Editor's Note: This is the third of a ten part series on Dr. Noe's "10 Steps to Optimal Health." See below for a recap of all 10 steps.

The widely varied colors of fruits and vegetables supply the body with a wide variety of nutrients. Different colors tend to be produced by different nutrients. Many of the reds, yellows, and oranges, for example, are produced by carotenoids (which are related to beta-carotene). Many of the blues and purples, on the other hand, are produced by compounds known as anthocyanidins, which are particularly beneficial to the retina of the eye. By eating a wide variety of colors including all the colors of the rainbow, you get a wide variety of these key nutrients. A good mnemonic to remember the colors is Roy G Biv: Red, Orange, Yellow, Green, Blue, Indigo, and Violet. Below are examples of some of these key nutrients, what they do for the body, and the foods they are found in.

1. Lutein: May reduce the risk of cataracts and other eye diseases including macular degeneration and retinopathy. Found in oranges, squash, corn, kiwi, and green vegetables.
2. Lycopene: May reduce the risk of prostate and other cancers, elevated cholesterol, heart disease, and macular degeneration. Found in tomatoes and watermelon.
3. Indole-3-carbinol, diindolylmethane (DIM), and sulforaphanes: May reduce the risk of cancer, particularly breast cancer. Found in green brassicas such as broccoli, cabbage, brussel sprouts, kale, and collards.
4. Anthocyanidins: May reduce the risk of gout, cataracts and other eye diseases including macular degeneration and retinopathy. Found in blueberries, blackberries, cherries, and red grapes.

In addition to eating a variety of colors, it is also important to eat enough fruits and vegetables. While the USDA (producers of the food pyramid guide to eating) recommends "5 A Day" of fruits and vegetables, this should really be considered a bare minimum. The National Academy of Sciences recommends 9 servings a day. Studies that examine fruit and vegetable intake almost always determine that people who eat 8-10 servings of fruits and vegetables are at lower risk for most chronic diseases including diabetes, heart attack, stroke, high blood pressure, obesity, and many cancers.

Most Americans, on the other hand, don't even come close to getting the minimum of "5 A Day." Only 26% of Americans even get 3 servings a day, and that is only if you include the slice of tomato and piece of iceberg lettuce on a hamburger.

While 8-10 servings may sound like a lot, it doesn't have to be when you look at the definition of the serving size:

• Vegetables: 1 serving = 1 cup of lettuce or other greens, or ½ cup of cooked or chopped vegetable
• Fruits: 1 serving = 1 medium piece of fruit, ½ cup chopped, ¾ cup pure fruit juice, or ¼ cup dried fruit

 Here is an example of what a typical 10-serving day might look like:

• Breakfast: Whole grain cereal (without added sugar), milk, ¼ cup raisins, ¾ cup fruit juice (2 fruits)
• Lunch: 2 cups chili and a piece of fruit (2 vegetables and 1 fruit)
• Afternoon snack: 1 piece fruit or ½ cup baby carrots in hummus or salad dressing (1 fruit or vegetable)
• Dinner: Salad with 2 cups lettuce and ½ cupped chopped vegetable (3 vegetables), whole grain pasta or rice, and meat, fish or poultry.
• Dessert: ½ cup fresh or frozen berries with ½ cup plain yogurt (1 fruit)

For recipes, menu ideas, newsletters, shopping tips, and other tools, try the free online resource www.FruitsAndVeggiesMoreMatters.org and start eating a rainbow today!

Exercise Reduces Breast Cancer Risk

A study has found that, compared to women who do not exercise, postmenopausal women who exercise vigorously for as little as two hours a week have a 64 percent lower risk of developing breast cancer. For the purposes of this study, more than two hours of aerobics, running or similar activity over the span of a week counted as vigorous activity. Vigorous exercise did not significantly benefit pre-menopausal women but a larger sample might have a different outcome. Also, moderate exercise such as walking provided a 17 percent reduced risk of breast cancer. The study subjects were all postmenopausal African-American women. This is significant because, although more white women are diagnosed with breast cancer, more African-American women develop postmenopausal breast cancer. Also, previous studies suggest that physical activity may help fight diabetes and high blood pressure, diseases that occur at high rates among African-American women, four out of five of whom are either obese or overweight. This study was presented at the Third Conference on the Science of Cancer Health Disparities, hosted in Miami from September 30 to October 3, by the American Association for Cancer Research. The study has not yet been published.

Vitamin D Deficiency Linked to Obesity in Children

A study has found an association between lower blood levels of vitamin D and higher levels of adiposity in 479 school-age children. Adiposity is the amount of fat stored in the body and is considered a strong risk factor for diabetes. Body Mass Index (BMI) readings are not always good indications of the amount of fat in the body. For this reason, researchers used several different measures to determine adiposity or "fatness" in these children, over a 30 month period: BMI, waist circumference (WC), skin-fold thickness ratio, and height. Using these indicators and specialized statistical analysis techniques, they found that adiposity was higher in these children to the extent that the blood levels of vitamin D were lower. Vitamin D levels are measured in nanomoles per liter or nmol/L; deficiency was defined as less than 50, insufficiency as 50 to less than 75, and sufficiency as 75 or more nmol/L. This study was released October 6, 2010 but won't be published until a future issue of the American Journal of Clinical Nutrition. It is now accessible online at http://bit.ly/bltKxJ to subscribers and those who pay an article access fee.

