Jessica Alba thinks she helps people live ''safer, healthier'' lives.

The 'Sin City: A Dame to Kill For' actress has her own eco-friendly business, The Honest Company - which she founded in 2011 and is now worth over $1 billion - and though she enjoys inspiring her fans with her movie roles, she is particularly pleased with the work done by her company.

She said: ''Knowing that I've reached people with any of my roles is a good feeling.

''I've gone from entertaining them to helping them live safer, healthier lives through a business that provides education, community and product.

''I've worked hard to achieve what I have, so it feels great to see results.

''Of course, there's always more to do, so the transformation is ongoing.''

The 34-year-old beauty - who has kids Honor, seven, and Haven, three, with husband Cash Warren - admits juggling her many commitments comes with both ''challenges and rewards'', especially as she wants to be with her family as much as possible.

She told Look magazine: ''Each job has its own set of challenges and rewards.

''As a mother, my desire to spend every waking hour with my kids is insatiable, knowing in a blink of an eye they'll be off to college - I have to take every moment I get with them.''