4 keys to staying well during cold and flu season

Image Credit:  William Brawley (Flickr)

We're smack dab in the middle of cold and flu season, and I'm sure that you'd like to avoid catching the bug, right?  Aside from practicing good hygiene, there are four key lifestyle behaviors that have been determined to be true guardians of health during this time of year.  Practice these behaviors and you'll better protect yourself from the misery of cold and flu season.

Eat enough nutrient-dense, immune-supportive foods.
One of the first lines of defense against cold and flu season starts in the grocery cart.  Make sure that you're including plenty of nutrient-dense, immune-supportive foods that will bolster your immune system.  What foods are these?  Eat fish for vitamin D, which helps regulate the immune system.  Include a variety of produce, especially citrus fruits, cruciferous vegetables, winter squash, and dark leafy greens, for immunoprotective vitamins A and C.  Also be sure to incorporate high quality meat and dried beans for protein, iron, and zinc, which help the immune system function at its best.  For more information on foods that support a strong immune system, check out this blog post that I wrote last year.

Get 7-9 hours of sleep every night.
When we sleep, the body's immune system recharges.  The release of infection-fighting cytokines from the immune system surges during sleep.  When we are sleep-deprived, the levels of cytokines and other immune-supportive cells in the body declines.  In fact, one study found that individuals who slept less than seven hours each night were nearly three times more likely to develop colds than those who slept at least eight hours or more.  So make sleep a priority!

Manage stress effectively.
Short-term, long-term, real or perceived, the body does not discriminate against the type of stress we experience.  When we experience stress, a cascade of biochemical reactions that lower the body's immune function begins.  When stress becomes chronic, the immune system becomes weaker.  While we cannot completely eliminate all sources of stress, we certainly can find ways to better manage it.  In fact, relaxation actually boosts certain activities of the immune system, including sending more infection-fighting cells into action in the bloodstream.  Remember that relaxation is not necessarily 'doing nothing', but rather, it is a learned behavior.  For more tips on managing stress effectively, check out this  advice from the American Psychological Association.

Perform at least 30 minutes of moderate-intensity exercise on 5+ days of the week.
Studies have found that exercise may boost the number and function of certain cells of the immune system.  Investigators also believe that exercise enhances the transport of these cells throughout the body making them more effective at eradicating the bacteria and viruses responsible for the cold and flu.  One study detected a 46% lower frequency of colds for participants that exercised at least 5 days a week compared to those who were sedentary.   Another investigation observed that women who performed 45 minutes of moderate-intensity activity 5 days a week experienced 50% fewer colds than women in the control group who stretched daily.  While getting enough exercise is essential, keep in mind that performing prolonged or intense exercise can actually depress the body's immune system.  If you participate in these types of activities, such as marathons or ultra-endurance events, adequate recovery time is vital and make sure to practice the other lifestyle behaviors listed above.

What are your best strategies for practicing these behaviors?  What behaviors would you add to this list?  

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Naturally Detoxifying Foods

Photo credit:  A Askew (Flickr)

If you haven't been on one yourself, then you've probably had a family member or friend on one.  Otherwise, maybe you've at least seen ads for products, programs, or books for them.  They're detox diets.  They're hot. They're happening.  They're one of those things that I think will never die.  While I understand that the body is regularly exposed to a laundry list of toxins from the environment, food, and typical metabolic processes and it's important to protect the body against them, I'm not one to promote detox diets or cleanses.  They're not for everyone anyway.  However,  I find nothing wrong with including detoxifying foods in your regular diet to take advantage of their health-promoting benefits.  If you want a daily detox, include at least some of these detoxifying foods in your diet everyday.

Citrus fruits:  Grapefruits, oranges, tangerines, lemons, and other citrus fruits are nutritious powerhouses!  Most of us know that they're chock full of vitamin C, which is known to fend off free radicals that can damage healthy body tissues and contribute to chronic diseases.  However, they are also packed with other vital nutrients and over 170 phytochemicals!  One of those phytochemicals includes limonin, which has been shown to participate in detoxification systems in the body.  Researchers are also investigating the role of such compounds in protecting the body against certain types of cancer.  Apparently, our bodies can access limonin as soon as we sip OJ or take a bite of a citrus fruit.  Amazingly, limonin also appears to stay in the bloodstream of some people for up to 24 hours during which time it can continue its possible cancer-fighting efforts.


