Health Benefits of Eating More Fruits and Vegetables

18 Mar Health Benefits of Eating More Fruits and Vegetables

Five-a-Day Keeps the Doctor Away

by Robert DePass B.S.

If I listen carefully, I can still hear my mother telling me to “eat your greens”! To some, fruits and vegetables are a poor second to a diet rich in gooey fats or sweet sugars. But is there anything in my mother’s advice? Does eating more fruits and vegetables actually benefit your health?

One of the leading dietary contributors to disease and malnutrition across the world is sub-optimal fruit and vegetable intake. Low fruit and vegetable intake is associated with an increased rate of total mortality, cardiovascular disease, cancer, and respiratory diseases such as COPD. Combined with a sedentary lifestyle and a history of smoking, reduced fruit and vegetable intake can increase the risk of death and is associated with a lower quality-of-life. The World Health Organization and the National Health Service of England recommend eating around 5 servings of fruit and vegetables a day. Healthy diet choices like these can also help to improve the functioning of the immune system, among other benefits. Despite the evidence and guidelines, most US adults eat about 1 serving of fruit and 1 serving of vegetables a day, far below the daily recommendations. While we know that those who eat more daily fruit and vegetables have better long-term health, the optimal intake is unclear. How many servings per day is the right amount? Is more always better? Do all fruits and vegetables have the same health benefits?

Recently, the American Heart Association reported a study, published in the journal Circulation, that aimed to answer some of these questions. Data was collected via questionnaires from female registered nurses participating in the Nurses’ Health Study and from male health professionals participating in the Health Professionals Follow-up Study. Over 100,000 men and women answered questions about the frequency and portions of individual fruit and vegetable items over the course of 30 years, with a 2-year follow-up in each participant to measure changes in diet over time. The AHA also performed a meta-analysis on 26 cohort studies analyzing the effect of optimal fruit and vegetable dose-response on long-term health and mortality in over 1 million men and women. Participants had no underlying health conditions. Subgroups of fruits and vegetables were assessed to see if there was a difference in health benefits among types of fruits and vegetables eaten.

When accounting for other factors, the study showed that people who eat more servings of fruit and vegetables live longer. Men and women who had at least 5 servings of fruits and vegetables per day were less likely to have cancer, cardiovascular or respiratory disease. Leafy greens (e.g. salads), non-starchy vegetables (e.g. tomatoes, mushrooms), cruciferous vegetables (e.g. broccoli, cabbage, kale, cauliflower), citrus fruits and vitamin C-rich and β-carotene-rich fruits and vegetables (e.g. apples, oranges, carrots) had a greater beneficial effect on health than either fruit juices or starchy foods (e.g. potatoes, corn). This is an important take-home message. The current Dietary Guidelines for Americans tell us to treat all types of fruits and vegetables the same, but this new study shows us that is not the case. These data encourage us to focus on non-starchy vegetables and whole fruits (not juices) if we want to maximize the potential health benefits. And how many servings do we need? The greatest reduction in mortality risk by any cause was seen in those who had at least 5 servings per day of these types of fruits and vegetables. There was no further reduction in mortality risk for a greater number of servings.

Overall, incorporating more fruits and vegetables into your diet, especially non-starchy vegetables and whole fruits (not juices), is a positive choice to optimize health benefits, quality of life, and longevity. See more information about nutrition for patients with respiratory diseases on our Basics pages.