In recent years, there has been much mention of the marked increase in the use of e-cigarettes by young people, a trend that has recently increased with the arrival of Juul (see our article on this topic). The often alarmist tone that accompanies the reports of these studies suggests that vaping currently reaches “epidemic” proportions and poses a serious threat to the health of young people by pushing them towards the traditional cigarette.
These fears are no doubt in good faith, but they are not at all consistent with the results of the serious surveys that have been conducted in recent years, particularly with regard to smoking rates among young people.
Smoking rates continue to plummet among young people.
Very little is said about it, but one of the most encouraging trends in tobacco control is the marked decline in youth smoking seen in recent years. One of the best examples of this reduction is provided by the “Monitoring the future” survey, a large epidemiological study conducted since 1975 by researchers at the University of Michigan, which annually measures the prevalence of users of different drugs among American high school students. As shown in Figure 1, while youth smoking peaked in 1997 with 37% of 12th grade youth who smoked occasionally and 25% who smoked daily, these proportions have since significantly fallen to 7.6% and 2%, respectively, in 2018. A similar trend is observed in Canada, with approximately 3.5% of 12–17-year-olds who were smokers (casual or regular) in 2017, a 25% decrease compared to 2013 (4.6%). It should also be noted that according to the latest data from Statistics Canada, the proportion of Canadians aged 12–17 who smoked cigarettes daily was only 0.9% in 2018.
Figure 1. Changes in the proportion of smokers among 12thgrade American high school students from 1975 to present day. From Bates (2019).
Can the introduction of e-cigarettes reverse these trends, as many fear? There has been a lot of evidence from studies (here, here and here, for example) that teens who have tried e-cigarettes are more likely to smoke a tobacco cigarette than those who have never been in contact with the electronic cigarette. But as several experts have pointed out, this interpretation is not scientifically valid, because it is impossible to establish a causal link between the two phenomena: a young person attracted by tobacco will experiment with several forms available, without necessarily meaning that trying one will lead to testing another.
To determine the impact of the e-cigarette, the best measure remains to examine the evolution of youth smoking. And in this regard, the results are reassuring: although these products have appeared relatively recently (around 2010), the available data suggest that they have not had negative impacts on the adoption of cigarettes by young people: in the United States, for example, the smoking cessation rate is 3 to 4 times higher between 2010 and today than between the period from 1975 to 2010, suggesting that e-cigarettes have instead accelerated the reduction of youth smoking (Figure 1). It should also be noted that Juul has been available since 2015 in the United States and has since conquered most of the e-cigarette market, but this has not resulted in a resurgence of youth smoking. The data are also reassuring for England, where e-cigarettes have been available for several years: the smoking rate has been steadily decreasing since 2011 and the largest decrease is observed among 18–24-year-olds.
According to the data currently available, the fear that vaping leads to smoking therefore seems totally unfounded. On the contrary, it seems that vaping represents an increasingly popular alternative to traditional cigarettes and could even replace conventional tobacco products in the short and medium term. This is very encouraging, since it is clearly established that e-cigarette vapour is much less harmful than cigarette smoke, particularly because of a very significant decrease in the presence of carcinogenic compounds.
Regular vapers are usually smokers.
A recent study found that the proportion of young e-cigarette users has increased significantly in Canada from 29% to 37%. At first glance, this may actually seem enormous, and it is this type of statistic that is at the root of the concerns raised by vaping critics.
However, it is important to know that in this type of study, individuals are considered smokers or vapers if they have used these products at least once in a given period (in the last month, for example) or during their lifetime. This approach fails to distinguish occasional users from those who regularly smoke or vape. To make a simple analogy, it is as if a study of pathological gambling considered that people who buy a lottery ticket from time to time belong to the same category as those who go to the casino every day. This is obviously not the case: it is the development of a dependence on a substance (tobacco, alcohol, drugs, opiates) or an activity (excessive gambling, for example) that poses risks, whereas occasional use is much more like an experiment, a phenomenon that is particularly common among young people.