Cruciferous vegetables: Cruciferous vegetables include broccoli, cauliflower, cabbage, Brussels sprouts, kale, bok choy, and more.  I'd almost consider these the jackpot of detoxifying foods since most are loaded with several detoxifying substances.  Not only are these high in vitamin C, but they are also rich in homocysteine-lowering folate.  Homocysteine is a naturally-occurring amino acid produced in the body and elevated levels have been linked to increased risk for cardiovascular disease.  Cruciferous veggies are also loaded with glucosinolates.  When broken down, glucosinolates produce other biologically active compounds that may play various roles in detoxification in the body.  In fact, because this is such a promising cancer-fighting compound, researchers are investigating glucosinolates more closely.

Dark leafy green vegetables:  Dark leafy green vegetables, like spinach, kale, turnip greens, and Romaine lettuce, offer another mother lode of detoxifying compounds.  Dark leafy green vegetables are another super source of folate and glucosinolates.  They also offer an excellent source of carotenoids, including lutein and zeaxanthin.  These two carotenoid pigments accumulate in the retina of the eye and absorb blue light. This protects our eyes from damage over time, preventing eye diseases like age-related macular degeneration.

Green tea:  Green tea is brimming with polyphenols.  One of its polyphenols, EGCG, has shown excellent promise as a potent antioxidant that may also reduce the risk for certain types of cancer.  Recommendations usually suggest consuming 3 cups daily.  No worries if you're trying to limit your caffeine intake as decaffeination of this tea only reduces the polyphenol content slightly.

Berries:  Several berries, including blueberries, cranberries, raspberries, and blackberries, are commonly referred to as super foods due to their high-ranking antioxidant capacity.  These super fruits serve up a good helping of vitamin C and colon-cleansing fiber.  They also contain generous amounts of flavanoids, especially anthocyanidins and quercetin, that act as powerful antioxidants scavenging the body for those abusive free radicals.  As if this isn't enough, berries are also high in ellagic acid, another known antioxidant.

Which of these your favorites?  Which would you like to add to your diet?

Guest Blog: Vitamin D - What you need to know

This blog post was written by Marina Vigil, a California State University, Long Beach Dietetic Intern.  She is one of my former students with whom I had the pleasure of working with during her self-select rotation.  Thank you for sharing your knowledge with us, Marina!

Photo credit:  pittaya (Flickr)

Vitamin D: What Do You Need To Know?

Vitamin D has been receiving a lot of attention lately. Why? Vitamin D is a fat soluble vitamin that has long been known to be an important part of the body’s bone growth and maintenance by helping to maintain proper levels of calcium and phosphorus. But now research suggests that Vitamin D may be involved in the treatment and/or prevention of many diseases including diabetes, multiple sclerosis, and some cancers. Even though some of this research is inconclusive, it is still important to get adequate Vitamin D.

Where can I get my Vitamin D?

Unlike most other nutrients, your body can make all the Vitamin D that you need with the help of sunlight.  This is why Vitamin D is sometimes called the sunshine vitamin. On a clear, sunny day, most people only need to expose their hands, face and arms (without sunscreen) for 5 to 30 minutes a few times a week. However, due to the risk of skin cancer, the American Academy of Dermatology does not recommend getting your Vitamin D from light, either naturally from the sun or artificially from indoor tanning. If you do get your Vitamin D from light, be aware of the risk of sun damage.  Wear sunscreen outdoors and limit use of tanning beds to decrease your risk of sun damage.

The best way to get your Vitamin D is through a healthy diet. Not many foods are naturally rich sources of Vitamin D, but the good news is that it is still easy to get the recommended amounts of Vitamin D! Because it is so important, many foods, such as dairy products, juices, and cereals, are fortified with Vitamin D. Tofu and other soy products are also often fortified. In addition, eggs and fatty fish, such as salmon, tuna, and mackerel, are natural sources of Vitamin D.   Try to include a variety of these foods to maintain an adequate amount of Vitamin D.

Who is at risk of deficiency?

