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Our body needs protein to help build and repair body tissue, maintain a healthy immune system, and give us energy. It is important to include protein in our diet - we can source it from foods such as eggs, lean meat, nuts and oily fish – but our body can also make protein from amino acids.

One of these amino acids is leucine which is highly concentrated in muscles. When our muscles are active during exercise, leucine breaks down to form hydroxymethylbutyrate (HMB). Research shows that HMB could increase muscle mass - particularly helpful for those recovering from illness – plus it can help lessen the damage of intensive exercise.

  • How does HMB work?

    “Like leucine, HMB is important for the production of muscle protein and has several beneficial actions on muscle cells,” explains Dr Sarah Brewer.

    “It appears to:

    • Enhance the use of cholesterol as a fuel for your muscles;
    • Lower levels of the enzymes involved in the breakdown of muscle protein;
    • Increase synthesis of muscle protein, and
    • Prolong muscle cell survival and proliferation

    “This is useful not only for those who exercise heavily and are looking to boost their performance and recovery, but also for those with long-term conditions associated with reduced muscle function.”

  • Sources of HMB

    As well as being made in the body, HMB is found in small quantities in foods such as grapefruit, alfalfa and certain fish.

  • Dose

    “The recommended dose of HMB is 500mg to 1,500mg daily,” advises Dr Brewer. “However, do not take more than 3g daily.” Increasing the amount of protein in your diet could also boost production of HMB.

  • Benefits of HMB

    Muscle wasting: In people with long-term conditions associated with muscle wasting, taking HMB in combination with other protein building blocks has been shown to prevent extreme weight loss (cachexia) and improve immune function.

    Blood pressure: Preliminary evidence indicates HMB may help lower blood pressure.

    Cholesterol: Some evidence suggests HMB could lower cholesterol.

    Muscle growth: Studies have shown combining exercise training with HMB supplements could lead to increased muscle mass and strength.

    Exercise performance: In one study, athletes taking HMB daily for up to nine weeks showed improved strength training and lean body mass.

    Exercise recovery: There is also evidence that HMB helps with exercise recovery. Athletes taking HMB for up to six weeks showed less muscle damage during an intensive exercise programme than those who did not.

  • Cautions

    HMB has the potential to lower blood pressure, so if you are taking medication for high blood pressure you may need to reduce your dose. “Although HMB is naturally found in mother’s milk, do not take it during pregnancy or breast-feeding, as there is no data on its effects in these cases,” warns Dr Brewer. If in doubt, seek medical advice.

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Nutrition Expert sources the latest information and advice from a range of qualified doctors, nutritionists and coaches. We always endeavour to have the most up to date information possible and publish new content weekly. However with the constant research in this field sometimes some of our older articles can become out of date. If you see anything that you believe needs to be updated please let us know via our Contact Us page