In fact, when we take into account the frequency of vaping and smoking habits, the situation is much less worrying. As shown in Figure 2, the vast majority of young people only vape occasionally (only 3.6% of 16-19-year-olds were vaping more than 15 days per month according to the latest estimates); 2) it is mainly young people who smoke cigarettes (regularly or occasionally) who are attracted to these products; and 3) only a tiny proportion of non-smokers (less than 1%) vape regularly.
Figure 2. Distribution of vapers according to the frequency and habits of tobacco use. Note the very low percentage of non-smoking youth who regularly vape (arrow). From Hammond et al. (2019).
The situation is not “out of control”, as we hear regularly, but rather reflects a new reality: the traditional cigarette is no longer popular with young people, possibly because of the exorbitant prices and smoking bans in almost all public places. The vast majority of those who want to experiment with the effect of tobacco are turning to new forms of nicotine such as e-cigarettes, but even then, regular users of these products remain relatively few, and are for the most part young people who are primarily attracted to tobacco or inclined to adopt higher-risk behaviours in general. This last point is well illustrated by a study in Colorado, where researchers have found that vapers are 5 to 10 times more likely to have previously tried hard drugs such as cocaine or regularly drink excessive amounts of alcohol than non-vapers (Table 1).
Table 1. Comparison of the prevalence of risky behaviours between vapers and non-vapers. From Ghosh et al. (2019).
Overall, and despite the sensationalist headlines in recent years, we must consider that e-cigarettes do not pose a threat to the enormous progress we have made in tobacco control. On the contrary, regular vapers are mostly smokers, and the adoption of these products can substantially reduce the risks associated with cigarette smoke. Based on the very low percentages of non-smokers who regularly vape, it also seems that nicotine vapour is less addictive than traditional cigarettes and it is very unlikely that it can be used as a gateway to tobacco.
It should also be remembered that the main utility of e-cigarettes remains one of the best ways to quit smoking, with twice the effectiveness of nicotine replacement therapy. The British have long recognized the usefulness of e-cigarettes in tobacco control and, hard to imagine here, have even made these products the emblem of anti-smoking campaigns (see photo).
(Public Health England advertising promoting e-cigarettes to quit smoking)
An extremely damaging collateral effect of the current “hysteria” towards e-cigarettes is to make smokers suspicious of these products and at the same time to deprive them of a valuable aid to quit smoking. The latest surveys also show a sharp increase in the number of smokers who think that the e-cigarette is as, if not more, damaging than the traditional cigarette. This is a very unfortunate situation, which shows how the best is sometimes the enemy of the good: by wanting at all costs to prevent vaping among young people, we are creating a climate which discourages the use of alternatives to tobacco that are infinitely less dangerous and would have a very positive impact on the health of smokers.
Of course, we must remain vigilant about the use of these products by young people and I will be the first to question the regulatory framework surrounding their marketing if it turns out that modern e-cigarettes (Juul, for example) lead to an upsurge in smoking among this population. With the current state of knowledge, on the other hand, there are many reasons to be optimistic and consider the electronic cigarette as a very promising tool to reduce smoking and even, hopefully, ultimately lead to the complete disappearance of the traditional cigarette.
So-called “sugary drinks” generally refer to beverages containing added sugars (sucrose, corn syrup, juice concentrates or other sweeteners) such as soft drinks, fruit punches, energy drinks or even sports drinks. These beverages are the main source of simple sugar in the diet of North Americans and a significant proportion of calories consumed daily, especially among teenagers and young adults. In the United States, for example, sugary drinks account for an average of 9.3% of calories among young men and 8.2% among young women. This is huge, especially considering that the World Health Organization recommends limiting the total daily energy intake of added sugars to a maximum of 10% of calories, or 50 g of sugar.
This 10% limit is based on a large number of studies showing that a high intake of added sugars promotes overweight and increases the risk of type 2 diabetes, coronary heart disease and stroke. The negative impact on cardiovascular health is of particular concern, as a recent study has shown that regular consumption of soft drinks for several years is associated with an increased risk of premature mortality of around 20%, mainly as a result of cardiovascular disease.
