Are you feeling confused by conflicting messages from various health experts? It may be because science is still in the process of integrating a long history of human experience with research.
While research advances, what's considered a nutritional certainty today may crumble under mounting evidence next year.
Here's what we know about a few of the most perplexing and persistent assumptions:
MYTH: Zero trans fat means zero.
The U.S. Food and Drug Administration has enforced the labeling of trans fats since January 2006. Despite the unmistakable "0 trans fat" label on many food products, zero may not actually mean zero.
Food manufacturers are allowed to label foods with less than 0.5 gram of trans fat as 0 (zero) on the Nutrition Facts panel.
Most everyone is aware that trans fats increase total blood cholesterol and LDL (the bad cholesterol), while lowering HDL (the good cholesterol). They also cause a rise in apolipoprotein A, another risk factor for heart disease, decrease insulin sensitivity affecting blood sugar balance, and enhance the production of pro-inflammatory hormones (prostaglandin E2) - bad news for arthritics or anyone with pain or allergies.
Read labels carefully. Avoid hydrogenated margarines as well as any foods that list "hydrogenated" or "partiallyhydrogenated" on the label. Look also at portion sizes. Some manufacturers limit portions to amounts providingjust under 0.5 grams of trans to avoid labeling them.
MYTH: Margarine is healthier than butter.
Butter won that debate a long time ago, but a great deal of misinformation still exists. Both have the sameamount of calories (about 100 calories per teaspoon); both taste great on toast. As far as health goes, butter isbetter. Butter has its issues: it is a saturated fat and a source of cholesterol, but the long-term studies on buttervs. margarine have not shown what health experts of yesterday expected. In fact, while margarine (nicknamed"plastic fat") may be cholesterol-free, trans fats found in margarine and shortening are a much bigger problem.
Non-hydrogenated spreads, like Earth Balance, are available at your local grocery and health food store. Organiccoconut oil is another option. It's a saturated fat (solid at room temperature) but is cholesterol-free.
The healthiest fat is fish oil, but you can't spread that on toast.
MYTH: Nuts contain cholesterol.
Plant foods do not contain cholesterol (despite what your doctor may think!). Cholesterol is found only in animalfoods. A number of studies have shown that regular intake of nuts, walnuts in particular, can result in aseven-fold improvement of arterial function thanks to omega-3 oils. A handful of nuts supply about 150 caloriesand one tablespoon of nut butter provides approximately 100 calories, so to avoid weight gain, they should besubstituted for another source of calories. Ensure that the nuts you purchase are unsalted and raw to protectthose precious omega-oils.
MYTH: Whole wheat is the healthiest grain.
"Whole grain" means that all three parts of a grain - the bran, germ, and endosperm are included. While wholewheat is a whole grain, it is only one of many available whole grains and is not necessarily the best. Wheat is themain source of dietary gluten, a stretchy protein found also in rye, and barley.
Gluten should be broken down by digestive enzymes, but it remains undigested, causing inflammation in theabsorptive tissues of the small intestine in people with gluten intolerance. While gluten intolerance isasymptomatic for a majority of us, those who experience symptoms may recognize that bloating, cramping, anddiarrhea are associated with the intake of wheat and other grains.
Food labeled "Multigrain" includes a mix of grains and is often a better option than whole wheat. Read the labelto determine if all grains included are whole grains. Look also for foods made from alternate grains such as brownrice pasta, spelt bread, and products labeled "gluten-free."
MYTH: All yogurt is healthy.
Probiotic yogurts have become a favorite marketing tool, and with good reason. More than 1,000 different speciesof bacteria make their homes on and in the human body.
While many of these bacteria are "friendly" and protective, combating digestive problems, yeast infections, and boosting immunity, some can have negative influences on human health. The balance of microbial strains should favor the beneficial bacteria over the potentially harmful ones.
Many natural food sources of probiotics, such as fermented foods like yogurt, contain bacteria similar to thosenaturally found in the human intestine, but flavored yogurts often contain unnecessary and unhealthy ingredientsincluding sugar, cream, corn starch, gelatin, aspartame, and sucralose (in the sugar-free varieties).
The healthiest yogurt is a plain, naturally-made yogurt. Feel free to add whatever you like to it, but start off with plain. Choose yogurts containing natural bacterial strains including Lactobacillus acidophilus and Bifidobacterium bifidus.
MYTH: Iceberg lettuce is just as healthy as other greens.
Iceberg lettuce has been teased for its low nutritional value and nicknamed the "polyester of lettuce." Comparedto other leafy greens, its nutrient make-up is extremely low, containing 95 percent water, a trace of fiber, and onlyone-twentieth the vitamins and minerals provided by other leafy greens.
If you cannot part with iceberg, mix other greens into your salad - spinach, kale or romaine; the darker the lettuce, the more nutrients it provides.
MYTH: Sodium is only found in salt.
A teaspoon of salt provides over 2,300 mg of sodium - a far cry from the recommended 1,200 mg - but salt is notthe only offender.
Tomato sauce, processed meat, condiments, prepared soup, cheese, and fast food will tip the sodium scales fasterthan a pinch of salt. Read labels carefully and watch for signs of excess sodium like swelling of fingers, ankles andfeet, tingling in your legs, and excessive thirst.
MYTH: Brown sugar is healthier than white.
Brown sugar is refined white sugar (sucrose) with some molasses mixed in. While the molasses contain a smallamount of minerals, differences in the nutritional make-up of brown and white sugar are negligible. Sugar cane,the plant from which sugar is derived, contains the nutrients riboflavin (vitamin B2), niacin (vitamin B3),potassium, calcium, iron, and magnesium. Sucanat ("Sugar Cane Naturally") is pure dried sugar cane juice. This isyour best option for nutritional value. Remember that all forms of sugar will raise blood sugar levels and shouldbe used in moderation.
MYTH: Low-fat diets are ideal.
Not necessarily. Fat should not exceed 25 percent of your total calories and most (if not all) of those fats shouldderive from omega-3 (fish, fish oil supplements, and nuts). Recent studies show that a low-fat diet is one of theleast effective methods of losing weight and body fat. They also show that since 70 percent of your brain is fat,low-fat diets can impair cognitive functions. Don't count calories and fat. Count nutrients instead.
Whenever in doubt about a product or health concept, do your own research and get the facts.