Electronic cigarettes drastically reduce exposure to toxic substances from tobacco

Electronic cigarettes drastically reduce exposure to toxic substances from tobacco

OVERVIEW

  • Cigarette smoke contains more than 7,000 chemical compounds, of which at least 250 are well-characterized toxic substances and 70 are established carcinogens.
  • By allowing the absorption of nicotine without the combustion of tobacco, e-cigarettes are therefore an alternative to reduce exposure to these toxic compounds.
  • According to an analysis by the Institut Pasteur, this reduction is very significant since the aerosols generated by electronic cigarettes contain less than 1% of the toxic compounds found in cigarette smoke.

There is nothing worse than smoking for heart and blood vessel health (and health in general), and quitting smoking is by far the best decision a person can make to lower their risk of developing cardiovascular disease. However, quitting smoking is very difficult for many smokers, and, for several years, I have recommended that my patients who are unable to quit by conventional means (patches, gum, etc.) use electronic cigarettes.

In an e-cigarette, a solution of nicotine is heated to around 80°C using an atomizer, which generates an aerosol that allows vapers to inhale a small amount of nicotine (like smokers) to satisfy their addiction, but which does not contain the multiple toxic molecules that are generated during the combustion of tobacco (at around 900°C). This last point is the most important: contrary to what many think (including the majority of doctors), it is the combustion products of tobacco cigarettes that cause health problems, not nicotine. The latter is a drug that creates tobacco addiction and encourages people to smoke, but it has no major health effects and is especially not responsible for cardiovascular disease or lung cancer that result from smoking. The advantage of the electronic cigarette is therefore that it allows smokers who are highly dependent on nicotine to considerably reduce their exposure to the many toxic substances of cigarette smoke. This is a classic example of what is called harm reduction.

In addition, not only is the e-cigarette less toxic than tobacco, but a randomized clinical study recently published in the prestigious New England Journal of Medicine shows that it can be very useful for smoking cessation, with twice the effectiveness of traditional approaches based on nicotine substitutes. These devices therefore represent a very interesting technological innovation that adds a new dimension to the fight against tobacco.

Large-scale misinformation
That being said, one of the most disconcerting aspects of the media coverage surrounding anything related to e-cigarettes is the negative, often even alarmist, tone that is used to report the latest research developments on these devices. Any study that claims to show a negative impact of e-cigarettes on health makes headlines, even those that are low-quality and published in second-rate journals, while studies that instead report a positive effect are simply ignored, even when they are very scientifically sound and published in prestigious medical journals. This imbalance means that the population is informed only of the potential risks associated with e-cigarettes, without knowing that there is also a whole body of literature showing that these devices have positive effects on the health of smokers.

Perhaps one of the best examples of this media bias is the coverage of a study claiming to show an increased risk of heart attack in vapers, a study that was widely circulated in the media around the world when it was published. However, a critical examination of the results revealed that the majority of the 38 patients in the study had suffered a heart attack on average 10 years BEFORE they started vaping and therefore that these heart attacks could not have been due to e-cigarettes. Since vapers are almost always ex-smokers, the increase in heart attacks observed in vapers is simply due to the fact that these people gave up smoking after being sick and now use e-cigarettes to avoid a recurrence. This is a blatant case of scientific misconduct that resulted in the retraction of the article, but the withdrawal of this fraudulent study was not reported by most media. It should be noted that the main author of this retracted article, Stanton Glantz, is one of the most committed researchers against the use of e-cigarettes.

This is all the more unfortunate because a randomized clinical study, which was very well done, showed that it is exactly the opposite phenomenon that occurs, i.e. that the transition of smokers to e-cigarettes is positive because it is accompanied by a rapid improvement (in only one month) in the health of the blood vessels. However, this important study has not been reported by the media, and the public therefore does not know that, far from being harmful to the heart, e-cigarettes are instead associated with concrete health benefits for smokers.

