The research was conducted by the University of Queensland, the University of Newcastle, and Monash University as part of the Australian Longitudinal Study on Women’s Health. The results were published in the journal Heart, Lung and Circulation.

CVD Risk In Women

According to the World Health Organization (WHO), cardiovascular disease is the number one cause of death globally and is responsible for approximately 32% of deaths worldwide.

While CVD can affect both men and women, Sarah Zaman, Associate Professor and academic interventional cardiologist at the University of Sydney as well as an author of the study, tells Verywell that “there is a vast amount of evidence recently to show that heart disease can have different risk factors in women versus men, and can manifest differently in women."

However, Zaman also points out that “many of our historical diet studies did not look at the differences between the sexes, or they included a high proportion of male participants.”

Specifically, women with diabetes and women who smoke have a higher relative risk of CVD compared to men.

Women also can have health conditions that increase their risk of CVD—such as menopause, gestational diabetes, and polycystic ovary syndrome (PCOS)—that their male counterparts would not have.

The Study

To evaluate whether dietary choices affect CVD risk in middle-aged women, the participants were grouped according to their carbohydrate and saturated fat intake as a percentage of total energy intake.

The group that got 41.0% to 44.3% of their energy from carbohydrates was classified as consuming the most carbs. The group with the lowest intake got 37.1% or less of their energy from carbs.

After following the participants for 15 years, the researchers recorded a total of 1199 cases of CVD and 470 deaths. They looked at whether carb intake was linked to CVD and deaths.

The study’s findings showed that:

Higher carbohydrate intake was linked to lower CVD risk. No significant relationship was noted when evaluating different amounts of carbohydrate intake and early death risk. Saturated fat intake did not play a role in CVD risk. However, higher intakes of saturated fat and carbohydrates were both linked to a decreased risk of hypertension, diabetes, and obesity.  

Limitations

One important note about the study is that the type of carbohydrate was not categorized, which means that ultra-refined carb sources were classified the same way as more nutrient-dense carbohydrate sources, like whole grains and fruit.

Zaman says that the finding “goes against a lot of historical data showing a detriment to saturated fat intake” and that it’s “consistent with large trials in women, such as the Women’s Health Initiative, showing a lack of benefit to a low-fat diet.”

“Whilst many people may associate carbs with bread, in fact, a lot of our carbohydrates come from fruit and vegetables," says Zaman. “Hence, it is likely that their protective aspect was related to intake of this type of carbohydrate rather than highly processed carbohydrates.”

Zaman believes that “whole and real foods” play a more protective role in a woman’s health than ultra-processed choices. The researchers plan to evaluate how the type of carbohydrate affects heart health in women in future research.

Reducing CVD Risk

Since the new study suggests that a moderate carbohydrate intake has the greatest protective effect against cardiovascular disease, following a very low carbohydrate diet (for example, the ketogenic or “keto” diet) might not be the best choice for middle-aged women who are trying to reduce their risk.

There are also other factors to consider when choosing carb sources. For example, a diet that’s high in added sugars may also contribute to an increased risk of heart disease. Most people will benefit from limiting their intake of carbs that contain a lot of added sugars (like baked goods, packaged snacks, and sweetened cereal and beverages).

Other ways that people can reduce their heart disease risk include:

Quitting smoking Maintaining a healthy weight Getting or staying physically active Hormone replacement therapy (HRT) for some people who are transitioning to menopause