DrG's Medisense Feature Article

Superfoods! … Really?
by Ann Gerhardt, MD
May 2017
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We know about vitamins, minerals, carbs, fats and proteins.  They are essential for life.  Many Americans get by on those nutrients alone, eating very few if any vegetables, fruits, nuts and seeds.  Chronic heart disease, stroke and diabetes usually hit them sooner than people who do eat those foods. 

Even knowing that vegetables, fruits and plant foods in general are healthful doesn’t compel many people to add them to their diet unless someone creates a ‘superfood’ fad.  But flitting from fad to fad doesn’t create a healthy long-term diet.

Plant foods contain fiber, which feeds the colonic bacteria that keep us healthy (see “Love Your Poop” in DrG’sMediSense, February 2017).  Plant foods also contain phytochemicals:  Phyto = plant, and chemical = some molecular component produced by the plant.  A few make the news and sound familiar, like bioflavonoid, which is not actually a single nutrient.  It is a general term for a group of thousands of structurally similar nutrients.

Some of these phytochemicals are poisonous, produced by the plant to deter insects and animals that would otherwise eat them.  Others, which we call phytonutrients, confer beneficial effects on the plant and for humans.  Plants evolutionarily acquired them for a purpose:  To enhance immunity that protect from invading organisms, to reduce oxidant, inflammatory and chemical damage, and to prolong life by preventing or repairing cell damage and maximizing metabolism.

Different plants contain different phytonutrients.  Every plant food contains more than one, in varying amounts.  Each phytonutrient can be found in more than one but not all plant foods.  We say we should eat apples for quercetin, but they also contain phloridzin, catechin and chlorogenic acid.  And we could just as easily eat onions for the quercetin.  Tea is known for its epigallocatechin gallate, but also contains caffeine, tannin, polyphenol, theobromine and anthocyanin content.  Apple and tea phytonutrients don’t overlap much, so using one as your exclusive phytonutrient source misses out on a bunch of others.

There is no superfood.  There are foods that contain an abundance of a few healthful nutrients, but no single food will save you from an otherwise lousy diet.  Dr. Oz perpetuates his show by promoting superfoods and miraculous supplements.  Eating all that food and taking all those supplements could take all day and break your budget.

Luckily a healthy diet doesn’t require consuming every healthy food every day.  The body stores most nutrients to some extent. Since there is overlap of phytonutrients in different foods, changing it up each day probably covers all the nutrient bases over time.  For example, tree nuts differ in their nutrient and fat content, but you don’t need to eat each kind every day.  Eating different nuts on different days works just as well.  

The ‘5 a Day’ program encourages people to eat five servings of vegetables and fruits daily, while the Mediterranean Diet pushes for nine.  Many people assume that fruits are just as good as vegetables and figure that their huge multi-fruit smoothie suffices for the day.  That’s better than nothing but is missing phytonutrients found in vegetables and other plant foods.  In addition, we shouldn’t overdo fruit consumption, as the sugar can induce insulin resistance (see “Fruit Contains Fructose – Is It OK?” in DrG’sMediSense December 2009). 

Vegetables come in many types, each of which has different phytonutrients, as do other plants, including tree nuts, legumes (including soy, beans and peanuts), seeds, tea, cocoa, coffee.  A variety of all of them each day is best.  Plus it’s easier to eat The Mediterranean Diet’s nine servings daily if you mix it up – Getting all nine from 4.5 cups of cooked kale is hard to stomach, but a half-cup of bean and corn salad, a peanut butter sandwich with jam, a cup of cooked green beans with almonds, a snack of celery and guacamole, a cup of tea, a peach and a strawberry-banana smoothie is easy to consume throughout the day.  It just takes thinking about it. 

Another good thing about variety is that some phytonutrients increase or decrease metabolism of other substances, including medication.  If you overdo one of those nutrients, you could suffer from acute excess or deficiency of your medicine.  An example of this is grapefruit, which contains bergamottin that inhibits a liver enzyme responsible for clearance of many medicines. 

Bottom Line at the Bottom:  There is no superfood.  Eat a variety of foods, including vegetables, fruits, seeds, nuts, legumes and whole grains to provide all the nutrients usually attributed to superfoods.

Nutrient/Food Addendum: Here are some of the common phytonutrients and their food sources:

Alkaloids:  caffeine, theobromine, capsaicin, glucosinolates and chemicals similar to human brain transmitters.
Found in tea, coffee, chocolate, chili peppers, broccoli, turmeric

Polyphenols:  Flavones, flavonols, isoflavones, flavanones, flavanols, anthocyanidins, tannins, stilbenes, coumarins, bergamottin, gingerol, zingerone, cinnamaldehyde, eugenol
Found in many fruits, tea, chocolate, parsley, onion, broccoli, grapes, cherries, beans, celery, leeks, apples, soy products, citrus fruits, oregano, wine, berries, pomegranate, walnut, grapes, seeds, ginger, cinnamon, clove and many other vegetables and fruits

Phenolic acids:  Hydroxycinnamic, chlorogenic, gallic, hydroxybenzoic, caffeic, coumaric, ferulic and vannilic acids
Found in almost every plant, bound to lignins, tannins, cellulose and proteins.