The immediate consequence of this misinformation is that fewer and fewer people see e-cigarettes as a less harmful alternative to tobacco, including smokers, and there is a risk that the number of smokers who make the leap to e-cigarettes will decrease. I see it already in my practice: patients who weaned themselves off tobacco through vaping have resumed smoking, while others are reluctant to try e-cigarettes to quit smoking. In both cases, the reason given is the same: if vaping is as bad as smoking, why make the switch? This shows that disinformation campaigns can have real consequences for people’s lives and even literally make the difference between life and death for some of them.

Toxics reduction
Yet no one can seriously argue that e-cigarettes are as bad for your health as cigarettes. Cigarette smoke contains more than 7,000 chemical compounds, of which at least 250 are well-characterized toxic substances and 70 are established carcinogens. Repeated exposure to these toxic emissions is directly responsible for 8 million deaths each year worldwide, making smoking the leading cause of preventable deaths, especially those caused by cancer (30% of all cancers are caused by tobacco) and cardiovascular and respiratory diseases.

Analyses by Public Health England, the American National Academies of Sciences, Engineering, and Medicine and the British Committee on Toxicity of Chemicals in Food, Consumer Products, and the Environment all show that aerosols from e-cigarettes contain a much smaller number and amount of toxic substances than cigarette smoke and are therefore less harmful to health than smoked tobacco. It is for this reason that organizations such as Public Health England and France’s Académie nationale de médecine strongly recommend that smokers do not hesitate and make the transition to vaping.

This does not mean that e-cigarettes are completely safe, but they are undeniably much less harmful than the product they replace (which is the principle of harm reduction). By focusing only on identifying the potential harmful effects of vaping, we come to forget that the basic principle of vaping is to reduce the harms of smoking in smokers who are repeatedly exposed to toxic substances from tobacco.

A recent study by the Institut Pasteur provides a clear view of this potential for harm reduction. In this study, scientists compared the presence of two major classes of toxics (carbonyl compounds and aromatic hydrocarbons) in aerosols from smoked cigarettes, heated tobacco products (IQOS) and e-cigarettes. The results are really impressive: for the 19 carbonyls and 23 aromatic hydrocarbons tested, the e-cigarette chosen for the study (high-capacity tank device, used at maximum power) reduces these toxic compounds by 99.8 and 98.9% compared to tobacco cigarettes (Figure 1). IQOS (heated tobacco product) is also less toxic than cigarettes, with reductions of 85% and 96% in the concentration of these toxic compounds, but these reductions nevertheless remain lower than those observed with e-cigarettes, in line with previous studies.

Figure 1. Content of carbonyl compounds (A) and polycyclic aromatic hydrocarbons (PAHs) (B) in aerosols produced by a cigarette, a heated tobacco product and an e-cigarette. Note the drastic reduction of these two classes of toxics in e-cigarette vapour compared to tobacco smoke. From Dusautoir et al. (2020).

The researchers then compared the toxicity of different types of cigarettes by measuring the viability of bronchial epithelial cells following repeated exposure to aerosol puffs generated by cigarettes, heated tobacco products and e-cigarettes. As shown in Figure 2, exposing the cells to only 2 puffs from a cigarette is enough to kill half of the cells, and no residual cells are detectable after coming into contact with 10 puffs of smoke. Heated tobacco products significantly reduce this toxicity (40 puffs are necessary to kill half of the cells and a hundred to eliminate them completely), but it is here again that e-cigarettes are by far the least toxic, with all cells remaining alive even after exposure to 120 puffs of aerosols.

Figure 2. Viability of bronchial epithelial cells after repeated exposure to aerosols from a regular cigarette, a heated tobacco product or an e-cigarette. Note the high toxicity of cigarettes, which cause 50% mortality after cells are exposed to just 2 puffs of smoke, while cells remain viable even after being in contact with 120 puffs of aerosols from an e-cigarette. From Dusautoir et al. (2020).

