Monthly Archives: May 2010

The Acai Berry: A Superfood?

Q: What are the health benefits of Acai?

A: The Acai berry is a small, round, black-purple fruit that grows on a certain species of palm tree found in Central and South America. You may have seen acai juices, snacks, powders and capsules flood the market in the past few years, as companies increasingly tout the berry as a “superfood,” packed with antioxidants that can protect against aging and cancer. Acai berry products are also said to help people lose weight, fight heart disease and improve arthritis.

In short, evidence to support these health claims is limited. Studies of the antioxidant capacity of acai berries are conflicting. Though supported by a competing company (POM), one study found that pomegranate juice, red wine and blueberry juice have greater antioxidant potency than acai juice (Seeram et al, 2008). In addition, acai products are marketed as dietary supplements, so they escape FDA regulation. The acai berry may not necessarily be harmful, but its presumed power – to enhance sleep and guard against wrinkles, for example – has yet to be verified scientifically. If you’re looking to save a buck, stick to what’s proven to work. Get your daily dose of antioxidants by meeting the recommend 2.5 cups of vegetables and 2 cups of fruit per day.

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Antioxidants: Free radical scavengers

Q: What’s an “antioxidant”?

A: Antioxidants are compounds that offset damage to the body’s cells. Antioxidants, including certain vitamins, minerals and phytochemicals, defend against injuries caused by free radicals. But what’s a free radical? Simply, free radicals are oxygen molecules floating around in your system that contain an unpaired electric charge. This single “electron” looks for a buddy to gain stability and so it destructively steals a second electron from substances like cell membranes and DNA.  Free radicals form naturally during the metabolism of food, but are also caused by cigarette smoke, air pollution and UV sun rays. While there are some benefits to free radicals, these highly reactive, unstable molecules are implicated in aging, neurodegenerative diseases and cancer. Fortunately, antioxidants can destroy free radicals, limit their formation and stimulate repair activity at the site of damage.

Antioxidant Food sources Recommended Daily Amount
Vitamin C Orange, grapefruit, mango, strawberries, broccoli 90 mg for men75 mg for women
Vitamin E Wheat germ oil, sunflower seeds, peanut butter 15 mg
Beta-carotene (Vitamin A  precursor) Carrots, sweet potatoes, broccoli None established
Selenium Brazil nuts, tuna, turkey, rice 55 µg
Lycopene Tomatoes, ketchup, watermelon None established
Lutein Dark, leafy greens (e.g. spinach) None established
Resveratrol Red grapes None established
Anthocyanin Blueberries, raspberries, plums, red grapes None established

There is no set daily recommendation for most antioxidants; however, eating more fruits and vegetables is the best way to boost your intake. Rely on whole foods, not supplements, since popping high dose capsules can have negative health effects. For example, beta-carotene supplements are associated with higher rates of lung cancer in men; however, smokers are recommended to increase vitamin C intake, due to smoke-induced oxidative damage. My take? Get your antioxidants from food sources, steer clear of mega-dose pills and stick to recommended daily amounts of vitamins & minerals.

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Filed under Fruits and Vegetables, Heart Healthy Choices, Medical Conditions, Supplements, Vitamins & Minerals

Getting Enough Calcium?

Q: My doctor recommended I take a calcium supplement. Which type do you suggest, and when is the best time of day to take it?

A: Calcium supplements come in two forms: calcium citrate or calcium carbonate. Calcium carbonate (e.g. Caltrate®, Viactiv®, Tums®) is cheaper than Calcium citrate (e.g. Citracal®), but research has shown that under normal circumstances, the two forms are equally absorbed and utilized by the body. The exception is in cases of reduced stomach acidity, which occurs often in the elderly or if you take medications that decrease gastric acid secretion. If this is the case, then calcium citrate is the way to go. Check the ingredient list on the back of supplements and multivitamins to know which form of calcium the product contains.

A few rules:

  1. Calcium carbonate products should be taken with meals.
  2. Calcium citrate products can be taken with food or on an empty stomach.
  3. Along with food and antacids, calcium supplements likely inhibit the absorption of medications intended to halt bone loss, such as Fosamax, Actonel or Didronel. After taking one of these drugs, wait at least 30 minutes before ingesting anything except plain water.
  4. Calcium may prevent iron absorption, so if you’re also on supplemental iron, space the two tablets several hours apart.

Healthy adults should aim for 1,000-1,200 mg elemental calcium per day. It’s important to buy a supplement that also contains vitamin D, which helps our body absorb calcium. The recommendation for vitamin D is set at 600 IU daily, but a number of researchers believe this number should even be doubled.

Let’s put things in perspective…One Caltrate®600+D tablet contains 600 mg calcium plus 400 IU of vitamin D. Daily goals can be met with two of these tablets daily. On the other hand, Citracal® Regular 250 mg + D contains 500 mg calcium and 400 IU vitamin D per serving, but a serving is 2 tablets! That means you would need to take 4 Citracal® tablets per day to meet the daily calcium requirement. Viactiv® flavoredchews each have 500 mg calcium and 500 IU vitamin D. Lastly, a single Tums® tablet contains 500 mg of calcium carbonate, but only 200 mg of that is elemental calcium. Bottom line? Be sure to read labels and, of course, inform your doctor of all vitamins, supplements and herbs you’re taking.

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Filed under Medical Conditions, Supplements, Vitamins & Minerals