Traditionally, 100% pure fruit juices are not included in the sugary drinks category as the sugar they contain is of natural origin and not artificially added. However, fruit juice sugar is identical to that of artificially sweetened drinks (glucose and fructose) and is present in quite comparable amounts (Figure 1). It is therefore possible that fruit juices, even when 100% pure, may cause the same adverse effects as other sugary drinks when consumed in large quantities.
Figure 1. Comparison of the sugar content of different fruit juices and beverages containing added sugars. Adapted from Gill and Sattar (2014).
This possibility has recently been explored by an analysis of the link between the consumption of sugary drinks and pure fruit juice and the risk of premature death. Looking at the eating habits of 13,440 participants, the researchers found that people who drank a lot of sugary drinks including pure fruit juice (10% or more of daily calories) were 44% more likely to die prematurely from coronary artery disease compared to people who limit the consumption of these drinks to less than 5% of daily calories. When the types of sugary drinks were analyzed separately, the increased risk of coronary death is 11% for each serving of 355 mL of sweetened beverages and 24% for each 355 mL of pure juice consumed. It should be noted, however, that the small number of deaths associated with coronary heart disease in the study does not support the conclusion that fruit juices are more harmful than other sugary drinks at these levels. Certainly, however, it seems that pure juices, when consumed in large quantities, can greatly contribute to the rise in premature death caused by sugary drinks. These results strengthen the case of the growing number of people (see here and here, for example) for whom fruit juices, even when 100% pure, are sugary drinks in the same category as the others and should therefore be totally eliminated from the diet.
A question of quantity
However, it should be noted that the negative effect of fruit juices on the risk of premature mortality is observed for fairly large quantities of juice, well above the quantities that are generally recommended (150 mL per day). At these more moderate amounts, the effect of fruit juice on health is much more nuanced: a review of the studies carried out to date shows that the consumption of reasonable quantities of fruit juice, i.e., a serving of 150–240 mL a day, has little effect on weight gain, both in adults (gain of about 0.2 kg over 3–4 years) and children (very slight increase in the BMI-z score, i.e., the body mass index of children adjusted for sex and age) (Table 1). These increases are significantly lower than those observed for sugary drinks such as soft drinks: for example, a study showed that each serving of soft drink consumed daily causes an increase in body weight of about 1 kg over a period of 4 years, three times more than the one associated with the consumption of a daily serving of pure fruit juice (0.3 kg).
Table 1. Health effects of consumption of pure fruit juices. Adapted from Auerbach et al. (2018).
* 240 mL serving; ** “BMI-z” (Body mass index z-score) is a relative measure of weight, adjusted for age and sex of the child.
|Outcome|| ||Population||Subjects||Amounts consumed||Results||Study
|Tooth decay||Children||1,919||≥1 serving*/d vs. ≤1 serving/week||20% increase in risk||Salas et al. (2015)
|Weight gain||Adults||108,708||Each additional serving/day||Gain of 0.22 kg over 4 years||Hebden et al. (2015)
|Children||20,639||Consumption vs. no consumption||No association||O’Neil and Nicklas (2008)
|Children||34,470||Each additional serving/day||BMI z score** change of 0.09 U over 1 year (0.03, 0.17 U) in children 1–6 y and no change in children 7–18 y||Auerbach et al. (2017)
|Adults||49,108||For each serving/day||Gain of 0.18 kg over 3 years||Auerbach et al. (2018)
|Cardiovascular diseases||Adults||114,279||Each additional serving/d of 100% citrus juice||28% decrease in risk of ischemic stroke||Joshipura et al. (2009)
|Adults||54,383||Highest vs. lowest consumers||15% decrease in the risk of acute coronary syndromes||Hansen et al. (2010)
|Adults||109,635||For each serving/day (citrus juice)||No significant effect||Hung et al. (2004)
|Adults||34,560||1–7 servings (150 mL)/week||17% decrease in risk of cardiovascular disease (24% risk of stroke)||Scheffers et al. (2019)
|Type 2 diabetes||Adults||137,663||Highest vs. lowest consumers||3% increase in risk||Xi et al. (2014)
|Adults||440,937||Each additional serving/day||7% increase in risk||Imamura et al. (2015)
|Adults||120,877||≥1 serving/day vs. ≤1 serving/month||No effect||Schulze et al. (2004)
A marked difference in the risk of developing type 2 diabetes has also been observed between artificially sweetened beverages and pure fruit juices. For example, one study found that daily consumption of soft drinks or fruit punches with added sugars caused an approximately two-fold increase in the risk of diabetes, while that of fruit juice had no impact (Figure 2). A meta-analysis of 4 studies reported similar results, i.e., fruit drinks containing added sugars increased the risk of diabetes while consumption of pure fruit juices had no effect. It should be noted, however, that other studies have reported a slight increase in the risk of diabetes in people consuming 240 mL and more per day of fruit juice (see Table 1).