Another study shows that this very significant reduction in toxicity is also observed for Juul, the e-cigarette which has recently captured the majority of the e-cigarette market (see our article on this subject). Compared to traditional cigarettes, the vapour generated by Juul contains almost 100% less carbon monoxide and carbonyl compounds like acetaldehyde, formaldehyde, and acrolein (a major irritant in cigarette smoke) (Table 1). Similar results were also reported in another study. These data are important because Juul is particularly popular among young vapers. Contrary to what we often hear, the vast majority of young people (> 99%) who regularly vape are occasional or regular smokers and these people can therefore substantially reduce their exposure to tobacco toxins by vaping. In addition, recent data indicates that nicotine absorbed through e-cigarettes is less addictive than when it comes from burning tobacco, which decreases the risk of developing longer-term dependence.

Table 1. Concentration of certain toxic compounds present in cigarette smoke or in the vapour generated by the Juul e-cigarette. From Son et al. (2020).

It is worth remembering that the ultimate goal of tobacco control is to reduce the incidence of smoking-related diseases, especially cardiovascular disease and lung cancer. To achieve this, total abstinence is desirable, but the large number of people who are unable to quit smoking on their own or by using current cessation tools and therefore remain at risk of dying prematurely must be taken into account. In my clinical experience over the past ten years, the electronic cigarette is the most popular nicotine replacement for smokers and for many of them represents the only approach that allows them to successfully quit smoking. Instead of constantly seeking to discredit these devices, as is currently the case, they should instead be seen as a technological innovation that can greatly contribute to the fight against diseases caused by smoking, and we need to clearly inform smokers of the benefits associated with the transition to vaping.

Time-restricted feeding: A tool to lose weight and improve cardiometabolic health

Time-restricted feeding: A tool to lose weight and improve cardiometabolic health

OVERVIEW

  • The two most popular forms of time-restricted feeding (intermittent fasting), limiting eating to 4 hours or 6 hours a day, were tested in obese people.
  • Both diets produced the same body weight loss (–3.2%) at the end of the two-month study.
  • Both diets reduced caloric intake by ∼550 kcal/day, without participants having to control the number of calories consumed.
  • Similar reductions in insulin resistance and oxidative stress were observed for both types of diet.

Intermittent fasting has grown in popularity in recent years, as several clinical studies have shown that it can help lose weight and prevent metabolic disease (see also our article: “Intermittent fasting: A new approach to weight loss?”).

There are three different types of diets that are part of intermittent fasting:

  • Alternate-day fasting where you alternate between a day of “fasting” when you consume very few calories (0–800 calories) followed by a day where you eat normally.
  • The 5:2 diet is a modified version of alternate-day fasting that includes two days of fasting per week (<600 calories), followed by five days of normal eating.
  • Time-restricted feeding recommends limiting the period during which food is consumed. The two most popular forms of this diet are the Warrior Diet, where you limit eating to a period of 4 hours a day, and the 18:6 diet, where you fast for 18 hours and eat over a period of 6 hours.

In a randomized controlled study recently published in Cell Metabolism, nutrition researchers wanted to answer the following question: does restricting feeding to a 6-hour window (18:6 diet) produce the same effects on body weight and metabolic risk factors as a 4-hour restriction (Warrior Diet or 20:4 diet)? The researchers hypothesized that compared to a diet limited to a 6-hour period, a diet limited to 4 hours would lead to greater weight loss, a greater drop in blood pressure, better blood glucose control, and more pronounced effects on oxidative stress.

The 58 obese participants (BMI: 30–50 kg/m2) in the 8-week study were divided into three groups:

  • A control group who could eat normally and without time restrictions.
  • A group that had to eat between 3 p.m. and 7 p.m., a restriction over a 4-hour
  • A group that had to eat between 1 p.m. and 7 p.m., a restriction over a 6-hour

There were no restrictions on the amount or type of food consumed and participants were not required to control their calorie intake. During the fasting period, participants were encouraged to drink plenty of water and were allowed to consume calorie-free drinks such as black tea, coffee (without sugar or milk), or diet soda.

