July 9, 2011
Question of the Week: “Why do I barely fill an A cup bra while my best friend, who is my height and weight, easily rounds out a D cup? I mean, is that really fair?”
Great question…and the short answer is…blame your parents! That’s because all three of the factors most responsible for determining your ultimate cup size are highly influenced by your heredity.
Your Genes: The moment you’re born, you already have a predisposition toward your grown-up cup size. That’s because you inherit a gene for breast size (either active or dormant) from each of your parents. The gene for breast size may either be active or dormant in any given generation, so your D cup mom could easily pass on an active A cup gene to you, even though it was dormant for her.
Your Hormones: I was surprised to learn that after puberty, we all have a pretty similar amount of glandular tissue in our breasts, but it’s our genes (thanks again, mom and dad!) that determine their growth potential once ‘the girls’ are exposed to estrogen hormone. You definitely witness this relationship on a monthly basis if you’re prone to dramatic changes in your own breast size as your hormones swing up and down around the menstrual cycle or when you go on or off ‘the Pill’.
Your Body Fat: Okay, our parents get a little reprieve on this factor, since how we eat and move usually has the greatest effect on how lean we are. Breasts are a natural storage area for extra fat, so overall higher body levels usually mean a bigger breast size. But that perfect relationship can break down because your inherited genes also dictate where on your body those fat cells gets stashed. If you’re an ‘apple’ body type, extra pounds tend to get stored in your breasts and mid-section first while your hips stay narrow; if you’re a ‘pear’, you may find your hips and thighs getting curvier as you gain pounds, while your breasts hardly budge up in size at all.
Bottom Line: So if you’re a 34A (small torso/small cups) and your BFF is a 34D (small torso/large cups) and you actually are the same height and weight, chances are most of the difference in your bra sizes is due to genetics and hormones rather than body fat levels. Her breasts are larger because her genetics gave her more growth potential, and she may have had higher hormone levels that boosted growth to the maximum. If you’re still bummed about being an A-cupper, don’t forget that when it comes to playing high-impact sports, smaller is always easier!
If you have your own pressing question about anything bra-, breast-, gear-, or fitness-related, just click on my “Ask the Expert” tab, and leave me a confidential message. I’ll be happy to shoot you off a rapid personal reply, or feature your topic in a future blog!
Thanks, and have a beautiful, active week!