麻豆传媒

New evidence backs up the advice of generations of moms ("eat your vegetables") and journalist/food activist Michael Pollan, who has told the world to "eat food, not too much, mostly plants."

A population-based observational study conducted in England found a "robust inverse association" between fruit and vegetable consumption and death from all causes, including cancer and cardiovascular disease.

The largest benefits were seen in people who ate seven or more servings of fruits and vegetables a day compared with those who ate less than one serving, with the higher level of consumption associated with significantly lower all-cause mortality (hazard ratio 0.67; 95% CI 0.58-0.78), lead researcher of University College London, and colleagues, reported online in the .

Consumption of seven or more servings of fruits and vegetables was associated with reduced cancer mortality (HR 0.75; 95% CI 0.59-0.96) and CVD mortality (HR 0.69; 95% CI 0.53-0.88). The association with reduced mortality risk was slightly stronger for vegetables (2 to 3 portion, HR 0.81; 95% CI 0.73-0.89) than for fruit (2 to 3 portions, HR 0.90; 95% 0.82-0.98).

Fruit and Veggie Consumption Too Low

Researchers analyzed self-reported lifestyle data for more than 65,000 randomly selected adults who participated in national health surveys in England between 2001 and 2008. Mortality data through the first quarter of 2013 were also analyzed, and the median time of follow-up was 7.7 years.

Survey respondents ate, on average, just under four portions of fruits and vegetables in the day prior to the survey and more than 50% reported eating less than five portions, the researchers noted.

, an author and professor in the department of nutrition, food studies, and public health at New York University, said she was somewhat surprised by the strength of the mortality benefit reported by the researchers, but not by the fact that the average consumption of fruits and vegetables was relatively low.

"Most Americans say they consume around three servings of fruits and vegetables (daily), and at least one of those servings is white potatoes," she told 麻豆传媒 in an email exchange. "So what we learn from this study is that eating vegetables is good for health, which we knew, and that eating more of them is better. Ten may be ideal, but even five is a great improvement."

Canned Fruits Linked to Increased Mortality

When Oyebode and colleagues considered different types of fruits and vegetables in the adjusted model, salad (HR 0.86; 95% CI 0.81-0.91, P<0.001), fresh fruit (HR 0.94; 95% CI 0.93-0.96, P<0.001) and dried fruit (HR 0.88; 95% CI 0.81-0.95, P=0.002) all showed significant associations with reduced mortality, while eating more frozen and canned fruit was significantly associated with a greater all-cause mortality (HR 1.18; 95% CI 1.07-1.29, P<0.001).

The researchers suggested that people who eat more canned and frozen fruit may have less access to fresh fruits and vegetables and they noted that canned fruit often contains high amounts of added sugar. Frozen fruit is generally considered as nutritious as fresh, but the survey did not distinguish between processed frozen and canned fruits and vegetables.

A major study limitation cited by the researchers was the self-reported measurement of fruit and vegetable intake at a single point in time, and they noted that the association between fruit and vegetable consumption and reduced mortality was not necessarily causal.

In an accompanying editorial, physicians of the University of Liverpool cited several results from the study that could help "inform professionals, policy makers, and journalists."

The finding that of lower mortality risk for each additional portion of vegetables eaten, versus fruit, is important for directing policy, as is the finding that cancer-specific mortality was reduced in association with higher fruit and vegetable consumption, they noted.

Seven Servings Better Than Five

But the result with perhaps the biggest potential implication for policy makers was that the association continued to grow with vegetable and fruit consumption of up to seven servings a day. In the U.K., the U.S., and elsewhere, many guidelines suggest five servings a day as a target minimum goal.

Nestle noted that it is not particularly hard to eat a variety of vegetables every day and even seven or more servings may be a reasonable goal.

"Standard serving sizes are half a cup for the most part and easy to manage," she noted. "An important feature of healthful diets is variety -- a mixed salad takes care of most. My bottom line: eat your veggies!"

From the American Heart Association:

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