Skills to Develop
- List some of the health-related conditions that might be mitigated by eating antioxidant- and phytochemical-rich foods regularly.
- Explain the importance of eating a variety of fruits, vegetables, nuts, legumes, teas, and grains to obtain antioxidants and phytochemicals.
Figure 8.4.1: Forget the antioxidant-pill hype and get all of the health benefits of antioxidants and phytochemicals by eating a variety of fruits and vegetables. © Thinkstock
A healthy diet incorporating seven or more servings of fruits and vegetables has been shown in many scientific studies to reduce cardiovascular disease and overall deaths attributable to cancer. The WHO states that insufficient fruit and vegetable intake is linked to approximately 14 percent of gastrointestinal cancer deaths, about 11 percent of heart attack deaths, and 9 percent of stroke deaths globally.World Health Organization. “Global Strategies on Diet, Physical Activity, and Health.” Accessed September 30, 2011. http://www.who.int/dietphysicalactivity/fruit/en/index.html. The WHO estimates that, overall, 2.7 million deaths could be avoided annually by increasing fruit and vegetable intake. These preventable deaths place an economic, social, and mental burden on society. This is why, in 2003, the WHO and the Food and Agricultural Organization of the United Nations launched a campaign to promote fruit and vegetable intake worldwide.
In the last section, we reviewed the health benefits of particular antioxidants and phytochemicals obtained from fruits and vegetables and discovered that naturally incorporating them into the diet rather than taking supplements is best. Here we will consider the scientific evidence that diets rich in antioxidants actually lower chronic disease risk.
Antioxidant Variety in Food Provides Health Benefits
Not only has the several-billion-dollar supplement industry inundated us with FDA-unapproved health claims, but science is continuously advancing and providing us with a multitude of promising health benefits from particular fruits, vegetables, teas, herbs, and spices. For instance, blueberries protect against cardiovascular disease, an apple or pear a day reduces stroke risk by over 52 percent, eating more carrots significantly reduces the risk of bladder cancer, drinking tea reduces cholesterol and helps glucose homeostasis, and cinnamon blocks infection and reduces the risk of some cancers. However, recall that science also tells us that no one nutrient alone is shown to provide these effects.
What micronutrient and phytochemical sources are best at protecting against chronic disease? All of them, together. Just as there is no wonder supplement or drug, there is no superior fruit, vegetable, spice, herb, or tea that protects against all diseases. A review in the July–August 2010 issue of Oxidative Medicine and Cellular Longevity concludes that the plant-food benefits to health are attributed to two main factors—that nutrients and phytochemicals are present at low concentrations in general, and that the complex mixtures of nutrients and phytochemicals provide additive and synergistic effects.Bouayed, J. and T. Bohn. “Exogenous Antioxidants—Double-Edged Swords in Cellular Redox State: Health Beneficial Effects at Physiologic Doses versus Deleterious Effects at High Doses.” Oxidative Medicine and Cellular Longevity 3, no. 4 (2010): 228–37. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2952083/?tool=pubmed. In short, don’t overdo it with supplements and make sure you incorporate a wide variety of nutrients in your diet.
Eating a variety of fruits and vegetables rich in antioxidants and phytochemicals promotes health. Consider these diets:
- Mediterranean diet. Fresh fruit and vegetables are abundant in this diet, and the cultural identity of the diet involves multiple herbs and spices. Moreover, olive oil is the main source of fat. Fish and poultry are consumed in low amounts and red meat is consumed in very low amounts. An analysis of twelve studies involving over one million subjects published in the September 2008 issue of the British Medical Journal reports that people who followed the Mediterranean diet had a 9 percent decrease in overall deaths, a 9 percent decrease in cardiovascular death, a 6 percent decrease in cancer deaths, and a 13 percent reduced incidence of Parkinson’s disease and Alzheimer’s disease.Sofi, F. et al. “Adherence to Mediterranean Diet and Health Status: Meta-Analysis.” Br Med J 337 (2008): a1344. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2533524/. The authors of this study concluded that the Mediterranean diet is useful as a primary prevention against some major chronic diseases.
- Dietary Approaches to Stop Hypertension (DASH diet). Recall from Chapter 11 "Nutrients Important to Fluid and Electrolyte Balance" that the DASH diet is an eating plan that is low in saturated fat, cholesterol, and total fat. Fruits, vegetables, low-fat dairy foods, whole-grain foods, fish, poultry, and nuts are emphasized while red meats, sweets, and sugar-containing beverages are mostly avoided. Results from a follow-up study published in the December 2009 issue of the Journal of Human Hypertension suggest the low-sodium DASH diet reduces oxidative stress, which may have contributed to the improved blood vessel function observed in salt-sensitive people (between 10 to 20 percent of the population).Al-Solaiman, Y. et al. “Low-Sodium DASH Reduces Oxidative Stress and Improves Vascular Function in Salt-Sensitive Humans.” J Hum Hypertens 12 (2009): 826–35. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2783838/?tool=pubmed.
