Can Body Fat Protect Women Against Heart Disease?


It might come as a shock, but a new study has found that higher body fat in women is associated with a lower risk of death from cardiovascular disease (CVD). But while this may be true in women, it’s not the same for men. The study also found that higher muscles mass in both men and women also means a lower mortality rate from CVD.

Cardiovascular disease or CVD actually refers to a multiple number of different conditions that affect the heart or cardiovascular system. Such conditions include heart disease, arrhythmia, heart attack, heart failure, stroke, and heart valve problems.

According to the research, females should actually focus more on building muscle mass than actually losing weight when it comes to their cardiovascular health.

The research team that conducted this study also share that over the last 50 years, CVD death rates have actually fallen in both men and women in the United States. But, the rate of decline was slower in women than it was in men, while in fact, the rate of heart attacks in women between the ages of 35 to 54 years in age has actually increased.

Moreover, research also suggests that despite women having lower episodes of CVD than men, the female mortality rate is still higher. In addition, female prognosis is also worse than men after they have an acute cardiovascular event or occurrence.

Although CVD seemingly affects genders differently, there is a pressing need to figure out whether doctors need to provide different advice that they give to their female and male patients when it comes to prevention.

Researchers from the University of California, Los Angeles conducted a new study, which was published in the Journal of the American Heart Association. The outcome showed that the focus on women should actually be more on maintaining or increasing their muscle mass and not on losing body fat.


Analyzing Body Composition

The research team scrutinized body composition data from the National Health and Nutrition Examination Survey(NHANES) 1999-2004, as well as the CVD mortality data from NHANES 1999-2014.

They took the data from 5,627 females and 5,836 males all aged 20 years and over. After which, they divided them into four separate groups as follows:

  • Low muscle mass and low body fat
  • Low muscle mass and high body fat
  • High muscle mass and low body fat
  • High muscle mass and high body fat

What the raw data showed in both the males and females was that those with higher fat levels were also associated with higher CVD mortality, no matter what the participants’ muscle mass were.

But when the research group began to look into other factors that are well known to affect CVD mortality, they began to see exactly how body fat in females actually affects their risk of dying from CVD.

After discovering these new adjustments, they did find that women that had high body fat and high muscle mass also ‘had 42% lower risk of dying from CVD compared with females who had a low muscle mass and low body fat.’

But when it comes to men, those with high muscle mass and high body fat were said to have had ‘a 26% reduced risk of dying from CVD compared with males with low measurements.’ Meanwhile, those with higher muscle mass and lower body fat had a decreased risk by at least 60%.


Should There Be Less Emphasis on Weight Loss?

With the results of their study, the research team believes that it supports the need to change the focus of advice that healthcare professionals give to women. They feel that this shift of advice needs to be towards ‘increasing muscles mass through physical exercise and away from weight loss.’

They explain, “[I]t demonstrates the potential importance of advice to maximize muscle mass in women. This diverges from the current emphasis on weight loss in CVD prevention, and thus methods to practically achieve such body composition alteration need to be further evaluated.”

Notably, the researcher group also feels that it is important to emphasize that the supposed protective effect of fat in women only revealed itself after they adjusted the other known risk factors for CVD.

Such CVD risk factors are as follows:

  • High blood pressure (hypertension)
  • Diabetes and prediabetes
  • Cholesterol levels
  • Hormone replacement therapy (HRT)

Researchers also point out that there is a very complex interplay between female body fat and the above mentioned risk factors. One such example is how excess body weight manages to increase the risk of hypertension and diabetes. But in doing so, it also raises the risk of CVD as well.

However, the research authors also explain how there are a number of positive ways that fat might help provide protection in females. For example, they emphasize how research shares that fat in the buttocks and thighs actually has a ‘protective effect on metabolism that offsets the harm from abdominal fat.’

The research also shows that for women in premenopausal states, their bodies tend to store around 50% of its fat right below the skin of the buttocks and thighs. While in males, their bodies store 98% of their total fat in their upper bodies instead.

Then again, for women during and after their menopause stages, their fat tissue normally accumulates in their abdomen which is then associated with a higher risk of CVD.

The researchers also share that women that are around the same weight and age normally accumulate fat by multiplying the number of fat cells they already have. While for men of the same weight and age, they normally grow larger fat cells. Larger, in this instant, is also considered hypertrophied, where the research team explains that ‘fat cells are associated with negative metabolic consequences.’


Here are the Limitations of the Study

Despite their findings, the researchers also acknowledge what the limitations of their study are, as explained below.

Primarily, the study design does not let them prove actual cause-and-effect relationships between the fat mass or the muscle mass and CVD mortality, but rather just associations.

Aside from that, they also share that due to the technique they used to measure the volunteers’ body composition – known as dual energy X-ray absorptiometry or DXA, is known to overestimate muscle mass in both older individuals as those that live more sedentary or non-active lives.