It’s no secret that poor dietary intake is linked with heart health issues and a contributor to other cardiovascular disease (CVD) risk factors, such as obesity, diabetes, hypertension, and dyslipidaemia.
In a recent study published in the British Medical Journal by researchers at Monash University, it has been found that specifically in middle-aged women, increasing the percentage of carbohydrates was significantly associated with reduced odds of CVD, hypertension, diabetes, and obesity.
In fact, they found that moderate carbohydrate intake between, 41-44.3% of total energy intake was associated with the lowest risk of CVD compared to women who consumed less than 37% energy as carbohydrates.
Looking at fat intake, researchers found that increasing proportional saturated fat intake was not associated with CVD or mortality in women. Interestingly, they found instead that increasing saturated fat intake was correlated with lower odds of developing diabetes, hypertension, and obesity.
Reportedly, the results contradict much of the historical epidemiological research that supported a link between saturated fat and CVD.
Instead, the results mirror contemporary meta-analysis of prospective cohort studies where saturated fat was found to have no significant relationship with total mortality or CVD.
While the cause of this inconsistency in the literature is unclear, it has been suggested that historical studies neglected to adjust for fibre, which is known to help prevent plaque from forming in the arteries.
“Controversy still exists surrounding the best diet to prevent CVD,” says Associate Professor Sarah Zaman, a former Monash University professor who is now an associate professor at the University of Sydney.
“A low-fat diet has historically been the mainstay of primary prevention guidelines, but the major issue within our dietary guidelines is that many dietary trials have predominately involved male participants or lacked sex-specific analyses.”
She adds: “Further research is needed to tailor our dietary guidelines according to sex.”
The study’s first author Dr Sarah Gribbin, a Doctor of Medicine and BMedSc (Hons) student, says: “As an observational study, our findings only show association and not causation.
“Our research is purely hypothesis-generating. We are hoping that our findings will spark future research into sex-specific dietary research.”
The Heart Foundation, which is one of the study’s funders, welcomes the focus on women and CVD, which has historically been under-researched.
Heart Foundation Manager, Food and Nutrition, Eithne Cahill, cautions that “not all carbohydrates are created equal”.
“We know that quality carbohydrate foods such as vegetables and whole grains – including whole grain bread, cereals, and pasta – are beneficial for heart health, whereas poor quality carbohydrates such as white bread, biscuits, cakes, and pastries can increase risk,” says Ms Cahill.
“Similarly, different fats have different effects on heart health. That is why the Heart Foundation focuses on healthy eating patterns – that is, a combination of foods, chosen regularly over time – rather than a single nutrient or food.
“Include plenty of vegetables, fruit, and whole grains, and heart-healthy fat choices such as nuts, seeds, avocados, olives and their oils for cooking and a variety of healthy proteins especially seafood, beans and lentils, eggs and dairy.”
To read the full paper titled, ‘Association of carbohydrate and saturated fat intake with cardiovascular disease and mortality in Australian women’, visit: https://heart.bmj.com/content/early/2021/09/11/heartjnl-2021-319654
