The mammoth Global Burden of Disease Study identified the typical American diet as the primary cause of Americans’ death and disability, and inadequate intake of vegetables as our fifth-leading dietary risk factor, nearly as bad as our consumption of processed meat.

Indeed, a more plant-based diet may help prevent, treat, or reverse some of our leading causes of death, including heart disease, type 2 diabetes, and high blood pressure, and may improve not only body weight, blood sugar levels, and ability to control cholesterol, but also our emotional states, including depression, anxiety, fatigue, sense of well-being, and daily functioning.

Dark-green, leafy vegetables are the healthiest foods on the planet, which is why I recommend two servings each day. As whole foods go, they offer the most nutrition per calorie. Of all the food groups analyzed by a team of Harvard University researchers, greens turned out to be associated with the strongest protection against major chronic diseases, including up to about a 20 percent reduction in risk for both heart attacks and strokes for every additional daily serving.

In my Daily Dozen, I also recommend two servings a day of other vegetables, as well as one daily serving of cruciferous vegetables like broccoli. Crucifers may potentially prevent DNA damage and metastatic cancer spread, activate defenses against pathogens and pollutants, help to prevent lymphoma, boost our liver detox enzymes and target breast cancer stem cells, and reduce the risk of prostate cancer progression. The component responsible for these benefits is thought to be sulforaphane, which is formed almost exclusively in cruciferous vegetables. Beyond being a promising anticancer agent, sulforaphane may also help protect our brain and our eyesight, reduce nasal allergy inflammation, manage type 2 diabetes, and was recently found to help treat autism.

The information on this page has been compiled from Dr. Greger’s research. Sources for each video listed can be found by going to the video’s page and clicking on the Sources Cited tab. References may also be found at the back of his books.

Image Credit: Hans Splinter / Flickr. This image has been modified.