After 8 weeks, the two groups that limited their diet to 4-hour and 6-hour periods both lost 3.2% ± 0.4% body weight, while the control group did not significantly lose weight (0.1% ± 0.4%). The 4-hour limited diet therefore did not lead to more weight loss than over a 6-hour period, contrary to the initial hypothesis.

Fasting blood glucose levels were not significantly different between the three groups, eight weeks after the start of the study. In contrast, fasting insulinemia, insulin resistance, and oxidative stress were reduced in both intervention groups, compared to the control group, with no significant difference between the two intervention groups (4 hours vs. 6 hours).

Several parameters, including blood pressure, LDL cholesterol, HDL cholesterol and triglyceride levels were not altered by the time-restricted diet, both for the 4-hour and the 6-hour limitation. These latest results are at odds with previous studies where significant reductions in these parameters were observed. The authors cannot explain these differences, but they suggest that their study may not have had enough participants to be able to observe significant effects on these secondary endpoints of the study.

Summary of key findings from previous studies on intermittent fasting
The effects of alternate-day fasting and the 5:2 diet (2 days of fasting and 5 days of normal eating) on the risk of metabolic disease have been the subject of more than a dozen studies in humans to date. Alternate-day fasting produces 5–7% body weight loss over a short period of time (less than six months). It also provides several metabolic benefits such as reduced blood pressure, LDL cholesterol, triglycerides, fasting insulinemia, insulin resistance, inflammation and oxidative stress. The effects of the 5:2 diet are similar to alternate-day fasting.

Time-restricted feeding has been the subject of fewer studies. There have been six clinical studies in humans to date, and only three of these studies have examined the effects of this diet on body weight loss. According to these few studies, the time-restricted diet produces a loss of body weight of around 2.6 to 3.6% and a reduction in calorie intake of 8 to 20% in 12 to 16 weeks. This type of intermittent fasting has significant effects on metabolic health: marked drop in fasting blood sugar, insulinemia, and insulin resistance. A drop in blood pressure has been observed in several studies, even without loss of body weight. The effects on blood lipid levels are less clear. A few studies of time-restricted feeding report lower triglycerides and LDL cholesterol, but most studies have found no effect on these same lipids.

Conclusion
Although the weight loss seen in this new study is moderate, the authors believe that time-restricted feeding is a promising intervention for those who wish to lose weight. Limiting feeding to a 6-hour period is easier to practice than a 4-hour restriction since someone can, for example, not eat breakfast and have the two meals of the day at relatively normal times (1 p.m. and 6:30 p.m., for example). This study indicates that the 18:6 diet will have as many health benefits as the Warrior Diet (20:4).

Chile, an example of aggressive state intervention to combat the obesity epidemic

Chile, an example of aggressive state intervention to combat the obesity epidemic

OVERVIEW

  • Chile, like most countries in Latin America, has seen the incidence of obesity in its population skyrocket over the past 20 years.
  • This rise in overweight is directly correlated with overconsumption of ultra-processed industrial foods, especially sugary drinks.
  • To reverse this situation, a law severely restricting the promotion, sale and labelling of these products was introduced in 2016, and this tough approach seems to be starting to bear fruit.

From a medical point of view, one of the greatest upheavals of the 20th century was certainly the dramatic increase in the body weight of the world population. Globally, recent estimates indicate that about 2 billion adults are overweight (BMI between 25 and 30), including 650 million who are obese (BMI> 30), about three times more than in 1975. This very rapid increase in the proportion of overweight people has several consequences on the health of the population because overweight and obesity are associated with significant increases in the incidence of several chronic diseases, including cardiovascular disease, type 2 diabetes and several types of cancer, that reduce healthy life expectancy. In addition to these chronic diseases, the COVID-19 pandemic has also shown that obesity is associated with an increased risk of developing serious complications of the disease and of dying from it. The increase in the number of overweight people is therefore one of the main public health problems of our time and is in the process of erasing the gains achieved as a result of the sharp decline in smoking in recent years.

