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Vegan Diets: Healthy and Humane

A vegan diet is as good for humans’ health as it is for animal welfare. There is no nutritional need for humans to eat any animal product; all our dietary needs, even as infants and children, are best supplied by a meatless diet. The American Dietetic Association notes that a vegetarian diet reduces the risk of many chronic degenerative diseases and conditions, including heart disease, cancer, obesity, hypertension, and diabetes.1

Animal Products Lead to Heart Disease
Cardiovascular disease is the number one health problem in the U.S., accounting for nearly 1 million heart attacks annually and 2,150 deaths each day.2 Because we now know what causes heart attacks, we can prevent them. In many studies, researchers have found that higher levels of cholesterol are linked to a greater risk of having a heart attack. For every 1 percent reduction in your LDL cholesterol level, your risk of coronary heart disease drops by 1 percent.3

Thanks to the dedicated efforts of the meat, dairy, and egg industries, many Americans still believe that animal products are necessary for good health. One of the largest studies on lifestyle and health found that heart disease mortality rates for lacto-ovo-vegetarian males was only one-third that of meat-eating men.4 The British Medical Journal published findings from a study concluding that lifelong vegans have a 57 percent reduced risk of death from heart disease.5

Plant foods contain no cholesterol, whereas meat, eggs, and dairy products contain large amounts of cholesterol and saturated fat. Also, the high fiber content of a vegan diet (meat, dairy products, and eggs are devoid of fiber) helps “wash away” excess cholesterol in your digestive tract.

A vegan diet can even reverse damage already done. When Dr. Dean Ornish put patients with coronary artery disease on a low-fat vegan diet combined with moderate exercise and relaxation techniques, he found that they reversed the buildup of plaque in their arteries.6

Cancer’s Connection to Animal Products
One of the primary recommendation in the American Cancer Society’s (ACS) Guidelines on Nutrition for Cancer Prevention is to eat a diet “with an emphasis on plant food.”7 Researchers have found that vegetarians are between 25 and 50 percent less likely to suffer from cancer, even after controlling for other factors, such as smoking.8 A study by the ACS found that people who ate 3 ounces of meat a day were 30 to 40 percent more likely to develop colon cancer.9 Researchers for the National Cancer Institute have found that eating meat raises men’s risk of prostate cancer, while a study from Yale University reports that meat-based diets can cause cancers of the stomach and esophagus, as well as lymphoma (cancer of the lymphatic system).10,11,12 Scientists have also found that people who regularly chow down on hot dogs, sausages, or other processed or cured meat suffer from a 70 percent increase in pancreatic cancer rates.13

Meat Can Be Poisonous
In addition to causing heart disease and cancer, animal products contain harmful contaminants—including bacteria, arsenic, dioxins, and mercury—that can affect our health both in the short and long terms.

Every year in the U.S., there are 48 million cases of food poisoning, and 3,000 of these cases are fatal.14 The overuse of antibiotics on factory farms has caused many of the bacteria found on animal flesh to become antibiotic-resistant. Scientists at the Johns Hopkins Bloomberg School of Public Health recently reported that 96 percent of Tyson chicken flesh is contaminated with dangerous antibiotic-resistant campylobacter bacteria, and Consumer Reports found that more than half of chickens it studied were tainted with fecal matter and “97% of the breasts we tested harbored bacteria that could make you sick.”15,16

Fish flesh is also not a healthy food. Polychlorinated biphenyls (PCBs), residual industrial compounds that can be found in the environment, have caused cancer in animals and skin problems and liver damage in humans.17 Fish flesh has been found to harbor levels of PCBs thousands of times higher than those in the water in which they live.18 Researchers at the University of Illinois found that fish-eaters with high levels of PCBs in their blood had difficulty recalling information that they had learned just 30 minutes earlier.19 Fish also accumulate methylmercury in their bodies, and pregnant women and children have been cautioned not to eat fish that may contain high levels of this toxic substance.20

Factory Farming Hurts Animals
Animals are much more intelligent and complex than most people realize, and scientists are providing more and more evidence of this all the time.

