Individual dietary choices can add – or take away – minutes, hours and years of life
There are roughly 9.7 million vegans in the United States today, up a staggering 3,000% from 2004, according to a 2020 study from Ipsos Retail Performance. These dietary changes have caught the attention of businesses and created a booming vegan market where even traditional meat industry giants have gotten into the faux meat game.
Sales of plant-based food in 2020 grew by 27%—twice as fast as food sales in general, according to data from SPINS for The Good Food Institute and Plant Based Foods Association. A full 57% of Americans say they buy plant-based alternatives to animal products.
People’s reasons for adopting a plant-based diet range from personal health to animal rights to environmental concerns related to factory farming. Thistle analyzed numerous academic studies published in peer-reviewed journals such as Frontiers in Nutrition and Nutrients to curate a list of 10 benefits of a plant-based diet.
Plant-based diets inherently focus on whole grains, beans, fresh produce, seeds, and nuts, but not everyone who eats plant-based diets eschews animal products entirely. As with all diets, it’s important to consider a person’s genetics, activity level, preexisting medical conditions, and any nutritional deficiencies or food allergies. In particular, those adopting plant-based diets are wise to make sure they’re getting sufficient levels of vitamins and minerals, from B12 to omega-3 fatty acids.
Keep reading to discover 10 benefits of plant-based diets.
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Inflammation is caused by white blood cells fighting off invaders—whether foreign objects, such as a splinter; irritations, such as allergies; or pathogens, such as bacterial or viral infections. In the case of autoimmune diseases, the immune system attacks healthy, normal tissue in the body. Overactive inflammatory response is widely considered by experts to contribute to chronic disorders including Type 2 diabetes or heart problems.
Acute, or short-term inflammation, comes on as localized pain, redness, loss of mobility, or swelling. The area may be hot to the touch, as in the case of a bee sting, and can last from a few hours to several days. Chronic inflammation can last months or years, and can come on as a hyper reaction to an external trigger, such as is the case with allergies; a mistaken reaction in which the immune system attacks healthy tissue, as with cancer or eczema; or long-term exposure to an irritant.
Diet and exercise have major effects on inflammation: Whereas obesity, smoking, lack of consistent sleep, and a diet heavy in added sugars and unhealthy fats can all increase inflammation in the body, nutrients found in fruits and vegetables have been shown to reduce inflammation.
A popularly cited 2018 analysis of the international food industry suggests that switching to a plant-based diet represents the largest single action a person can take to reduce their environmental impact. While those stats—such as the fact that the ecological footprint of livestock represents 18% of calories and 83% of farmland—are striking, they don’t take into consideration all the complexities of sustainable eating habits.
It is true that pound for pound, animal protein requires 100 times as much water as grain protein—and that the production of oat milk emits 80% fewer greenhouse gases and requires 60% less energy than cow’s milk. Still, switching to a plant-based diet doesn’t guarantee more eco-friendly food choices: Growing practices, treatment of workers, the distance food travels, packaging, and ingredient sourcing all contribute to how sustainable the food on your plate is—or isn’t.
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Consumption of red meat and poultry has been linked to an increased risk of diabetes, in part because of the high volume of heme iron in those meats, according to findings in the Singapore Chinese Health Study published in 2017.
That research involved recruiting more than 63,000 adults between 45 and 74 from 1993 to 1998, and following their health progress for 11 years, in addition to studying the correlation between various kinds of meats and the volume of heme iron in each. Participants who consumed the highest levels of red meat and poultry showed a 23% and 15% increase in diabetes risk, respectively. Consuming fish and shellfish showed no perceptible association with diabetes risk.
Meanwhile, plant-based diets have been shown to not only protect Type 2 diabetics from developing kidney disease, but to help reverse Type 2 diabetes itself. Plant-based diets may also reduce mortality rates in individuals with chronic kidney disease.
Whole plant-based foods contain plenty of fiber, zero dietary cholesterol, and low amounts of saturated fats—a winning combination for heart health. Meanwhile, meat, cheese, and eggs come with cholesterol and saturated fats that, in excess, may create plaque buildup in a person’s arteries.
But it’s not enough to just avoid meat: For heart health on a plant-based diet, it’s important to steer away from processed foods, including white rice and white bread, which lack nutritional value and contain a high glycemic index. This increases your odds for spiking blood-sugar levels and increased appetite. Similarly, whole fruits are healthier than fruit juice, even 100% juice, which often loses nutrients and vitamins while being processed and contains high levels of sugar.