From undernutrition to overnutrition
This rapid increase in the incidence of obesity is observed globally, but has been particularly noticeable in low- and middle-income countries. Until the late 1970s, the main nutritional problem faced by these countries was the high food insecurity of their populations and the high proportion of children suffering from malnutrition. With the globalization of trade that began in the 1980s, the standard of living of these populations began to resemble more and more that of richer countries, both for some of its positive aspects (access to safe drinking water, hygiene, reduction of infectious diseases and infant mortality, education) as well as for its negative ones (sedentary lifestyle, diet based on ultra-processed foods and fast food).

The result is that all countries, without exception, that have adopted these new eating habits and the Western way of life now have to deal with a greater proportion of obese individuals. In poorer countries, this “nutritional transition” has been so rapid that the increase in the body weight of the population can also coexist with malnutrition. For poor people, the high availability and low cost of ultra-processed foods provide for their energy needs, but the lack of nutrients in these foods means that the excess of calories ingested is paradoxically accompanied by a nutritional deficiency. While this may seem surprising at first glance, overnutrition and undernutrition can therefore occur simultaneously in a population, sometimes within the same family.

Latin America hit hard
Latin America is probably one of the best examples of the impact of these dietary changes on the incidence of obesity and the diseases associated with being overweight. Mexico, for example, was the country that experienced the largest increase in obesity globally between 1990 and 2010, and in 2014, more than 300 million adults living in Latin America were overweight, including 100 million who were obese. The situation may even worsen over the next few years due to the high incidence of childhood obesity, which reaches, for example, 12% in Chile and 11% in Mexico (a percentage similar to that of Canadian children, among the highest in the world).

The economic growth of the 1990s led to a rush for typical North American products such as fast food, televisions and cars, leading to increased calorie intake and a parallel decrease in physical activity levels. The very high consumption of ultra-processed foods, in particular sugary drinks, is certainly one of the new eating habits that contribute to the increase in overweight of the inhabitants of these regions. Globally, three of the four countries consuming the highest number of calories in the form of sugary drinks are in Latin America, with Chile and Mexico in first and second place, followed by Argentina in fourth place just behind the United States (Figure 1).


Figure 1. Comparison of the number of calories from sugary drinks sold in different countries in 2014. Note the very high consumption of these drinks in Chile (red asterisk), more than twice as high as in Canada (black asterisk). From Popkin (2016).

Several studies indicate that this overconsumption of added sugars is generally associated with a poor quality diet (low in nutrients) and significantly contributes to the development of obesity, type 2 diabetes and cardiovascular disease. This is especially true in Latin America, as some studies indicate that in the presence of a high sugar intake, some people of Hispanic descent are genetically predisposed to develop nonalcoholic fatty liver disease, an abnormal buildup of fat in the liver that is closely related to the development of type 2 diabetes and metabolic syndrome.

Government response
The close link between the consumption of ultra-processed foods and the increased risk of obesity illustrates the chasm between the financial interests of the multinational food companies that manufacture these products and the health of the population. The goal of these companies is obviously not to make people sick, but it is undeniable that their primary goal remains to generate profits, without worrying too much about whether the consumption of their products can lead to the development of a large number of chronic diseases.

Governments do not have this luxury, however, as they have to deal directly with the enormous pressures that diseasesassociated with being overweight place on health systems. A simple and straightforward approach that has been adopted by several countries is to introduce a tax on these industrial food products, in particular soft drinks. The principle is the same as for all taxes on other unhealthy products such as alcohol and tobacco, i.e. higher prices are generally associated with lower consumption. Studies that have examined the impact of this approach for soft drinks indicate that this is indeed the case, with decreases in consumption observed (among others) in Mexico, Berkeley (California) and Barbados. Despite the legendary reluctance of politicians to impose new taxes, there is no doubt that this approach represents a promising tool, especially if the amounts collected are reinvested in order to improve the diet of the population (subsidies for the purchase of fruits and vegetables, for example).