According to researchers, cows enjoy mental challenges and get excited when they use their intellect to overcome an obstacle. Dr. Donald Broom, a professor at Cambridge University, says that when cows figure out a solution to a problem, “The brainwaves showed their excitement; their heartbeat went up and some even jumped into the air. We called it their Eureka moment.”21 Scientists now know that pigs have the cognitive skills of 3-year-old human children.22 Biologists wrote in Fish and Fisheries that fish are “steeped in social intelligence, pursuing Machiavellian strategies of manipulation, punishment and reconciliation, exhibiting stable cultural traditions, and cooperating to inspect predators and catch food.”23 Chickens form friendships and social hierarchies, recognize one another, develop a pecking order, and even have cultural knowledge that is passed between generations.24

Nearly all the animals raised for food in America today spend their lives on factory farms. These animals, who feel pain and fear just as the dogs and cats who share our homes do, are separated from their families and crammed by the thousands into filthy warehouses. They are mutilated without the use of painkillers and deprived of everything that is natural and important to them—they won’t be permitted to see the sun or breathe fresh air until the day when they are forced onto trucks bound for the slaughterhouse. On the killing floor, many animals are completely conscious and struggling to escape while their throats are cut—and some are still conscious while their bodies are hacked apart or when they are dunked into tanks of scalding-hot water.

Factory Farming Hurts Our Planet
Raising animals for food requires massive amounts of resources. Of all the agricultural land in the U.S., 80 percent is used to raise animals for food and to grow the grain to feed them—that’s almost half the total land mass of the lower 48 states.25 Chickens, pigs, cattle, and other animals raised for food are the primary consumers of water in the U.S.: a single pig consumes 21 gallons of drinking water per day, while a cow on a dairy farm drinks as much as 50 gallons daily.26,27 It takes more than 2,400 gallons of water to produce 1 pound of cow flesh, whereas it takes about 180 gallons of water to make 1 pound of whole wheat flour.28

Each day, factory farms produce billions of pounds of manure, which ends up in lakes, rivers, and drinking water. A single cow on a dairy farm produces 120 pounds of waste every day.29 That same cow, according to a California study, also “emits 19.3 pounds of volatile organic compounds per year, making dairies the largest source of the smog-making gas, surpassing trucks and passenger cars.”30 For more on how switching to a vegan diet reduces your “ecological footprint,” please see our factsheet on Vegetarianism and the Environment.

What You Can Do
With so many great vegan options, eating green has never been more delicious. Whether you go vegan for the environment, for your health, or for animals, you have the power to change the world, simply by changing what’s on your plate.

• Include high-fiber foods in your diet. Whole-wheat bread, brown rice, oats, flax seeds, and vegetables supply fiber, which helps lower cholesterol.
• Avoid dairy products; they contain cholesterol and saturated fats. Calcium can be obtained from beans, broccoli, sesame seeds, and green, leafy vegetables.
• Visit for delicious eggless, nondairy vegan recipes.
• Visit for our free vegan starter kit.

