Following a specialized plant-based diet aimed at lowering cholesterol levels — known as the Portfolio diet — is linked to a lower risk of developing type 2 diabetes in women, according to a recent study published in the journal Diabetes Care.
The Portfolio diet is an eating pattern that emphasizes certain healthy plant-based foods, with the goal of improving blood cholesterol levels — a risk factor for atherosclerosis (fatty deposits on the inside walls of the arteries) and related forms of heart disease, such as coronary artery disease (CAD). The Portfolio diet is based on eating fruits, vegetables, beans and other legumes, nuts and seeds, and other healthy sources of fat, with an added emphasis on plant sterols and soy protein (getting protein from foods like tofu and tempeh). Plant sterols are substances found in plant-based foods that are related to cholesterol but look different at the molecular level. But because plant sterols resemble cholesterol, they compete with cholesterol for absorption in your digestive system. When less cholesterol is reabsorbed by your digestive system (cholesterol is a key component of bile, which works to break down fat in your diet), that cholesterol is instead excreted as waste — resulting in lower blood cholesterol levels. Previous research has found that following the Portfolio diet is linked to a reduced risk for cardiovascular disease in older women.
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For the latest study, researchers were interested in whether the Portfolio diet could be linked to a lower risk for type 2 diabetes in a group of 145,299 postmenopausal women who took part in a general health study called the Women’s Health Initiative. None of the participants had diabetes at the beginning of the study, which lasted from 1993 to 2021, with an average follow-up period of 16.0 years. During this period, 13,943 new cases of type 2 diabetes were identified (meaning that 9.6% of participants developed diabetes).
The researchers assessed how closely all participants’ eating patterns fit the recommendations of the Portfolio diet — participants were not asked to follow any sort of eating pattern as part of the study. This measuring of adherence to the Portfolio diet was based on six different elements that the researchers scored — a high intake of plant protein, nuts, viscous fiber (a type of soluble fiber found in certain foods), plant sterols, and monounsaturated fat, and a low intake of saturated fat and cholesterol. The researchers then compared participants’ scores — for each dietary category, as well as overall — with whether they developed type 2 diabetes.
Adherence to the Portfolio diet linked to lower type 2 diabetes risk
Based on their overall Portfolio diet score, the top fifth of participants was found to be 23% less likely to develop type 2 diabetes. This was similar to what was seen among participants who most closely followed the Mediterranean diet (22% lower diabetes risk) and slightly less of a risk reduction than was seen for participants who most closely followed the DASH diet (31% lower diabetes risk).
When it came to individual elements of the Portfolio diet, a few categories stood out when it came to the risk of developing diabetes, as noted in a Healio article on the study. Participants with the highest intake of viscous fiber were 7% less likely to develop diabetes, while those with the highest intake of plant sterols were 15% less likely to develop diabetes. Those with the lowest intake of saturated fat and cholesterol were 17% less likely to develop diabetes.
These findings, the researchers noted, indicate that following the Portfolio diet may be beneficial in preventing type 2 diabetes — and that even following just some elements of the diet may reduce your diabetes risk. Of course, the Mediterranean and DASH diets were also found to be beneficial, so there isn’t any single diet recommended to help prevent type 2 diabetes — instead, there are many potentially beneficial options that people can choose based on their health goals and preferences.
Want to learn more about plant-based eating? Read “Vegetarian and Vegan Type 1 Diabetes”, “Myths About the Vegetarian Diet,” and “Four Plant-Based Proteins to Try Now.”