Another, even more promising, approach is to help consumers make an informed choice by informing them of the sugar, fat, salt and calorie content of products. This information currently exists, but in the form of nutritional labels that are quite difficult to interpret. The amounts of sugar, saturated fat, sodium and calories are indeed indicated on these labels, but refer to percentages of the recommended daily intake. For most people, seeing that the sugar content of a particular food is, for example, “15% of the recommended intake” is a rather abstract concept that does not specify whether this amount is low, adequate or too high. A simpler and more straightforward way is to clearly indicate on the front of the product whether it is high in sugar, fat or salt, as is the case in Chile. In response to the rampant rise in obesity in its population, the country’s Ministry of Health has introduced a labelling system, featured on the front of the package, which allows consumers to immediately see whether a product contains high amounts of sugar, saturated fat, sodium and calories (Figure 2).Figure 2. Labels produced by the Chilean Ministry of Health (Ministerio de Salud) and affixed to the packaging of products sold in stores. The labels indicate a high content (alto) in sugar (azúcares), saturated fat (grasas saturadas), salt (sodio) or calories (calorías). From Kanter et al. (2019).

These labels help consumers make better choices and can encourage the industry to reformulate their products to escape this labelling and become more attractive. It should be noted that Health Canada has also developed a labelling project of the same type, but the adoption of this practice is still pending, more than two years after the end of public consultations. Mexico, meanwhile, has recently moved forward with a system similar to that of Chile, as have Peru, Uruguay and Israel.

The Chilean approach is part of a comprehensive plan to fight obesity, largely based on changing a food culture that is far too focused on ultra-processed products. In addition to the new labelling system, Chile’s Law of Food Labelling and Advertising introduced in 2016 prohibits the sale of caloric products (ice cream, soft drinks, chips, etc.) in schools, imposes severe restrictions on the marketing of industrial products (elimination of characters loved by children on cereal boxes, ban on sales of candy containing toys, e.g., Kinder), prohibits the advertising of these products on programs or websites aimed at young people, and imposes an 18% tax on sugary drinks, one of the highest in the world. This strong government intervention seems to be paying off: a recent study shows that the consumption of sugary drinks fell 25% within 18 months of the law’s implementation, while that of bottled water increased by 5%. The authorities are now considering expanding the scope of the law by introducing an additional tax on all junk food products.

In North America, we remain extremely passive in the face of the dramatic increase in the number of overweight people in our society. Yet the burden of overweight-related illnesses weighs heavily on our health care system here too, and as mentioned earlier, the future looks bleak as we are now among the world leaders in childhood obesity. The example of Chile shows that governments have concrete legislative means that can be used to try to reverse this trend. Faced with an industry that refuses to self-discipline, the authorities must take a much more aggressive approach to protect the population from the health problems associated with the overconsumption of ultra-processed foods, especially among young people. The risk of obesity is established very early in life, since half of children and adolescents who become obese are already overweight when they enter kindergarten.

Plant-based meat substitutes reduce certain cardiovascular risk factors

Plant-based meat substitutes reduce certain cardiovascular risk factors

OVERVIEW

  • Participants in a study were divided into two groups, for eight weeks, one consumed two daily servings of plant-based meat substitutes (Beyond Meat products: burger, mock beef, sausage, mock chicken), while the other group ate the same amount of real meat (beef, pork, chicken).
  • Participants who ate plant-based meat substitutes lost some weight and had significantly lower blood levels of trimethylamine oxide (TMAO) and LDL cholesterol than those who consumed meat during the same period.
  • Plant-based meat substitutes appear to be beneficial for health compared to meat since high levels of TMAO and LDL cholesterol are two risk factors for cardiovascular disease.

