WHAT WE’VE LEARNED

Our 10 Essential Nutrition Lessons

The first widely read nutrition study was published in 1872 in the British Medical Journal.  In 2011, more than 16,000 nutrition studies were released in peer-reviewed scientific journals.  It’s no wonder our understanding of nutrition is always expanding and shifting.   Let’s take a moment to look at the top ten revelations of the past decade.

  1. Our genes and diet are related.  We now know that certain cancers, cardiovascular disease and other chronic diseases that accompany aging can be prevented or delayed.  For instance, about 58 percent of people with hypertension are genetically salt-sensitive, so simply limiting the amount of salt they eat can lower blood pressure.   While there are still many challenges in classifying people by their genotype, nutrigenomics is an exciting new field.
  2. Not all fat is bad fat.  At the end of the 20th century, ‘low-fat’ seemed to be the ubiquitous mantra of health professionals, government organizations and countless food products, but today research suggests that trimming fat to less than 25% of total calories isn’t a good idea.  Cutting too much fat from the diet can increase serum triglycerides and reduce HDL (good) cholesterol, and both are risk factors for heart disease.  Low-fat diets get a failing grade for weight loss as well.  Low-fat often translates to high carbohydrate which prompts glucose and insulin spikes.  Instead, aim for 30% of your calories from fat.  The type of fat matters too.  For optimal health, choose mostly monounsaturated fats (think liquid vegetable oils, nuts, and avocados) and limit saturated fat.  Trans-fats (partially hydrogenated oils) should not be consumed at all.
  3. A calorie isn’t just a calorie.  Our bodies handle processed and unprocessed carbohydrates differently.  When you use a machine to strip away the bran, husk and fiber from carbohydrates, that machine is essentially expending energy that your body would normally use to break down those food components.  Eat whole, unprocessed foods!
  4. Food sensitivities aren’t all in our head.  Roughly one percent of us suffer from celiac disease, an autoimmune reaction triggered by gluten in grains like wheat, barley, and rye.  Estimates are that 20 million Americans (6 percent) suffer from gluten sensitivity.  Many of the symptoms of gluten sensitivity, such as abdominal bloating, difficulty concentrating and fatigue, are present in celiac disease.  Many people who test negative for celiac disease still see their symptoms improve on a gluten-free diet.  This led us to believe that there was another condition, which we now call gluten sensitivity.
  5. We need more vitamin D than we thought.  Thanks to our obsession with sunscreens, a short list of vitamin D-rich foods and hours spent indoors, three out of four Americans don’t get enough vitamin D.   Normal vitamin D levels are critical for strong bones, but we may need even more to lower the risk for heart disease, type 2 diabetes, multiple sclerosis and many types of cancer.  Moreover, it’s nearly impossible to get enough D from food; especially when vitamin D-fortified foods have so little vitamin D added (it’s also usually D2, which is not well-absorbed).  The amount of vitamin D you make from sun exposure depends on several factors, such as the color of your skin, where you live and even how old you are.  A three-pronged approach is best: try to eat more vitamin D-rich foods (wild-caught sockeye salmon, UV exposed mushrooms and vitamin D-fortified foods), 10-15 minutes of sun exposure on your arms, legs and back three times per week in the spring, summer and fall, and take a supplement based upon recommendations from your physician and registered dietitian.
  6. There’s more than one reason to avoid BPA.  The synthetic chemical bisphenol-A (BPA) has been used in the linings of metal food containers and bottles since the 1960’s.  It’s also found in everything from food-storage containers to recycled paper, dental fillings and sealants.  And BPA will persist in our food supply: in March, the FDA rejected a petition from environmentalists to ban the chemical from food and drink packaging.  Science has linked BPA to early puberty, reproductive irregularities, and cardiovascular and neurological damage.  Now, a growing body of research suggests it may be making us heavier.   In a study published in the Journal of the American Medical Association, obese subjects had 30-77% more BPA in their urine than normal weight adults.  Experts suspect BPA promotes weight gain by simulating the pancreas to rev up its production of insulin, leading to decreased insulin sensitivity.  The good news is that we don’t store BPA in our bodies for long.  Avoiding contact with it for just one week will flush it from your blood (it may still be stored in fat cells).  While we might not be able to eliminate it entirely, try to buy fresh or frozen foods or foods in cans labeled BPA-free, and store food in glass containers or plastic ones labeled BPA-free.
  7. How we get our nutrients matter.  Even though more than half of all U.S. adults pop at least one dietary supplement a day, recent research reveals pills can’t match the disease-preventing power of food.  In their natural form, nutrients in food—like vitamins, minerals and phytochemicals—are present  in specific, balanced concentrations and work together a highly synergistic way.  Consider avocados: they’re rich in heart-healthy fat as well as vitamin E, a nutrient that requires fat for absorption.  While you could get vitamin E from a pill, you can’t absorb it without the fat that nature conveniently packaged in the avocado.  What’s more, some supplements taken in excess can be harmful, or can interfere with the absorption of other nutrients.
  8. Dietary cholesterol isn’t so evil.  Years ago, if you had a cholesterol problem you were under strict orders to avoid cholesterol-rich foods like eggs and shrimp.  Today, we know these foods are fine to eat in moderation.  The truth is our bodies need some cholesterol to make hormones, vitamin D, bile acids (compounds that help us digest fat) and the membranes that line our cells.   While a small amount of the cholesterol in your blood comes from the food you eat, your liver manufactures anywhere from 2.5-5 times that amount every day.  When your liver senses incoming cholesterol from food, it simply produces less.  What is much more important is limiting the total amount of saturated fat (7% or less of total calories) from your diet rather than axing all cholesterol from your diet.
  9. We’re eating too many concentrated sweeteners.  In the past 40 years, the amount of concentrated sweeteners in our diets has skyrocketed.  Today, the average American eats about 420 calories (28 teaspoons) a day—essentially a meal—from added sugars/concentrated sweeteners.  That’s a 12 percent increase from 25 teaspoons in 1970.  This spells bad news for our waistlines.  All these concentrated sweeteners (high fructose corn syrup, etc.) have been linked to increased risk of diabetes, hypertension, metabolic syndrome and heart disease.  About 75 percent of all processed foods have added sugar, all types of corn syrup (high fructose/high maltose), agave syrup and other sweeteners.  But the major shift is added sweeteners in beverages rather than foods.  Over 35% of the added sweeteners in our diet comes from soda, sweetened drinks and sports drinks.  The easiest way to trim your added sweetener intake is to banish all sweetened drinks.
  10. Our bodies don’t want us to lose weight for good.  If you’ve ever lost weight only to gain it back again, you’ll be glad to know it might not necessarily be your willpower that’s the problem.  Losing weight wreaks havoc on your hunger hormones in two ways: it triggers a decrease in hormones that suppress appetite (leptin and cholecystokinin) and boosts production of hormones that tell you to eat, namely ghrelin and neuropeptide Y.  The good news is that you can outsmart these hormones by eating a balanced snack or small meal (one containing protein, healthy fat and unprocessed carbohydrate) every 3 hours during the day.  That’s news we like to hear!

Source: Karen Ansel, MS, RD