Dear Doctor: Our dad is a meat-and-potatoes guy who always skips the vegetables. But he’s crazy about his grandkids and wants to see them grow up. I just read about a study where people who ate vegetables live longer. Can you tell us about it? It might help persuade our dad.
Dear Reader: The links between improved health and a diet rich in fresh vegetables, leafy greens and fruit are quite strong. Numerous studies over the course of decades continue to reveal an array of health benefits. These include improved blood pressure and blood lipid levels; lower risk of heart disease and certain cancers; better blood glucose control; and improved gut health. Now, a team of researchers from the Harvard School of Public Health in Boston has added longevity to that impressive list.
The new study you’re asking about appeared in March in the journal Circulation. It took the veggies-are-good health claims a step further by getting specific about how many daily servings give you a better shot at a longer life. The authors found a connection between eating five servings of vegetables and fruits per day and a longer life span.
To reach that conclusion, researchers analyzed health and behavioral data from two different decadeslong health studies. They selected 66,719 women from the Nurses’ Health Study, which is a collection of 30 years of information about lifestyle factors, behaviors and personal characteristics, and the incidence of more than 30 diseases during the course of the research. They also used 28 years of data from the all-male Health Professionals Follow-up Study, from which they selected 42,016 men. To be included in this new research, each participant had to have been free from diabetes, cardiovascular disease and cancer at the start of their respective studies. They also had to have been diligent in reporting their dietary intake. Any significant gaps in that reporting disqualified them from being included in the new study.
Once the researchers crunched the numbers, they found the optimal consumption to be three servings of vegetables and two servings of fruit per day. The groups who reported eating those amounts had a reduced risk of death from any cause -- 13% less -- than those who ate two or fewer servings. The reduced risk of death from heart disease was 10%, and the risk of death from a respiratory illness was 35% lower. While eating more than those five servings was fine, it wasn’t associated with additional longevity. And apologies to you potato and fruit juice lovers, but these foods were not associated with the same health benefits.
So how do you measure servings? A small to medium-sized fruit -- such as an apple, peach or a pear -- is considered a single serving. If you’re eating berries or melon, it’s 1 cup. A serving of cooked vegetables is 1/2 cup, and for fresh leafy greens, it’s 1 cup.
We hope that this newest addition to the veggies-are-good canon of research helps you in your quest to get more fresh foods on your dad’s plate.
(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)
