Eat More Plants!

This week I’m focusing on the second of six tenets from My Nutrition Philosophy (See post on October 11).

Eat more plants.

Plants contain phytochemicals, antioxidants, vitamins, minerals, and fiber; compounds that do amazing things in the body to improve health. You do not need to be a vegetarian to do this. Include fruits and vegetables with each meal and fill the majority of your plate with a variety of colorful, plant-based foods.

“Eat your vegetables” is a classic refrain from mothers around the world.  Most people know that fruits and veggies are good for them.  But have you ever wondered why they’re so good?  Today we’ll break down the good stuff inside plant-based foods, and why it is so good for you.  Population studies have shown plant-based diets may be protective against many diseases; especially certain cancers and cardiovascular disease.  For example, the Mediterranean diet, which is not only full of fruits and vegetables, but also whole grains, plant-based oils, nuts, seeds, and legumes; has shown to be especially beneficial in terms of chronic disease prevention.  Here are a few reasons why plants are vital to a healthy diet:

Phytochemicals – Phytochemicals are naturally occurring, biologically active compounds found exclusively in plants (“phyto” means plants).  Phytochemicals are responsible for the color, flavor, and smell of a plant.  For example, the heat of a hot pepper is due to a phytochemical known as capsaicin and the red color of a tomato can be attributed to the phytochemical lycopene.  Phytochemicals are essentially the immune system of a plant.  They protect plants from disease, and when consumed, can protect humans from disease as well.  There are literally thousands of known phytochemicals, with nearly as many functions in the human body.  Some phytochemicals act as powerful antioxidants; others inhibit tumor growth, help lower cholesterol, and stimulate detoxification enzymes in the liver.  Because phytochemicals serve so many different functions, it’s important to consume a variety of types and colors of plants throughout the day.  Fruits, vegetables, legumes, grains, herbs, tea, and spices are all good sources.  Phytochemicals are categorized into families according to chemical structure and function.  Here are a few examples:

Carotenoids—tomato, pumpkin, squash, carrots, watermelon

Flavonoids—green tea, onions, kale, soybeans, legumes, cocoa

Terpenes—citrus fruits, cherries, ginko biloba

Lignans—flaxseed, berries, nuts

Vitamins and minerals – Also known as micronutrients, vitamins and minerals occur in animal based foods as well, but some of the richest sources of micronutrients come from plants.  Micronutrients are essential to proper body functioning.

Antioxidants – Many of the phytochemicals, vitamins, and minerals contained in plants serve as antioxidants.  Antioxidants defend against harmful, highly reactive molecules in the body known as free radicals.  Damage to cells caused by free radicals can lead premature aging of cells and body tissues, and can increase the risk of many diseases including cancer, heart disease, and cataracts.  A diet rich in antioxidants – vitamins C and E, beta-carotene, lycopene, and selenium for example – has shown to protect the body from the premature aging and disease caused by free radical damage.

Fiber – Whole plant foods are an excellent source of fiber.  Fiber, a non-digestable carbohydrate, is important for digestive health, and it can help regulate blood sugar and lower blood cholesterol levels.  Fiber is also very helpful for weight management as it promotes satiety, meaning you will feel fuller faster on fewer calories.  High fiber diets have been linked to lower body weight, and decreased risk of cardiovascular disease and many types of cancer.

One very important thing to keep in mind when looking at the list above is that the whole is greater than the sum of the parts.

It’s the synergy of phytochemicals, micronutrients and other antioxidants working together in whole foods that have beneficial health effects.

When phytochemicals and antioxidants have been isolated and studied individually in supplement form, benefit is usually minimal, nonexistent, or even harmful.  For example, a large study in 2008 was stopped prematurely because researchers were finding that vitamin E and selenium supplements were actually increasing participants’ risk of prostate cancer, despite population data suggesting that dietary vitamin E and selenium intake from whole foods decreased risk.

Lastly, one of the reasons why plant-based foods are good for us is not because of what they contain, but what they don’t contain.  All plants are cholesterol free and most are low in saturated fat.  Plant foods, particularly fruits and veggies, are also high in nutrients but low in calories.

Now that we’ve learned about the health benefits of eating more plants, here are some practical strategies for increasing the amount of plants (and thus phytochemicals, vitamins, minerals, and fiber!) in your diet:

• Add sautéed veggies into an omelet or egg scramble
• Add berries to yogurt or cereal
• Add beans to soups, salads, and casseroles
• Try raw veggies with hummus as an afternoon snack
• Use spices in place of salt – spices contain phytochemicals, plus you’ll cut down on sodium too!
• Make your own stir-fry sauce with plenty of garlic and ginger
• Carry a banana or apple with you for a snack on the go
• Participate in Meatless Mondays – plan a meal with veggies as the star of the meal
• Get creative with sandwiches – try adding avocados, roasted red peppers, cucumbers, spinach, sprouts, mushrooms, etc.
• Add ground flax seeds into fruit smoothies
• Try to fit in at least 2 servings of fruits and vegetables by lunch.  That way, you’ll be more likely to meet the recommended 5-9 servings by the end of the day.
• As I’ve said before, think proportionally.  Keep your meat and starch portions reasonable, then fill the rest of your plate with plants.

Happy Eating!  -CS

Sources:

Whitney, Ellie and Sharon Rady Rolfes. Understanding Nutrition. Belmont: Thomson Wadsworth, 2005.

Gropper, Sareen S., et al.  Advanced Nutrition and Human Metabolism.  Belmont: Thomson Wadsworth, 2005.

American Institute of Cancer Research www.aicr.org

Dana Farber Cancer Institute Nutrition Services http://www.dana-farber.org/Adult-Care/Treatment-and-Support/Patient-and-Family-Support/Nutrition-Services.aspx#About