In a recent study published in Nutrients, researchers assessed the association between diet and health outcomes among United Kingdom Biobank (UKBB) participants.
Study: Associations of Diet with Health Outcomes in the UK Biobank: A Systematic Review. Image Credit: Yulia Furman/Shutterstock/com
Background
Diet is crucial in preventing and controlling chronic diseases, with dietary patterns associated with cardiovascular diseases and cancer. Understanding the association between nutrition and disease necessitates a comprehensive approach considering environmental, genetic, psychological, and behavioral aspects.
Large epidemiological studies, like the UKBB, which leverage big data, can provide valuable insights into the association between diet and disease. However, qualitative and quantitative reviews of previous research are required to acquire a comprehensive overview of the progress made with these data.
About the study
In the present systematic review, researchers evaluated the impact of diet on health outcomes among UK Biobank participants aged between 40 and 69 years, focusing on the relationship between diet and non-communicable disease (NCD) incidence.
The team searched the Web of Science and PubMed databases for relevant studies published from 2018 to 2022.
Eligible studies evaluated the diet of UKBB participants using 24-hour Oxford WebQ dietary recalls, food frequency questionnaires (FFQs), and food preference questionnaires (FPQs).
The studies assessed individual food components, dietary patterns, a priori-determined diets and health indices, and specific nutrients as estimation variables and the relationship between food and non-communicable diseases, with known risk factors as environmental variables (e.g., diabetes, cancer, hypertension, and cardiovascular disease).
The team excluded studies focusing on dietary intake for deficiencies, exploring dietary influence on cognitive function-related NCDs (such as Alzheimer’s disease and dementia), or individual studies examining a particular disease.
They used the Newcastle-Ottawa scale (NOS) to assess study quality. The effect estimate summary was gathered from multiple studies using hazard ratio (HR) values of models maximally adjusted for identical dietary exposures.
The team used risk estimates to compare the most and least adherence categories for healthy diets, focusing on healthy patterns and comparing their risk estimates to unhealthy ones.
For studies recording varying food proportions, they obtained risk estimates from the most to the least intake and converted odds ratios (OR) as HR values.
They used bubble plots to visually depict effect distribution, while descriptive statistics and box-and-whisker plots assessed effect distribution by disease types.
Results
Initially, the team identified 346 records, of which they considered only 36 for the systematic review, including 11 studies on cardiovascular diseases (CVDs), eight on T2DM, ten on cancer, and seven on other non-communicable diseases.
The number of participants in the included studies ranged between 5,000 and 400,000. Almost all (except one of medium quality) studies were high quality.
Most studies focused on specific macronutrients or food categories, with only a handful examining dietary patterns. Several studies found that eating more processed and red meat increases the chance of developing colorectal and lung cancer.
Fish-eating and vegetarian diets can reduce cancer incidence. A well-balanced diet with high diet quality scores could lower diabetes risk. A study reported that eating dried fruit reduced the risk of breast and lung cancer.
The study findings indicated that higher adherence to healthy diets (eating a variety of foods with a minimum of three servings of whole grains, vegetables, and fruits per day and limiting processed meat intake to once a week) modestly lowers the incidence of cardiovascular disease, T2DM, and colorectal cancer.
Healthy diets include a higher intake of plant-based foods and a lower intake of processed meats, refined grains, sugar-sweetened beverages, and foods rich in saturated fat, added sugars, and sodium.
Studies found a favorable relationship between processed foods and CVD incidence but not death. Consuming raw vegetables reduces the risk of CVD, whereas cooked vegetables do not. High fiber, sugar, and saturated fat consumption may impact their effects.
However, genetics may be more significant than nutrition in avoiding colorectal cancer. A healthy diet, red meat consumption, and processed meat consumption all produced consistent findings for CVD, T2DM, and some cancer types. A healthy diet had median HRs of 0.9 for colorectal cancer, 0.8 for CVD, and 0.9 for T2DM.
Conclusion
Overall, the study findings showed that a healthy eating pattern considerably lowers the risk of cardiovascular disease, colon cancer, and type 2 diabetes.
The UK Biobank cohort data confirms these findings, with high consumption of whole grains, fruits, vegetables, and meat marginally decreasing the incidence of type 2 diabetes, cardiovascular disease, and colorectal cancer.
Future research should use multi-omics data and machine learning algorithms to account for the intricate interactions between dietary components and their impact on disease risk.
Focusing on healthy dietary patterns that include a range of foods can strengthen correlations with CVD and T2DM.
Healthy low-carb diet and time-restricted eating improve weight loss and gut health beyond calorie restriction