Everyone knows about the importance of vitamins and minerals in our diet, but the phytonutrients in our food also play a huge role in keeping us healthy.
Phytonutrients are the many chemicals that plants produce in order to help them survive from diseases, insects, animals, and the like, and those same chemicals ingested by humans help us to survive as well.
While we know that a handful of vitamins and minerals are needed for our health, there are more than 8,000 phytonutrients that have been identified so far in fruits and vegetables. Most plants contain at least several hundred. Many of these nutrients work together to keep us healthy – they serve as antioxidants; they help to lower blood pressure and improve our vascular health; they boost our immunity and help us to fight infection; and they even seem to protect the brain.
Fruits and vegetables that are raised organically are felt to have more phytonutrients than those raised commercially, since organic plants tend to be hardier as they learn to survive without the benefit of pesticides and insecticides.
Some of our modern varieties of fruits and vegetables, however, are lower in phytonutrients, in part because they have been bred to contain more sugar to please our modern palates. Some foods can also lose huge amounts of these nutrients if they are stored or cooked improperly. It can be challenging to know how to get the most out of the foods that we buy.
Now Jo Robinson, a health writer, food activist and farmer, has written a wonderful book called "Eating on the Wild Side" to help us make the best choices in fruits and vegetables so that we can maximize our nutrient intake and get the most from the beautiful produce at farmers markets or on the grocery store shelves.
From its pages, you will get a wonderful education on the changes that have taken place in agriculture over the past century, and you will discover new ways to enhance your health by choosing the best that nature has to offer us. For example, did you know that the precursor to modern corn as we know it was 30 percent protein and 5 percent sugar, while some of the newer species of super-sweet corn contain up to 40 percent sugar? That's like putting a candy bar on your plate instead of a vegetable!
Here are some of Robinson's recommendations for choosing the healthiest fruits and veggies:
When purchasing greens for your salad, choose red, red-brown, purple or dark-green loose-leaf greens – these have the most nutrients including antioxidants. Pale lettuces like iceberg that form a tight head are the least nutritious. Include other leafy veggies in your salad like arugula, radicchio, endive and spinach – these are also high in phytochemicals.
Cruciferous veggies lose the lion's share of their phyotochemicals if they are stored for long periods of time or if they are cooked, so look for the freshest ones you can find at the farmers market. Raw broccoli has 20 times more sulforaphane than cooked broccoli, and sulforaphane helps to fight cancer. Kale, another cancer-fighting member of the cruciferous vegetable family, is also most nutritious when eaten raw.
White-skinned white-flesh potatoes tend to raise blood sugar more than sweet potatoes or yams. If sweet potatoes don't float your boat, then a next-best option is to choose other varieties of potatoes with dark skins and dark flesh – these have more phytonutrients than light-skinned potatoes, and are also less likely to raise your blood sugar. Be sure to eat the skin, which contains about half of all the antioxidants in the potato.
Certain apple varieties are much more nutritious than others; these include Braeburn, Gala, Discovery, Fuji, Cortland, Granny Smith, Honeycrisp, Liberty and Red Delicious. If buying red apples, choose the reddest ones you can find – the red color is an indicator of nutrient content. Less nutritious apples include Golden Delicious and Pink Lady – they tend to be higher in sugars and lower in phytochemicals.
Citrus fruit is known mainly for its vitamin C content, but citrus fruits like oranges are loaded with more than 170 phytonutrients, which provide far more antioxidant punch than just the vitamin C. The Cara Cara orange has two to three times as much antioxidant activity as the standard navel orange, and other varieties like blood oranges, Valencias and mandarins have even more. And don't forget to eat the pith of the fruit (the spongy white stuff just under the skin) and use the peel in beverages, marinades, salads, etc. – these are even richer sources of nutrients than the flesh of the fruit.
Tropical fruits, especially bananas, papayas and pineapples, along with melons, have much lower levels of antioxidants than other fruits, and are also higher in sugar. They're a great treat to have once in a while, but other fruits offer more nutritional benefit and less sugar.
For a more complete overview of what to shop for at your local farmers market and grocery store, check out Robinson's book, which is chock-full of great tips to make the most of your fruits and veggies. And with summer in full swing, there's no better time to make a trip to your local farmers market.
Drs. Kay Judge and Maxine Barish-Wreden are medical directors of Sutter Downtown Integrative Medicine program. Have a question related to alternative medicine? Email firstname.lastname@example.org.