Healthy Heart Diet

Definition

     A healthy heart diet is an eating plan designed to keep blood cholesterol low and prevent the risk of heart disease. This is usually achieved by eating foods that are low in saturated fat, total fat, cholesterol, and sodium. Some diets help people lower their cholesterol levels.

Origins

     The healthy heart diet is the result of ongoing nutrition research by organizations including the United States Department of Agriculture (USDA) and the American Heart Association (AHA). The department first issued dietary recommendations for Americans in an 1894 Farmer’s Bulletin, according to the 1996 USDA report Dietary Recommendations and How They Have Changed Over Time.

     The 1894 recommendations came from W.O. Atwater, first director of the USDA’s Office of Experiment Stations. He proposed a diet for American men based on protein, carbohydrate, fat, and mineral matter. In a 1902 Farmer’s Bulletin, he warned about the danger of a dieting consisting of too much protein or fuel ingredients (carbohydrates and fat). “The evils of overeating may not be felt at once, but sooner or later they are sure to appear—perhaps in an excessive amount of fatty tissue, perhaps in general debility, perhaps in actual disease,” Atwater cautioned.

    More was known about nutrients in 1941 when the USDA first issued the Recommended Dietary Allowances (RDAs). The allowance allowances covered areas like calorie intake and nine essential nutrients: protein, iron, calcium, vitamins A and D, thiamin, riboflavin, niacin, and ascorbic acid (Vitamin C). The USDA also released national food guides during the 1940s. The guides provided a foundation diet with recommendations for foods that contained the majority of nutrients. The guide was modified in 1956 with recommended minimum portions from food groups that the USDA called the “Big Four”: milk, meats, fruits and vegetables, and grain products.

     The guides remained in effect until the 1970s when an increasing amount of research showed a relationship between the over-consumption of fat, saturated fat, cholesterol, and sodium and the risk of chronic diseases such as heart disease and stroke. In 1979, the USDA guide included the Big Four and a fifth category that included fats, sweets, and alcoholic beverages.

     The following year, the USDA and the Department of Health and Human Services (HHS) issued the first edition of Nutrition and Your Health: Dietary Guidelines for Americans. The recommendations for healthy Americans age 2 and older included consuming a variety of foods, avoiding too much fat, saturated fat, cholesterol, and sodium. Those guidelines were recommended for people older than age 2 because younger children need more calories and fat in their diet to aid in their growth and development.

   The USDA and HHS update the federal guidelines every five years. The 1990 edition recommended a diet low in fat, saturated fat, and cholesterol. Salt and sugars were to be consumed in moderation. In Dietary Guidelines for Americans 2005, the federal departments featured more specific recommendations.

     The recommendations for healthy Americans came from two departments that are part of the National Institutes of Health (NIH). Within NIH is the National Heart, Lung, and Blood Institute (NHLBI), which was formed by Congress in 1948. In the 21st Century, the institute’s focus on heart disease included the creation of a Heart Healthy Diet to keep cholesterol low and the Therapeutic Lifestyles Changes (TLC) Diet to help people lower their blood cholesterol.

     Furthermore, the American Heart Association (AHA)has long been concerned with educating the public about the relationship between diet and heart health. The association started in 1924 as an outgrowth of local organizations including the Association for the Prevention and Relief of Heart Disease in New York City. That group was founded in 1915 and consisted of physicians and social workers.

     The national organization’s public education activities include issuing nutritional guidelines that are periodically revised. The title of the association’s “2006 Diet and Lifestyle Recommendations” reflected the importance of diet and physical activity on health,

    

Description

     Healthy heart diets share fundamental elements about how to prevent heart disease. The process starts with an understanding of why some foods should be avoided and others are beneficial to the heart. The first step is for the person to be aware of how food affects heart health.

    The heart is a muscle, and the body’s muscles require a steady supply of oxygen and nutrients. This supply is brought to the heart by blood in the coronary arteries. Healthy heart diets are designed to keep the coronary arteries open for the delivery of oxygen and nutrients. When the arteries become narrow or clogged, the heart will not receive enough blood. This blockage causes coronary heart diseases. If the heart doesn’t receive enough of the blood containing oxygen, the person feels a chest pain, which is known as angina. If the coronary artery is totally blocked off and no blood reaches the heart, the person experiences a heart attack.

    The narrowing or clogging of the arteries is designated as atherosclerosis when the blockage is caused by deposits of cholesterol and fat. Cholesterol is a soft, waxy substance that is similar to fats (lipids). Cholesterol occurs naturally and is found throughout the body in the bloodstream and cells.

Cholesterol is used by the body to produce VitaminD, hormones, and the bile acids that dissolve food, according to NHBLI. However, the body doesn’t need much cholesterol to perform those functions, and the extra cholesterol is deposited in the arteries.

    Cholesterol and fats don’t dissolve in the bloodstream and are moved through the body by lipoproteins. These are a combination of a lipid (fat) surrounded by a protein, according to the American Heart Association. Total cholesterol consists of low-density lipoprotein (LDL), high-density lipoprotein (HDL), and very-low density lipoprotein (VLDL).

     VLDL carries triglycerides, a form of blood fat that could affect the heart. LDL is known as “bad” cholesterol, and HDL is called “good” cholesterol. HDL may help the body by clearing fat from the blood and removing extra cholesterol, according to the AHA.

The body produces LDL and receives more of it from food. When foods rich in cholesterol and some fats are consumed, the body creates more LDL. The dietary cholesterol comes from animal products such as meat. Also contributing to the LDL build-up are foods that are high in trans fats and saturated fats.

