Data from hundreds of studies and analyses have been reviewed and pooled together in the most exhaustive review of research into associations between food and beverage groups and the risk of diet-related chronic disease (DRCD) – that ‘confirms previous findings’ but also provides new results.
The findings, published in Nutrition Reviews, pull together more than 300 meta-analysis and systematic reviews of evidence – finding that plant food groups are more protective than animal food groups against DRCDs.
“Within plant food groups, grain products are more protective than fruits and vegetables,” noted the French research team – led by Yves Boirie from INRA de Theix and the Université d'Auvergne.
“Among animal food groups, dairy/milk products have a neutral effect on the risk of DRCDs, while red/processed meats tend to increase the risk.”
However, Boirie and her colleagues noted that all of the data analysed compared those consuming the highest with the lowest amount of any particular food group.
“Thus, the results do not mean that no animal-based food group should be consumed, rather that individuals with the highest level of consumption should restrict their consumption, and conversely, those with the lowest consumption of plant-based food groups should increase their consumption,” they wrote.
In addition to pulling together the evidence linking certain food and beverage categories to disease states, the analysis also emphasises the need for future research by highlighting DRCDs which have been studied very little.
“For example, it is curious that no observational studies have been carried out to investigate the association between risk of sarcopenia and consumption of the main food groups and beverages,” noted the research team.
“Surprisingly, the number of meta-analyses investigating the associations of animal-based food group consumption with weight gain, overweight and/or obesity, and, to a lesser extent, diabetes, is quite low,” they added.
Better recommendations?
The team also said the results substantiate certain nutritional recommendations that are "sometimes based on assumptions" about the foods that should be included in a balanced diet or on characteristics of “healthy” foods.
“One typical example is that of milk: the results from the present analysis showed that regular and/or high consumption of milk has a rather neutral effect, i.e., it is not associated with major DRCD risks,” said the team.
“In other words, scientifically speaking, drinking milk should not be discouraged, contrary to what might be read or heard within various media today.”
Indeed, the team also suggested that grain products should probably be emphasised over fruits and vegetables, rather than the reverse.
“Grain products show promise as foods with a potential to reduce DRCD risk, most likely even more so than fruits and vegetables,” said Boirie and colleagues. “Even more compelling, grain products are a superior source of energy (based on starch content, especially whole-grain cereals), proteins (especially leguminous seeds), and lipids (especially nuts and oleaginous seeds) and are less expensive and easier to store than fruits and vegetables.”
In addition, they suggested that the margin for increasing grain consumption in Western countries is high - particularly with regard to legumes, nuts, and seeds, which remain niche products today.
“This exhaustive and holistic review also confirms that consumption of tea and unrefined plant-based food groups should continue to be highly recommended,” concluded the team.
“In contrast, the consumption of refined cereal products, red/processed meat, eggs, very hot tea (but not tea in general), sweetened beverages, pickled vegetables, and fermented soy foods clearly should be limited, while consumption of poultry and milk and dairy products appears to have a rather neutral effect on DRCD risk.”
Source: Nutrition Reviews
Published online ahead of print, doi: 10.1111/nure.12153
“Associations between food and beverage groups and major diet-related chronic diseases: an exhaustive review of pooled/meta-analyses and systematic reviews”
Authors: Anthony Fardet and Yves Boirie