Fear Not the Healthy Fats
Foods like salmon, avocado, olive oil, walnuts and flax seeds are high in healthy fats
Kevin P. Casey
"Fat" has become such a dirty word in our vocabulary that we try to eliminate it whenever we can.
That's not such a good idea for children, especially in the womb and in the first five years of life when the brain is developing, says Karen Lamphere, a certified nutritionist and owner of Whole Foods Nutrition, a holistic nutritional counseling practice in Edmonds.
The brain is 60 percent fat, so high-quality fats are important to keep it healthy, Lamphere said at a recent conference hosted by La Leche League, a breastfeeding advocacy group. Additionally, all cells have a fatty/lipid membrane. Good fats are incorporated right into the cell membranes and keep them porous so that messages are transmitted easily between cells.
Healthy fats also help reduce cholesterol and lower the risk of heart disease, reduce inflammation in the body, provide nutrients to cells, contribute to normal growth and development, give the body energy, keep the body warm and help produce hormones.
The American Heart Association recommends that children ages 2 to 3 get 30 percent to 35 percent of their calories from fat, and those ages 4 to 18 get 25 to 35 percent from fat. The American Academy of Pediatrics has endorsed those recommendations. All types of fats have 9 calories per gram, more than twice as much as proteins and carbohydrates. This means that the amount of fats will be lower than the amount of protein and carbohydrates. A 2,000-calorie diet should include about 67 grams of fat.
The trick is knowing which kinds of fats to feed your child.
The Good the Bad and the Ugly
Saturated fats are bad guys in excess, but OK in moderation. Their name stems from their chemical structure, in which carbon atoms are "saturated" with hydrogen atoms. They are usually solid at room temperature – think beef or pork lard, butter, cream and high-fat cheese. Whole milk is also high in saturated fat. Plant sources include coconut oil, cocoa butter, palm oil and palm kernel oil. The American Heart Association recommends keeping these at less than 7 percent of total calories, as too much – especially from animal sources – can raise cholesterol levels.
"Naturally-occurring saturated fats get a bad rap – we do need some of them for brain development," Lamphere says. Butter, in moderation, is better than margarine, which is made from artificial fats that researchers believe can contribute to cardiovascular disease. Lean cuts of meat, also in moderation, can provide important nutrients.
Lamphere joins the American Heart Association, the Mayo Clinic, the U.S. Department of Agriculture and other nutritionists in recommending that most fats in our diets come from monounsaturated and polyunsaturated sources.
Monounsaturated fats have one doubled-bonded carbon (unsaturated by hydrogen) per molecule. These fats are usually liquid at room temperature. Examples include vegetable oils such as olive, canola, peanut, sunflower and sesame oils, as well as avocados, peanut butter, almonds and other nuts and seeds. They can help reduce bad cholesterol, lower the risk of heart disease and provide nutrients to cells, and they are high in beneficial vitamin E.
Extra-virgin olive oil and other unrefined oils – those that have been filtered only slightly to remove large particles – are the healthiest and have the best anti-inflammatory properties, Lamphere says. Unrefined oils, which are labeled as such, retain more of their nutrients than refined oils, but their shelf life is shorter and they can turn rancid if kept too long.
Polyunsaturated fats have more than one double-bonded (unsaturated by hydrogen) carbon per molecule, and are usually liquid at room temperature and when chilled. They also help reduce the cholesterol levels and the risk of heart disease.
Omega 6s and Omega 3s are two families of polyunsaturated fatty acids that have been getting the most attention over the past five years. They are called essential fatty acids because the body needs them, but cannot make them, itself.
Omega 3 fatty acids (including DHA, EPA and ALA) are the ones associated with brain and cell health. The best sources are cold water, fatty fish, including salmon, mackerel, herring, sardines, anchovies and trout. In response to parents' concerns about mercury in fish, Lamphere recommends wild salmon and smaller fish, such as sardines or trout. "The larger the fish, the bigger the problem, because mercury accumulates in the bodies of fish higher on the food chain," Lamphere says. She recommends substituting canned salmon for canned tuna fish because it has higher levels of omega 3 fatty acids; also, Federal Drug Administration tests found the average mercury level of canned albacore tuna to be at least 35 times higher than that of canned salmon. Light tuna has lower mercury levels than albacore tuna because it is a smaller fish, lower on the food chain.
There are also omega 3 fatty acids in grass-fed beef and lamb, and in plant sources, including walnuts, sunflower seeds, flaxseeds and some greens. Vegetable sources of omega 3s are not as easy for the body to use as animal sources, so you have to eat more of them to get the same benefit, Lamphere says.
Omega 6s are also essential fatty acids, found mostly in vegetable oils, including soybean, cottonseed, sunflower seed, corn and safflower oils. They are good in moderation, but most scientists now believe we get too much of them compared to the amount of omega 3's we consume. "Omega 6 is in a lot of processed foods – "chips, stuff you buy in a box, packaged salad dressings – it's everywhere," Lamphere says.