     Food contains three types of fats that should be monitored on a healthy heart diet:

• Saturated fat is the popular term for saturated fatty acid. Saturated fat tends to raise cholesterol levels and is found in meat, poultry, whole-milk dairy products including cheese and butter, cocoa butter, lard, and tropical vegetable oils like coconut and palms oils. Saturated fat remains solid at room temperature.
• Trans fat is a type of vegetable oil that was processed to make the liquid more solid. The process called hydrogenation produces hydrogenated and partially hydrogenated vegetable oils. These oils are found in stick margarine, vegetable shortening, commercial fried food, and baked goods such as cookies and crackers.
• Unsaturated fats include polyunsaturated fats and monosaturated fats. Polyunsaturated fats are found in fish, walnuts, corn oil, and safflower oil. Mono-saturated fats are found avocadoes, olives, olive oil, canola oil, and peanut oil.

     Sodium and salt are sometimes used interchangeably in information about healthy heart diets. The AHA recommends that people consume less than 2,300 milligrams of salt per day. This amounts to about 1 teaspoon of salt. Some organizations recommend a slightly higher amount of less than 2,400 milligrams. The recommended amount is for healthy people and may be lower for people with some health conditions.

    The diets of most Americans contain too much salt, and processed foods are generally the source of this sodium. A diet high in salt tends to raise blood pressure, and this could lead to heart disease, stroke, and kidney damage.

     Reducing the amount of sodium in a diet will lower blood pressure, and aid in reaching healthy cholesterol levels. In addition, foods high in potassium counteract some of the effect of sodium on blood pressure, according to the USDA guidelines.

     The federal government and the American Heart Association are among the organizations that provide recommendations for a healthy lifestyle. The recommendations frequently parallel those of the healthy heart diet, a plan that emphasizes the consumption of less fat, less cholesterol, and less sodium. There is also agreement that diets should include fiber-rich foods like fruits, vegetables, and whole-grain products.

     Guidelines also focus on the importance of regular physical activity to prevent or lower the risk of conditions like heart disease. Generally, people are advised to exercise at least 30 minutes most days of the week. While some recommendations are designed for healthy people, the guidelines also apply to a healthy heart diet. There may be more specific instructions in plans to lower cholesterol levels.

DIETARY GUIDELINES FOR AMERICANS 2005. Nutrition and Your Health: Dietary Guidelines for Americans defines a healthy eating plan as one that:

• Emphasizes fruits, vegetables, whole grains, and fat-free or low-fat milk and milk products.
• Includes lean meats, poultry, fish, beans, eggs, and nuts.
• Is low in saturated fats, trans fats, cholesterol, salt, and added sugars.
• The total fat intake should be between 20% to 35% of the daily calories consumed.

     People can create a diet with those foods by using online tools like the USDA’s MyPyramid Plan and calculators on the NHBLI pages for the Heart Healthy and TLC diets. Someone Internet sites produce an individualized plan with specific calorie amounts, recommended foods, serving portions, and a system to track physical activity.

     AMERICAN HEART ASSOCIATION 2006 DIET AND LIFESTYLE RECOMMENDATIONS. The heart association’s plan starts with the person determining how many calories are needed to maintain a healthy weight. People are advised not to eat more calories then they burn through activity. They should create a meal plan that includes:

• A variety of vegetables and fruits and unrefined, whole-grain food.
• Fish at least twice a week. Oily fish such as salmon, trout, and herring contain omega-3 fatty acids. These acids may help reduce the risk of fatal coronary disease.
• Lean meats and poultry without skin. These proteins should be prepared them without added saturated and trans fat.
• Less than 300 milligrams of cholesterol each day.
• A moderate amount of alcohol, with one drink per day for women and two drinks per day for men.
• Dairy products that are fat-free, 1% fat, and low-fat dairy.
• Food containing little or no salt.The association advises the public to cut back on:
• Foods containing partially hydrogenated vegetable oils to reduce trans fat in their diets.
• Foods high in dietary cholesterol.
• Beverages and foods with added sugars.

     The association certifies grocery products that meet the organization’s standards. Certification on packaging is indicated by a red heart with a white check mark inside. Products with that symbol meet association criteria for recommended amounts of saturated fat and cholesterol for healthy people above the age of 2. The standard-certification designation is based on one serving that contains 1 gram or less of saturated fat, 20 milligrams or less of cholesterol, and 480 milligrams or less of sodium. The wholegrains certification is issued to foods containing those quantities and an amount of whole-grain at a proportion of 51% by weight with reference to the amount customarily consumed.

     THE NHBLI HEART HEALTHY DIET. The NHBLI website in the spring of 2007 featured heart healthy diet guidelines and an online tool to create a personal eating plan. The online activity starts with the person providing information about height, weight, gender, age, and level of physical activity. This action generates a recommendation for a daily calorie allowance. That allowance is used to determine the percentage of total fat and saturated fat permitted at that calorie level. The consumer then receives prompts to select food choices for three meals and a snack.

     As information is received, the person sees the amounts of calories, fat, total fat, cholesterol, and sodium that would be consumed. After the final entry is made, the nutritional information is totaled. The total is compared with the recommended amounts. Along with that data are recommendations on how to modify the meal plan to lower fat and cholesterol consumption.

Meal planning on the heart healthy diet is based on these guidelines:

• A person should eat just enough calories to achieve or maintain a healthy weight and reduce blood cholesterol level. A doctor or registered dietitian can determine what a reasonable calorie level.
• Saturated fat should account for 8 to 10% of the day’s total calories.
• Total fat should be 30% or less of the day’s total calories.
• Dietary cholesterol should be limited to less than 300 milligrams per day.
• Sodium intake should be limited to 2,400 milligrams a day.

