Do Vegetarians Live Longer?

Written by Dr. Steve Chaney on . Posted in Vegetarian Diet

What Are The Health Benefits Of A Vegetarian Diet?

Author: Dr. Stephen Chaney

“Vegetarians don’t live longer, it just seems that way.” Many of you have probably heard that joke, but is it true? Are vegetarians healthier? Do vegetarians live longer? Is meat going to kill you? Let’s take a deep dive into the pros and cons of vegetarianism.

What Is Vegetarianism?

Vegetarianism encompasses a wide range of diets. At one extreme is the vegan diet. Vegans eat only plant derived foods. They don’t eat fish, meat, milk, eggs, or honey. It also goes without saying they eat only whole foods (whole grains, plant proteins, and fruits & vegetables) and avoid things like sodas, sugary foods, junk foods, and convenience foods. The most extreme form of veganism, popularized by such recent movies as “Eating You Alive” and “What the Health,” also eliminates all oils. This keeps fat at <10% of total calories.

do vegetarians live longerTo avoid confusion, I will refer to this as a “very low fat vegan diet.”  I will use the term “vegan diet” to refer to the more common veganism that includes vegetable oils in the diet. The vegan diet is still 100% plant based. It is also still relatively low in fat, generally in the 20-30% range. Since the fat comes from plants, it is predominantly the healthy monounsaturated and polyunsaturated fats.

Lacto-ovo vegetarians add low fat dairy foods and eggs to a plant based diet. The Ornish diet is a modified lacto-ovo vegetarian diet that also eliminates all oils and keeps fat at <10% of calories. Pesco-vegetarians add fish to a plant based diet, and semi-vegetarians add limited amounts of meat to a plant based diet.

Can Vegetarian Diets Reverse Atherosclerosis?

Let me start with studies on the very low fat vegan and Ornish diets. In addition to the diet, both programs emphasize regular exercise and stress reduction practices. Adherents to both plans generally achieve a serum total cholesterol of 150 or less. The Ornish diet and lifestyle program was designed to reduce the risk of cardiovascular disease, and it has been very well studied from that perspective. In studies of patients with severe atherosclerosis (clogged arteries) for periods of up to 5 years, the Ornish program results in a significant reduction in the degree of atherosclerosis (unclogs the arteries), inflammation, cardiac events (heart attack, stroke, etc.), and cardiac deaths (H.S. Dod et al, American Journal of Cardiology, 105: 362-367, 2010 ). vegetarianism good for the heartStudies with the very low fat vegan diet are more limited, but suggest that it also reverses atherosclerosis and reduces cardiac deaths (C.B. Esselstyn et al, Journal of Family Practice, 63: 356-364, 2014 ).

Before moving on to other forms of vegetarianism, let me make the point that these are the only diets that have been shown to actually reverse atherosclerosis. That is a big deal.

 

The Seventh-Day Adventist Studies

Perhaps the largest group of studies on the health effects of vegetarians has been conducted on the Seventh-day Adventist population located in Southern California. Seventh-day Adventists believe that “God calls us to care for our bodies, treating them with the respect a divine creation deserves.” The Adventist church advocates a vegan diet consisting of legumes, whole grains, nuts, fruits, and vegetables. However, it allows personal choice, so a significant number of Adventists choose lacto-ovo vegetarian, pesco-vegetarian, or semi-vegetarian diets.

That diversity has not only allowed studies of the Adventist population to not only compare a vegetarian diet to the standard American diet of the non-Adventist population living in the same area, but also to compare the various forms of vegetarian diets. There are dozens of published studies and several reviews on this topic. I will cite only the most recent review here (L.T. Le  and J. Sabate, Nutrients, 6: 2131-2147, 2014 ), but I will provide a complete list in my upcoming book.

This and other reviews have concluded that vegetarians weigh less, have less inflammation, have lower cholesterol levels and have lower risk of diabetes, heart disease, and hypertension than non-vegetarians. When we compare the various forms of vegetarianism, vegan diets appear to offer somewhat greater protection against obesity, hypertension, diabetes, and cardiovascular mortality than lacto-ovo and semi-vegetarian diets. The health benefits of vegetarian diets also seem to be somewhat greater for men than for women. One might speculate that might be because the average American male has a worse diet than the average American female. So, when men adopt a vegetarian diet, it may represent a greater improvement.

The reviews also looked at the nutritional adequacy of vegetarian diets. Vegetarian diets in general are very rich in antioxidants, most B vitamins, and polyphenols. Nutrients of concern for vegan diets are vitamin B12, vitamin D, calcium, iron, zinc, and long chain omega-3 fatty acids. Of those, vitamin B12 and long-chain omega-3 fatty acids are the ones most likely to require supplementation. Adequate levels of the other nutrients can be achieved by a well-designed vegan diet.

