A recent study published in The American Journal of Clinical Nutrition examined the link between different types of plant-based diets and the risk of developing cancers in various organs. A vegetarian diet typically includes more vegetables, fruits, nuts, and legumes, while limiting or completely excluding meat. This type of diet increases the intake of phytochemicals with anti-cancer properties and lowers the risk of obesity, a condition associated with the development of many cancers.
The study drew on data from the Adventist Health Study-2 (AHS-2) cohort, which included nearly 96,000 participants from the United States and Canada. Based on questionnaires, participants were classified as vegetarians, lacto-ovo-vegetarians, pesco-vegetarians, semi-vegetarians, or non-vegetarians. Vegetarians completely avoided animal products; lacto-ovo-vegetarians avoided meat and fish but consumed eggs and dairy products; pesco-vegetarians included fish at least once a month; and semi-vegetarians consumed meat only occasionally.
The study involved 79,468 participants, including 26% Black individuals and 65% women, who were followed for an average of nearly eight years. Compared with non-vegetarians, all types of vegetarian diets were associated with a reduced risk of developing both overall and moderate-to-severe cancers. These effects were partly attributed to the lower body mass index observed in vegetarians.
Different types of plant-based diets have been shown to be beneficial for specific types of cancer. Vegan diets appear to reduce the risk of breast and prostate cancer in younger participants, while pesco-vegetarian diets are associated with a lower risk of colorectal and breast cancers in older participants. Vegetarians also show a reduced risk of lymphoproliferative diseases and stomach cancer. Some findings for individual organs are based on small numbers of cases and should therefore be interpreted with caution.
The study confirms that a plant-based diet can reduce the risk of developing several types of cancer, and no type of cancer was found to have an increased risk associated with such a diet.