     THE TLC DIET. The Therapeutic Lifestyles Changes (TLC) Diet helps to lower the cholesterol of people who have a heart disease or at risk of developing one. The TLC section of the NHLBI contains online tools similar to those for the Healthy Heart diet. The guidelines for the low-saturated fat, low-cholesterol TLC diet are:

• The person should eat just enough calories to achieve or maintain a healthy weight and reduce the blood cholesterol level.
• Saturated fat should account for less than 7% of the daily total calorie total.
• Fat consumed amounts to 25 to 35%% of the day’s total calories.
• The person should eat less than 200 milligrams of dietary cholesterol per day.
• Sodium intake should be limited to 2,400 milligrams per day.

Function

      A healthy heart diet helps people age 2 and older reduce the risk of cardiac disease. This is achieved by the consumption of foods that keep total cholesterol and LDL cholesterol at healthy levels. A healthy heart diet may involve lowering cholesterol levels by reducing the amount of foods high in cholesterol, fat, and sodium. At the same time, people work to increase HDL levels through diet and exercise.

      The healthy heart diet is a lifelong process that starts with education about the effects of food on the heart. People on this diet learn to make wise food choices, relying on information including the nutritional labels on processed food. The labels provide information about the calories, fats, sodium, and sugar in a single serving of the product.

Benefits

     The benefits of a healthy heart diet are that people lower their cholesterol levels and reduce their risks of cardiovascular disease. A healthy heart diet is a preventive plan for people age 2 and older since high cholesterol could become an issue in childhood. Parents who place their children on healthy heart diets not only help them with physical health, they give their children with the basics for a lifetime of healthy habits.

     Diet and regular physical activity keep cholesterol at healthy levels. The healthy heart diet that is also a weight loss plan will help obese and overweight people shed excess pounds. Smoking is another risk factor that will be lowered when people stop smoking. Diabetes and high blood pressure also put people at risk for heart disease. Both may be treated with medication, and people diagnosed with those conditions will benefit from a healthy heart diet.

     Factors like heredity can’t be changed, so people with a family history of high cholesterol or early heart disease should prescribe to a heart healthy diet. The NHLBI defined the person at risk as someone with a father or brother diagnosed with this condition before the age 55. There is also a risk to someone with a mother or sister with this condition before age 65.

     Furthermore, cholesterol levels rise as a person ages. The level rises in men at age 45 and older. For women, the increase is generally seen at age 55 and older, according to NHLBI.

Precautions

     A healthy heart diet is safe for people age 2 and older. However, some people may to consult with their doctor before eating some foods such as fish. The United States Food and Drug Administration and the Environmental Protection Agency in 2004 warned pregnant women and nursing mothers to limit their consumption of fish and shellfish to 12 ounces (340.2 grams) per week. The warning was issued because of the risk that toxins in seafood would cause developmental problems in babies and children. Furthermore, women who are pregnant or nursing should not eat shark, marlin, and swordfish because of the high mercury content in these fish.

Risks

     When following a healthy heart diet, people need to be aware of the nutritional content of the foods they consume. They need to evaluate that information and make wise food choices. For example, the AHA points out that nuts and seeds are cholesterol-free sources of protein and a source of unsaturated fat. However, nuts and seeds are high in calories. Furthermore, frozen meals that are low in calories and fat should be examined for their sodium content.

     Those foods can be part of a healthy heart diet. However, people need to observe nutritional recommendations for daily fat, sodium, and calorie allowances. Otherwise, their diet will aggravate a condition like high blood pressure or obesity.

Research and general acceptance

     More than a century ago, W.O. Atwater of the UDSA cautioned about the dangers of overeating. His warning proved accurate. Cardiovascular disease (CVD) was the leading cause of death in the United States in each year since 1900, with the exception of 1918, according to the American Heart Association’s Heart Disease and Stroke Statistics—2007 Update. The heart association compiles that report in conjunction with government agencies.

     According to the report, nearly 2,400 Americans die of CVD each day. That amounts to an average of one death every 36 seconds. In addition, an estimated 79,400,000 American adults (one in three) have one or more types of cardiovascular disease. Of those, 37,500,000 were estimated to be age 65 or older.

     By the 1970s, research showed the link between chronic diseases like heart disease and stroke and a diet high in fat, saturated fat, cholesterol, and sodium. Research in the decades since then has affirmed the connection between poor diet and disease.

     During those years, Americans ate more of the foods that put them at risk for heart disease. The average calorie consumption rose 16% between 1970 and 2003, according to USDA figures cited in the heart association report.

     Information from the National Health and Nutrition Examination Survey for 1999-2000 indicated that Americans have not yet accepted the nutritional guidelines of a heart health diet. According to the report:

• The average daily intake of total fat in was 79 grams, with men averaging 91 grams and women averaging 67 grams.
• The average daily intake of saturated fat was 27 grams, with 31 grams for men and 23 grams for women.
• The average amount of dietary fiber consumed was 15.6 grams, below the recommended amount of 25 grams or more. Men ate 17.8 grams of fiber and women consumed 13.6 grams.

     In the 21st century, obesity in the United States is considered an epidemic. Federal agencies and organizations are responding with a range of programs to promote the benefits of a healthy heart diet.

Resources

American Heart Association. The new American Heart Association Cookbook. Clarkson Potter/Publishers, 2004.

American Dietetic Association, 120 South Riverside Plaza, Suite 2000, Chicago, IL 60606. (800) 877-1600. http://eatright.org.

American Heart Association National Center, 7272 Greenville Ave., Dallas, TX 75231. (800) 242-8721. http://www.americanheart.org..

National Heart, Lung, and Blood Institute. Choosing Foods on the Heart Healthy Diet.http://www.nhlbisup-port.com/cgi-bin/chd1/diet1.cgi. (April 21, 2007).

National Heart, Lung, and Blood Institute. Introduction to the TLC Diet. http://www.nhlbi.nih.gov/cgi-bin/chd/step2intro.cgi. (April 21, 2007).