I would add protein to the list. Don’t misunderstand me. It is possible to get adequate protein on a vegetarian diet that includes beans and other legumes as a protein source. However, vegan advocates have been telling people they get all the protein they need from broccoli and other vegetables. That is incredibly bad advice, especially for seniors who are likely to suffer from sarcopenia (age related loss of muscle mass). Broccoli only provides 3 grams of protein per serving. You would need 15 servings to meet the protein RDA for women and almost 19 servings for men. Unfortunately, I often run across seniors who think they are getting all the protein they need from green salads and steamed vegetables. The bad advice from vegan advocates may be condemning them to unnecessary frailty in their old age.

What about the health claims of the low carbohydrate diets? Most of those “health benefits” are inferred from changes in blood parameters that occur over the first few weeks or months someone adopts those diets. There are no long-term data showing that low carbohydrate diets reduce the prevalence of diabetes, heart disease or cancer. Moreover, the few studies that compare low carbohydrate and vegetarian diets suggest the vegetarian diet is superior. For example, a recent study (M. Miller et al, Journal of the American Dietetic Association, 109: 713-717, 2009 ) compared the Atkins diet (the granddaddy of the low carb diets) with the Ornish diet. People on the low-fat Ornish diet had significantly lower LDL-cholesterol, apoB, and C-reactive protein (a marker of inflammation) and had better arterial function than people on the high fat Atkins diet.

Do Vegetarians Live Longer?

What about the original question. Do vegetarians live longer? The answer isn’t clear. The Adventist Health Studies have reported that Adventist men live 6-7 years longer and Adventist women live ~4 years longer than their non-Adventist neighbors. However, the Adventist population may have other characteristics that contribute to their longevity. I will cover that in the section on “Blue Zones” in my upcoming book. In contrast, a very recent Australian study(S. Mihrshahi et al, Preventive Medicine, 97: 1-7, 2017 ) concluded that all-cause mortality was virtually identical for vegetarians and non-vegetarians. However, the authors of this study speculated that vegetarians in Australia have become less healthy in recent years because they are now consuming more high-sugar, processed “vegetarian” foods. Remember what I said about “Big Food Inc.” not being your friend.

What Does This Mean For You?

do vegetarians live longer or notThere are a few simple take-home messages from the research on the various forms of a vegetarian diet:

  • The Ornish diet and the very low fat vegan diet are the only diets shown to reverse atherosclerosis. If you have serious heart disease and would like to minimize your reliance on drugs and surgery, you should consider them. You will, of course, want to let your doctor know what you are doing.
  • Vegetarians are leaner and significantly healthier than non-vegetarians.
  • Vegans are slightly healthier than lacto-ovo and semi-vegetarians, but even vegetarians who include some dairy, eggs & meat in a primarily plant-based diet are much healthier than most Americans.
  • Vegetarians may not live longer, but they do live healthier longer.

There are also several subtle, but equally important, implications from these studies:

  • You can forget the claims you must be a vegan purist to obtain any health benefits from vegetarianism.If you watch movies like “Eating You Alive” or “What the Health”, you are led to believe you will suffer terrible health consequences if you add any dairy, eggs, or meat to a vegan diet. In fact, the evidence for reversing atherosclerosis is stronger for the Ornish diet, which is a lacto-ovo-vegetarian diet, than it is for a pure vegan diet. For several other health outcomes, the vegan diet is slightly more effective, but both lacto-ovo-vegetarian and semi-vegetarian diets are much healthier than the standard American diet.
  • Vegetarian diets are whole food diets.If you start adding in processed and convenience foods, even if they are labeled “vegan,” you are likely to lose all the health benefits of a vegetarian diet.
  • You can forget claims that you get all the protein you need from vegetables like broccoli. That is incredibly bad advice which is likely to condemn seniors to unnecessary frailty in old age.
  • You can forget the claims that you must avoid carbs at all costs. The proponents of the low carb diets will tell you that recommendations to limit fat are based on a lie. They tell you that fat is good for you and carbs will cause you to gain weight, increase inflammation, and increase your risk of diabetes, heart disease, and cancer. You are told to avoid grains and any other foods containing carbohydrate, including some fruits and vegetables. The “danger” of carbohydrates is only true for the refined grains, sugary sodas and junk foods in the standard American diet. Vegetarian diets emphasize whole grains, fruits and vegetables. They are high in carbohydrate and low in fat, and they reduce weight, inflammation, diabetes, heart disease, and some cancers.
  • You can forget most claims of weight loss. Most low carb diets tout rapid initial weight loss. Unfortunately, most of that weight comes back a year or two later. Only vegetarian diets are associated with lower weight over a period of many years.

In summary, a pure vegan diet is probably the healthiest form of vegetarianism, but it is difficult to follow. Vegetarian diets that are primarily plant based, but contain small amounts of dairy, eggs, or meat are also very healthy, and may be easier for the average American to follow.

 

The Bottom Line

 

Vegetarianism encompasses a wide range of diets. The standard vegan diet is entirely plant-based. There is a very low fat version of the vegan diet that also eliminates all oils. Lacto-ovo-vegetarian diets include some dairy and eggs. Semi-vegetarian diets include some meat. The Ornish diet is a very low fat version of the lacto-ovo-vegetarian diet.

