• EN    |    TH
  • +66 2-038-5115

Some key scientific studies and work of many medical researchers that established the health benefits of plant based whole food diet and lifestyle are elaborated here

In the past decades, the European countries have cooperated for a large prospective case-cohort study called EPIC study to investigate the association between food consumption and illness by following 448,568 cases for more 10 years. The aim of this study was to examine the association of food consumption with the risk of early death. The study was well-designed and used appropriate methods. A remarkable result which came out was the significant positive association of the incidence of type 2 diabetes with increasing consumption of total meat especially processed meat (sausages, bacon, and ham) and not with carbohydrates (flours and sugars).

High intake of fruits (either sweetened fruits or unsweetened fruits) or vegetables was associated with lower the risk of type 2 diabetes 

There were 26,344 deaths during the study. The result of EPIC study showed that high consumption of red meat (meat of mammals such as beef, pork) and processed meat was related to the higher all-cause mortality, much higher than the median of mortality rate, while the mortality rate of participants who ate poultry, fish or veggies were similar to median of all-cause mortality.

T. Colin Campbell is a famous nutritional researcher at Cornell University. He had started his research on the development of liver cell cancer from the dietary aflatoxin. He had found a remarkable fact that aflatoxin causes liver cell cancer in people who ate high meat-derived protein, while people who ate plant-derived proteins, did not develop liver cell cancer even though they were exposed to heavy aflatoxin contamination.

In 1970, Zhou Enlai, the President of China, had cancer. He started a 12 types of cancers research in 880 million people (96% of people in China) from 2,400 Provinces in China. The remarkable results of this survey provided information on the morbidity rate of same types of cancers in each province was different even though 80% of Chinese are Huns. It was indicated that the cancer caused by environmental rather than genetics.

The suspicious results of this survey led T. Colin Campbell to work in partnership with the investigators at the Chinese Academy of Preventive Medicine and Oxford University for cross-sectional study called “The China Study” to survey disease incidence and lifestyle factors in rural China and Taiwan. Sixty five Provinces throughout China, where over 90% of native people live since they were born, were selected and 6,500 participants were chosen from these provinces to fill up the questionnaires which covered over 40 variables including various cancers and heart disease. Participants’ blood and urine samples were taken and all foods they consumed for 3 days were assessed. Investigators found that rural Chinese people ate plant-based diet which derived most calories from carbohydrate and just 10% of total calories from protein and ninety percent of all protein came from plants as compared to Americans who eat only 20% of proteins from plant sources.

They also found that the wealthy people who embraced animal-based foods had the most chronic disease such as cancer, diabetes and heart disease. These diseases including cancer were associated with high blood cholesterol. Normally, rural Chinese people have lower blood cholesterol, 70-170 mg/dl, than average (127 mg/dl). The results also showed that if blood cholesterol is reduced from 170 mg/dl to 90 mg/dl, then the risk of western chronic diseases including cancer decreases. Chinese blood cholesterol tended to increase when they ate more animal-based foods. However, the Western chronic diseases incidence is very low in rural Chinese population. For example, heart disease is 17-fold and breast cancer is 5-fold lower than Americans.

T. Colin Campbell concluded that people who ate the most animal-based foods had the most chronic diseases such as heart disease, diabetes, and cancer and Americans can avoid Western chronic diseases death by eating plant-based foods and avoiding animal-based foods

Dan Buettner is an American, he is a National Geographic journalist. He is also New York Times bestselling author. His bestselling book named The Blue Zones is about exploring communities around the world where most people live more than 100 years of age.

After exploring around the world and studying retrospective census data, people interviews, lifestyles and foods habits and statistical analysis, he has finally discovered the five places where people live longest as below-

  1. Barbagia region of Sardinia – Mountainous highlands of inner Sardinia in Italywith the world’s highest concentration of male centenarians.
  2. Ikaria, Greece – Aegean Island with one of the world’s lowest rates of middle age mortality and the lowest rates of dementia.
  3. Nicoya Peninsula, Costa Rica – World’s lowest rates of middle age mortality, second highest concentration of male centenarians.
  4. Seventh-Day Adventists – Highest concentration is around Loma Linda, California. They live 10 years longer than their North American counterparts.
  5. Okinawa, Japan – Females over 70 are the longest-lived population in the world.

Dan Buettner created a team of medical researchers, anthropologists, demographers, and epidemiologists to search for evidence-based common factors among all places.

They found nine factors as follow-

1. Move Naturally : The world’s longest-lived people don’t pump iron, run marathons or join gyms. Instead, they live in environments that constantly nudge them into moving without thinking about it. They grow gardens and don’t have mechanical conveniences for house and yard work.