United States Department of Agriculture. MyPyramid Plan. http://www.mypyramid.gov/mypyramid/index.aspx. (April 21, 2007).

American Heart Association. American heart Association’s Heart Disease and Stroke Statistics— 2007 Update http://www.americanheart.org/presenter.jhtml?identifier=1200026. (April 9, 2007).

Centers for Disease Control and Prevention National Center for Chronic Disease Prevention and Health Promotion. Physical Activity and Good Nutrition: Essential Elements to Prevent Chronic Diseases and Obesity At A Glance 2007. http://www.cdc.gov/nccdphp/publications/aag/dnpa.htm. (April 9, 2007).

Davis, Carole and Sallo, Etta; U.S. Department of Agriculture Dietary Recommendations and How They Have Changed Over Time. http://www.ers.usda.gov/publications/aib750/aib750b.pdf. (April 21, 2007).

U.S. Department of Agriculture and the Department of Health and Human Services. Dietary Guidelines for Americans 2005. http://www.health.gov/dietaryguidelines/dga2005/document. (April 9, 2007).

Liz Swain.

Acne Diet

Definition

     The acne diet—or, more accurately, the acne-free diet—is a way of eating that claims to improve or eliminate acne. There is some debate in the medical community about the impact of diet on acne; however, there is a body of evidence to support the idea that certain foods affect the skin.

     By reviewing research from over 40 years, doctors such as dermatologist Dean Goodless have  developed a set of recommendations regarding foods that may prevent acne. Goodless presents his recommendations in his book The Acne-Free Diet Plan. He suggests eating a diet low in fat and high in fiber along with avoiding peanut products, fried foods, excessive salt, dairy products, foods high in refined sugars, and high-carbohydrate foods.

Origins

     Most cultures had folk remedies to help clear the skin, but it was not until the later part of the twentieth century that serious scientific research began to confirm or disprove these folk tales and myths. One of the earliest studies about food and acne focused on chocolate, based on the belief that chocolate contributed to acne. (The study found that chocolate did not increase acne breakouts, and other studies since have confirmed this finding.) Other studies have investigated ethnic groups and communities where there is little or no incidence of acne, such as in the Pacific Islands and Africa. When the diets of these areas were compared to the typical Western diet, there were nutritionally significant differences: the ethnic groups with very low incidence of acne ate predominately plant-based diets that were low in fat and virtually sugar free, whereas the Western diets were heavy in meats, saturated fat, refined sugar, and processed foods. By studying these differences, doctors and researchers developed suggestions for dietary changes to improve or eliminate acne.

Description

     Acne is caused when glands in the skin called sebaceous glands begin to form a sticky oil called sebum. These glands are stimulated by hormones that become active at puberty, which is why acne occurs most often in adolescence, when these hormones are produced in abundance. The oils formed by the sebaceous glands hold dead skin cells, preventing them from being sloughed off. As these cells die, they create the perfect environment for bacteria to grow. When these bacteria, called acne vulgaris, become too plentiful, they will attempt to erupt from the skin, causing a pimple. Sometimes, when the bacteria grow, the body sends white blood cells to fight the infection. This natural reaction can cause large, painful cysts to form in the deeper layers of skin.

     Opinions vary in the medical community as to whether or not diet plays a significant role in acne. Some dietary changes that have been proposed to help prevent acne breakouts include:

• Eat 20 to 30 grams of fiber every day. Fiber helps keep the colon clean and may remove toxins from the body before they reach the skin.
• Eat a low-fat diet. High fat consumption may elevate hormone levels in the body that cause blemishes on the skin.
• Avoid peanut products. Peanut products were found to cause acne flare ups in a study of 500 adolescents.
• Avoid fried foods.
• Limit salt intake, especially table salt or iodized salt. Many people with acne have elevated levels of iodine, found in table salt, in their bloodstream during acne flare-ups.
• Avoid dairy products such as milk, cheese, and ice cream.

     Other vitamins and minerals proposed to affect acne include vitamins A, E, and B; selenium; zinc; omega-3 fatty acids; and chromium.

     Many high-carbohydrate foods are believed to worsen acne, due to the spike in blood sugar caused by eating white sugar or refined carbs. This spike raises the level of insulin in the body, and elevated insulin levels may increase production of acne-causing hormones. However, some carbohydrates, such as those made with whole grains, digest more slowly than others, causing a gradual (as opposed to rapid) rise in blood sugar after eating. A system known as the glycemic index ranks carbohydrates and other foods according to the effect they have on blood sugar.

     The glycemic index ranks foods based on a scale of 0–100. Foods with higher glycemic index ratings break down quickly and cause a sharp spike in blood sugar. When blood sugar rises quickly, the body produces a surge of insulin to lower the amount of glucose (sugar) in the blood. Insulin is a hormone that helps the body take glucose out of the bloodstream and put it into cells, where it can be used for energy or stored in fat. Foods with lower glycemic index ratings break down more slowly and cause a more gradual rise in blood sugar, meaning that less insulin will be needed.

Foods that have a high glycemic index rating include:

• white bread
• white rice
• white potatoes, depending on how they are cooked
• beer
• corn products and some products containing refined sugars

     Foods with moderate glycemic index ratings include:

• whole grain breads and pastas
• brown rice
• sweet potatoes
• green peas
• many fruits (especially when eaten alone)
• yogurt

     Low glycemic index foods may be enjoyed often without worsening acne. These include:

• rye grain
• nuts
• legumes such as black beans and lentils
• green vegetables
• apricots
• cherries

     Foods that are high in fiber tend to have lower glycemic index numbers, because fiber takes longer to digest. Studies have shown that the presence of healthy fats, such as olive oil, can also slow digestion and keep blood sugar from rising too quickly.