- Diets high in fruits and vegetables. An analysis of The Nurses’ Health Study and the Health Professionals’ Follow-up Study reported that for every increased serving of fruits or vegetables per day, especially green leafy vegetables and vitamin C-rich fruits, there was a 4 percent lower risk for heart disease.Joshipura, K.J. et al. “The Effect of Fruit and Vegetable Intake on Risk for Coronary Heart Disease.” Ann Intern Med 134, no. 12 (2001): 1106–14. http://www.ncbi.nlm.nih.gov/pubmed/11412050.
Americans Typically Eat Fewer than the Recommended Servings of Fruits and Vegetables
An article in the January 2009 issue of the Medscape Journal of Medicine reports that fewer than one in ten Americans consumes the recommended amount of fruits and vegetables, which is between five and thirteen servings per day.Kimmons, J. et al. “Fruit and Vegetable Intake among Adolescents and Adults in the United States: Percentage Meeting Individualized Recommendations.” Medscape Journal of Medicine 11, no. 1 (2009): 26. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2654704/?tool=pubmed. According to this study, the largest single contributor to fruit intake was orange juice, and potatoes were the dominant vegetable.
The USDA recommends that you fill half your plate with fruits and vegetables. The number of servings of fruits and vegetables that a person should consume every day is dependent on age, sex, and level of physical activity. For example, a forty-year-old male who exercises for sixty minutes per day should consume 2 cups of fruit and 3½ cups of vegetables, while a fifteen-year-old female who exercises for thirty minutes per day should consume 1½ cups of fruit and 2½ cups of vegetables. (One cup of a fruit or vegetable is equal to one banana, one small apple, twelve baby carrots, one orange, or one large sweet potato.) To find out the amount of fruits and vegetables the Centers for Disease Control and Prevention (CDC) recommends, see the Interactive 8.4.1.
The CDC provides a fruit- and vegetable-intake calculator.
Improving Fruit and Vegetable Intake at Home and in Your Community
Eating more fruits and vegetables can make you think better, too. According to a study published in 2009 in the Journal of Alzheimer’s Disease, no matter your age, eating more fruits and vegetables improves your brain function.Polidori, M.C. et al. “High Fruit and Vegetable Intake Is Positively Correlated with Antioxidant Status and Cognitive Performance in Healthy Subjects.” Journal of Alzheimer’s Disease 17, no. 4 (2009): 921–7. http://www.ncbi.nlm.nih.gov/pubmed/19542607. Check out "Interactive 8.4.2" for thirteen fun ways to increase your fruit and vegetable intake.
Visit the University of Nebraska-Lincoln’s website to discover thirteen fun ways to increase your fruit and vegetable intake. http://food.unl.edu/web/fnh/freezer-bags
For individually based strategies on how to stretch your fruit and vegetable budget see "Interactive 8.4.3".
The Department of Health and Human Services provides “30 Ways in 30 Days to Stretch Your Fruit and Vegetable Budget.” www.fruitsandveggiesmatter.gov/downloads/Stretch_FV_Budget.pdf
Tools for Change
Accept the challenge of optimizing your fruit and vegetable intake. Make it easier on your wallet by choosing five of the thirty ways ("Interactive 8.4.2) to stretch your fruit and vegetable budget, and implement them in the next seven days.
The CDC has developed seven strategies to increase American’s intake of fruits and vegetables.Centers for Disease Control and Prevention. “The CDC Guide to Fruit and Vegetable Strategies to Increase Access, Availability, and Consumption.” March 2010. www.cdph.ca.gov/SiteCollectionDocuments/StratstoIncreaseFruitVegConsumption.pdf.
- Support local and state governments in the implementation of a Food Policy Council, which develops policies and programs that increase the availability of affordable fruits and vegetables.
- In the food system, increase the availability and affordability of high-quality fruits and vegetables in underserved populations.
- Promote farm-to-where-you-are programs, which is the delivery of regionally grown farm produce to community institutions, farmers markets, and individuals.
- Encourage worksites, medical centers, universities, and other community and business establishments to serve more fruits and vegetables in cafeterias and onsite eateries.
- Support schools in developing healthy food messages to students by incorporating activities such as gardening into curricula.
- Encourage the development and support of community and home gardens.
- Have emergency food programs, including food banks and food rescue programs, increase their supply of fruits and vegetables.
The seven strategies developed by the CDC are based on the idea that improving access to and availability of fruits and vegetables will lead to an increase in their consumption.
- Antioxidants and phytochemicals from fruits and vegetables are thought to reduce disease risk.
- Antioxidants and phytochemicals may be beneficial in low doses but not in high doses.
- Eat a variety of foods rich in micronutrient antioxidants and phytochemicals to promote health.
- Fewer than one in ten Americans consume the recommended amount of fruits and vegetables, which is between five and thirteen servings per day.
- National and international campaigns aim to increase the intake of fruits and vegetables worldwide.
- Discuss the various strategies you use, or plan to use, to increase the quantity of fruits and vegetables in your diet. Learn other interesting and fun ways to do so from your peers.
- Share with your classmates your favorite spices, how you use them, and where you buy them.