By Jennifer Sygo, Postmedia News December 26, 2011, The Province
We know that certain foods are near-indisputable nutritional winners. Green, leafy vegetables, berries, almonds, yogurt, salmon: You'll find these foods in almost every diet book available today. But there are some foods that, for what-ever reason, don't get the respect they deserve. Here's a closer look at some that are often overlooked and under-appreciated.
EGGS
Eggs became nutritional persona non grata when cholesterol fell out of favour in the 1970s and '80s. High in cholesterol, egg yolks were labelled as risky choices for those who were concerned about their hearts.
More recent research, however, has revealed that dietary cholesterol not only has a limited impact on blood cholesterol, but population studies have found that the association between egg consumption (up to seven yolks per week) and heart disease is relatively weak (the exception being those with type 2 diabetes, who seem to see an increased risk of cardiovascular events with egg consumption).
What's more, eggs are a good source of protein, and the yolks contain lutein and zeaxanthin, two nutrients that are important for eye health, as well as choline, which is important for brain development.
LEAN RED MEAT
Red meat has fallen out of favour because it has been associated with colorectal cancer, and fatty cuts of beef and pork are believed to raise cholesterol levels, and, in turn increase our risk of cardiovascular disease.
But despite the negative attention, red meats are actually remarkably nutritious and provide some nutrients that can be difficult to obtain from other sources. In particular, the meat from four-legged animals is high in heme iron, a type of iron that is absorbed about three times better than the non-heme iron found in plant foods such as spinach and beans. This makes red meats particularly beneficial for those who have reduced iron stores, most commonly women of child-bearing years.
Beyond iron, red meats are also among the best food sources of zinc, important for wound healing and immune system function, and vitamin B12, important for red blood cell formation: A 3-oz. serving of most red meats will provide between a third and a half of your daily needs for both nutrients.
PEANUT BUTTER
Once a lunchtime staple, peanut butter has tumbled down the nutritional ladder, not only because of its high fat and calorie content, but also because of its potential to trigger severe food allergies.
Poor public image aside, however, peanut butter boasts an impressive nutritional resume, not only for being one of the relatively few foods rich in vitamin E (a 2-table-spoon serving provides 17 per cent of your daily needs), but because of research demonstrating that regular nut and nut butter consumers tend to have a lower body weight than their nut-avoiding counterparts.
While this seems counterintuitive - after all, nuts and nut butters are among the highest-calorie foods around - nuts may help with weight control by serving as natural appetite suppressors, and research suggests that we don't actually absorb all of the fats from nuts, but rather excrete a portion in our waste.
BANANAS
If I had a nickel for every time I've heard someone make the statement that "bananas are high in sugar," well, I'd have a nice sweater. Reviled in much of the popular diet press for apparently causing unwanted blood sugar spikes, many have been left with the impression that bananas somehow fall in the same dietary category as chocolate bars.
Not fair. Rich in potassium (a medium banana provides 422 mg, or about 12 per cent of your daily needs), a nutrient important for blood pres-sure control, and a good source of fibre, a medium banana provides a modest 105 calories and 27 grams of carbohydrates, which is one gram less than the much less-reviled pear, and a good 50 grams (and several hundred calories) fewer carbohydrates than a small milkshake.
But perhaps more importantly, the glycemic (blood sugar-raising) impact of bananas is actually quite modest: According to The Glyce-mic Index (glycemicindex.com), most studies have demonstrated that bananas are actually low, or at best moderately glycemic, meaning that they have a relatively limited impact on blood sugar. To put it another way, I don't think that our intake of bananas is the reason we have an obesity crisis.
POTATOES
Almost every diet book now puts potatoes on the "no-no" list. You'll frequently hear of recommendations that we reduce our intake of "whites," namely white flour, white sugar, white rice and white bread. Potatoes are usually included in this list. The problem seems to be the potato's ability to rapidly raise blood sugar, otherwise known as its glycemic index.
Unlike nutritional weaklings like white sugar, however, a whole potato is rich in a variety of nutrients, in particular fibre (four grams per medium potato with skin) and potassium. In fact, when it comes to potassium, which seems to play an important role in blood pressure control, potatoes are a chart-topper: a medium potato provides 610 mg of the mineral (the recommended daily intake is 4,700 mg), compared with 422 mg in the more ballyhooed banana.
Moreover, while boiled, peeled potatoes eaten on their own are high on the glycemic index (meaning they do cause blood sugar levels to rise quickly after eating), a modest-sized baked potato with skin, eaten as part of a mixed meal (i.e. with protein and fats) generally has a glycemic index in the moderate range.
For my money, potatoes can still be a part of a healthy diet, but your best bet is to keep the skin on and keep the portions moderate - a half of a baked potato is plenty for most of us.
COFFEE
Let's get this out of the way first: coffee, and more specifically, caffeine, is not a diuretic. Yes, you may have heard this numerous times on TV, and even in your doctor's office, but it is a myth, provided that you consume it regularly (you do see a modest increase in urine output when you first start to consume caffeine, but the effect wears off in a few days).
On the other hand, coffee is quite rich in antioxidants, and even contains modest amounts of magnesium and B vitamins, which can become nutritionally relevant for those who drink multiple cups per day. More importantly, while we see evidence of impaired glucose metabolism in the hours after drinking a cup of coffee, numerous studies suggest that coffee consumption could reduce your risk of cardiovascular disease, type 2 diabetes, and even some cancers.
Disease prevention aside, the effect of all that caffeine on your quality of life might make for some food for thought as you lie in bed, staring at the ceiling after your sixth cup of the day. But good news there, too: Research has shown that you can obtain a similar health benefit from a cup of decaf.