Numerous studies have shown the positive effects of plant-based diets—particularly a vegetarian or vegan diet combined with nuts, soy, and fiber—on cholesterol levels. Five observational studies, cited in a study published in 2009 in the American Journal of Cardiology, found lower blood concentrations of TC and LDL cholesterol in populations consuming plant-based diets.
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A direct correlation was found between high intakes of fruit and vegetables and a significantly reduced risk of cognitive impairment and dementia, according to a report published in Frontiers in Aging Neuroscience in 2017. The key is likely in nutrients abundant in plant-based diets, including antioxidants, vitamins, and folate, that have been shown to have significant cognitive benefits.
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Vegetarian and vegan diets have been shown to promote a healthy mix of beneficial bacteria promoting gut and overall health. A healthy gut biome promotes a high-functioning metabolism, strong immune system, healthy bowel movements, and appropriate levels of hormones that contribute to adequate appetite regulation.
Just 16 weeks of a healthy vegan diet focused on whole fruits and vegetables has been shown to cause a documented improvement in gut health, according to research led by Hana Kahleova, M.D., Ph.D., of the Physicians Committee for Responsible Medicine and presented in 2019 at the European Association for the Study of Diabetes in Barcelona.
Plants create an abundance of phytochemicals that help to protect cellular damage as well as being anti-inflammatory. A variety of long-term studies suggest that benefits like these from eating whole plant foods, as opposed to processed foods, may actually be able to prevent up to a third of all cancer cases. Most-studied have been plant-based diets’ capacity to help protect against breast, colorectal, gastrointestinal, and prostate cancers.
A growing number of professional athletes have turned to a whole-foods, plant-based diet to reach optimal performance. Colin Kaepernick, Venus Williams, United States soccer star Alex Morgan, professional surfer Tia Blanco, WNBA player and four-time Olympic gold medalist Diana Taurasi, and dozens more pros are all vegan.
Like the rest of us, dietary choices of athletes come with, at times, complex reasoning behind them. But there’s a lot of science backing up whole plants as a great choice for athleticism: Heart-healthy foods, such as whole fruits, vegetables, legumes, and nuts, are also largely plant-based. The anti-inflammatory principles and immune support of plants also benefit athletes in major ways. Tennis pro Venus Williams transitioned to a plant-based diet after being diagnosed with an autoimmune disease called Sjögren’s syndrome and said a vegan diet allowed her to manage the disease without prescription medications.
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Low-fat, high-fiber diets are proven to reduce inflammation, which is great news for those following a whole-foods, plant-based diet. Because of how effective plants are at reducing inflammation, plant-based diets have been shown to work wonders for those living with inflammatory types of arthritis.
In a 2015 study, published in Arthritis, researchers investigated the effect of a plant-based diet on osteoarthritis. Those adhering to a whole-foods, plant-based diet experienced significant drops in pain levels and jumps in motor function in just two weeks.
This story was produced and distributed in partnership with Stacker Studio.
Eating more fruits, vegetables and nuts can make a meaningful impact on a person’s health – and the planet’s too. kerdkanno/iStock via Getty Images Plus
Vegetarian and vegan options have become standard fare in the American diet, from upscale restaurants to fast-food chains. And many people know that the food choices they make affect their own health as well as that of the planet.
But on a daily basis, it’s hard to know how much individual choices, such as buying mixed greens at the grocery store or ordering chicken wings at a sports bar, might translate to overall personal and environmental health. That’s the gap we hope to fill with our research.
We are part of a team of researchers with expertise in food sustainability and environmental life cycle assessment, epidemiology and environmental health and nutrition. We are working to gain a deeper understanding beyond the often overly simplistic animal-versus-plant diet debate and to identify environmentally sustainable foods that also promote human health.
Building on this multi-disciplinary expertise, we combined 15 nutritional health-based dietary risk factors with 18 environmental indicators to evaluate, classify and prioritize more than 5,800 individual foods.
Ultimately, we wanted to know: Are drastic dietary changes required to improve our individual health and reduce environmental impacts? And does the entire population need to become vegan to make a meaningful difference for human health and that of the planet?
Putting hard numbers on food choices
In our new study in the research journal Nature Food, we provide some of the first concrete numbers for the health burden of various food choices. We analyzed the individual foods based on their composition to calculate each food item’s net benefits or impacts.
The Health Nutritional Index that we developed turns this information into minutes of life lost or gained per serving size of each food item consumed. For instance, we found that eating one hot dog costs a person 36 minutes of “healthy” life. In comparison, we found that eating a serving size of 30 grams of nuts and seeds provides a gain of 25 minutes of healthy life – that is, an increase in good-quality and disease-free life expectancy.