Function

     Eliminating certain foods from the diet and increasing the amount of specific vitamins and minerals may help reduce the amount of sebum produced and prevent acne breakouts. However, the interaction between diet and acne is not a simple cause-and-effect relationship—if an oily food is eaten, the oil does not travel to the skin or cause it to be oily. However, high levels of fat in the blood may effect the production of hormones such as testosterone, and higher levels of hormones may cause acne to worsen.

Benefits

     Habits such as limiting sodium, processed foods, and saturated fats (found in fried foods) and increasing intake of whole grains, vegetables, and fiber are in line with federal dietary recommendations and support overall health. However, foods such as fruits and low-fat dairy products provide important nutrients like calcium and vitamin C, and eliminating entire food groups could potentially lead to vitamin or mineral deficiencies. People interested in the acne diet should consult with a physician or registered dietitian before starting the diet.

Precautions

     Some acne diets suggest zinc or vitamin A supplementation. People should always consult with their physicians before taking any supplements or other drugs. Zinc supplements can cause stomach upset, and authors of acne diet plans recommend no more than 30 mg of zinc per day to avoid this.

Pregnant women or those who may become pregnant should not take vitamin A supplements or any medications containing vitamin A, as excessive amounts of vitamin A may cause birth defects.

     Limiting the amount of dairy products in the diet may limit the amount of calcium consumed. A calcium supplement may be needed to ensure that daily dietary calcium requirements are met.

     Dietary supplements could potentially interact with medications prescribed for acne. Some acne medications contain retinol, a form of vitamin A. Taking a vitamin A supplement with these prescriptions can cause a dangerous buildup of vitamin A in the body.Dietary supplements

Risks

     There are few risks associated with an acne diet. Most relate to taking dietary supplements. Zinc may prevent the body from absorbing enough copper. To avoid this, consumers should look for supplements that specifically state that they do not prevent copper absorption.

    Vitamin A is a fat-soluble vitamin. That means that excess vitamin A is stored in the body rather than eliminated in the urine. Many acne prescriptions contain concentrated forms of vitamin A, but too much vitamin A can be toxic. Consult a doctor before taking vitamin A supplements.

Research and general acceptance

     There is no consensus on whether or not diet plays a role in causing or preventing acne. Many dermatologists do not believe that diet has a significant effect on acne. Early studies about diet and acne focused on specific foods believed to trigger acne breakouts. Most of these studies found no evidence that individual foods cause acne.

     Studies of the diets of ethnic groups that have a low incidence of acne form the basis of most of the acne diets. Studies of the diets of tribes in New Guinea, Paraguay, and the Bantu of South Africa, all of whom have little or no acne, found that they ate a primarily plant-based diet. Similar studies on populations in Japan and Korea support these findings.

     A 2005 study of over 45,000 nurses claimed a link between the amount of dairy products consumed and severity of acne; women who reported consuming higher amounts of dairy products also reported more severe acne. However, of the women who drank at least two glasses of milk a day, only 8% experienced more severe breakouts.

     The theory with the strongest support is that foods high on the glycemic index contribute to acne. Studies have shown that half of acne patients tested had abnormal glucose levels, and in another study, 80% of premenstrual women with acne had abnormal glucose metabolism. This data and others that show a high-carbohydrate diet increases the levels of testosterone in the blood have led to the recommendation of limiting consumption of refined carbohydrates as a means of treating acne.

     Several studies have compared the results of zinc supplementation with oral antibiotic therapy to resolved acne and found zinc to be almost as effective as the antibiotic tetracycline.

Resources

Goodless, Dean R. The Acne-Free Diet. Celebration, FL: New Paradigm Dermatology, 2005.

Logan, Alan C., and Valori Treloar. The Clear Skin Diet. Nashville: Cumberland House, 2007.

Perricone, Nicholas. The Acne Prescription: The Perricone Program for Clear and Healthy Skin at Every Age. New York: HarperCollins, 2003.

Adebamowo, C.A., et al. “High School Dietary Intake and Teenage Acne.” Journal of the American Academy of Dermatology 52, no. 2 (2005): 207–14.

Bae, Y.S., et al. “Innovative Uses for Zinc in Dermatology.” Dermatologic Clinics 28, no. 3 (2010): 587–97.

Bowe, Whitney P., Smita S. Joshi, and Alan R. Shalita. “Diet and Acne.” Journal of the American Academy of Dermatology 63, no. 1 (2010): 124–41.

Cordain, L., et al. “Acne Vulgaris: A Disease of Western Civilization.” Archives of Dermatology 138, no. 12 (2002): 1584–90.

Davidovici, Batva B., and Ronni Wolf. “The Role of Diet in Acne: Factsand Controversies.” Clinics in Dermatology 28, no. 1 (2010): 12–16.

Deplewski, D. and R. L. Rosenfield. “Growth Hormone and Insulin-like Growth Factors Have Different Effects on Sebaceous Cell Growth and Differentiation.” Endocrinology 140, no. 9 (Sept 1999): 4089–94.

Smith, R.N., et al. “The Effect of a High-Protein, Low Glycemic-Load Diet Versus a Conventional, High Glycemic-Load Diet on Biochemical Parameters Associated with Acne Vulgaris: A Randomized, Investigator-Masked, Controlled Trial.” Journal of the American Academy of Dermatology 57, no. 2 (2007): 247–56.

Veith, W.B., and N.B. Silverberg. “The Association of Acne Vulgaris with Diet.” Cutis 88, no. 2 (2011): 84–91.

Williams, Hywel C., Robert P. Dellavalle, and Sarah Garner. “Acne Vulgaris.” The Lancet 379, no. 9813 (2012): 361–72. http://dx.doi.org/10.1016/S0140-6736%2811%2960321-8 (accessed August 9, 2012).

Bowers, Jan. “Diet and Acne: Role of Food Remains Controversial.” American Academy of Dermatology Association. http://www.aad.org/dermatology-world/monthly-archives/2012/acne/diet-and-acne (accessed August 9, 2012).

