A higher consumption of fruits, vegetables and whole foods are associated with a lower risk of developing type 2 diabetes, according to two studies published by the journal ‘The BMJ’ that suggest that even a modest increase in the consumption of these foods as part of a healthy diet could help prevent type 2 diabetes.
At first study, a team of European researchers examined the association between blood levels of vitamin C and carotenoids (pigments found in fruits and vegetables colorful) at risk of developing type 2 diabetes.
Vitamin C and carotenoid levels are more reliable indicators of fruit and vegetable intake than the use of dietary questionnaires.
Their findings are based on 9,754 adults who developed type 2 diabetes new-onset and a comparison group of 13,662 adults who remained diabetes-free during follow-up out of 340,234 participants who participated in the European Prospective Investigation into Cancer and Nutrition (EPIC) -InterAct Study in eight European countries.
Lower risk of type 2 diabetes
After adjusting the lifestyle, the social and dietary risk factors For diabetes, higher blood levels of each of vitamin C and carotenoids and their sum when combined into a “composite biomarker score” were associated with a lower risk of developing type 2 diabetes.
Compared with people who had the lowest composite biomarker scores, the risk in people whose biomarker scores were in the top 20% of the population was 50% lower. The risk in those with biomarker scores between these two extremes was intermediate.
Researchers estimate that every 66 grams per day increase in total intake of fruits and vegetables partnered with a 25% lower risk of developing type 2 diabetes.
In the second study, researchers from the United States examined the associations between total and individual intake of whole foods and type 2 diabetes.
Their findings are based on 158,259 women and 36,525 men free from diabetes, heart disease, and cancer who participated in the Nurses ‘Health Study, the Nurses’ Health Study II, and the Health Professionals Follow-up Study.
After adjusting the lifestyle and dietary risk factors for diabetes, participants in the highest category for total whole grain consumption had a 29% lower rate of type 2 diabetes compared to those in the lowest category.
For individual whole foods, the researchers found that consuming one or more servings a day of whole grains for cold breakfast or dark bread was associated with a lower risk of type 2 diabetes (19% and 21% respectively) compared to consuming less of one serving a month.
For other individual whole grains with lower average intake levels, consuming two or more servings per week compared to less than one serving per month was associated with a 21% lower risk of oats, a 15% lower risk of bran added and 12% lower risk of brown rice and wheat germ.
These reductions in risk seemed stabilize at about two servings a day for total whole grain intakes, and about half a serving a day for cold whole grain breakfast cereals and black bread.
These findings further support current recommendations.
Both studies are observational, so the cause cannot be established, and there is a possibility that some of the results may be due to unmeasured (confusing) factors. However, both studies took into account several well-known lifestyle risk factors and markers of diet quality, and the findings support other research linking a healthy diet with better health.
As such, both research teams say their findings provide a increased support for current recommendations of increasing the consumption of fruits, vegetables and whole grains as part of a healthy diet to prevent type 2 diabetes.
And in the case of fruit and vegetables, the findings also suggest that consuming even moderately higher amounts among populations that typically consume low levels could help prevent type 2 diabetes.