By Laird Harrison

Does it seem just a little bit harder to run, jump, swing a racquet and do all the other sporting things you used to do? It’s not just your imagination.

According to some estimates, we lose  an average of 1% of our strength every year after age 30. That accelerates after age 70.

So I was excited to read about a new study published last week on nutritional supplements that could stop this process. Researchers at the University of Iowa got promising results with ursolic acid, which is found in apple peel, and tomatidine, which comes from tomato plants and green tomatoes.

Age-Related Muscle Loss in Mice

It’s too early to say whether these compounds work in human beings. This study was in mice.

Still it’s a promising turn of events for a phenomenon called sarcopenia that has long puzzled scientists.

There’s no obvious reason for age-related muscle loss. Yes, many people become less active in middle age. Too many give up the sports they used to love (the problem this newsletter was created to solve.)

But even those who keep on doing what they’ve always been doing lose muscle mass. Lean turns to fat. And for reasons that are also not clear, strength fades even faster than muscle.

That has led researchers to ponder whether age-related muscle loss has to do with genes, hormones, nerves that regulate muscles, or some interaction of these.

The mouse experiments point to the genetic explanation.

Two Supplements Studies for Muscle Loss

Like humans, mice suffer from age-related muscle loss. The researchers divided elderly mice into three groups of 32. One got mouse chow containing 0.27 percent ursolic acid. One got 0.05 percent tomatidine. One got the same chow without the supplements.

After two months, the tomatidine group’s muscle mass increased by 10 percent and strength (measured as “specific force”) by 33 percent compared to the mice that did not get the supplements. The ursolic acid group’s muscle mass increased by 9 percent and strength by 30 percent.

The researchers killed and dissected the mice to understand why these substances seemed to work. They found that both tomatidine and ursolic acid turn off a group of genes that are turned on by a protein, transcription factor ATF4.

This inspired them to genetically engineer a new strain of mice that lack ATF4 in skeletal muscle. Like mouse muscles that were treated with ursolic acid and tomatidine, mouse muscles lacking ATF4 were resistant to age-related muscle loss.

By this point you may be wondering, “How can I get me some of that there ursolic acid and tomatidine?” As you can imagine, various vitamin companies are happy to fix you up.

The problem is that what works for a mouse doesn’t always work for people. Researchers are just now beginning to try these chemicals out in humans, and we don’t know yet whether there are side effects.

What You Can Do to Prevent Muscle Loss

In the mean time, there is something you can do to reduce your age-related muscle loss: exercise even more. Master athletes on average have the fitness levels of people 20 years younger. To stop muscle loss, the most important exercise is resistance training, such as weightlifting.

A lot of people go about this the wrong way, focusing on muscles that look good at the beach at the expense of those that truly contribute to performance. We’ve put together a whole set of videos showing you how to train the ones that too often get ignored.

Middle-aged people tire out faster than younger ones, so you may want to spread out your training over a longer period of time.

But the good news is that this type of training remains effective no matter how old you get. Unless you are already pumping as much iron as you possibly can, you still have the capacity to increase your strength. The same can be said for endurance training.

The bottom line is that you have to spend more time exercising the older you get, even if you only want to maintain a constant level of fitness.

I do think eventually we’ll be able to swallow or inject something that will help, even if tomatidine and ursolic acid don’t work out. Testosterone, for example, increases strength, though it comes with potential risks.

Researchers are also looking at another group of compounds called selective androgen receptor modulators (SARMs), which might achieve some of the same effects as testosterone, without the risks.

In the meantime, you’ll have to excuse me. I’m going to work out.

Featured Photo by Charles Smith.

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