Topic summary contributed by volunteer(s): Linda

Animal products are a central part of the standard American diet and appear to be linked to a range of unhealthy conditions. As early as 1907, the New York Times reported on a study that suggested increased consumption of animal foods was a key factor in 4,600 studied cancer cases. The massive Cornell-Oxford-China study conducted in the 1970’s and 80’s showed that even small amounts of animal-based food were associated with a measurable increase in risk of some chronic diseases. Diets rich in animal foods have been linked in numerous studies to higher risk for heart disease and cancer mortality. Animal food consumption is also associated with an increased risk of being overweight, possibly because the regular consumption of calorie dense animal foods and junk foods can so blunt our brain’s pleasure center that we can tend to overeat. 

Researchers in one study saw improvement in key health measures in people who went on a diet free of animal products for just 21 days. Another study showed that cutting out all animal products and putting Parkinson’s disease patients on a strict vegan diet led to a significant improvement in symptoms. Cutting down on junk food and animal products for even a few weeks may help one’s tongue become more sensitive to fat and less prone to overeating.

Research studies have found potential links between the intake of animal products and risks of the following diseases and conditions:

• Allergic, autoimmune, and inflammatory disorders
• Cancer
• Cataracts
• Cellulite 
• Dementia
• Diabetes: Type 2 diabetes, prediabetes, and gestational diabetes
• Life-threatening reactions to E. coli toxins 
• Gallstones
• Recurrent gout attacks
• Neurological diseases
• Prepuberty
• Prostatic hyperplasia
• Rheumatoid arthritis
• Declining sperm counts 

Reducing animal product consumption while also increasing whole plant food intake has many potential benefits, based on research studies, including:

• Helps treat acne
• Slows the aging process 
• Slows body cell death rates
• Increases the chances for breast cancer survival
• Increases antioxidant intake
• Slows the growth of certain cancers
• Increases the intake of fiber
• Helps improve mood
• Avoids inflammation caused by endotoxemia
• Helps lower LDL cholesterol levels
• Helps manage mental health conditions
• Slows the shrinking of muscle mass as a person ages
• Decreases oxidative stress
• Increases the intake of phytate, an anticarcinogen
• Slows the progression of rheumatoid arthritis, cancer, and heart disease
• Boosts levels of serotonin
• Helps with weight control

   There are a number of unhealthy substances (naturally occurring, added, or accumulated from feed and the environment) contained in some animal products, including:

• AGEs
• Arachidonic acid
• Arsenic
• Cadmium
• DDT and dioxins
• Organochlorine pollutants
• Phosphates
• Pollutants, especially from fish products
• Steroid hormones

   U.S. government policy as it relates to animal products has at times been controversial, due especially to lobbying by powerful animal product industries. See Dietary Guidelines and USDA for details. Some health advocates have proposed reducing subsidies that help make animal food products artificially cheap.     

See related health topics animal fat, animal protein, beef, chicken, eggs, fish, meat, milk, Neu5Gc, pork, and poultry.