Do bigger breasts increase the risk of breast cancer?

What is the number one risk factor for breast cancer? It’s about being a woman! 99% of breast cancer patients are women, so the best way to avoid breast cancer is to be a man. What is the second leading risk factor for breast cancer?It’s getting old! Like most cancers, breast cancer incidence increases with age. Eating a magic pill to stay young is a good way to prevent cancer. These two factors sound funny, but from a scientific and statistical point of view, they are true. A clear conclusion can also be drawn from this: as China’s female population continues to age, breast cancer will certainly increase. In addition to the two factors mentioned above, what other clear cancer risk factors are there for bigger breasts?

It can be roughly divided into congenital and acquired factors.

Congenital factors

The first is hormone levels. Most breast cancer cells rely on estrogen for growth. Studies have shown that the longer a woman is exposed to estrogen throughout her life, the higher her risk of developing breast cancer. Early menarche (before age 12), late menopause (after age 55), no childbirth experience, and no breastfeeding experience all result in women being exposed to estrogen for a longer period of time and at higher levels. Therefore, statistically speaking, these factors all increase the risk of breast cancer.

The second is genetic genes.

Certain congenital gene mutations increase the risk of breast cancer, most notably those in the BRCA1 and BRCA2 genes. Carrying a BRCA1/2 mutation increases the risk of breast cancer by dozens, even hundreds, of times. Hollywood actress Angelina Jolie , unfortunately, inherited the BRCA1 mutation from her mother and chose to undergo a preventative mastectomy before the age of 40.

The third is breast density.

This is something most people don’t know. Studies have found that dense breasts are more likely to develop cancer. This isn’t a physical sensation, but rather a characteristic seen in medical imaging . Generally, breasts with less fat and more glandular tissue are more dense.

From left to right, the density increases. The leftmost breast contains a lot of fat and has the lowest density, resulting in many seemingly transparent areas on the image; while the rightmost breast is almost entirely glandular and has a very high density.

Therefore, it is not simply that having a larger cup size will increase your risk of breast cancer. If the breasts are mainly fat, then the risk does not increase.

Why is the incidence higher in people with dense breasts? It’s not entirely clear, but it may be related to the origin of breast cancer. As mentioned in the first issue, breast cancer typically originates in mammary ducts and acinar cells , not fat cells. Therefore, dense breasts, with their numerous glands , may harbor more cells that are likely to become cancerous.

Dense breasts also bring another problem, which is that it is difficult to detect tumors by X-rays , which makes screening more difficult and easily delays the opportunity for early intervention.

Compared with Europe and the United States, Chinese women have relatively more dense breasts, so special attention should be paid to avoid the cancer risks brought by other lifestyles. At the same time, early screening requires some special methods.

Acquired factors

Next, let’s discuss acquired factors, specifically the risk of breast cancer caused by lifestyle . The following three factors are the most studied and should be avoided.

The first is drinking.

The World Health Organization has long classified all alcoholic beverages, whether red wine, white wine, or beer, as Class I carcinogens . This is because alcohol is metabolized into acetaldehyde , which can cause irreversible mutations in cellular DNA, leading to cancer. One of the biggest lies in Chinese society is the so-called “health wine” that is brainwashed by television commercials.

Red wine deserves special mention. Many women start drinking red wine because they hear it may reduce the risk of cardiovascular disease, a claim that’s controversial. However, what’s undisputed is that red wine is a proven carcinogen for women! A 2017 analysis of data from over 12 million women found that even drinking just one small glass of wine per day significantly increased the risk of breast cancer.

Therefore, if women want to prevent cancer, the official recommendation is very simple: it is best not to drink it, and if that is not possible, try to drink as little as possible.

The second is obesity.

Due to the prevalence of high-calorie foods, obesity has become a growing social problem worldwide. Being overweight carries many health risks, including cardiovascular disease, diabetes, osteoarthritis , and breast cancer.

Weight gain significantly increases the risk of breast cancer. Studies have shown that overweight or obese middle-aged and older women have a 30% to 60% increased risk of breast cancer. Therefore, weight management is crucial for postmenopausal women.

Why does obesity increase breast cancer risk? Two possible reasons are currently believed. First, fat cells contain an enzyme called aromatase , which converts androgens secreted by the female adrenal glands into estrogen. As previously mentioned, high estrogen levels increase breast cancer risk. Second, obese individuals often have higher insulin levels, which is also positively correlated with breast cancer incidence.

The third is often staying up late or working night shifts.

We all know that staying up late is bad for your health, but perhaps fewer people know that it can directly cause cancer. As early as 2007, the International Agency for Research on Cancer (IARC) classified “night shift work” as a Category 2A carcinogen. Two large-scale independent studies have found that nurses who frequently work night shifts have a higher risk of breast cancer than the general population. Another study found that flight attendants who frequently experience jet lag also have an increased risk of breast cancer.

Please note that this does not mean that “going to bed late and getting up late” is worse than “going to bed early and getting up early”, but that frequently changing the rhythm of life and sleep will lead to disrupting the biological clock and is harmful.

Reduce risk

Having mentioned so many factors that increase the risk of breast cancer, is there anything that can reduce the risk?Of course.

The following two points are clearly supported by data.

The first is exercise.

In 2017, a study analyzing data from 1.44 million people found that exercise can significantly reduce the incidence of at least 13 types of cancer, including breast cancer. Furthermore, exercise can still prevent cancer even in obese people!

Experts generally recommend 30 to 60 minutes of daily exercise and physical activity. To prevent cancer, the amount of exercise is important, not the type of exercise. And it doesn’t need to be strenuous. Choose an activity you enjoy and that suits you, whether it’s running, playing ball, doing Tai Chi, or square dancing. Sticking with it is key.

The second is to eat more vegetables and fruits.

Through a comprehensive analysis of more than 10 studies, scientists found that women who eat more vegetables or more fruits can slightly reduce their breast cancer risk. However, the best cancer prevention effect is achieved by eating more vegetables and fruits.

And eating more fruits and vegetables not only prevents cancer, it also reduces the risk of cardiovascular disease , stroke, and many other chronic diseases. So there’s really no reason not to do it.

The Dietary Guidelines for Chinese Residents recommends consuming 300-500g of vegetables daily, with dark vegetables accounting for half. Also, eat fruit daily, ensuring a daily intake of 200-350g of fresh fruit. Note that fruit juice cannot be used as a substitute.

In summary, breast cancer has many risk factors, both inherited and acquired. While we can’t change our inherited factors, we can choose to adopt healthy lifestyle habits. Not smoking, not drinking, staying up late, exercising regularly, and eating more fruits and vegetables can all effectively reduce a person’s risk of breast cancer.

I hope everyone understands the disease and stops panicking.

Let’s work together to pay tribute to life!