Eating whole grains is linked to health benefits in older adults, including a smaller waist size, lower blood pressure, and lower blood glucose levels, according to a new study published in The Journal of Nutrition.
The study’s authors noted that prior studies have found a link between higher whole-grain consumption and a lower risk for cardiovascular disease. Not many studies, though, have looked at what effect eating whole grains has on intermediate factors that can affect a person’s cardiovascular disease risk, such as waist size or blood pressure. So for this study, the goal was to look at how eating more whole grains might affect risk factors for cardiovascular disease.
Higher whole grain intake linked to reduced cardiovascular risk factors
The study’s subjects were participants in a large general health study called the Framingham Offspring Study, and included 3,121 people with an average age of 54.9 at the beginning of the study. Data related to health and lifestyle were collected every four years over a median follow-up period 18 years. Over this time period, a higher intake of whole grains was linked to a smaller increase in waist circumference every four years — an average increase of 1.4 centimeters (0.6 inches) in participants with the highest whole-grain intake, compared with 3.0 centimeters (1.2 inches) in those with the lowest whole-grain intake.
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Fasting blood glucose levels also went up less every four years in participants with the highest whole-grain consumption, rising by an average of 0.7 mg/dl compared with 2.6 mg/dl in participants with the lowest whole-grain intake. Systolic blood pressure — the “top number” measured during heartbeats — rose by an average of only 0.2 mm Hg in the group with the highest whole-grain intake, compared with 1.4 mm Hg in the group with the lowest whole-grain intake.
When results were broken down by the sex of participants, the researchers found that whole-grain consumption had a larger effect on waist size in women than in men. And while greater whole-grain consumption was also linked to lower levels of triglycerides and higher levels of HDL (high-density lipoprotein, or “good”) cholesterol in participants’ blood, these differences disappeared when the researchers adjusted for waist size — demonstrating that the effect of whole-grain consumption on waist size could explain these other changes in lab test values.
The researchers also found that the beneficial effects of consuming whole grains weren’t seen with refined grains. In fact, participants who consumed the largest amount of refined grains had a greater increase in waist circumference than those who consumed the smallest amount — an average increase of 2.7 centimeters (1.1 inches) every four years, compared with 1.8 centimeters (0.7 inches).
The researchers concluded that for middle-aged to older adults, replacing refined grains with whole grains in the diet may be an effective strategy to limit increases in waist size, blood pressure, and fasting blood glucose over time — and, ultimately, reduce the risk of developing cardiovascular disease.
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