University of Maryland Medical Center. “Acne.” http://www.aad.org/dermatology-world/monthly-archives/2012/acne/diet-and-acne (accessed August 9, 2012).

Wilson, Bee. “Acne: Is Our Diet the Cause?” The Telegraph UK: Health, August 21, 2011. http://www.telegraph.co.uk/health/8701775/Acne-is-our-diet-the-cause.html (accessed August 9, 2012).

American Academy of Dermatology, 930 E Woodfield Rd., Schaumburg, IL 60173, (847) 240-1280, (866) 503-SKIN (7546), Fax: (847) 240-1859, MRC@aad.org, http://www.aad.org.

Deborah L. Nurmi, MS

6 Healthy-Sounding Foods That Really Aren’t

     Find out which healthy-sounding foods aren't actually good for your health.

Many foods sound healthier than they really are. You can avoid being fooled by health halos if you know what to look for. Here are some of the worst offenders for "healthy" foods that really aren't.

Energy Bars

     Energy bars usually contain protein and fiber—nutrients that help you feel full—but also may be loaded with calories. That’s fine if you occasionally make one a meal, but most of us eat them as snacks. You might as well enjoy a Snickers, which at 280 calories is in the same range as many energy bars.

     Lesson learned: If you need something to tide you over until dinner, look for a calorie-controlled bar with about 5 grams of protein (e.g., Balance 100-calorie bar, Promax 70-calorie bar).

Granola

    Granola sounds healthy. But it’s often high in fat, sugar and calories. Don’t be fooled by a seemingly reasonable calorie count; portion sizes are usually a skimpy 1⁄4 or 1⁄2 cup. Low-fat versions often just swap sugar for fat and pack as many calories as regular versions.

     Lesson learned: Read granola labels carefully and stick with recommended portion sizes (which are teeny), perhaps as a topping on fruit or yogurt.

Salads

     “Salads trip up many of my clients,” says my friend Anne Daly, R.D., director of nutrition and diabetes education at the Springfield Diabetes & Endocrine Center in Springfield, Illinois. Most of us could use more vegetables—so what’s not to love? In a word, toppings. The pecans and Gorgonzola cheese on Panera Bread’s Fuji Apple Chicken Salad (580 calories, 30 grams fat, 7 grams saturated fat) propel it into double-cheeseburger territory. A McDonald’s double cheeseburger has 440 calories, 23 grams fat, 11 grams saturated fat.

     Lesson learned: Before ordering a salad, check its nutrition information plus that of the dressing and all add-ons (often, they’re listed separately).

Smoothies

     Smoothies may seem like a tasty way to help get your recommended fruit servings—but studies show that beverages are less filling per calorie than solid foods. And added sugars can make some the equivalent of drinking fruit pie filling: the smallest (16-ounce) serving of Jamba Juice’s Orange Dream Machine weighs in at 340 calories, with 69 grams of sugars that don’t all come from orange juice. You’re better off with fresh-squeezed juices; orange juice has 110 calories per cup.

     Lesson learned: Some smoothies pack as many calories as a milkshake. Look for those made with whole fruit, low-fat yogurt and no added sugars.

Yogurts

     Yogurt is a great way to meet your calcium needs, but not all are created equally. Some premium whole-milk yogurts can give you a hefty dose of saturated fat. Shop around: many low-fat versions of these products are every bit as creamy. Enjoy a fruit-flavored low-fat yogurt, but understand that the “fruit” is really jam (i.e., mostly sugar). Or opt for low-fat plain and stir in fresh fruit or other sweetener to suit your taste; you’ll probably use less. My favorite, a tablespoon of Vermont maple syrup (52 calories), provides all the sweetness I need.

     Lesson learned: Although they are still good sources of calcium, some yogurts can be closer to dessert than to a healthy snack. Don’t let fat and added sugars spoil a good thing.

Sushi Rolls

     Sushi is big in my family. There is a wide variety of sushi rolls out there and in some the fried tidbits and mayonnaise can really tuck in the calories. The Southern Tsunami sushi bar company, which supplies sushi to supermarkets and restaurants, reports its 12-piece Dragon Roll (eel, crunchy cucumbers, avocado and “special eel sauce”) has ­almost 500 calories and 16 grams of fat (4 grams saturated).

     Lesson learned: Signature sushi rolls often come with a creamy “special sauce”; you should ask what’s in it. Or just order something simple: for example, a 12-piece California roll (imitation crabmeat, avocado and cucumber) or a vegetarian roll with cucumbers, carrots and avocado supplies around 350 calories and 6 or 7 grams of fat, and most of it is the heart-healthy mono­unsaturated type.

4 Health Rules You Really Can Break

     Everyone from government agencies to your mother is constantly telling you about the "right" steps to take for your health. So you'll be glad to hear that there are some so-called laws you can actually blow off—and doing so can be not only easier but also more effective than toeing the good-for-you party line. Not to mention, these little rebellions are totally backed by the latest science. We think you're going to like being a rule-breaker.

The rule: Do at least 30 minutes of moderate exercise five days a week.

The new thinking: Up the intensity and you can cut your workout time in half (or more!). 

     You'll love this recent research discovery: The cardiovascular benefits experts used to believe you could get only via half an hour of a medium-intensity activity (like jogging or a brisk ) can also be scored by doing much shorter, less frequent spells of , or HIIT, which alternates quick bursts of crazy-vigorous exercise with brief recovery periods.

     Those super short intervals trigger metabolic changes not seen with more moderate activity, explains Yuri Feito, PhD, assistant professor of exercise science at Kennesaw State University in Georgia. These changes seem to make the heart more efficient at pumping oxygen-rich blood to muscles, leading to bigger health gains than you'd get from less intense training—in a fraction of the time of a traditional workout.