Unfortunately, research shows that many people are not getting enough of this vital nutrient, even in areas with plenty of sun. With our busy lifestyles nowadays many people spend the sunniest part of the day inside and are missing out on Vitamin D production. The elderly are also at higher risk for deficiency because the body makes less Vitamin D with age. So, how do you know if you are deficient? The answer is you don’t unless you get tested. You should talk to your doctor about getting tested.  It’s important to know that your levels will be lower in the winter.

Can I have too much Vitamin D?

Now, some people say that you can never have too much of a good thing, but that is not always true. Although vitamin D is great for your health, too much vitamin D can have toxic effects. High levels of vitamin D can cause high levels of calcium known as hypercalcemia. But the good news is that you cannot get vitamin D toxicity from the sun. If you are in the sun too long, your body will stop making Vitamin D and will break it down instead to prevent toxic levels. Vitamin D toxicity is usually caused by taking supplements.  For this reason, I would not recommend taking supplements unless you know you are deficient. Then, you and your doctor or dietitian can determine whether a supplement is right for you.

For more info on the Institute of Medicine's dietary reference intakes for vitamin D, click here.

Do you know your Vitamin D level? What Vitamin D rich foods do you enjoy? 

8 Mistakes That You Could Be Making With Your Supplements

Photo courtesy of Michelle Loy. Copyright 2010. All rights reserved.

Are you currently taking dietary supplements? Could you be making some mistakes with your supplements?  I get asked a lot of questions regarding supplements, so today I thought I'd share my insight on some of the biggest mistakes I see people making with their supplement usage.

Are you relying on the advertisement or supplement label for information regarding the safety and effectiveness?  Many people rely on the supplement labels, advertisements, or sales people for information about a supplement, but keep in mind that the information may be inaccurate, misleading, or biased.  Advertisements also often rely on testimonials or anecdotal evidence; however, one person's experience does not necessarily make a supplement safe or effective.  It's best to do your own research of scientific, peer-reviewed, evidence-based resources so that you can make an informed decision about the supplements you choose to use.  Believe me, your time and effort will be worth it!  You may want to check out these resources for starters:  The National Institutes of Health Office of Dietary Supplements, The National Center for Complementary and Alternative Medicine, or ConsumerLab.com.

Are you taking the correct dosage?  When talking with people about their supplements, I often find that many people aren't taking the dosage indicated on the container.  Some take more, some take less.  Most recently someone mentioned that she started taking a supplement upon the recommendation of her eye doctor.  She stated that she just takes the supplement "whenever her vision gets blurry", but the directions indicate that users should take "three capsules three times a day".  So keep in mind that if a supplement actually does what it claims, then taking it "whenever you feel like it" or "whenever you remember" may not benefit you as much as it would if you took the supplement as directed.  On the other hand, more isn't necessarily better when it comes to supplements either.  I know some people who pop extra vitamins to give them a boost of "energy" or to stave off a cold; however, there is a risk of toxicity associated with some supplements.  For example, taking too much iron can lead to iron toxicity, which has harmful effects, especially in children.  So be sure to follow the dosage directions carefully.

Are you timing it right?  Just as some medications indicate a specific time frame during which they should be taken (eg, morning, between meals), some supplements require the same.  For example, those who use zinc lozenges to recover from a cold quicker are usually advised to start taking the supplement at the first onset of symptoms and to continue for at least 48 hours after that. In addition, users are also directed to consume one tablet every two to three hours until symptoms subside.  However, I know  many people who do not follow the proper timing when taking zinc lozenges to treat the common cold.  These instructions are a little tough to follow, yet based on the evidence, they appear to be most effective when consumption is timed right.

Could your supplement be negatively interacting with a food, nutrient, drug, or other supplement?  While people may consider these things when taking medications, I often find that they do not give the same attention to supplements.  Many nutrients compete for the same sites of absorption in the gastrointestinal tract.  So consuming nutrients in supplement form can interfere with the absorption of nutrients from food.  For example, did you know that consuming calcium supplements with a type of iron in plant foods (non-heme iron) may reduce the bioavailability of the iron since they compete for absorption in the GI tract?  Also, some dietary supplements may increase or decrease the absorption, metabolism, or action of certain medications.  Did you know that many medications are derived from or modeled after herbal remedies?  It's true! For example, the chemical composition of aspirin is similar to that of willow bark.  For that reason, many herbal remedies can interfere with the metabolism or amplify the effects of medications.  For instance, consuming ginkgo biloba with blood-thinning drugs, such as coumadin or heparin, may prolong bleeding time and increase the risk for hemorrhage.  Or taking St. John's wort with antidepressant medications may intensify their effects.  Because of these potentially harmful interactions, you may want to have the supplements your taking evaluated by a Registered Dietitian, physician, or other health care provider.
  
