"Fruits and veggies 5 times a day keep DEATH away", Circulation study
Figure: Potential mechanisms and benefits of suggested fruit-vegetable rich diet
The optimal intake levels of fruit and vegetables for maintaining long-term health are uncertain. Citing the importance of daily fruit and vegetable intake, in the latest issue of Circulation, Wang and colleagues have related fruit and vegetable intakes to future total, cardiovascular, respiratory, and cancer mortality outcomes across a near 30 years follow-up of the NHS (Nurses' Health Study) and the HPFS (Health Professionals Follow-Up Study).
They followed 66 719 women from the Nurses' Health Study (1984–2014) and 42 016 men from the Health Professionals Follow-up Study (1986–2014) who were free from cardiovascular disease (CVD), cancer, and diabetes at baseline. Diet was assessed using a validated semiquantitative food frequency questionnaire at baseline and updated every 2 to 4 years. They also conducted a dose-response meta-analysis, including results from our 2 cohorts and 24 other prospective cohort studies.
Major findings from this study were:
1. In adults who ate 5 fruit and vegetable portions per day versus those eating only 2, the relative risk for total, cardiovascular, and cancer mortality in NHS and HFPS cohorts combined was lower by 10% to 13%.
2. Interestingly, respiratory mortality was lower by 35%.
3. There did not appear to be any further lowering of risks beyond 5 portions per day.
4. Not all fruit and vegetables appeared to associate with lower mortality risks, with no clear associations for fruit juice, starchy vegetables, or potatoes.
As the authors highlight, eating fruit and vegetables provides excellent sources of fiber and potassium and a range of micronutrients and bioactive compounds that are necessary for good health (Figure). These findings support current dietary recommendations to increase intakes of fruits and vegetables and that the succinct 5-a-day message is consistent with available evidence.
Beyond their high glycemic load values and reduced nutrient content during production, juices, as fluids, may lead to more rapid and pronounced increases in postprandial blood glucose and insulin than whole fruits and vegetables without significantly enhancing appetite. It should be noted that certain types of juice, such as citrus juice, may have higher levels of antioxidant activity and ability of lowering atherogenic lipids than other juices.
Similarly, higher intake of starchy vegetables like peas and corn may not confer the same health benefits as other fruits and vegetables. Protective effects of fruit and vegetable intake against total cancer risk were uncertain from previous studies, in particular, for hormone-dependent cancers such as breast and prostate cancer. Data from this study support that high intake of fruit, but not vegetables, may confer a protective effect against cancer mortality.
These findings support current dietary recommendations to increase intake of fruits and vegetables, but not fruit juices and potatoes.
Source: Circulation Journal: Wang DD, Li Y, Bhupathiraju SN, Rosner BA, Sun Q, Giovannucci EL, Rimm EB, Manson JAE, Willett WC, Stampfer MJ, et al.. Fruit and vegetable intake and mortality: results from 2 prospective cohort studies of US men and women and a meta-analysis of 26 cohort studies.Circulation2021; 143:1642–1654. doi: 10.1161/CIRCULATIONAHA.120.048996