Skipping Breakfast Linked to Heart and Diabetes Risk

A study has linked habitually skipping breakfast to greater cardiometabolic risk factors, also known as metabolic syndrome. Cardiometabolic risk factors are measures making up a constellation of apparently separate risk factors - such as waist circumference (WC), fasting insulin, higher LDL or "bad" cholesterol, and high total cholesterol - that often precede development of cardiovascular disease and diabetes. (A quarter of normal weight and 50 percent of overweight, people suffer metabolic risk factors.) Children who were then 9 to 15 years of age were asked in 1985, if they ate breakfast or not; then they were examined 19 to 21 years later. Compared to those who regularly ate breakfast both during childhood and adulthood, those who regularly skipped breakfast both during childhood and adulthood, were found to have a WC that was almost 2 inches greater, higher fasting insulin, higher overall cholesterol, and higher LDL cholesterol. The quality of foods consumed at breakfast affected cardiometabolic risk factors to some degree, but the effect of skipping breakfast remained significant despite actual foods consumed. Released October 6, 2010, this study won't be published until a future issue of the American Journal of Clinical Nutrition. It is available now online at http://bit.ly/c26AG0 to subscribers or those who pay an article access fee.

Dim Light During Sleep Time Can Increase Weight, Without Additional Calories

A study conducted on mice has found that exposure to even a dim light at night (LAN) can increase weight by 50 percent over those who experience a normal dark-light sleep time, even if they do not consume more calories. The reason seems to be that mice exposed to even a dim light at night (LAN) during normal sleep hours have a tendency to eat at times that they normally wouldn't. This resulted in weight gain and in impaired glucose tolerance, which is a risk factor for diabetes. The researchers believe LAN could disrupt levels of the hormone melatonin, which is involved in metabolism. In addition, it may disrupt the expression of clock genes, which help control when animals feed and when they are active. This shows that the Western tendency towards obesity may not be tied exclusively to food consumption or even to a lack of exercise: it may be related to late-night computer viewing and television use, which in turn disrupts normal eating schedules, and therefore, metabolism. This study was released ahead of future print publication by the journal, Proceedings of the National Academy of Sciences. It is available now online at http://bit.ly/aP9GGS for subscribers or those who are willing to pay an article access fee.

Vegetable Consumption Linked To Lower Breast Cancer Risk

An analysis of information derived from a long-term study of 59,000 women has found that eating more vegetables is linked to a reduced risk of developing a particular type of breast cancer, a type with a generally poorer prognosis. (All of the participants in the study were African American women and this type of cancer, "estrogen receptor-negative breast cancer," is more common in this population.) The incidence of this type of cancer was 43 percent lower among women consuming at least two vegetables per day compared with women who ate fewer than four vegetables per week. Specific vegetables had a greater impact on this cancer: in particular, cruciferous vegetables and carrots were linked to a lower risk. Cruciferous vegetables include broccoli, spinach, cauliflower, and cabbage, all sources of glucosinolates, which may help through their effects on both estrogen metabolism and detoxification enzymes. Carrots contain carotenoids, which may help through their antioxidant properties. The study was released October 11, 2010 and will be published in a future issue of the American Journal of Epidemiology. It is available online at http://bit.ly/cNhq2G for subscribers and those who pay the article access fee.

Yoga Fights Fibromyalgia Symptoms

A study has found that yoga produces improvements among fibromyalgia (FM) patients, in terms of pain, fatigue, mood, acceptance, and pain "catastrophizing." (Pain catastrophizing is unnecessarily viewing pain as being awful, horrible and unbearable. Fibromyalgia is a medical disorder characterized by chronic widespread pain and a heightened and painful response to physical pressure that would not normally produce pain.) Conventional therapy for FM includes medications accompanied by exercise. But researchers involved 25 of 53 women in a regular class that included 40 minutes of gentle stretching poses; 25 minutes of mindfulness meditation (awareness of breathing, and awareness of awareness itself); 10 minutes of breathing techniques (full yogic breath); 20 minutes of educational presentations on the application of yogic principles to optimal coping; and 25 minutes of group discussions. Following treatment, the yoga participants showed marked improvements in pain, functioning and attitude, as well as more involvement in life. This study was released October 14, and is being published in the November, 2010 issue of the journal, Pain. It is available online now at http://bit.ly/aH0xM9 to subscribers or those who pay the article access fee.

