The Magic Number: 7 continued...
Quantifying the effect more precisely is difficult, Stewart-Brown says. For example, she says, the effect on the life-satisfaction score for those who ate less than one serving a day is equal to about one-third the effect on life satisfaction reported by those who lose their jobs. That's a substantial effect, she says.
The study was not funded by any produce organizations.
Only about 1 of 10 British people eat seven or more servings of fruits and vegetables daily, the researchers say.
In the U.S., the USDA recommends adults eat at least 1.5-2 cups a day of fruits and 2-3 cups of vegetables, depending on sex and age. But fewer than 1 in 10 people eat the recommended amount, according to the CDC.
Fruits, Vegetables, Happiness: Explaining the Link
The researchers found a link, not cause and effect, Stewart-Brown says.
And it's possible that the link goes in the opposite direction -- happy people may just eat more fruits and vegetables, she says.
How the fruits and vegetables may help well-being is not known, the researchers say.
"Initially, we thought it might give people more energy and they exercise more," Oswald says. But the link held even when they took exercise habits into account.
Fruits, Vegetables, Happiness: Perspectives
The study validates changes that some dietitians see when clients begin eating more fruits and vegetables, says Andrea Giancoli, RD, a spokeswoman for the American Academy of Nutrition and Dietetics. She reviewed the findings for WebMD.
"I can tell you that anecdotally, when they improve their diet, clients tell me, 'I feel good,'" she says.
Even those who say they hate fruits and vegetables can find ones they like, she says. "Usually it's just certain ones they don't like. Once we go through [the list] we find ones they do like."
"When they start to cook them in ways tasty to them, or add them to a meal, they start to like them more."
When eating plenty of fruits and vegetables becomes a habit, people don't feel as well when they skip them, Giancoli finds.