     The best part? There's no right way to do HIIT. The moves can be equipment-based (runs on a treadmill) or gear-free (jumping jacks). And it's adaptable to all fitness levels. If you're a newbie, try alternating 15 to 30 seconds of moves with 15 to 30 seconds of rest; a pro might go hard for one minute, then stop for 30 seconds or less.

     The American Heart Association supports the power of intense exercise, recommending 150 minutes of moderate activity—or 75 minutes of vigorous activity—a week. But many researchers and trainers say doing 10 minutes (that includes the intervals plus rest time) three times a week is as effective—as long as you're pushing yourself. Says Craig Ballantyne, author of "Interval training is supposed to be taxing— but it's easier to stay with, so people enjoy it."

The rule: You always need a solid seven to eight hours of sleep.

The new thinking: Go ahead, stay up late—you can make up for it. 

     Doctors used to warn that if you lose out on , you can't catch up. New science to the rescue: "If you've skimped on sleep a couple of nights in a row, research shows that you can absolutely catch up by getting more shut-eye over the next day or two," says Christopher Winter, MD, medical director of Charlottesville Neurology and Sleep Medicine in Virginia. To do so, turn in early and wake up at your normal time rather than sleeping late the following day. "Sleeping in throws off your regular cycle and sets you up for more restless nights," says sleep specialist and clinical psychologist Michael Breus, PhD.

     The caveat: If your debt exceeds a week (sorry, new moms) or you've pulled all-nighters, a binge or two won't be enough to offset the effects of sleeplessness, such as weight gain or a weakened immune system. Once life becomes more manageable, Dr. Winter advises, go to bed when you're tired and try to keep regular wake-up times for as long as you were deprived in order to undo the damage.

The rule: Toss expired meds.

The new thinking: Save 'em; they might be A-OK. 

     "Many over-the-counter pills are effective past their expiration date," says Holly Phillips, MD, a New York City internist. And a 2012 study in the showed that some prescription drugs could be good for up to past the expiration date.

     So why the conservative sell-by dates? They tell you how long a drug's manufacturer can guarantee the product's stability, per FDA rules. The drug may stay potent beyond that time. And for some household staples, such as over-the-counter heartburn meds and painkillers, a lowered potency won't hurt you, says pharmacologist Joe Graedon.

     To be totally safe, throw these staples out a year after the expiration date. And strictly heed the dates on "any medicine meant to treat a life-threatening situation, such as insulin and epinephrine," Graedon says, or that go inside the nose and mouth, such as nasal spray or an inhaler—they can grow bacteria over time. And if you don't want to get pregnant, don't chance old birth control pills.

The rule: Never use the ER as your doctor.

The new thinking: Why wait to see your MD? 

     If you have an after-hours illness—hacking cough with fever, crippling UTI pain—it is perfectly OK to go to an emergency room. When you suddenly feel miserable, it's wise to get checked out ASAP; "better safe than sorry" is one rule that still applies.

4 Rules You Should Stick To

     Hate to break it to you, but some health guidelines are set in stone.

If you plan to be outdoors, safeguard your skin with a broad- spectrum SPF 30 (or higher).

Not taking every last pill increases the risk that the infection may rebound even stronger.

Even an occasional cigarette can set you up for the health issues regular smokers have, from saggy skin to cancer.

     Ideally, you'd pick up the toothbrush twice a day and the floss at least once.

Why walking to work is more than just good exercise

Slip your heels or loafers into your bag, and lace up those walking shoes.

Assuming the distance between your home and workplace allows for it, there's a whole slew of reasons to take a more active approach to your commute. (And yes, even 'burbs-dwellers can reap the benefits by parking a little farther away from work and walking the rest of the way!) Check out our list below, and tell us in the comments -- do you walk or bike to work? 

1. It's a way to get in some morning (and/or evening) exercise.

2. It'll make you feel less strained. A recent study from researchers at the University of East Anglia and the Center for Diet and Activity Research found that people who switched their modes of commute from driving to walking or cycling experienced greater well-being, specifically a greater ability to concentrate and feeling less under strain. 

3. It'll give you the opportunity to actually look up and see the beauty that's all around you. 

4. It could help you think up a creative solution to that work problem. A Stanford University study showed that people do better on tests for creative thinking when they walk, compared with when they sit or are pushed in a wheelchair. 

5. You're being a good influence on those around you. Your partner and other coworkers are more likely to bike or walk to work if you do it, according to a Penn State University study. 

6. It won't take as long as you think it will. As HuffPost blogger Amy Arndt points out, it only takes her about 45 minutes to an hour to walk three miles. Just pop in the headphones and the time will fly by quicker than you realize! 

7. You could be lowering your risk of chronic conditions. Walking and cycling instead of driving to work is associated with a lower risk of diabetes, according to a 2013 study in the American Journal of Preventive Medicine. Walking to work is also associated with a lower risk of high blood pressure. 

8. It could lessen your genetic tendency toward obesity. Researchers from Harvard presented a study in 2012 showing that it's possible to cut the effects of a genetic predisposition to obesity in half if you walk at a brisk pace for an hour each day. And what better way to get in that hour of walking than by getting to work? 

9. It'll help you in the body fat arena. Researchers from the University of Quebec found that walking 10,000 steps a day or more is associated with smaller body fat percentage and lower weight among 50-to-70-year-old women. You know a good way to ensure you get more than 10,000 steps in your day? Walking to work.

10. It'll get you in the right frame of mind for a busy workday ahead -- or for a hectic evening at home. Walking outdoors through green spaces can actually put the mind in a meditative state, according to a 2013 study in the British Journal of Sports Medicine. Other studies also show evidence that walking reduces stress.

