5-a-day and human nutritional needs

Question
Hello!
I've heard over and over to eat at least 5 fruits or vegetables every day in order to fill my daily requirement of vitamins. How scientific is that statement? Fruits and vegetables all vary in amount of respective vitamins, and even on a fruit-to-fruit basis.

Putting that aside, vitamins can be found elsewhere in our diets. Is the number an average that will get you roughly what you need even if you eat nothing else? Or is the number a rough average assuming one also eats something else that day?

Could you provide some published papers on the matter? That would be most welcome! Thank you in advance for taking the time to read my question!

Sincerely,
Erlend

Answer
Dear Erlend,

I found it difficult to believe in "requirements" and let me explain why.

A human being has a basic biological nature, but it's the only biological species to radically evolve and advance without changing its basic body structure. As a result, our bodies need the same nourishment that was good for our predecessors tens of thousands of years ago, but our current lifestyle doesn't give us a chance to get it. Yet, if you eat right and exercise right, you're healthy and no need to worry about, right?

Let's see. The Wellness Letter Berkeley from University of California-Berkeley, published a book of recipes for healthy foods with tables of vitamins, minerals, microelements, proteins, fats, carbohydrates and calories per serving.

I calculated the calorie intake from a diet based on these recipes and the Recommended Daily Allowance (RDA) values for 50 essential nutrients. The result was incredible: from 4,000 to 10,000 calories! That's a lot! Is there anybody who could burn them all?

This amount was about the same that was needed by our cave dwelling ancestors simply to survival. Theirs was a life spent on their feet; hunting prey; escaping predators; spending enormous amounts of energy to stay warm during winter or to cool during hot weather; fighting infections and parasites; losing blood; healing wounds; gathering edible plants; and women being either pregnant or nursing.

To gain some fat for the rainy days was bliss. Those 4,000 to 10,000 calories were spent as almost as soon as were gained. Since our ancestors most likely created so-called omnivorousness, or eating anything they could stomach, it mattered little where the calories were coming from: prey, plants or wild honey. Some people were lucky to have mostly prey, others could get more leaves or tubers, and very few could get honey in amounts that would lead us to believe there was any high-carbohydrate diet available.

Now, it turns out that specific health conditions seem to require specific, mostly much higher than recommended, nutrients - vitamins, minerals, essential fats, etc. Read more:

http://www.infotonic.net/2009/10/nutrients-for-better-learning.html
http://www.infotonic.net/2009/10/nutrients-to-fight-alzheimers-disease.html
http://www.infotonic.net/2009/11/most-fats-seem-to-be-protective-against.html

However, if you do believe in requirements, you might want to consult with USDA (RDA) for nutrients.

Hope is helps,

Tanya Zilberter

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