In the news: Two Small Diet Changes Pack Potentially Big Health Impacts

Beans & Tomatoes For a Healthy New Year

Two recently published studies suggest that making a few simple dietary changes can support health in meaningful ways. One study looks at the impact of beans on the intestinal tract, while the other reports that tomatoes may favorably influence blood pressure.

Beans Benefit the Gut in Multiple Ways

Beans, lentils and chickpeas are good sources of prebiotics, which are undigestible carbohydrates that serve as food to fuel and grow healthy bacteria.

Investigators studied participants in the BE GONE trial to see what effects beans might have on gut and metabolic health in high risk, overweight patients – in this case patients with a history of colorectal cancer or polyps. The BE GONE trial stands for ‘Beans to Enrich the Gut microbiome vs. Obesity’s Negative Effects’, and was conducted by the MD Anderson Cancer Center(1).

After a run in period where participants followed their usual diet, they were then randomly assigned to stay on their usual diet without beans or to continue their normal diet while adding 1 cup of canned organic navy beans daily for a month. At end of 4 weeks the groups crossed over to the other intervention.

The addition of the beans led to increased counts of friendly bacteria, mostly Bifidobacterium, as well as increased levels of the beneficial metabolites they produce.

Importantly, favorable changes in immune and inflammatory markers were also seen during the bean consumption period – biomarkers associatied with metabolic obesity and colorectal cancer.

Notably, the effect of returning to the usual diet without beans was quite stricking according to the study authors. The favorable changes in bacteria and metabolites was reversed within 4 weeks.

Including beans to the diet as frequently as possible appears to be a simple and straightforward way to promote gastrointestinal tract health.

Tomatoes: A Healthy Blood Pressure Food

The PREDIMED trial is a large study(2) designed to assess the effects of the Mediterranean diet on the prevention of cardiovascular disease.

Researchers recently anlyzed information from over 7,000 PREDIMED participants to investigate the potential effects of tomato intake on blood pressure. Tomatoes are a good source of potassium, vitamin C and especially the antioxidant lycopene.

Participants were grouped into four categories representing highest, upper intermediate, intermediate and lowest tomato intakes. The groups were then followed for a 3-year period.

Comparing highest to lowest intake groups at the end of the study period showed that those who eat the most tomatoes were 36% less likely to experience hypertension.

The lowest intake was less than 44 grams of tomato daily or about 1 ½ ounces, while the highest intake was at least 110 g (approx.. 4 oz).

The study authors suggest aiming for a large sized tomato daily, and recommend consuming tomato products as well. They also speculate that lycopene may be driving the study results through it’s ability to quench free radicals as well as to inhibit an enzyme (ACE) that has a direct effect on blood pressure.

Along with physical activity, eating well, and maintaining a healthy weight, tomatoes may be one additional way to help tame high blood pressure – important because hypertension is a big contributor to stroke, heart attack and renal disease.

References

1. Zhang X, et al. Modulating a prebiotic food source influences inflammation and immune-regulating gut microbes and metabolites: insights from the BE GONE trial. eBioMedicine Vol. 99, Dec. 2023.
2. Mercia Les-Mes, et al. Association between tomato consumption and blood pressure in an older population at high cardiovascular risk: observational analysis of PREDIMED trial. Eur J Prev Cardiol. Nov. 2023.