Is there a reason you shouldn't be taking a supplement?  Some supplement labels will provide a list of contraindications or reasons that one should not take the supplement, and this list typically includes pregnant or lactating women and children.  Other than that, there aren't always comprehensive lists of contraindications.  However, we do need to be cautious about taking supplements given certain circumstances, conditions, or illnesses.  For instance, smokers are advised against long-term supplementation of beta carotene, a form of vitamin A, due to a possible increased risk for development of lung cancer.  Competitive athletes may need to avoid certain supplements because they contain a banned substance. For example, guarana is banned by the NCAA; however, this caffeine-loaded substance is found in many supplements designed to "improve athletic performance".  Taking such a supplement could result in suspension or disqualification from the sport.  Given the potential risks, it is wise to check with your physician, dietitian, or the athletic staff, in the case of athletes, to make sure that all substances contained in a supplement are considered safe, effective, and approved for use.

Are there other ingredients in the supplement that could be harmful to you?  I find that people often select a supplement based on the label claims or the major ingredients highlighted on the front of the label or on the supplement facts panel.  However, few people read through the entire ingredient list to see all that the supplement contains. Many supplements include other substances, such as binders and dyes, to which some people may be sensitive or allergic.  For example, some supplements contain soybean oil or soy lecithin, which may be harmful for someone with a soy allergy.  Someone with a wheat allergy may need to avoid products made with modified food starch as this may come from wheat.  If you do have food allergies or sensitivities, then it would be beneficial to thoroughly review the supplement ingredient list yourself for any potentially harmful substances or have your dietitian or health care provider do so with you.

Are you taking multiple supplements with the same ingredients?  When evaluating supplements, I often discover that a person is taking multiple supplements that contain the same nutrients.  For instance, they may be taking a multivitamin-mineral along with a B-complex supplement.  Each supplement contains some amount of all of the B vitamins, typically at least 100% of the Daily Value, so they're basically taking more than necessary.  In fact, since B vitamins are water-soluble and not stored to any great extent in the body, so the excess is basically excreted from the body in the urine. Pretty pricey urine, if you ask me!  So, examine your supplements carefully to make sure that you're not taking more than what's necessary.

Are you taking a supplement to make up for what you lack in your diet?  Some people readily admit that they take supplements to make up for what their diet lacks.  Usually what's lacking are vegetables, fruits, legumes, and whole grains, which are also packed with vitamins, minerals, fiber, and phytochemicals.  I understand that it may be challenging to eat a healthful, well-balanced diet that includes a variety of foods from the various food groups everyday and that some people opt to take supplements as a safety net.  However, some people simply do not want to or do not like to include foods like vegetables and fruits into their diet, so they think that they're getting the next best thing with supplements.  It is important to keep in mind that they are called supplements for a reason.  They are meant to supplement the diet rather than serve as a substitute for food consumption.  Okay, so maybe it's better than nothing, but we need to consider what a person misses out on when s/he consumes supplements instead of food as a source of nutrients.  How is it possible to truly package the full nutritional value of a whole vegetable or fruit into one or even a few pills?  Also, research suggests that it is the combination of nutrients and phytochemicals of whole foods that work together synergistically to provide optimal nutrition to the body, and those processes would be lacking if we singled out nutrients or phytochemicals.  I also find that some people take supplements and still consume an unbalanced diet that provides less than optimal nutrition.  So far, it doesn't appear that taking a slew of supplements makes up for a diet loaded with less nutritious, processed foods.  Finally, when consuming supplements instead of whole foods, we are missing out on the FOOD!  While popping a pill or two might provide some of the essential nutrients one needs for basic physiological functioning, it will not necessarily help with satiety.  A person will still need to eat food to satisfy hunger.  Eat 5 cups of vegetables and fruits daily and most will find themselves very satiated and well-nourished!

If you're really ready to dig into some solid information regarding supplements, you may want to check out the titles below. Some of these can even be checked out at your local library!

