NEW SCIENCE REVEALS: The Shocking Truth About Magnesium, Zinc, and Muscle Growth

If You Only Know One Thing About Muscle Nutrition, It Should Be This

When most people think about getting stronger, they focus on training and protein. But a new study published in the Archives of Gerontology and Geriatrics in May 2025 shows there's more to it. Micronutrients play a bigger role than we once thought.

This large-scale genetic study found strong links between certain nutrients and muscle mass, strength, and mobility. The standout players with direct causal evidence from this study were Magnesium, zinc, and omega-3 fatty acids.

Here’s what the study uncovered and how it can help shape your training and nutrition.

What the Study Looked At

The research team used something called Mendelian randomization. It’s a way of using genetic data to test cause-and-effect relationships. Instead of just spotting trends, it asks: are people genetically set up to have more of these nutrients, and if so, do they have better muscle health?

This study specifically looked at five physical traits tied to sarcopenia:

• Grip strength
• Physical activity levels
• Walking pace
• Ability to walk or cycle for 10 minutes unaided
• Adjusted lean muscle mass (especially in the limbs)

They tracked seven nutrients:

1. Magnesium
2. Zinc
3. Calcium
4. Iron
5. Selenium
6. Phosphorus
7. Omega-3 fatty acids

What They Found

1. Magnesium protects muscle mass. People with higher magnesium levels were more likely to have more lean muscle. It’s linked to better muscle retention and supports strength as we age.
2. Zinc helps with movement and energy. Zinc was tied to higher physical activity and faster walking pace. It appears to support overall movement and stamina.
3. Omega-3s had a nuanced result. Surprisingly, this study found a link between higher omega-3 levels and lower lean muscle mass. While this specific finding warrants further research to understand factors such as dosage, inflammation, or overall diet quality, it's crucial to remember its broader importance for health. Beyond muscle mass, omega-3s are vital fatty acids that supercharge your heart, brain, eyes, and joints while fighting inflammation throughout your body.

What If You Don’t Know Your Genetics?

You don’t need a genetic test to take action. The takeaway is clear: higher levels of these nutrients support better muscle health. Whether your levels come from your genes or your diet, the impact is the same. Most people can improve how they feel just by getting enough through food. This isn’t about luck. It’s about giving your body what it needs to stay strong and mobile.

What Does “Genetically Predisposed” Actually Mean?

The body can’t make minerals like magnesium, zinc, calcium, or iron. So when someone is genetically predisposed to have higher levels of these nutrients, it means their body is naturally better at managing them.

Some people have genetic traits that help them:

• Absorb more of a nutrient from food
• Retain more of it in the bloodstream (less lost through urine)
• Store and transport it more efficiently in tissues like muscle, bone, or liver

These small genetic differences can lead to higher baseline levels of certain nutrients in the body, even with the same diet. This is why studies like this one are so useful. By comparing people with different genetic profiles, researchers can better understand whether a nutrient is actually causing better muscle health, rather than simply being associated with it.

Why This Matters for Your Training

Micronutrients often get overlooked, but they affect everything from recovery to energy. Low levels of magnesium, zinc, calcium, or iron can lead to:

• Fatigue during workouts
• Slower recovery
• Less endurance
• Trouble building or keeping muscle If you’ve been feeling stuck or run-down, these are worth a closer look.

Where to Get These Nutrients

Start with food. It’s the simplest and most effective approach for most people.

Magnesium

• Leafy greens
• Pumpkin seeds
• Almonds
• Whole grains
• Dark chocolate

Zinc

• Beef
• Chicken
• Eggs
• Chickpeas
• Hemp seeds

Some people may need supplements, especially older adults or those with dietary limits.

Bottom Line

Training and protein are essential, but they’re not the whole story. This new research provides strong causal evidence that magnesium and zinc have a real impact on strength, mobility, and performance related to muscle health. The study also presented a novel, though complex, finding regarding omega-3s. It’s not about chasing trends. It’s about using proven tools to support your health, one meal at a time.

References

1. Jia, X., et al. (2025). Causal relationships between micronutrients and sarcopenia: a two-sample bidirectional Mendelian randomization study. Archives of Gerontology and Geriatrics, 122, 105423. https://pubmed.ncbi.nlm.nih.gov/40483991/
2. Harvard T.H. Chan School of Public Health, The Nutrition Source. Magnesium. Available at: https://nutritionsource.hsph.harvard.edu/magnesium/
3. Healthdirect (Australian Government). Foods high in zinc. Available at: https://www.healthdirect.gov.au/foods-high-in-zinc
4. Garrison, S. R., et al. (2023). Effects of magnesium supplementation on muscle soreness in different type of physical activities: a systematic review. Journal of the International Society of Sports Nutrition, 20(1), 1-13. https://pubmed.ncbi.nlm.nih.gov/38970118/
5. Hashimoto, K., & Takamura, M. (2020). Zinc at the crossroads of exercise and proteostasis. Frontiers in Physiology, 11, 570. https://pmc.ncbi.nlm.nih.gov/articles/PMC7284914/
6. Smith, G. I., et al. (2019). The Influence of Omega-3 Fatty Acids on Skeletal Muscle Protein Turnover in Health, Disuse, and Disease. Frontiers in Nutrition, 6, 144. https://www.frontiersin.org/articles/10.3389/fnut.2019.00144/full