Two recent studies demonstrated how the antioxidant vitamins C and E may protect our bodies from oxidative stress that damages cells, tissues and organs.

Vitamin E for Boomers

In the first study, vitamin E supplementation greatly improved two established markers for oxidative stress in middle age and elderly subjects—cell membrane fluidity in red blood cells and reduced levels of malondialdehyde (MDA), a bi-product of lipid oxidation.

Why is this important?

Cell membrane integrity and fluidity is necessary for cell function, viability, growth and reproduction. And since all cell membranes are composed of lipids, preventing lipid oxidation is important to maintain the health and function of all cells.

As vitamin E resides primarily in cell membranes, researchers believe it helps protect fatty acids in cell membranes from oxidative damage.

For the study, researchers randomly assigned 180 healthy participants between the ages of 55 and 77 into four groups that received vitamin E in doses of 0, 100, 200, or 300 mg of d-alpha tocopheryl acetate per day for four months.

At the end of the study, blood levels of alpha-tocopherol increased by 71, 78 and 95 respectively.

MDA levels were significantly decreased in all three vitamin E groups and there were dramatic improvements in the membrane fluidity of red blood cells. There was also decreased rupturing of red blood cells.

Women Using Contraceptives

Another study indicated that vitamin C and E supplementation resulted in less oxidative damage in women using oral contraceptives.

The researchers randomly assigned 120 healthy women to one of three groups. One group received oral contraceptives only (.03 mg ethinylestradiol/.15 mg levonorgestrel), another group received the contraceptives plus 150 mg of vitamin C and 200 IU of vitamin E, and the remaining group received no intervention (the control group).

At the end of four weeks, the contraceptive-only group had increased levels of MDA indicating lipid oxidation, and reduced activity of the antioxidant enzymes glutathione peroxidase and glutathione reductase—the body’s primary defense.

However, the group that received vitamin supplementation along with contraceptives had significantly reduced levels of MDA and increased  activity of glutathione enzymes.

According to study authors, the data suggests that low-dose oral contraceptives, by increasing oxidative stress and lipid peroxidation, may represent a potential cardiovascular health risk factor, and the use of vitamins E and C may be beneficial in providing additional antioxidant protection.

Sources:

Nutraingredients

Contraception

Researchers at Georgia Health Sciences University have identified another essential function of vitamin E—helping to repair tears in the plasma membranes of cells. These tears occur as part of everyday wear-and-tear as well as through more strenuous physical activities.

When the researchers simulated the damaging effects of exercise by using hydrogen peroxide to produce free radicals, they found that tears in skeletal muscle cells would not heal without the presence of vitamin E. Without repair of muscle cells, muscles eventually waste away and die.

Vitamin E appears to aid repair in several ways, say study authors. As an antioxidant, it helps stop free-radicals that impede repair. Because it's lipid-soluble, vitamin E can actually insert itself into the membrane to prevent free radicals from attacking. It also can help keep phospholipids, a key membrane component, compliant so they can better repair after a tear.

Their research may have implications for a variety of muscle conditions in which inadequate plasma membrane repair is involved.

In previous studies using animal models, researchers found that soaking cells in a membrane-stressing solution for eight to 12 weeks, caused a repair defect. Alpha tocopherol, the most biologically active form of vitamin E significantly reversed membrane repair deficits and increased cell survival after tearing cells in culture.

Other Vitamin E Benefits

In addition to its activities as an antioxidant, vitamin E is involved in immune function, cell signaling, regulation of gene expression, and other metabolic processes. It also inhibits the activity of an enzyme involved in cell proliferation and differentiation. Vitamin E-rich cells lining the interior surface of blood vessels are better able to resist blood-cell components adhering to this surface. Vitamin E also facilitates normal vasodilatation and supports healthy platelet aggregation.

