When it comes to keeping us healthy, fruits and vegetables do yeoman’s work, as science continues to confirm. Here are five random pieces of healthful trivia that help explain why Mom was right.
BY: Cuyler Gibbons
I. AN APPLE A DAY
Originally from central Asia with over 7,500 varieties now cultivated world wide, the apple is one of the healthiest fruits. A member of the rose family, archeologists have found evidence of hominid apple consumption dating to 6,500 B.C. The amazingly versatile apple is rich in the antioxidant polyphenols, important compounds that reduce inflammation, and have proven effective in the prevention of cancerous cell growth. According to the Linus Pauling Institute1, apples supply 22 percent of the phenols we consume, and increased apple consumption has been correlated with reduced risk of heart disease and diabetes.
Additionally, the antioxidant activity promoted by phenols reduces the free radicals that cause cell damage and are believed to contribute to cancer. According to Cornell University, however, apple variety matters. Liberty, Fuji and Red Delicious were found to have high antioxidant activity while Empire and Golden Delicious, with relatively low activity, were considerably less delicious in this regard.
II. MORE THAN AN ANTI-VAMPIRE AIDE
A 2009 landmark laboratory study pitted 34 vegetables against eight kinds of cancer with markedly varying results2. Radishes for example, had no effect on the growth of pancreatic cancer cells, but reduced stomach cancer cell growth to almost nothing. Orange bell peppers on the other hand had no effect on stomach cancer cells, but reduced prostate cancer cell growth by over 75 percent.
Science has so far been unable to identify a single vegetable that can stop cancer in its tracks, but it has identified many that have been demonstrated to retard cancer cell growth. But which is best? In the laboratory study above garlic was the clear winner, displaying the greatest negative effect on cancer cell growth of all the 34 vegetables tested, on seven of the eight types of cancer. So definitely load up on the garlic,
but have it with some broccoli. And maybe some breath mints.
III. NOW YOU’RE COOKIN’
There is a school of thought that, nutritionally speaking at least, says the only good vegetable is a raw vegetable. But a study in the Journal of Agriculture and Food Chemistry3 has shown that the nutritional value of not all vegetables suffer upon cooking. In fact, the healthful benefits of some vegetables are actually improved when cooked properly.
Take kale for instance. The current darling of the leafy greens set, this rustic leaf is a heavy lifting vegetable when it comes to cholesterol reduction. Cholesterol is used by the liver to manufacture the bile acids that aid the body in the digestion of fats, in a process known as emulsification. It turns out that when we eat kale, some fiber-related nutrients bind with these bile acids and escort them out of the body without being absorbed in the intestine. The body then, recognizing this shortage of bile acid, draws on the existing supply of cholesterol to make more, thus lowering the overall amount of cholesterol. And, in a fortunate dietary twist, studies have shown that cooking enhances this binding property.
IV. THE MOST POWERFUL VEGETABLE
You don’t get to be the father of medicine without demonstrating a bit of prescience. And Hippocrates was no exception. A study at William Patterson University in New Jersey4, set out to determine what might be the most potent vegetable, as determined by its “nutrient density.” It turns out Hippocrates had an inkling for the results some 2,400 years ago.
The study looked at 17 critical vitamins and nutrients such as Potassium, Vitamin B12, niacin, calcium and Vitamin A along with 12 others. Nutrient density was calculated based on the percentage of the required daily amounts of each element found in the 41 fruits and vegetables tested. A 2,000 calorie diet and 100 grams of each food were assumed, and a “nutrient density score” was established based on the amount of nutrients per calorie of energy each fruit or vegetable delivered.
Not only is watercress one of the oldest leafy vegetables known to be consumed by humans, it was also the clear winner in the study. With a nutrient density score of 100, watercress proved the most potent of all 41 foods tested. Chinese cabbage (91.9) and chard (89.2) rounded out the top three winners. In the same family as broccoli, cabbage and Brussels sprouts, not only is watercress delicious, but it’s also nature’s own multi-vitamin.
And what of Hippocrates? Over 2,000 years before Christ, Hippocrates was calling watercress “the cure of cures.” And, while the subject of some debate, the story persists that he built his first hospital on the shore of a river to ensure an adequate supply of watercress with which to treat his patients.
V. FRUIT TOPPING
It is an indisputable fact that consumption of fruits and vegetables is essential for a healthy diet. It is further understood that a varied diet that includes a wide variety of these most healthy foods is the best way to ensure you are ingesting all the essential vitamins and minerals your body requires. But, just in case you are confronted with the desert island question —you know, the one about what minimal things you’d want if you were “stranded on a desert island” —you might be curious as to what the single healthiest fruit actually is.
Strictly speaking the answer is “it depends.” It depends on what criteria you are using to define healthy. Many fruits are recognized as very healthy due to their high antioxidant levels. Other fruits are loaded with essential vitamins like Vitamin C, Vitamin A and the “Bs,” one and two, along with minerals such as potassium, iron and calcium. But that of course doesn’t help you with the hypothetical single fruit you take on your next “island adventure.”
Fortunately for those who need to know what fruit tops the list, the health Internet site Leanitup.com has devised a comprehensive ranking of 30 different fruits based on a composite score comprised of 12 different healthful indicators5. These include the amount of four essential vitamins, as well as potassium levels, the amount of omega 3s, antioxidant content, and calories, sugar, and fiber doses. Different elements are given different weights depending on their dietary importance with a measure called glycemic load being one of the most important. This key metric measures how quickly the food tends to increase blood sugar levels. Higher GL levels indicate spikes in insulin production and increased fat storage that can lead to diabetes and inflammation.
So, crunch all those numbers and what do you get? BLACKBERRIES! It turns out, that based on this ranking blackberries possess the most healthful composite profile of the 30 fruits tested. The study made no mention, however, of those pesky little seeds that get caught so easily between your teeth.