There are a few simple take-home messages from the research on the various forms of a vegetarian diet:

  • The Ornish diet and the very low fat vegan diet are the only diets shown to reverse atherosclerosis.
  • Vegetarians are leaner and significantly healthier than non-vegetarians.
  • Vegans are slightly healthier than lacto-ovo– and semi-vegetarians, but even vegetarians who include some dairy, eggs & meat in a primarily plant-based diet are much healthier than most Americans.
  • In a head to head comparison, the Ornish diet was significantly healthier than the Atkins diet.
  • Vegetarians may not live longer, but they do live healthier longer.

There are also several subtle, but equally important, implications from these studies:

  • You can forget the claims you must be a vegan purist to obtain any health benefits from vegetarianism. Primarily plant-based diets with small amounts of dairy, eggs or meat are also very healthy.
  • Vegetarian diets are whole food diets. If you start adding in processed and convenience foods, even if they are labeled “vegan,” you are likely to lose all the health benefits of a vegetarian diet.
  • You can forget claims that you get all the protein you need from vegetables like broccoli. That is incredibly bad advice which is likely to condemn seniors to unnecessary frailty in old age.
  • You can forget the claims that you must avoid carbs at all costs. That is only true for the refined grains, sugary sodas and junk foods in the standard American diet. Vegetarian diets are high in carbohydrate, low in fat, and  very healthy.
  • You can forget most claims of weight loss. Only vegetarian diets are associated with lower weight over a period of many years.

In summary, a pure vegan diet is probably the healthiest form of vegetarianism, but it is difficult to follow. Vegetarian diets that are primarily plant based, but contain small amounts of dairy, eggs, or meat are also very healthy, and may be easier for the average American to follow.

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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Comments (6)

  • eroca

    |

    What a refreshing common sense overview. I do not hesitate to share this REAL NEWS. Thanks, Dr Chaney, I appreciate your wisdom.

    Can you imagine living a world not poisoned and also having the great innovations to manage bringing up our vibration?

    Keep on keeping on, thank you.

    Reply

  • Caroline

    |

    Having studied Oriental Medicine with several, I found them sick more, and their teeth, lacking calcium,turning grey to black. Some were thin but others were FAT. What bothered me was treating their babies and small children on either a vegan or vegetarian diet. The plant protein does not have the same health effect on the body. Even Dr. Scala, a vegan, ate a hamburger patty monthly simply because red meat does many health needs in the body, especially getting calcium to the bones. In all my years as a health consultant, I would never ever recommend a vegan/vegetarian diet as too risky with good vibrant health. They do tend to eat more sweets and way too much fruit which is hard on the liver, AND they never want to hear about good nutrition and I think this means they will never (and many have not) make great Chinese medicine whether at Master’s level and definitely NOT at the doctoral level and we are obliged to talk nutrition in CA as acupuncturists but many avoid talking nutrition. Sure glad I studied nutrition because at 80 and my spouse at 85 we are in great condition due to Shaklee nutrients and eating what our bodies need and want. AND we have good teeth, complexion, energy and don’t look our ages (vanity is good!) and I started Youth just less than 3 weeks ago due to product delays but am noticing some good happenings already.

    Reply

  • Caroline

    |

    Sad to say but the Adventists I knew for years both died of cancer and not pretty deaths either. The vegans I studied with wound up with darken teeth and one with absolutely black teeth, gray hair in their 30’s and constantly down with something. Sorry, but the body does need red meat for many purposes. We grow and eat a lot veggies along with good proteins and thus far in our “older years” have our teeth, I have very little gray hair, and we have energy! Those vegans I knew had been getting FAT and not a lot of energy. We have choices for sure, but I will stick to a diet that gives real health including some flesh and not just all veggies which ruin the yin/yang of soil in which to grow them healthily. We use no chemicals on our garden nor trees either.

    Reply

    • Dr. Steve Chaney

      |

      Dear Caroline, One can always pick individual stories to “prove” or “disprove” any diet. What I report on is clinical studies. They provide evidence for what diet works best for most people.. If you have been following “Health Tips From the Professor” for a while, you would know that I also recommend primarily plant-based diets that include some animal protein, like the Mediterranean or DASH diets.
      Dr. Chaney

      Reply

  • Diana

    |

    I enjoyed reading this article. I am part of the Vegan Living Group here on Long Island. Most “Pure Vegans” I know have become so because of animal Advocacy-To save the animals, the rainforest and other Eco environmental factors. We know that Factory farming and even Grass fed smaller farming are ruining the environment. (Cowspiracy is a film that shows us the ills of factory farming.) A lot of these consciencious people eat oreos and tofudogs and other processed vegan foods. So I dont like the label Vegan because it doesnt necessarily mean healthy . I prefer the term Whole Foods Plant Based inspired by Dr T Colin Campbell and Dr. Essylstein featured in films such as Forks over knives and Plant Pure Nation. Although I myself am not 100% consistant, when I am-I feel amazing. Thank You.

    Reply

    • Dr. Steve Chaney

      |

      Dear Diana,
      You are right. Any diet can be corrupted if we start eating processed foods and goodies. Whole unprocessed, foods are the cornerstone of any healthy diet.
      Dr. Chaney

      Reply

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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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