We’ve long known that “an apple a day” is a healthy habit. Apples are loaded with fiber and pack a healthy dose of vitamin C. They also provide smaller amounts of several other vitamins and minerals. Plus, apples contain powerful antioxidants – such as quercetin and catechin.

Now University of Iowa researchers have discovered that another substance found in apples may have even more amazing health benefits.

The substance is called ursolic acid, and apple peel is a very rich source.

Ursolic acid has interested scientists for several years. Animal studies show it enhances antioxidant activity and promotes heart health.(1) In studies on cultured human skin, ursolic acid promotes production of collagen and ceramides – two important building blocks of healthy skin.(2)

But this new study shows ursolic acid may provide an even bigger anti-aging benefit. It may help you hold on to lean muscle mass as you get older.

Here’s what the Iowa researchers found…

They gave ursolic acid to mice that had been put on a fast. Usually, this would result in their muscles slowly wasting away. But mice given ursolic acid didn’t lose as much muscle as expected.

Next, they Iowa team added ursolic acid to the diets of healthy mice… and they all packed on lean muscle and lost fat. Plus, their blood sugar levels dropped – along with the levels of unhealthy fats in their blood.(3)

No one has tested ursolic acid on people yet, so we can’t be sure humans will get the same benefit. But I think this study is promising. Especially because muscle wasting is such a challenge for mature adults.

You see, sickness or injury can cut your activity levels. And muscles waste away when they’re not being used. That’s because muscle mass uses a lot of energy.

When your muscles aren’t being used much, your body sees them as “energy wasters.” So while you’re sidelined, your body increases efficiency by dropping the muscle mass it thinks it doesn’t need.

Of course, less muscle makes getting active again harder… and less activity leads to more muscle loss. You can probably see how easily it could become a vicious circle. And that circle can wind up keeping you from your favorite activities.

That’s why being able to slow or stop muscle wasting would be such a breakthrough. It could help you bounce back from an injury or illness much faster. Further research may show “an apple a day” could even help you trim down and add muscle – whether or not you’ve been sick or injured.

The amount of ursolic acid varies among different types of apple. A medium Fuji apple, for example, contains about 50 mg of ursolic acid. Granny Smith and Gala varieties have a bit less – about 35 mg.

A number of other fruits and spices contain ursolic acid, too. These include cranberries, bilberries, prunes, thyme and oregano.

Right now it’s too soon to say if humans will have the same reaction as mice. But apples are such a healthy food, eating a few more a week couldn’t hurt. (To avoid pesticide residues, I recommend organic apples.) They may just help you stay stronger longer… and add more enjoyment to your life.

References:

1 Saravanan R and Pugalendi V. Impact of ursolic acid on chronic ethanol-induced oxidative stress in the rat heart. Pharmacol Rep. 2006 Jan-Feb;58(1):41-7.

2 Both DM, et al. Liposome-encapsulated ursolic acid increases ceramides and collagen in human skin cells. Arch Dermatol Res. 2002 Jan;293(11):569-75.

3 Kunkel SD, et al. mRNA Expression Signatures of Human Skeletal Muscle Atrophy Identify a Natural Compound that Increases Muscle Mass. Cell Metabolism, Volume 13, Issue 6, 627-638, 8 June 2011.

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