Sources:

Science Daily

Linus Pauling Institute

Office of Dietary Supplements

If you’re like most Americans you grew up eating PB&J. It is estimated that children consume about 1,500 peanut butter and jelly sandwiches by the time they graduate high school. But the love of peanut butter knows no age limit as 89 percent of households in this country consume it regularly.

Despite it’s popularity, there seems to be some debate about whether it’s really good for you. Some call peanut butter a superfood, while others believe it’s too high in fat and calories to be healthy. We’ll give you the facts and let you decide.

What is Peanut Butter?

By law, any product labeled "peanut butter" in the United States must be comprised of at least 90 percent peanuts. Dr. John Harvey Kellogg, a physician wanting to help patients eat more plant-based protein, patented his procedure for making peanut butter in 1895.

Benefits of Peanut Butter:

• Peanut butter is a good source of vitamin E, vitamin B6, folate, niacin, potassium, phosphorous, magnesium, zinc, copper, and manganese – which are vitamins and minerals essential for our body’s strength and health.
• Peanut butter is chock-full of heart-healthy monounsaturated fat. A recent study found that insulin-resistant adults who ate a diet high in monounsaturated fat had less belly fat than people who ate more carbohydrates or saturated fat.
• Peanut butter is naturally cholesterol-free and trans-fat free.
• Peanut butter has been found to contain phytochemicals (or plant chemicals), which are thought to be beneficial to health. In fact, resveratrol, a phytochemical that is also found in grapes and red wine, is present in peanuts and peanut butter.
• Peanut butter is an excellent source of protein, which your body needs to keep your muscles, skin, bones and other tissues healthy.
• Peanut butter can help you lose weight. It has the enviable combination of fiber (2 g per serving) and protein (8 g per serving) that fills you up and keeps you feeling full longer, so you eat less overall.
• Research shows that eating peanuts can decrease your risk of heart disease, diabetes, and other chronic health conditions.
• Once study found that consuming 1 ounce of nuts or peanut butter (about 2 tablespoons) at least 5 days a week can lower the risk of developing diabetes by almost 30%.

How to Buy the Best

Most brands have about the same amount of fat and calories, but there are some other factors such as sodium, sugar and fat-substitutes that make some a better pick.

• Look for brands that contain about 40-60 mg of sodium per 2-tablespoon serving. Too much sodium can mask the peanut flavor.
• Natural brands usually have 1-2 grams of sugar per serving—that’s about half as much as commercial brands. If you are using peanut butter for making savory sauces like satay or combining with a sweet ingredient like jelly, you can save a few calories by choosing an unsweetened brand.
• Choose natural or organic brands for the best peanut flavor.

A Little Goes a Long Way

At about 190 calories for 2 tablespoons, the only potential downside to peanut butter is its calorie count. So, watch your portion sizes and savor every gooey bite.
For more information about the health benefits of nuts, read our Healthy Tips article about the top five healthiest nuts

Sources:

Prevention

Associated Content

National Peanut Board

LiveStrong

In another case of fuzzy labeling, a recent report from ConsumerLabs.com identified three products with vitamin E problems.

One supplement contained the correct amount of vitamin E as noted on its label, but the tablets didn't disintegrate within a half-hour as specified by the United States Pharmacopoeia method. The problem: Because the tablets took more than two hours to break apart, the vitamin E contained in the supplement may not be properly absorbed after leaving the stomach and entering the small intestine.

Tablets that are compressed too tightly or coated improperly create these problems, even when they contain the accurate amount of vitamin E or any other ingredient.

Additionally, ConsumerLabs.com discovered two oils that contained synthetic forms of vitamin E. The entire amount of vitamin E found in one oil-based product (containing 1,000 IU) was synthetic, while the other contained some 81 percent of the vitamin E advertised on its label, yet about 95 percent of it was man-made.

Learn more about the quality problems associated with other supplements, and get a better understanding what you're really paying for, by reviewing CNCA's Nutritional Supplement Quality -- the Facts.

ConsumerLab.com August 4, 2009 Subscription Required