Ingrained health

Plain English summary of protocol

Background and study aims
There is a lot of evidence to suggest that eating more wholegrain foods, for example millet, brown rice and oatmeal, reduces the risk of developing several diseases including cardiovascular disease (e.g. heart disease), type 2 diabetes and some cancers. This had led to a dietary recommendation of eating 48g of whole grains being suggested in the United States and 75g per day being recommended in Denmark. In other European countries, there is no specific dietary recommendation, but it is recognized that whole grains should be an important part of a healthy diet. Although the epidemiological evidence is strong, results from studies that compare different diets (intervention studies) have been more varied. Some studies have shown a whole grain diet as beneficial, others have not. This means that, at the moment, no definite conclusions regarding the protective role of whole grains against disease can be made. In particular, the amount of whole grains that should be eaten in order to get any health benefits is not proven, with estimates ranging from as little as one to more than three servings per day. We have already carried out two large intervention studies looking at including whole grains in the diet. One study, the WHOLEheart study, showed no beneficial effects of eating whole grains, but the amount of whole grain being eaten was not well controlled and the participants ate mixtures of grains (wheat, rice and rye). In our second study, the GrainMark study, the amount of whole grain being eaten was much better controlled and the participants ate only wholegrain wheat or wholegrain rye foods. This time, there was significant improvements in cholesterol levels and blood pressure, but, as the study did not include a control group (a group of participants that did not eat a whole grain diet) we cannot say for sure that these improvements were due to the whole grains. This study is a third whole grain intervention study, building on previous experiences, using a “gold standard” experimental design developed to reduce the variability of the whole grains being eaten, to ensure a substantial increase in the amount of whole grains being eaten compared to the average in the UK and to improve statistical robustness.

Who can participate?
Generally healthy nonsmoking men and women aged between 40-70, with a BMI between 25 and 35 kg/m2, slightly increased blood pressure and slightly increased cholesterol levels.

What does the study involve?
Participants are asked not to eat any wholegrain foods for the four weeks leading up to the start of the study. After this “washout period” they are randomly allocated into one of two groups. Those in group 1 are given a wholegrain bread and breakfast cereal to eat in place of that they normally eat and asked to eat 4 servings per day if a woman and 6 servings a day if a man for 4 weeks. One serving is equal to one slice of bread or half a bowl of cereal. Those participants in group 2 are given similar instructions but are given bread and breakfast cereal made from refined wheat. After the 4 weeks, all participants are asked to not eat wholegrain foods for a further 4 weeks before swapping diets. This means that those in group 1 now eat the refined bread and cereal and group 2 the wholegrain foods for the last 4 weeks of the study. Urine and blood samples from each participant are taken at 4-weekly intervals throughout the trial. On the evening before samples are collected, each participant is asked to eat a supplied standard meal and then fast from 9pm. Height, weight, waist, hip, body fat and blood pressure measurements are also taken throughout the trial and the participant asked to fill in questionnaires.

What are the possible benefits and risks of participating?
If any abnormalities of significance are discovered while measuring their cholesterol, blood pressure or blood glucose levels, the participant and their GP are told so that appropriate steps can be made. Taking blood samples can cause minor discomfort and bruising. If a new diagnosis of high blood pressure is made, however, this could affect a person’'s future life or private medical insurance.

Where is the study run from?
The Clinical Research Facility, Royal Victoria Infirmary (Newcastle)

When is the study starting and how long is it expected to run for?
June 2014 to June 2015

Who is funding the study?
Cereal Partners Worldwide (Switzerland)

Who is the main contact?
Prof. Chris Seal
chris.seal@ncl.ac.uk

Study website

Contact information

Study information

Eligibility

Locations

Countries of recruitment

• England
• United Kingdom

Study participating centre

Sponsor information

Funders

Funder type

Industry

Results and Publications

Study outputs

Editorial Notes

13/08/2020: No publications found.
11/08/2017: No publications found, verifying study status with principal investigator.