In an article published in these pages in 2019, we discussed the merits and drawbacks of new food products that mimic the taste and texture of meat, such as Beyond Meat and Impossible Burger. These products are certainly more environmentally friendly than red meat (beef and pork in particular), which requires a lot of resources that tax the global environment. On the other hand, they are ultra-processed products that contain significant amounts of saturated fat and salt.

To determine whether plant-based meat substitutes could be healthier than meat, the Beyond Meat company funded Dr. Christopher D. Gardner, an independent and renowned researcher at Stanford University School of Medicine in California, to conduct a randomized controlled study. One must be extremely careful with studies funded by the food industry, since publishing only the results that will support the sale of their products is to their advantage. On the other hand, in the case of this study, all precautions seem to have been taken so that there is no influence on the results: study design (randomized and controlled with a crossover design), statistical analyses conducted by a third party who was not involved in the design of the study and data collection. Beyond Meat was not involved in the design of the study, the conduct of the study, or the analysis of the data. In addition, Dr. Gardner stated that he has already completed six food industry-sponsored studies with null findings from the original hypothesis.

The 36 study participants were randomly divided into two groups. During the first eight weeks, one group of participants were assigned to eat two servings/day of plant-based meat substitutes (Beyond Meat products: burger, mock beef, sausages, mock chicken), while the other group consumed two servings/day of meat (beef, pork, chicken). The two groups then switched their diet for the next eight weeks (crossover study design). Fasting levels of lipids, glucose, insulin, and trimethylamine oxide (TMAO) were measured before the start of the study and every two weeks during both phases of the study.

The main endpoint of the study was the blood level of TMAO, an emerging risk factor associated with atherosclerosis and other cardiovascular diseases. The group that consumed meat during the first eight weeks had a significantly higher TMAO mean level than the group that consumed plant-based meat substitutes (4.7 vs. 2.7 µM), as well as a higher LDL cholesterol (the “bad cholesterol”) mean level (121 vs. 110 mg/dL), while the mean HDL cholesterol (the “good cholesterol”) level was not significantly different.

A surprise awaited the researchers: Participants who first consumed plant-based products during the first eight weeks did not see their TMAO levels increase when they ate meat during the second part of the study. Researchers were unable to identify any changes in the microbiome (gut flora) that could have explained this difference. However, it appears that making the participants “vegetarian” for eight weeks caused them to lose the ability to produce TMAO from meat. This effect of a vegetarian diet on the microbiome has already been demonstrated by Dr. Stanley L. Hazen’s team at the Cleveland Clinic. After a few weeks of returning to a carnivorous diet, the microbiome begins to produce TMAO again from red meat and eggs.

TMAO is a metabolite produced by the gut microbiome from carnitine and choline, two compounds found in large quantities in red meat such as beef and pork. High concentrations of TMAO can promote atherosclerosis and thrombosis. Indeed, numerous observational studies and animal models have shown that there is an association between TMAO and cardiovascular risk, and that it is beneficial to reduce the levels of TMAO. It should be noted, however, that a causal link between TMAO and cardiovascular disease has not been established and that it is possible that it is a marker rather than a causal agent of these diseases.

In addition to the favourable effect on TMAO, participants who ate plant-based meat substitutes lost weight (1 kg on average) and had significantly lower LDL-cholesterol levels than those who ate meat (110 vs. 121 mg/dL). These differences were observed regardless of the order in which participants followed the two diets.

Beyond Meat probably hopes that these results will allow them to respond to criticisms about their products, which areultra-processed and contain a lot of salt and almost as much saturated fat as meat. Many people want to reduce their consumption of red meat, but do not like classic vegetarian dishes. It seems to us that if these meat substitutes appeal to consumers concerned about maintaining good health and allow them to reduce their meat consumption, this will be beneficial for them and may encourage them to cook veggie burgers and other plant-based meat substitutes themselves. Who knows, maybe these products will lead to significant changes in diet in the future. Considerably reducing our meat consumption can only be beneficial to our health and that of the planet.