Findings from a longitudinal nutrition study led by Dr. Guillaume Ruel showed that a diet consisting of more fruits, vegetables, and whole grains (excluding rice and wheat) was associated with a lower risk of developing a multimorbidity (two or more diseases in one person).
The study encompassed 1,020 participants of Chinese descent and each individual had to keep a 3-day log of the foods they ate from the start of the trial. Researchers then went through these logs to see what macro and micronutrients were being consumed and also looked to see if participants developed any chronic diseases or if their condition at the start of the study improved, remained stable or worsened. Status for the development of 11 chronic diseases was determined via "biomedical measures" or "self-reports."
The results from the study were adjusted for several factors such as the participants' age, sex, BMI, income, smoking status, etc.
The main finding from the study demonstrated that individuals that were classified as "healthy" were consuming much more fruits, vegetables, and grains when compared to participants with multiple chronic diseases. The intake of grain products for these healthier individuals was "highly correlated with dietary fibers (r = 0.77, p < 0.0001), iron (r = 0.46, p < 0.0001), magnesium (r = 0.49, p < 0.0001) and phosphorus (r = 0.57, p < 0.0001) intake" as well.
Ruel G, et al., Association between nutrition and the evolution of multimorbidity: The importance of fruits and vegetables and whole grain products, Clinical Nutrition (2013), http://dx.doi.org/10.1016/j.clnu.2013.07.009