"Specific Receptors for Specific Fruits and Vegetables"
According to a recent survey, the number of Americans who say they are eating
"pretty much whatever they want" is at an all-time high,
which unfortunately includes too few fruits and vegetables,
as well as too little variety.
Half of all fruit servings are taken up by just six foods:
OJ, bananas, apple juice, apples, grapes, and watermelons.
And half of vegetables are made up of iceberg lettuce,
frozen potatoes, fresh potatoes, potato chips, and canned tomatoes.
Not only are we not eating enough period
and missing out on the healthiest fruits—berries,
and the healthiest vegetables— dark green leafies,
the fruit and vegetable palette for our palate is sadly lacking.
Why does dietary diversity matter?
Because different foods may affect different problems.
Cabbage, cauliflower, broccoli, and Brussels sprouts are associated
with lower risk of colon cancer in the middle and right side of our body,
whereas risk of colon cancer further down on the left side of our body
appears to be better lowered by carrots, pumpkins, and apples.
So different fruits and vegetables may confer different risks for cancer
of different parts of even the same organ.
Variety is the spice of life and may prolong it.
Independent of quantity, variety in fruit and vegetable consumption
may decrease lung cancer risk, meaning if two people eating the same number
of fruits and vegetables, the one eating a greater variety may be at lower risk.
And it's not just cancer.
In a study of thousands of men and women,
a greater quantity of vegetables and a greater variety
may independently be beneficial for reducing the risk of type II diabetes.
Even after removing the effects of quantity,
each different additional two items per week increase in variety of fruit
and vegetable intake was associated with an 8% reduction in incidence of diabetes.
Why? Well, it may be attributable to individual or combined effects of the
many different bioactive compounds contained in fruits and vegetables,
thus consuming a wide variety will increase the likelihood
of consuming more of them.
All the vegetables may offer protection against chronic diseases,
but each vegetable group contains a unique combination
of these phytonutrients, distinguishing them from other groups.
Because each vegetable contains a unique combination,
a greater diversity of vegetables should be eaten to get all the health benefits.
Does it matter, though, if we get alpha-carotene or beta-carotene?
Isn't an antioxidant an antioxidant? No, it's been shown
that phytochemicals bind to specific receptors and proteins in our bodies.
For example, there appears to be a green tea receptor in our body,
a receptor for EGCG, a key component of green tea.
There are binding proteins for the phytonutrients
in grapes, onions, and capers. I've talked about the broccoli receptor already.
Recently, a cell surface receptor was identified
for a nutrient concentrated in apple peels.
And importantly these target proteins are considered indispensible
for these plant foods to do what they do,
but they can only do it if we actually eat them.
Just like it's better to eat a whole orange than just take a vitamin C pill,
because otherwise we'd miss out on all the other wonderful things
in oranges that aren't in the pill, by also eating a different fruit, like an apple,
we won't miss out on all the wonderful things in apples that aren't in the orange.
When it comes to the unique phytonutrient profile
of each fruit and vegetable, it's like comparing apples to oranges.