Best Diet for Pregnant Women Who Are Obese

A study suggests that a low-glycemic load (low-GL) diet for pregnant women who are also obese could possibly help prevent premature births and other negative maternal and infant outcomes. (A low-GL diet contains fewer carbohydrates that, in a particular quantity, cause sustained spikes in blood sugar; such spikes may increase diabetes risk.) Forty-six overweight or obese pregnant women were assigned randomly to either a low-GL or a low-fat diet. Those on the low-GL diet experienced longer pregnancy duration, greater baby head circumference, and improved maternal cardiovascular risk factors. Specifically, mothers on the low-GL diet showed smaller increases in triglycerides, less total cholesterol, and greater decreases in C-reactive protein, a marker for inflammation. The researchers concluded that large-scale studies are warranted to evaluate whether dietary intervention during pregnancy to lower GL could help prevent premature births as well as other baby and mother health issues. For information on a low-GL diet, talk to your naturopathic health practitioner. This study was released October 20, 2010 and will appear in a future issue of the American Journal of Clinical Nutrition. It is available online at http://bit.ly/cnB4lN for subscribers and those who pay the access fee.

Heavy Smoking in Midlife Doubles Later Alzheimer's Risk

A first-of-its-kind study of 21,123 people has concluded that heavy smoking in middle age more than doubles the risk of developing Alzheimer's and other forms of dementia in later life. Race and gender made no difference to the outcome and the actual increase in Alzheimer's and dementia risk was found to be 114 percent. Smoking contributes to oxidative stress and inflammation, believed to be important in the development of Alzheimer's disease. However, this study did not find an association between smoking and dementia for those who were nonsmokers at middle age, defined as 50-60 years old, or who smoked less than half a pack a day during this period. (Smoking is already known to increase the risk of most diseases, including cancer, heart disease, and stroke, and of death.) Because smoking is a risk factor for stroke, it may be through miniature, unnoticed strokes that it raises the risk of vascular dementia. This study was released October 25, 2010 but will not appear in print until the February 28, 2011 issue of the Archives of Internal Medicine. The study can be read online now at http://bit.ly/doQpQg by subscribers and those who pay the access fee.

Lifestyle Tips Could Prevent a Quarter of All Bowel Cancer Cases

Lifestyle changes in just five areas could prevent twenty-three percent of all cases of colorectal cancer, reports a new study. Those healthy lifestyle areas are: physical activity, waist circumference, smoking, alcohol and diet. The advice for each of those areas is: being physically active for at least 30 minutes a day, having no more than seven drinks a week for women and 14 drinks a week for men, being non-smoker, having a waist circumference below 88 cm (34.5 in) for women and 102 cm (40 in) for men and consuming a healthy diet, respectively. The researchers merged recommendations from the World Health Organization, World Cancer Research Fund and the Nordic Nutrition Recommendations. The study found that if everyone adhered to only one recommendation, thirteen percent of all colorectal cancer cases could be prevented. Bowel cancer is rare in people under 40 and so the study focused on 55,487 men and women aged 50 to 64, following them for almost 10 years. This study was published in the October 26, 2010 issue of the British Medical Journal and it is available online at http://bit.ly/cqP8P5 with no fee required.

Frequent White Rice Consumption Increases Diabetes Risk

A study of 25,666 men and 33,622 women in Japan, where white rice is a staple, has found that women who consume a lot of white rice have an increased risk of developing diabetes 2, compared to women who eat less. The link for men was less clear. Men who ate white rice most often exhibited a greater risk of diabetes unless they were often engaged in strenuous activity. It has been suggested that refined carbohydrates cause a deterioration of the glucose metabolism process but whether this applies to refined rice has never been determined. (Processors remove the outer husk and mill away the layers of bran to refine white or "polished" rice. Brown rice also lacks its outer husk but retains the nutritious bran. Wild rice is not actually rice at all; it is a wild aquatic grass of North America.) This study was released October 27, 2010 but won't be published until a future issue of the American Journal of Clinical Nutrition. It is available online now at http://bit.ly/aUuI01 to subscribers or those who pay the article access fee.

Olive Oil Protects Against Liver Damage

According to a new study, extra virgin olive oil has the capacity to offset some of the damage to liver tissue caused by an insufficient supply of antioxidants. An herbicide ('2,4-Dichlorophenoxyacetic acid') was fed to four groups of rats who were also fed: no olive oil, whole olive oil, hydrophilic fraction olive oil extract, or the lipophilic fraction extract, respectively. This herbicide is known to cause, if ingested in substantial amounts, depletion of antioxidants and resultant oxidative stress to the liver. All rats developed significant liver damage due to oxidation but those on a diet of whole olive oil or hydrophilic extract of olive oil sustained less damage. The hydrophilic fraction of olive oil appears to be the protective factor for protecting against toxin-induced oxidative stress. Olive oil is a main component of the so-called Mediterranean diet and is high in monounsaturated fatty acids. This study was released October 29, 2010 by the journal, Nutrition and Metabolism. It will be published in a later issue of the journal but is available online to the public now at http://bit.ly/czsA66 without charge.

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