A
major meta-analysis examined about 350 studies performed in various parts of
the world to try and pinpoint the various effects of consuming both fruits and
vegetables. They looked at health outcomes, which included cardiovascular
events, cancers, and early death. All the studies were prospective cohort
studies, and therefore, the results proved an association between the preceding
events and the outcomes but could not prove causation.
The
conclusion was that the people who habitually ate 800g or more of fruit and
vegetables a day – which, at ten portions, is considerably higher compared to
the 5 currently recommended – lowered their risk of adverse health conditions.
Cancer risk was reduced around the 600g mark. This study also tried to identify
the benefits of different fruits and vegetables in various health conditions.
However, this study is unlikely to translate into a current recommendation for
the simple fact that most people today do not eat even the five portions that
public health agencies have promoted.
This
is a classic case of expediency overcoming scientific accuracy in determining
what advice is given to the general population, on the plea of not wanting to
put pressure on them by unrealistic goals. However, the truth is that in one
study, the easily achievable intervention of physically providing food to a
target group of very young adults, without any other reminders or nagging,
immediately lifted the number of portions in this group by 1.2 servings a day,
as well as producing significant improvements in many aspects of their mental
health. This was in contrast to the lack of benefit seen in a control group who
received vouchers to purchase roughly the same amount of fruits and vegetables
of their own choice and to prepare them for consumption as they wished, with
twice-daily reminders, even though these latter messages were not perceived as
irritating but somewhat helpful. The bottom line may be that making fresh fruit
available and accessible wherever people gather to eat may be the best way to
increase consumption rather than endless education campaigns.
Increased
fruit and vegetable consumption was analyzed by 200g increments, concerning:
- Ischemic heart disease: each 200g increase in consumption reduced the risk by 8%,
especially with sources of vitamin C and with apples or pears, fruit
juices, green leafy vegetables, carrots, and sweet potato
- Stroke: risk reduced by 16% per 200g increase in consumption,
particularly apples or pears, citrus, green leafy vegetables, and
vegetable pickles
- Cardiovascular disease in general: 8% reduction per 200g
increase, especially with apples or pears, citrus, carrots, green leafy
vegetables, and other vegetables outside the cruciferous (Brassica) family
- Cancers: 3% reduction per 200g increase, with cruciferous vegetables
in particular, and with increases up to 600g per day
- Mortality from all causes together: 10% reduction per 200g increase,
especially with apples or pears, citrus fruit, berries, vegetables of all
kinds, and potatoes
In
other words, 5.6 million early deaths occurred in the year examined (2013)
because these individuals ate less than 500g of fruits and vegetables daily. On
the other hand, eating 800g of these daily could prevent the deaths of 7.8
million people a year.
Of
course, it goes without saying that simply eating more fruits and vegetables is
not a magic wand to make disease vanish. But it certainly is one of the best
ways to make your food work for you and not against you, and if you also remain
physically active and don’t consume harmful things, such as smoke, alcohol, and
other toxins, you are likely to live longer and more healthy than those who do.
Eating
fresh fruit is even helpful in preventing diabetes mellitus as well as reducing
the risk of some small-vascular complications of diabetes, such as renal
disease or diabetic retinopathy, by an astonishing 28%. Apart from a 12% lesser
risk of new-onset type 2 diabetes in people who regularly ate fruit, people with diabetes who
did so had a 14% lower risk of death or secondary cardiovascular disease
compared to those who ate fruit less than once a week. Apples and pears are
preferred because of their low glycemic index (GI) and prolonged slow release
of sugar into the blood. Bananas, grapes, and tropical fruits have a higher GI
than grapes.
The
global pattern is dismal, with less than 20% of people eating fruit regularly
and over 6% admitting to eating it rarely or never.
Health Benefits
Fruit
does a lot of things for the body:
- It
reduces weight and prevents weight gain
- It
reduces the risk of diseases brought on by obesity, such as diabetes
mellitus and heart disease, and protective effects increase as the
consumption of fruit increases.
- Lower
blood pressure
- Lower
blood glucose levels
- Prevents
dyslipidemia
- It
reduces the rate of death due to all causes
How Does Fruit
Reduce Body Weight?
Many
mechanisms have been suggested for the anti-obesity effect of increasing fruit
consumption:
- Reduced caloric intake because of the low fat
content and the high water and fiber content of most fruits
- Producing a feeling of fullness, which reduces
overall food intake and meal frequency, by the gelling of dietary fiber
within the gut, and the prolonged digestion process of fruit means that
satiety receptors are occupied for a longer duration.
- Providing micronutrients and vitamins, which
are negatively associated with weight gain by reducing gene expression in
relation to fat cell production and maturation
- Phytochemicals such as resveratrol,
proanthocyanidins, catechins, caffeic acid, and the like are potent
anti-oxidants that suppress fat cell formation and storage.
- Undigested fruit fiber provides a vital
substrate for gut microbiota to feed upon, to produce changes in the
relative proportions of various bacterial groups, increasing the number of
Bacteroides and Actinobacteria (abundant in lean people) but reducing
Firmicutes and Proteobacteria, which are found in obese individuals.
Acting
via these numerous pathways, fruit succeeds in both reducing total energy
intake and maintaining satiety. This, in turn, leads to a net lowering of fat
stores (especially central) by their utilization within the body for daily
energy and metabolic needs, reducing body mass. In addition, its nutrient
composition favors adipocyte non-differentiation and reduces obesity.
Apples
and pears are consistently associated with risk reductions in many types of
disease. Notably, these contain 6% fructose and less than half that amount of
sucrose. The fructose is mostly fermented within the colon because it is not
well absorbed. The resulting increase in short-chain fatty acid (SCFA)
production is of great value in many metabolic and physiological processes.
The
few trials that support a pro-obesity effect of fruit have often failed to
distinguish natural and processed fruit forms and are usually confined to a
specific age group or category, in contrast to the numerous population-based
trials confirming its anti-obesity activity. A single trial suggested that an
overly high consumption of high-GI fruits during the second trimester led to
increased rates of gestational diabetes. Still, the authors recommend further
study to confirm and examine the findings. Another trial showed increased body
mass with increased fruit intake at dinner time. It is yet to be confirmed that
fresh fruit carries such a risk rather than preserved or juiced fruit.
In
short, the net conclusion is that increasing fruit intake is rarely a health
risk and carries a host of benefits – which only improve with more fruit in its
natural form, whatever the glycemic load of the individual fruit.
Content Source : https://www.news-medical.net/health