"Our ratio of omega 6 to omega 3 is way off," Lamphere says. "It used to be 1:1 or 2:1, but in our modern diet, it's 20:1 (in favor of omega 6)." Too much omega 6 contributes to inflammation in the body, and excess inflammation is linked to dozens of diseases, including heart disease and asthma. Additionally some researchers, particularly in the naturopathic community, believe that omega 6 may displace omega 3 in the brain cells, possibly contributing to depression or attention deficit problems.
The fourth kind of fat contains trans-isomer fatty acids, commonly called trans fats. They occur naturally in animal products, but most sources of trans fats in the American diet are formed when hydrogen atoms are artificially added to unsaturated fats so that they are "partially hydrogenated." They are widely used in processed, fried and baked goods and in many margarines and salad dressings because they are solid, but spreadable, at room temperature; they have a higher melting point than most fats; they add desirable taste and texture; they're cheap; and they have a long shelf life.
Until recently, they were thought to be healthier than natural saturated fats, but researchers now believe they increase cardiovascular disease by raising bad cholesterol and lowering good cholesterol. Lamphere notes that these "bad fats" make cell membranes in the brain more rigid and less porous, while "good" omega 3 fatty acids help cell membranes stay healthy.
The American Heart Association and the American Academy of Pediatrics recommend that less than 1 percent of our total calories come from trans fats. Many nutritionists, like Lamphere, recommend eliminating them from the diet entirely. "Don't just believe labels that say ‘0 percent trans fats,'" Lamphere adds. "A food can have up to .5 grams of trans fat per serving, and still be labeled 0 percent. If you have several servings, the fat accumulates." A food is truly 0 percent trans fat if it has no partially hydrogenated oils on the ingredient list.
Whole or Low-Fat Milk for Toddlers?
For many years, the American Academy of Pediatrics and other experts have advised that children younger than 2 need a higher-fat diet because of their rapid growth and development. Therefore, whole milk was recommended for toddlers 1 to 2 years old after they're weaned from breast milk or formula.
Last year, the American Academy of Pediatrics issued new recommendations based on its nutrition committee's July 2008 clinical report, "Lipid Screening and Cardiovascular Health in Childhood." Because of increasing rates of obesity, high cholesterol and formation of fatty deposits in the arteries of children, the new recommendation is for reduced-fat milk for children ages 12 to 24 months if they are overweight or have a family history of obesity, high cholesterol or cardiovascular disease.
Dietary intervention – lowering total calories and fat content – has usually been studied with children 8 and older, and found to be beneficial with no harmful affects. The clinical report sites the ongoing Special Turku Risk Intervention Program, which measures the effect of a restricted fat diet on children 7 months and older, including giving 1.5 percent cow's milk after 12 months. There were no adverse affects on growth or neurological function.
Lamphere is still in favor of whole milk for most children younger than age 2, because the fat in milk contains omega 3 fatty acids and beneficial conjugated linoleic acids (CLA), which seem to lower the risk of cancer and heart disease, boost immunity and reduce symptoms of inflammatory disorders, such as allergies and asthma.
She recommends that parents look for organic brands of milk that are labeled "grass-fed" or "pasture-fed" (Organic Valley is the largest national supplier). She points to a 2006 study by the Union of Concerned scientists, which reviewed several studies comparing grass or grain-based diets for cattle. Milk from grass-fed cows has higher levels of healthy omega 3 and CLA fatty acids.
The Basics on Good Fats vs. Bad Fats
Eat plenty of foods rich in omega 3 fatty acids:
• Coldwater fish (wild salmon, mackerel, herring, sardines, anchovies and trout)
• Walnuts, sunflower seeds and flax seeds
Eat moderate amounts of mono- and polyunsaturated fats:
• Olive oil – especially extra virgin
• Canola, peanut, sunflower and sesame oils – especially unrefined
• Soybean, cottonseed, sunflower seed, corn and safflower oils
• Seeds and nuts and their butters, especially almonds
Eat very moderate amounts of saturated fats:
• Milk, butter and dairy products
• Lean meats, especially from grass-fed animals
Avoid foods containing trans fat (also known as partially hydrogenated vegetable oils):
• Many kinds of margarine, salad dressings and mayonnaise
• Cookies, crackers, and microwave popcorn (the biggest sources)
• Cakes, donuts, snack chips, chocolate candy, processed breakfast cereals’
• French fries
• Fried foods
• Some kinds of cooking oil
The American Heart Association’s Web site has an easy-to-understand summary of good and bad fats; type in “Fats 101” in the search box on the home page. You can plug your child’s age, gender, height, weight and activity level into the “My Fats Translator” to figure out the amounts of different fats he or she should eat daily. www.americanheart.org.
The “Eat Wild” Web site is a nonprofit site funded by donations and promoting the benefits of grass-fed meats, eggs and dairy products. Find lists of local producers, as well as lots of articles. www.eatwild.com.
Fat: An Appreciation of a Misunderstood Ingredient, with Recipes, by Jennifer Mclagan, (Ten Speed Press, 2008).
The Good Fat Cookbook, by Fran McCullough, (Scribner, 2006).
Wenda Reed is a Bothell health writer, frequent contributor to Seattle’s Child and sometimes frustrated nutrition label reader.