People who eat plenty of fruits and vegetables tend to be more
optimistic about the future, new research suggests, reports UK-based
news portal Mail Online.
Scientists have discovered that optimistic folk have higher levels of plant compounds called carotenoids in their blood
A commonly-known carotenoid is beta-carotene, a pigment found in high levels in orange fruit and green, leafy vegetables.
Previous
studies have shown that high blood levels of antioxidants - of which
carotenoids are one form - may be a marker of good health.
Antioxidants
help keep other molecules in the body from producing free radicals,
which can damage cells and contribute to disease.
'Individuals
with greater optimism tended to have greater levels of carotenoids such
as beta-carotene,' said lead investigator Julia Boehm, of the Harvard
School of Public Health.
'This is the first study of its
kind to report a relationship between optimism and healthier levels of
carotenoid concentrations,' she added.
One theory is that antioxidants might have a de-stressing effect.
The
current study evaluated blood concentrations of nine different
antioxidants, including carotenoids such as beta-carotene and vitamin E
in nearly 1,000 American men and women ages 25 to 74.
Participants
filled out a questionnaire about their life attitudes and provided
blood samples to the researchers, according to the report in
Psychosomatic Medicine.
They also measured the degree of optimism in the same group.
Researchers
found that people who were more optimistic had up to a 13 per cent
increase in carotenoid concentrations in their blood compared with
people who were less optimistic.
The researchers believe
that higher levels of fruit and vegetable consumption among more
optimistic people may at least partially explain the results.
They
found that people who ate two or fewer servings of fruits and
vegetables a day were significantly less optimistic than people who ate
three or more servings a day.
They added that the
relationship between optimism and carotenoid levels was only partially
explained by the fact that more optimistic people tended to engage in
healthier behaviors such as eating fruits and vegetables and avoiding
cigarette smoking.
Last year, scientists at Warwick
University found that people who ate seven portions of fruit and
vegetable a day are the happiest.
The study found that
those who ate around eight portions of fruit and vegetables a day had an
average score that was one point higher than people who did not eat
any.
The link remained even when people’s exercise levels and overall diet – both of which can influence mood – were accounted for.
Although
it is not known exactly how fruit and vegetable improve wellbeing, they
contain chemicals known as antioxidants, which are thought to reduce
stress levels.
At the time, lead researcher Professor Andrew Oswald said he was 'stunned ' when he looked at the data.
‘We
think we’re on to something really important here,' he said. 'However,
we don’t really know why this is – whether there is something in the
biochemistry of the fruit and vegetable which works inside humans.
‘We
know that fruit and vegetable carry a lot of antioxidants and those
protect us against attacks on the body. But how that works through into
our minds and emotions, researchers have no idea.'
The Department of Health has spent at least £4million on its ‘five a day’ advertising campaign since it was launched in 2003.
In
contrast, the French are told to eat ten portions a day, the Canadians
between five and ten, and the Japanese 13 portions of vegetables and
four pieces of fruit.