This article originally appeared in The Huffington Post

Exercising May Bolster Your Brain Wires in Old Age

     People who stay physically active into old age may be improving their brain health by preventing a decline in the brain's white matter, a new study suggests.

     The white matter is composed of fiberlike parts of brain cells that enable communication between brain regions.

     "We hope that this will encourage people to take better care of their brains by being more active," said study co-author Agnieszka Burzynska, a researcher at the University of Illinois.

     In the study, 88 people between ages 60 and 78 who had low cardiovascular fitness but were otherwise healthy wore accelerometers for a week to track their daily physical activity, as well as how much time they spent sitting. Older adults are recommended to do at least 150 minutes of moderate exercise (or 75 minutes of vigorous exercise) per week.

     The researchers examined the brain scans of the participants to look at how structurally sound the white matter was. One way they did this was by looking for lesions called "white matter hyperintensities," which are common in older people.

     The results showed that the more people engaged in moderate or vigorous exercise, the fewer white-matter lesions they had.

     The findings may explain why researchers have found links between exercising and better cognitive function among people of older ages in previous studies. The new results suggest that increasing physical activity and avoiding a sedentary lifestyle could be beneficial for brain health, the researchers said.

     The researchers also found that light physical activities, such as housework and gardening, was related to how structurally sound people's white matter was in some parts of the brain. The more people engaged in light physical activities, the more structurally sound their white matter was in the temporal lobe, a part of the brain that lies behind the ears and is involved in memory and language.

In contrast, the more time people spent sitting, the more they showed lower structural soundness in the white-matter tracts connecting the hippocampus, a brain area important for learning and memory, according to the study published Sept. 17 in the journal PLOS ONE.

     The link held even when the researchers adjusted the results for participants' age, gender and fitness level.

     It's not entirely known how exercising may protect the aging brain from wear and tear, the researchers said. But it is possible that fitness and physical activity counteract the age-related vascular changes that are involved in the development of white-matter lesions, they said.

Email Bahar Gholipour or follow her @alterwired. Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science.

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The Pros and Cons of Group Training

From barbell bootcamps to dance-based classes, group fitness is exploding in popularity as a way for gym-goers to get in a great workout alongside friends and motivators. And why not? The group atmosphere provides a unique environment that's hard to re-create in a solo lifting session with your headphones. But group fitness classes aren't for everyone. We've outlined their top pros and cons to help you decide if they deserve a spot in your weekly routine.

Pros

1. MORE MOTIVATION

    The thought of pushing through a gut-wrenching workout on your own might not get you excited about hitting the weights—but killing it in an hour-long workout alongside 20–30 other people? That's a different story. Group fitness classes are known to be a great way to kick yourself into gear on those days when all you really want to do is plant yourself on the couch. Between vibrant instructors and motivational music, group classes help rev up lackluster energy levels, making them ideal for individuals who consistently find themselves skipping the gym for beers with coworkers.

2. ACCOUNTABILITY FACTOR

    Skipping a solo workout has few consequences. Ditching your friends, however, could lead to some unwanted social shunning. Simply put, meeting workout buddies for a sweat session makes you much more likely to head to the gym. Now, multiply that effect by, say, 20 (the number of fitness buddies counting on you to show up), and you're that much less likely to slough off your workout.

3. VARIETY AND FUN

     Doing the same old routine over and over can feel dull and mundane after a while. But group fitness classes tend to emphasize variety, providing an always-fresh level of fun while still getting you in shape. And, with the growing number of class types, there's bound to be one to fit whatever mood you happen to be in. Also, since instructors usually vary from session to session, even an "identical" class can seem unique depending on who's teaching.

Cons

1. LACK OF INDIVIDUAL PROGRAMMING

    Whereas fun and variety may help ward off boredom, this same lack of consistency from class to class could actually keep you from seeing any results. Since a group workout is, by its very nature, written for everyone (read: not just you), it may fail to address individual differences or weaknesses. For example, someone with a previous shoulder injury performs the same workout as another participant with an ankle injury. Granted, good teachers are quick to provide progressions and regressions for individual cases, but it's often difficult to address each unique situation.

2. LACK OF ATTENTION TO FORM

    The motivational benefit of having a crowd of other bodies sweating next to you also has some downsides. With larger class sizes, it becomes difficult for instructors to watch and critique individual performance. This means that, for example, if your form on new exercises is less than perfect, there's a good chance no one will be available to correct you. Although talented instructors give cues both orally and through demonstration, it can still be difficult for participants to nail down a technique—particularly when using new equipment.

3. OVERTRAINING POTENTIAL

   Group fitness classes, including many bootcamps, often have a similar "work till you drop" mindset. While this may push you to do a great workout at the time, it's not a sustainable mantra in the long run. In fact, attending too many classes that push you to your limit and beyond may well set you up for a case of overtraining. Since most classes feature a different mix of attendees, it's impossible for instructors to plan for repeat visitors, leading them instead to push each class to go 110%. Eventually, participants may find themselves feeling listless and lacking motivation.

    To prevent overtraining, avoid relying solely on group fitness classes as your only method of training. Instead, incorporate them into a well-rounded program that also includes days specifically designated for rest and recovery. You'll see better results and also feel better the next time you hit your favorite group workout.

IT'S YOUR CALL

   Group fitness classes certainly offer abundant benefits. The camaraderie and group atmosphere make them far more enjoyable than solo adventures. Instructors also have a knack for pushing you harder than you'd normally push yourself. However, for every benefit, there are also some negatives to be aware of. The group atmosphere makes individual coaching hard to come by. The constant "go hard" mentality can also set a lifter back rather than helping him progress.

    To get the best of both worlds, program group fitness classes into your schedule alongside a structured workout routine. That way, you'll reap the benefits of the group experience, while at the same time gaining the success brought by proper progression in your own training.