Figure 2. Comparison of the increased risk of type 2 diabetes associated with the consumption of soft drinks, fruit juices containing added sugars, and 100% pure fruit juices. From Schulze et al. (2004).
The effect of moderate amounts of pure fruit juice is particularly interesting with regard to cardiovascular health. It has long been known that people who eat a lot of fruits are less likely to be affected by cardiovascular disease. These benefits are due, at least in part, to the high fruit content of polyphenols (including flavonoids) that prevent the oxidation of LDL cholesterol and prevent the development of atherosclerotic plaques. Since these polyphenols are extracted during fruit pressing and are therefore present in pure fruit juices, it is possible that these juices may also have positive effects on cardiovascular health. This has recently been highlighted by a study in the Netherlands among 34,560 participants aged 20 to 69 (EPIC-NL study). The researchers found that people who regularly consumed small amounts of pure fruit juice (150 mL daily, 7 days a week) were 17% less likely to be affected by cardiovascular disease, especially stroke (24% less risk). However, these protective effects disappeared at higher amounts of juice (> 8 glasses of pure juice per week), suggesting that the window of consumption associated with these preventive effects is relatively narrow. Decreases in the risk of ischemic stroke and acute coronary events following consumption of pure fruit juice have also been reported. It is also interesting to note that a study recently reported that people who consumed 150 mL of orange juice every day had half the risk of cognitive decline compared to those who rarely consumed it (once a month).
It is therefore possible that the different molecules present in fruit juices (vitamins, minerals, polyphenols) in some way counteract the negative effects of high amounts of sugar by reducing oxidative stress and chronic inflammation, two phenomena involved in the development of cardiovascular and neurodegenerative diseases. In any event, these observations suggest that it is clearly an exaggeration to say that pure fruit juices, in small quantities, are as harmful to health as beverages containing added sugars. It is only in high quantities that pure fruit juice becomes a sugary drink like any other and can cause the many health problems that are associated with excess sugar.
That being said, everyone agrees that the best way to consume fruits is in their whole form. In addition to the different bioactive compounds that are present in juices, whole fruits also contain fibres that increase the feeling of satiety (which reduces the amount of sugar ingested), prevent excessive fluctuations in blood sugar, and contribute to the maintenance of a diversified intestinal microbiome. Ideally, we should therefore favour the consumption of fresh fruits and drink water rather than juice to quench our thirst.
However, for people who may have difficult access to fresh fruit or prefer to consume it in a liquid form, the studies mentioned earlier suggest that pure fruit juice may be a valid alternative, but only when consumed in moderate amounts, around a small glass (150 mL) a day. At these amounts, juices significantly contribute to the daily intake of vitamins and minerals, and studies to date suggest a positive impact on the prevention of cardiovascular disease, especially stroke. It also appears that a moderate intake of pure juices does not have a major impact on the risk of overweight and diabetes, including in young children, confirming the validity of the recommendations of the American Academy of Pediatrics to limit the consumption of pure juice to 150 mL per day.
Red meat: An issue for human health and the health of the planet.
