a much more nuanced viewpoint. For example, the fact that the study conditions were so tightly controlled makes it difficult to translate these findings to the real world.
  • In fact, the authors of the study acknowledged that multiple clinical studies show this almost never happens in the real world. These studies show that most people regain the weight they have lost on low-carb diets. More importantly, the rate of weight regain is virtually identical on low-carb and low-fat diets. Consequently, the authors of the current study concluded “…translation [of their results to the real world] requires exploration in future mechanistic oriented research.” Simply put, the authors are saying that more research is needed to provide a mechanistic explanation for this discrepancy before one can make recommendations that are relevant to weight loss and weight maintenance in the real world.
  • The authors also discussed the results of their study in light of a recent, well-designed 12-month study (CD Gardener et al, JAMA, 319: 667-669, 2018 ) that showed no difference in weight change between a healthy low-fat versus a healthy low-carbohydrate diet. That study also reported that the results were unaffected by insulin secretion at baseline. The authors of the current study noted that “…[in the previous study] participants were instructed to minimize or eliminate refined grains and added sugars and maximize intake of vegetables. Probably for this reason, the reported glycemic load [effect of the diet on blood sugar levels] of the low-fat diet was very low…and similar to [the low-carb diet].” In short, the authors of the current study were acknowledging that diets which focus on healthy, plant-based carbohydrates and eliminate sugar, refined grains, and processed foods may be as effective as low-carb diets for helping maintain a healthy weight.
  • This would also be consistent with previous studies showing that primarily plant-based, low-carb diets are more effective at maintaining a healthy weight and better health outcomes long-term than the typical American version of the low-fat diet, which is high in sugar and refined grains. In contrast, meat-based, low-carb diets are no more effective than the American version of the low-fat diet at preventing weight gain and poor health outcomes. I have covered these studies in detail in my book “Slaying The Food Myths.”

Consequently, the lead author of the most recent study has said: “The findings [of this study] do not impugn whole fruits, beans and other unprocessed carbohydrates. Rather, the study suggests that reducing foods with added sugar, flour, and other refined carbohydrates could help people maintain weight loss….” This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.

The Bottom Line

 

  • A recent study compared the calories burned per day on a low-carb, moderate-carb, and high-carb diet. The study concluded that the low-carb diet burned significantly more calories per day than the other two diets and might be suitable for long-term weight control. If confirmed by subsequent studies, this would be the first real evidence that low-carb diets are superior for maintaining a healthy weight.
  • However, the study has some major limitations. For example, it used a methodology that may overestimate the benefits of a low-carb diet, and it was performed under tightly controlled conditions that can never be duplicated in the real world. As acknowledged by the authors, this study is also contradicted by multiple previous studies. Further studies will be required to confirm the results of this study and show how it can be applied in the real world.
  • In addition, the kind of carbohydrate in the diet is every bit as important as the amount of carbohydrate. The authors acknowledge that the differences seen in their study apply mainly to carbohydrates from sugar, refined grains, and processed foods. They advocate diets with low glycemic load (small effects on blood sugar and insulin levels) and acknowledge this can also be achieved by incorporating low-glycemic load, plant-based carbohydrates into your diet. This is something we all can agree on, but strangely this is not reflected in the headlines you may have seen in the media.
  • Finally, clinical studies report averages, but none of us are average. When you examine the data from the current study, it is evident that some participants burned more calories per hour on the high-carb diet than other participants did on the low carb diet. That reinforces the observation that some people lose weight more effectively on low-carb diets while others lose weight more effectively on low-fat diets. If you are someone who does better on a low-carb diet, the best available evidence suggests you will have better long-term health outcomes on a primarily plant-based, low-carb diet such as the low-carb version of the Mediterranean diet.

For more details read the article above.

 

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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