Medical Bulletin 23/ May/ 2024

In a study published in the journal Current Developments in Nutrition, researchers investigated the long-term dietary associations of various food items, primarily dairy products, with non-communicable diseases (NCDs) such as all-cause mortality, type 2 diabetes (T2D), and cardiovascular disease (CVD).

Chronic, age-associated non-communicable diseases (NCDs) are the leading cause of death globally, accounting for about 73% of all deaths. Despite medical advances, NCD prevalence is rising, with health behaviours such as sleep patterns, physical activity, and diet playing significant roles.

Diet, particularly, is a key modifiable risk factor. The Global Burden of Disease study identifies suboptimal diets as the primary cause of 22% of global deaths. Debates continue over the benefits of low-fat dairy versus regular dairy, but comprehensive analysis comparing different dairy and food items' contributions to NCD risk has been lacking.

In the study, researchers analyzed over 30 publications from three online scientific repositories to examine changes in NCD risk and general health outcomes when substituting dairy items with other dairy products, plant-based foods, or other animal-derived food products. Data extracted included study-specific, demographic, and medical information. The Risk Of Bias In Non-randomized Studies - of Exposure tool was utilized to assess and account for differential risk between included studies, with statistical models weighted accordingly.

The results showed that the risk of NCDs did not significantly differ between consuming 'healthy' low-fat dairy products and 'unhealthy' high-fat dairy products, indicating that the quantity of consumption is more important than the specific type of dairy. However, substituting butter with olive oil significantly reduced NCD risk, highlighting the benefits of replacing dairy-based foods with plant-based options. Conversely, replacing dairy with red meats or processed animal foods substantially increased NCD risk.

The findings suggested that substituting dairy items with red meats and processed meats was associated with an increase in NCD risk, while replacing the items with whole grains and olive oils was found to improve long-term NCD outcomes.

Reference: Kiesswetter, E., Neuenschwander, M., Stadelmaier, J., Szczerba, E., Hofacker, L., Sedlmaier, K., Kussmann, M., Roeger, C., Hauner, H., Schlesinger, S., & Schwingshackl, L. (2024). Substitution of Dairy Products and Risk of Death and Cardiometabolic Diseases: A Systematic Review and Meta-Analysis of Prospective Studies. In Current Developments in Nutrition (Vol. 8, Issue 5, p. 102159). Elsevier BV, DOI – 10.1016/j.cdnut.2024.102159

A recent study published in Health Data Science, a Science Partner Journal, revealed the significant impact of high cumulative body mass index (BMI) on brain health

The research, led by Associate Professor Han Lv from Beijing Friendship Hospital, Capital Medical University, found that high BMI is associated with smaller brain volume, larger white matter lesions, and abnormal microstructural integrity.

The health burden of overweight and obesity has substantially increased over the last two decades. Characterized by high body mass index (BMI), overweight and obesity are associated with poorer brain health, resulting in accelerated cognitive decline and dementia.

Several cross-sectional studies that acquired BMI and neuroimaging data simultaneously have found that individuals with high BMI had smaller brain volumes and altered white matter (WM) integrity. Several previous studies have analysed the effect of BMI on features of the brain, but the number of neuroimaging features was limited.

In the study, researchers analysed data from a 16-year population-based cohort to investigate the effects of cumulative BMI on neuroimaging features in adults aged 25 to 83 years and discovered that high BMI was linked to smaller brain volume and larger volumes of white matter hyperintensity (WMH), particularly in adults younger than 45 and those older than 60.

The study utilized a generalized linear model to evaluate the association between cumulative BMI and various neuroimaging features, including brain macrostructure, white matter integrity, and brain microstructure.

The results indicated that high BMI is causally linked to smaller grey matter volume and increased fractional anisotropy, a useful measure of connectivity in the brain, in certain brain regions, highlighting the importance of maintaining a healthy BMI throughout adulthood to preserve brain health.

“High cumulative BMI is detrimental to brain health, especially for younger adults under 45 years, where it corresponds to approximately 12 years of brain aging. Maintaining a BMI below 26.2 kg/m² is suggested for better brain health. This research provides crucial insights into the relationship between BMI and brain health, emphasizing the need for public health strategies to control BMI for better neurological outcomes,” concluded Associate Professor Han.

Reference: Han Lv, Na Zeng, Mengyi Li, Jing Sun, Ning Wu, Mingze Xu, Qian Chen, Xinyu Zhao, Shuohua Chen, Wenjuan Liu, et al. Association between Body Mass Index and Brain Health in Adults: A 16-Year Population-Based Cohort and Mendelian Randomization Study. Health Data Sci. 2024;4:0087.DOI:10.34133/hds.0087

According to a study by researchers at the University of Rochester Medical Center and Wilmot Cancer Institute, women with breast cancer who exclusively ate a whole-foods, plant-based diet lost weight, improved cholesterol levels and other key metabolic factors, had less fatigue, and perceived that they felt sharper mentally and generally more well.

The results were published in the journal Breast Cancer Research and Treatment.

While many anti-cancer treatments lead to weight loss, breast cancer treatment often results in weight gain. A 1997 review found that 50% to 96% of women undergoing chemotherapy for early-stage BC gained between five and 13.6 pounds. This weight gain is linked to elevated insulin, insulin resistance, blood glucose, cholesterol, sex hormones, and IGF-1, all of which can worsen BC progression, increase mortality risk, and reduce quality of life.

Dietary therapy can affect both obesity and its related cardiometabolic and hormonal risk factors. A plant-predominant dietary pattern, lower in processed foods, is commonly recommended by many organizations, including the American Institute for Cancer Research and the American Cancer Society.

In the study, 30 patients on stable treatment were randomly divided into two groups. One group received standard care, while the other followed an eight-week diet of fruits, vegetables, whole grains, legumes, potatoes, nuts, and seeds, avoiding animal-based foods, oils, and added fats. Participants also took a daily multivitamin.

Researchers observed that starting with an average BMI of 29.7, the whole-foods plant-based group lost one to two pounds per week without mandated exercise. They also noticed a reduction in blood samples of IGF-1, a growth factor that has been associated with many common cancers, as well as less inflammation.

“Although we cannot say anything yet about whether the diet can stop cancer progression from this small study, we saw preliminary results that suggest favourable changes within the body, which is very positive. Patients should first consult with their oncologists or healthcare providers before making major dietary changes and this is especially important for people who take blood thinners or insulin medications,” said research leader Thomas M. Campbell, an assistant professor of Family Medicine at URMC.

Reference: Campbell, T.M., Campbell, E.K., Culakova, E. et al. A whole-food, plant-based randomized controlled trial in metastatic breast cancer: weight, cardiometabolic, and hormonal outcomes. Breast Cancer Res Treat 205, 257–266 (2024). https://doi.org/10.1007/s10549-024-07266-1