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Epidemiological studies have repeatedly found that whole-grain (WG) cereal foods reduce the risk of several lifestyle-related diseases, though consistent clinical outcomes and mechanisms are elusive. To compare the effects of a WG-rich diet with a matched refined-grain (RG) diet on plasma biomarkers and bowel health parameters, seventeen healthy subjects (eleven females and six males) completed an exploratory cross-over study with a 2-week intervention diet based on either WG- or RG-based foods, separated by a washout of at least 5 weeks. Both diets were the same except for the use of WG (150g/d) or RG foods. Subjects undertook a 4h postprandial challenge on day 8 of each intervention diet. After 2 weeks, the WG diet tended to decrease plasma total and LDL-cholesterol (both P=0·09), but did not change plasma HDL-cholesterol, fasting glucose, C-reactive protein or homocysteine compared with the RG diet. Plasma betaine and alkylresorcinol concentrations were elevated after 1 week of the WG diet (P=0·01 and P<0·0001, respectively). Clostridium leptum populations in faeces were increased after the WG diet, along with a trend for decreased faecal water pH (P=0·096) and increased stool frequency (P<0·0001) compared with the RG diet. A short controlled intervention trial with a variety of commercially available WG-based products tended to improve biomarkers of CVD compared with a RG diet. Changes in faecal microbiota related to increased fibre fermentation and increased plasma betaine concentrations point to both fibre and phytochemical components of WG being important in mediating any potential health effects

Estimation of whole-grain (WG) food intake in epidemiological and nutritional studies is normally based on general diet FFQ, which are not designed to specifically capture WG intake. To estimate WG cereal intake, we developed a forty-three-item FFQ focused on cereal product intake over the past month. We validated this questionnaire against a 3-d-weighed food record (3DWFR) in thirty-one subjects living in the French-speaking part of Switzerland (nineteen female and twelve male). Subjects completed the FFQ on day 1 (FFQ1), the 3DWFR between days 2 and 13 and the FFQ again on day 14 (FFQ2). The subjects provided a fasting blood sample within 1 week of FFQ2. Total cereal intake, total WG intake, intake of individual cereals, intake of different groups of cereal products and alkylresorcinol (AR) intake were calculated from both FFQ and the 3DWFR. Plasma AR, possible biomarkers for WG wheat and rye intake were also analysed. The total WG intake for the 3DWFR, FFQ1, FFQ2 was 26 (sd 22), 28 (sd 25) and 21 (sd 16)g/d, respectively. Mean plasma AR concentration was 55·8 (sd 26·8)nmol/l. FFQ1, FFQ2 and plasma AR were correlated with the 3DWFR (r 0·72, 0·81 and 0·57, respectively). Adjustment for age, sex, BMI and total energy intake did not affect the results. This FFQ appears to give a rapid and adequate estimate of WG cereal intake in free-living subjects

Estimation of whole-grain (WG) food intake in epidemiological and nutritional studies is normally based on general diet FFQ, which are not designed to specifically capture WG intake. To estimate WG cereal intake, we developed a forty-three-item FFQ focused on cereal product intake over the past month. We validated this questionnaire against a 3-d-weighed food record (3DWFR) in thirty-one subjects living in the French-speaking part of Switzerland (nineteen female and twelve male). Subjects completed the FFQ on day 1 (FFQ1), the 3DWFR between days 2 and 13 and the FFQ again on day 14 (FFQ2). The subjects provided a fasting blood sample within 1 week of FFQ2. Total cereal intake, total WG intake, intake of individual cereals, intake of different groups of cereal products and alkylresorcinol (AR) intake were calculated from both FFQ and the 3DWFR. Plasma AR, possible biomarkers for WG wheat and rye intake were also analysed. The total WG intake for the 3DWFR, FFQ1, FFQ2 was 26 (sd 22), 28 (sd 25) and 21 (sd 16)g/d, respectively. Mean plasma AR concentration was 55·8 (sd 26·8)nmol/l. FFQ1, FFQ2 and plasma AR were correlated with the 3DWFR (r 0·72, 0·81 and 0·57, respectively). Adjustment for age, sex, BMI and total energy intake did not affect the results. This FFQ appears to give a rapid and adequate estimate of WG cereal intake in free-living subjects

Epidemiological studies have repeatedly found that whole-grain (WG) cereal foods reduce the risk of several lifestyle-related diseases, though consistent clinical outcomes and mechanisms are elusive. To compare the effects of a WG-rich diet with a matched refined-grain (RG) diet on plasma biomarkers and bowel health parameters, seventeen healthy subjects (eleven females and six males) completed an exploratory cross-over study with a 2-week intervention diet based on either WG- or RG-based foods, separated by a washout of at least 5 weeks. Both diets were the same except for the use of WG (150g/d) or RG foods. Subjects undertook a 4h postprandial challenge on day 8 of each intervention diet. After 2 weeks, the WG diet tended to decrease plasma total and LDL-cholesterol (both P=0·09), but did not change plasma HDL-cholesterol, fasting glucose, C-reactive protein or homocysteine compared with the RG diet. Plasma betaine and alkylresorcinol concentrations were elevated after 1 week of the WG diet (P=0·01 and P<0·0001, respectively). Clostridium leptum populations in faeces were increased after the WG diet, along with a trend for decreased faecal water pH (P=0·096) and increased stool frequency (P<0·0001) compared with the RG diet. A short controlled intervention trial with a variety of commercially available WG-based products tended to improve biomarkers of CVD compared with a RG diet. Changes in faecal microbiota related to increased fibre fermentation and increased plasma betaine concentrations point to both fibre and phytochemical components of WG being important in mediating any potential health effects