Consumption of red meat and processed meat is associated with an increase in all-cause mortality and mortality from cardiovascular diseases, diabetes, respiratory diseases, liver and kidney diseases, and certain cancers. On the contrary, consumption of white meat and fish has been associated with a decreased risk of premature death. Another troubling aspect with the production of red meat is that it is harmful to the global environment.
In traditional European agricultural societies, meat was consumed once or less than once a week, and annual meat consumption rarely exceeded 5 to 10 kg per person. In some rich countries (U.S.A., Australia, New Zealand), meat consumption now stands at 110–120 kg per person per year, > 10 times more than in traditional agricultural societies. Livestock farming occupies more than 30% of the world’s land area, and more than 33% of arable land is used to produce livestock feed. World consumption of red meat is rising sharply, especially in developing countries. This has adverse consequences for the environment and represents an unsustainable situation according to several experts.
The main harmful effects to our planet caused by meat production (Potter, BMJ 2017)
- Depletion of aquifers (producing 1 kg of meat requires more than 110,000 L of water).
- Groundwater pollution.
- Decrease of biodiversity.
- Destruction of rainforest for livestock and the production of greenhouse gases by livestock. Both combined contribute more to climate change than fossil fuels used for transport.
- Production of 37% of methane (CH4) from human activity (with 23 times the global warming
potential of CO2).
- Production of 65% of nitrous oxide (N2O) from human activity (almost 300 times the global
warming potential of CO2).
- Production of 64% of ammonia (NH3) from human activity, which contributes significantly to
acid rain and acidification of the ecosystem.
Other potential negative effects associated with red meat include accelerated sexual development, caused either by the consumption of meat and fat, or by the intake of growth hormones naturally present in meat or added to livestock feed; more extensive antibiotic resistance caused by their use to promote animal growth; a reduction in the food available for human consumption (for example, 97% of the world’s soybeans are used to feed livestock); and higher risks of infections (such as bovine spongiform encephalopathy or “mad cow disease”) due to faulty practices in intensive farming.
Experts agree that we will have to reduce our consumption of red and processed meat in order to live longer, healthier lives, but especially so that our planet is in better condition and can support human activity long term. Eating mostly cereals, fruits, vegetables, nuts, and legumes, and little or no meat is probably the ideal solution to this environmental problem, but for many, red meat is a delicious food that is hard to replace. To satisfy meat lovers who still want to reduce their consumption, companies have recently developed products made only from plants whose appearance, texture and taste are similar to meat, whereas others are trying to produce artificial meat from in vitro cell cultures.
New plant-based patties: Beyond Burger and Impossible Burger
Plant-based burgers have long been available in grocery stores, but these meatless products are intended for vegetarians and consumed mainly by them. New products made from plants, but designed to have the same appearance, texture, and taste as meat have appeared on the market recently. These meat alternatives target omnivorous consumers who want to reduce their meat consumption. Among the most popular products, there is the Beyond Burger, available at the fast food chain A&W and recently in most supermarkets in Quebec, as well as the Impossible Burger, which will soon be on the menu at fast food chain Burger King under the name “Impossible Whopper.”
The main ingredients of Beyond Burger are pea protein isolate, canola oil and refined coconut oil. This food also contains 2% or less of other ingredients used to create a meat-like texture, colour and flavour, as well as natural preservatives (see box). It is an ultra-processed food that does not contain cholesterol, but almost as much saturated fat (from coconut oil) and 5.5 times more sodium than a lean beef patty. Nutrition and public health experts have suggested avoiding coconut oil in order not to increase blood LDL cholesterol (“bad cholesterol”) and maintain good cardiovascular health (see “Saturated fats, coconut oil and cardiovascular disease”). Moreover, the nutritional contribution of these two products is similar (calories, proteins, total lipids).
Beyond Burger ingredients:
Water, pea protein isolate, canola oil, refined coconut oil, 2% or less of: cellulose from bamboo, methylcellulose, potato starch, natural flavour, maltodextrin, yeast extract, salt, sunflower oil, vegetable glycerine, dried yeast, gum arabic, citrus extract, ascorbic acid, beet juice extract, acetic acid, succinic acid, modified food starch, annatto.