2. Purpose : The Okinawans call it “Ikigai” and the Nicoyans call it “plan de vida;” for both it translates to “why I wake up in the morning.” Knowing your sense of purpose is worth up to seven years of extra life expectancy

3. Down Shift : Even people in the Blue Zones experience stress. Stress leads to chronic inflammation, associated with every major age-related disease. What the world’s longest-lived people have that we don’t are routines to shed that stress. Okinawans take a few moments each day to remember their ancestors, Adventists pray, Ikarians take a nap and Sardinians do happy hour.

4. 80% Rule : “Hara hachi bu” – the Okinawan, 2500-year old Confucian mantra said before meals reminds them to stop eating when their stomachs are 80 percent full. The 20% gap between not being hungry and feeling full could be the difference between losing weight or gaining it. People in the Blue Zones eat their smallest meal in the late afternoon or early evening and then they don’t eat any more the rest of the day.

5. Plant food : Beans, including fava, black, soy and lentils, are the cornerstone of most centenarian diets. Meat—mostly pork—is eaten on average only five times per month that too in very small serving sizes

6. Wine : People in all Blue Zones (except Adventists) drink alcohol moderately and regularly. Moderate drinkers outlive non-drinkers. The trick is to drink 1-2 glasses per day with friends and/or with food. And no, you can’t save up all weekend and have 14 drinks on Saturday.

7. Belong :  All but five of the 263 centenarians we interviewed belonged to some faith-based community. Research shows that attending faith-based services four times per month will add 4-14 years of life expectancy.

8. Loved Ones First :  Successful centenarians in the Blue Zones put their families first. This means keeping aging parents and grandparents nearby or in the home (It lowers disease and mortality rates of children in the home too.). They commit to a life partner (which can add up to 3 years of life expectancy) and invest in their children with time and love (They’ll be more likely to care for you when the time comes).

9. Right Tribe : The world’s longest lived people chose–or were born into–social circles that supported healthy behaviors. Okinawans created “moais”–groups of five friends that committed to each other for life. Research from the Framingham Studies showed that smoking, obesity, happiness, and even loneliness are contagious. So the social networks of long-lived people have favorably shaped their health behaviors.

The Blue Zones book is a good overview of epidemiological evidence indicating that consumption of plant-based diet and eliminating animal-based diet, is associated with longevity.

The city of Loma Linda in California, USA, is built on the edge of the desert of Southern California by the Seventh Day Adventists.

The growing community gradually embraced different dietary patterns. The community comprised:

  1. Vegans: No meat at all, no fish, no eggs, and no dairy products
  2. Pesco-vegetarians: Consumed fish and sea foods
  3. Lacto-ovo-vegetarians: Consumed dairy products and eggs
  4. Semi-vegetarians: Not restricted to all meat
  5. Non-vegetarians or Omnivores: Consumed all meat

All of them are the Seventh Day Adventists and they live in the same city, go to the same church, have the same traditions, participate in the same social events, and manage stress in similar ways.

The medical researchers at the Loma Linda University followed 73,308 Seventh Day Adventists for 6 years and found that all vegetarians were at a lower risk of mortality compared to non-vegetarians.

Vegans had the lowest all-cause mortality, followed by pesco, lacto-ovo and semi-vegetarians, respectively. The highest mortality was among non-vegetarians or omnivores in whom there were high variations in cause-specific mortality due to heart disease, diabetes and renal disease.

According to other global large community studies, the researchers have demonstrated that people who consumed plant-based diet with limited or no animal-based diet, had lived longer than people who ate only animal-based diet 

Lyon Heart Study, was a randomized control trial that compared the effect of Mediterranean diet which is rich in tubers, vegetables, fruits, legumes and nuts with that of American Diet which has more meat and less plant to assess the risk of cardiovascular deaths. A total of 6,500 participants were randomized into 2 groups- an experimental group adhering Mediterranean diet and a control group adhering American Diet for 5 years. The trial was stopped after 27 months follow-up because control group who ate American Diet, had 70% markedly higher rate of recurrence of cardiac events and overall mortality than Mediterranean group.

An interesting finding was that blood cholesterol was similar in both groups (239 md/dl). This indicated that eating plant-based diet has more health benefits than just cholesterol reduction

Dr. Caldwell Esselstyn is a surgeon at Cleveland clinic in the United Stated of America. He had observed countless his diabetic patients (who had either undergone bypass surgeries or had not undergone bypass surgeries) die from cardiovascular disease.