Our study also showed that substituting only 10% of daily caloric intake of beef and processed meats for a diverse mix of whole grains, fruits, vegetables, nuts, legumes and select seafood could reduce, on average, the dietary carbon footprint of a U.S. consumer by one-third and add 48 healthy minutes of life per day. This is a substantial improvement for such a limited dietary change.
Relative positions of select foods, from apples to hot dogs, are shown on a carbon footprint versus nutritional health map. Foods scoring well, shown in green, have beneficial effects on human health and a low environmental footprint. Austin Thomason/Michigan Photography and University of Michigan, CC BY-ND
How did we crunch the numbers?
We based our Health Nutritional Index on a large epidemiological study called the Global Burden of Disease, a comprehensive global study and database that was developed with the help of more than 7,000 researchers around the world. The Global Burden of Disease determines the risks and benefits associated with multiple environmental, metabolic and behavioral factors – including 15 dietary risk factors.
Our team took that population-level epidemiological data and adapted it down to the level of individual foods. Taking into account more than 6,000 risk estimates specific to each age, gender, disease and risk, and the fact that there are about a half-million minutes in a year, we calculated the health burden that comes with consuming one gram’s worth of food for each of the dietary risk factors.
For example, we found that, on average, 0.45 minutes are lost per gram of any processed meat that a person eats in the U.S. We then multiplied this number by the corresponding food profiles that we previously developed. Going back to the example of a hot dog, the 61 grams of processed meat in a hot dog sandwich results in 27 minutes of healthy life lost due to this amount of processed meat alone. Then, when considering the other risk factors, like the sodium and trans fatty acids inside the hot dog – counterbalanced by the benefit of its polyunsaturated fat and fibers – we arrived at the final value of 36 minutes of healthy life lost per hot dog.
We repeated this calculation for more than 5,800 foods and mixed dishes. We then compared scores from the health indices with 18 different environmental metrics, including carbon footprint, water use and air pollution-induced human health impacts. Finally, using this health and environmental nexus, we color-coded each food item as green, yellow or red. Like a traffic light, green foods have beneficial effects on health and a low environmental impact and should be increased in the diet, while red foods should be reduced.
Where do we go from here?
Our study allowed us to identify certain priority actions that people can take to both improve their health and reduce their environmental footprint.
When it comes to environmental sustainability, we found striking variations both within and between animal-based and plant-based foods. For the “red” foods, beef has the largest carbon footprint across its entire life cycle – twice as high as pork or lamb and four times that of poultry and dairy. From a health standpoint, eliminating processed meat and reducing overall sodium consumption provides the largest gain in healthy life compared with all other food types.
Beef consumption had the highest negative environmental impacts, and processed meat had the most important overall adverse health effects. Clinton Austin/iStock via Getty Images Plus
Therefore, people might consider eating less of foods that are high in processed meat and beef, followed by pork and lamb. And notably, among plant-based foods, greenhouse-grown vegetables scored poorly on environmental impacts due to the combustion emissions from heating.
Foods that people might consider increasing are those that have high beneficial effects on health and low environmental impacts. We observed a lot of flexibility among these “green” choices, including whole grains, fruits, vegetables, nuts, legumes and low-environmental impact fish and seafood. These items also offer options for all income levels, tastes and cultures.
Our study also shows that when it comes to food sustainability, it is not sufficient to only consider the amount of greenhouse gases emitted – the so-called carbon footprint. Water-saving techniques, such as drip irrigation and the reuse of gray water – or domestic wastewater such as that from sinks and showers – can also make important steps toward lowering the water footprint of food production.
A limitation of our study is that the epidemiological data does not enable us to differentiate within the same food group, such as the health benefits of a watermelon versus an apple. In addition, individual foods always need to be considered within the context of one’s individual diet, considering the maximum level above which foods are not any more beneficial – one cannot live forever by just increasing fruit consumption.
At the same time, our Health Nutrient Index has the potential to be regularly adapted, incorporating new knowledge and data as they become available. And it can be customized worldwide, as has already been done in Switzerland.
It was encouraging to see how small, targeted changes could make such a meaningful difference for both health and environmental sustainability – one meal at a time.
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This research was funded by an unrestricted grant from the National Dairy Council and the University of Michigan Dow Sustainability Fellowship. Olivier Jolliet. has received funding on unrelated projects from US EPA, USDA, American Chemistry Council Long-Range Research Initiative, and Unilever, and became part, after submission of the present manuscript of the Sustainable Nutrition Scientific Board created with the unrestricted support from Nutella. The funding organizations did not have a role in the manuscript development.
This research was funded by an unrestricted grant from the National Dairy Council and the University of Michigan Dow Sustainability Fellowship.