Impossible Burger ingredients: Water, soy protein concentrate, coconut oil, sunflower oil, natural flavours, 2% or less of: potato protein, methylcellulose, yeast extract, dextrose, food starch modified, soy leghemoglobin, salt, soy protein isolate, mixed tocopherols (Vitamin E), zinc gluconate, thiamine hydrochloride (vitamin B1), sodium ascorbate (vitamin C), niacin (vitamin B3), pyridoxine hydrochloride (vitamin B6), riboflavin (vitamin B2), vitamin B12.
The Impossible Burger is made from soy protein, coconut oil and sunflower oil. It also contains ingredients that are used to create a meat-like texture, colour and flavour, as well as vitamins and natural preservatives. Among the ingredients added to mimic the colour and flavour of meat is soy leghemoglobin, a hemoprotein found in the nodules on the roots of legumes that has a similar structure to animal myoglobin. Rather than extracting this protein from the roots of soybean plants, the manufacturer uses leghemoglobin produced by yeast (Pichia pastoris) in which the DNA encoding for this protein has been introduced. The use of P. pastoris soybean leghemoglobin was approved by the US Food and Drug Administration in 2018. The fact that the leghemoglobin used is a product of biotechnology rather than from a natural source does not appear to pose a particular problem, but some researchers suspect that the heme it contains could have the same negative health effects as those associated with the consumption of red meat, i.e., an increased risk of cardiovascular disease and certain types of cancer. A causal link between heme and these diseases has not been established, but population studies (see here and here) indicate that there is a significant association between heme consumption and a rise (19%) in mortality risk from all causes. In contrast, non-heme iron from food (vegetables and dairy products) is not associated with an increased risk of mortality.
Beyond Burger and Impossible Whopper, served with mayonnaise and white bread, are not suitable for vegans (eggs in mayonnaise) or a particularly healthy option because of the saturated fat and salt they contain. However, the manufacture of these products requires much less energy and has a much smaller environmental footprint than real red meat, which is their strong selling point. According to one study, the production of a Beyond Burger patty generates 90% less greenhouse gas emissions and requires 46% less energy, 99% less water and 93% less arable land than a beef patty.
We believe that it is preferable, as much as possible, to obtain unprocessed fresh plant products and to do the cooking yourself, in order to control all the ingredients and thus avoid ingesting sodium or saturated fat in excessive amounts, as is the case with most ultra-processed products, including these new meatless patties. Fatty and salty foods taste good to a large majority of human beings, and the food industry takes this into account when designing the ultra-processed food products it offers on the market. If you want to eat a “burger” without meat, why not try to prepare it yourself with black beans (recipes here and here), oats, lentils or quinoa?
Production of “meat” in the laboratory
In vitro “meat” production involves culturing animal muscle cells (from undifferentiated cells or “stem cells”) in a controlled or laboratory environment. The first beef patty produced in a laboratory in 2013 cost 215,000 pounds (Can$363,000), but the price has dropped considerably since then. However, this product is not yet ready to be commercialized, as there are still several technological problems to solve before it can be produced on a large scale. Moreover, if the current experimental product can be used to successfully mimic ground meat, we are still far from being able to grow cells in a three-dimensional form that looks like a steak, for example.
The technology could be used to produce, for example, “Fugu” (puffer fish) meat, a delicacy prized by the Japanese, but which can be deadly if the chef or specialized companies do not prepare the fish properly. Indeed, tetradoxine contained in the liver, ovaries and skin of the fugu is a powerful paralyzing poison for which there is no antidote. Laboratory-made fugu meat would not contain any poison and would be safe for consumers.
Another example of an advantageous application would be the production of duck foie gras. A majority of the French (67%) are against the traditional method of production by gavage, which makes the animals suffer. One company (Supreme) is developing a method to obtain fatty liver from isolated duck egg cells.
Other companies are developing methods to produce egg white and milk proteins by fermentation rather than using animals. Although this “cellular agriculture” still seems a little “futuristic”, it could become increasingly important in the food industry and help reduce the production of meat that is harmful to our planet.