He decided to conduct a study in which patient with severe coronary artery disease would be treated by adhering strictly to a plant-based whole food diet with 10% of calories derived from fat.

With help of his doctor friends he finally, shortlisted 24 participants, most of whom had no hopes from further medical interventions (some of the participants had undergone bypass surgeries or balloon angioplasties and consequent recurrent angina) . These participants had heart attacks up to 48 times for 8 years before the study.

 At the onset of study, all participants had undergone coronary angiography and were asked to adhere to very low fat, plant-based, no extraction, and no refined diet. Oil and sugar (being extracted food) was not allowed to them

Participants were encouraged to eat grains, legumes, lentils, vegetables, fruits and nuts. They were asked to eliminate oil (even olive oil), dairy products (except skim milk and no-fat yogurt), fish, fowl and meat.

The goal was to achieve total serum cholesterol of 150 mg/dl.

Six patients were released and returned to standard care because they could not adhere to plant-based diet. The remaining 18 patients adhered to the study diet for 5 years. All adherent patients underwent angiographic analysis, which demonstrated disease arrest and regression and even reversal of blockade of arteries which became normal eventually.

Dr. Caldwell Esselstyn’s studies were published in various peer reviewed journals many times. His patients are still alive at the time of writing this article and have no incidences of angina, best part being none of them is on any medications.

Outcomes of his studies are important evidence showing coronary artery disease reversal through a very low fat, plant-based whole food diet.

At the same time that Dr. Caldwell Esselstyn had been studying about reversal of coronary artery disease through vegetarian diet, Dr. Dean Ornish, was planning for another research study .

When he was a medical student, he researched on Western lifestyles and also eating plant-based foods and doing yoga, in India. When he came back, he practiced as a cardiac surgeon and he started his study.

Ornish’s study was a randomized control trial - a high level of evidence- determining intensive lifestyle change on coronary heart disease. Ninety-three patients with moderate to severe coronary heart disease were randomized into 2 groups, a usual-care control group and an intensive lifestyle change group that included;

  1. A 10%-fat whole food vegetarian diet by eliminating oil, dairy products, fish, eggs, and meat, avoiding simples sugars and emphasizing complex carbohydrates and whole foods intake.
  2. Moderate aerobic exercise 30 minutes per day, at least 5 days per week.
  3. Stress management training - meditation and doing yoga.
  4. Group psychosocial support - once a week

All patients underwent qualitative coronary angiographies at baseline, 1 year, and 5 years. At the end of 1 year, they found that intensive lifestyle change group had a 4.5% improvement in the average of diameter of arteries and a 91% reduction in the frequency of anginal episodes. In contrast, usual-care control group had a 5.5% worsening in the average percent diameter and a 165% increase in the frequency of reported anginal episodes. At 5 years, the results were similar to 1 year wherein intensive lifestyle change group had a 7.9% improvement in the average percent diameter stenosis and had 0.89 cardiac events per patient. In usual-care control group had a 5.5% worsening in the average percent diameter and had 2.25 cardiac events per patient.

This indicated that usual-care control group were more likely to have undergone coronary angioplasty and bypass surgery and/or might have been hospitalized for cardiac-related problems than were intensive lifestyle change group.

The researchers investigated the changes of myocardial perfusion abnormalities by using Positron Emission Tomography (PET) in their patients at baseline and 5 years. PET images supported the previous study that percent diameter stenosis is poorly related to flow capacity of coronary arteries at baseline.

By adhering to whole food vegetarian diet and lifestyle change, the size of the perfusion abnormalities decreased indicating improvement at 5 years after plant-based diet adherence.

This indisputable results confirmed that adherence to a very low fat plant-based diet with routine exercising, mediation, doing yoga, and group support can reverse coronary heart disease

Dr. Dean Ornish also worked for the Multicenter Lifestyle Demonstration Project Research Group. A total of 333 patients who had angiographically documented coronary artery disease severe enough to warrant revascularization from all hospitals were divided to 2 groups, an experimental group and a control group and they were followed-up for 3 years.

The researchers found that experimental group of patients who reported angina at baseline had obvious reductions in angina compared with control group and were able to avoid balloon angioplasty or bypass surgery for at least 3 years by making comprehensive lifestyle changes

Later, Bill Clinton, the 42nd President of the United States, was diagnosed with coronary artery disease. He underwent bypass surgeries and had 2 coronary stents implanted in his heart, but again he experienced chest pain. His doctor advised him to balloon angioplasty again, but he refused. He consulted Dr. Dean Ornish’ and as per Dr Ornish’s advice he turned vegan. It helped him to loose more than 20 pounds and he became healthy and symptom free.