1The American Dietetic Association, “Position of the American Dietetic Association and Dieticians of Canada: Vegetarian Diets,” Journal of the American Dietetic Association 103 (2003): 748-65.
2American Heart Association, “AHA Statistical Update: Heart Disease and Stroke Statistics 2013 Update,” Circulation 127(2013): e6-e245.
3J.C. LaRosa, “Low-Density Lipoprotein Cholesterol Reduction: The End Is More Important Than The Means,” American Journal of Cardiology 100 (2007): 240-2.
4R.L. Phillips et al., “Coronary Heart Disease Mortality Among Seventh-Day Adventists With Differing Dietary Habits: A Preliminary Report,” American Journal of Clinical Nutrition 31 (1978): S191-8.
5M. Thorogood et al., “Plasma Lipids and Lipoproteins in Groups With Different Dietary Practices Within Britain,” British Medical Journal 295 (1987): 351-3.
6Dean Ornish et al., “Can Lifestyle Changes Reverse Coronary Heart Disease?” The Lancet 336 (1990): 624-6.
7Lawrence H. Kushi et al., “American Cancer Society Guidelines on Nutrition and Physical Activity for Cancer Prevention: Reducing the Risk of Cancer With Healthy Food Choices and Physical Activity,” CA Cancer Journal for Clinicians 62 (2012): 30-67.
8J. Chang-Claude et al., “Mortality Pattern of German Vegetarians After 11 Years of Follow-Up,” Epidemiology 3 (1992): 389-91.
9Jessica Heslam, “Don’t Have a Cow, Man: Docs: Meat Hikes Cancer Risk by up to 50 Percent,” Boston Herald 12 Jan. 2005.
10R. Sinah et al., “Meat and Meat-Related Compounds and Risk of Prostate Cancer in a Large Prospective Cohort Study in the United States,” American Journal of Epidemiology 9 (2009): 1165-77.
11Yale University, “Animal-Based Nutrients Linked With Higher Risk of Stomach and Esophageal Cancers,” news release, 15 Oct. 2001.
12Daniel DeNoon, “Diet Linked to Non-Hodgkin’s Lymphoma: Lots of Meat, Saturated Fat, Dairy May Raise Risk,” WebMD Medical News 9 Mar. 2004.
13China View, “Processed Meat May Cause Pancreatic Cancer” Xinhua News 22 Apr. 2005.
14United States Food and Drug Administration, “Foodborne Illnesses: What You Need To Know,” 29 Jan. 2015.
15Johns Hopkins Bloomberg School of Public Health, “Drug-Resistant Bacteria on Poultry Products Differ by Brand,” Johns Hopkins Public Health News Center 16 Mar. 2005.
16“Dangerous Contaminated Chicken,” Consumer Reports Jan. 2014.
17Agency for Toxic Substances and Disease Registry, “ToxFAQs for Polychlorinated Biphenyls (PCBs),” Jul. 2014.
18Agency for Toxic Substances and Disease Registry.
19Susan Schantz et al., “Impairments of Memory and Learning in Older Adults Exposed to Polychlorinated Biphenyls via Consumption of Great Lakes Fish,” Environmental Health Perspectives June 2001.
20U.S. Department of Health and Human Services and U.S. Food and Drug Administration, “Fish: What Pregnant Women and Parents Should Know,” draft, Jun. 2014.
21Jonathan Leake, “Cows Hold Grudges, Say Scientists,” The Australian 28 Feb. 2005.
22“New Slant on Chump Chops,” Cambridge Daily News 29 Mar. 2002.
23“Scientists Highlight Fish ‘Intelligence,'” BBC News, 31 Aug. 2003.
24Valerie Elliott, “Why Did the Chicken Cross the Road” Times Online 18 Mar. 2005.
25Marlow Vesterby and Kenneth S. Krupa, “Major Uses of Land in the United States, 1997” Statistical Bulletin No. 973, U.S. Department of Agriculture, 1997.
26Theo van Kempen, “Whole Farm Water Use,” North Carolina State University Swine Extension, Jul. 2003.
27Rick Grant, “Water Quality and Requirements for Dairy Cattle,” NebGuide, Cooperative Extension, Institute of Agriculture and Natural Resources, University of Nebraska-Lincoln, 1996.
28Marcia Kreith, “Water Inputs in California Food Production,” Water Education Foundation, 27 Sept. 1991.
29“EPA Progress Report 2002, Pacific Southwest Region,” Environmental Protection Agency Apr. 2002.
30Jennifer M. Fitzenberger, “Dairies Gear Up for Fight Over Air,” Fresno Bee 2 Aug. 2005.

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