• PDR for Nutritional Supplements 2nd Edition (PDR for Nutritional Supplements)
• PDR for Herbal Medicines, 4th Edition
• A-Z Guide to Drug-Herb-Vitamin Interactions Revised and Expanded 2nd Edition: Improve Your Health and Avoid Side Effects When Using Common Medications and Natural Supplements Together
• Understanding Dietary Supplements (Understanding Health and Sickness Series)

The 4-1-1 on Vitamin C and the Common Cold

It's definitely that time of year again...cold and flu season. It seems like people are succumbing to the seasonal plague left and right lately.  And maybe you, like many others, are ready to down some vitamin C to ward off that cold. Don't worry, I just went to Target the other day and their shelves are fully stocked with products, like Emergen-C, just for you.  But before you head on over to build up your own stash, let's take a look at the 4-1-1 on whether or not such products really work.

When researchers set out to see if our "cure" for the common cold really was a cure, their analysis of over 30 clinical trials conducted over a stretch of about 40 years uncovered some interesting results.  Overall, investigators found no significant effect of supplemental vitamin C on preventing the common cold for most healthy people.  I say most because the combined results of six studies detected a 50% reduction in risk of catching a cold for certain groups taking routine doses of 250-1000 mg/day of vitamin C  -- marathon runners, young skiers, and soldiers working in freezing temperatures to be exact. So, for the general population, loading up on vitamin C throughout the year or when cold season hits apparently doesn't really fend off those colds, but if you're exposed to extreme physical stress or cold temperatures, it might actually be helpful.

As far as vitamin C's use as a cold remedy goes, the evidence is mixed.  Thirty studies exhibited a slight reduction in the duration of colds for adults and children taking daily megadoses of vitamin C compared to those on placebo. What does this amount to?  If the average cold lasts about 7 days, this means that a routine vitamin C supplement may lessen the duration of a cold by 1/2 a day for adults and 1 day for children.  However, seven studies showed no difference between vitamin C megadoses and placebo for lessening the duration of a cold when supplementation started at the onset of symptoms.  In an analysis of 15 studies, regular megadoses or those taken after the onset of symptoms did not significantly affect the severity of cold symptoms.

One important note to make is that vitamin C is a water-soluble vitamin, which means that little of it is stored in the body.  A few studies suggest that the body's cells become saturated with daily doses of 200-400 mg and that digestive absorption decreases at doses >200 mg/day.  Given some of the hefty doses in available supplements, often around 1000-2000 mg, do you wonder what happens to the excess if our body cannot store it?  We eliminate it via the urine. And at intakes >2000 mg/d, one can potentially experience adverse effects, such as kidney stone formation, nausea, abdominal cramps, excessive gas, and diarrhea.

I know...you swear that you take (or have taken) vitamin C and it's truly helped prevent a cold, right?  Well, there may be good reason -- placebo effect.  In a surprising twist, investigators in one study found that individuals who took placebo but thought they were taking vitamin C recounted fewer colds than those who actually consumed vitamin C but believed they were receiving a placebo. 

So, where does this leave us -- the real, live persons surrounded by this onslaught of sneezes and sniffles?  If you don't mind sparing the expense and feel that saving yourself from 1/2 a day's worth of a cold (when you catch one) is worth it, then daily supplementation with up to 200 mg of vitamin C may be worthwhile to you. (The recommended intake is 75 mg/d for women, 90 mg/d for men, and an additional 35 mg/d for smokers.)  Will you be harmed by taking doses of up to 2000 mg/d? It's unlikely as the risk of potential adverse effects at that level is low.  However, one can easily obtain the recommended intake (and more) through food alone by aiming for at least 5 cups of vegetables and fruits daily.  Let's see how this is done.

• Breakfast: 1 large orange = 91 mg
• Snack:  2 kiwis = 128 mg
  
• Lunch:  1/2 c cherry tomatoes = 9.5 mg, 1 c romaine lettuce = 11 mg
  
• Snack:   1/2 c red bell pepper = 95 mg
• Dinner:  1 large baked sweet potato = 35 mg, 1/2 c broccoli = 40 mg
• Total =  409.5 mg of Vitamin C from the equivalent of 5 c of vegetables and fruits!

Stay tuned for future posts related to this timely topic.