Paleo Diet May Be Bad For Cardiovascular Health

Research published earlier this month in the European Journal of Nutrition questions the health benefits of the Paleolithic diet. The Paleo diet claims to mimic the diet of our ancestors. It’s high in meat, fruits, vegetables, nuts and seeds but avoids dairy, legumes and grains.

Genoni et al. studied a group of about 100 people over a year. Half the group followed a Paleo diet and the rest followed a diet typical of national recommendations. The authors found that there was a significant difference in the gut bacteria between groups, with an increased presence of Hungatella in the paleo group. Hungatella produces trimethylamine-N-oxide (TMAO), a gut-derived metabolite associated with cardiovascular disease. Consequently the levels of TMAO were higher in the Paleo group and this was inversely associated with whole grain intake.

The authors conclude that “although the Paleo diet is promoted for improved gut health, results indicate long-term adherence is associated with different gut microbiota and increased TMAO. A variety of fiber components, including whole grain sources may be required to maintain gut and cardiovascular health.”

Fibre Helps Treat Osteoarthritis By Decreasing Inflammation

It’s well-known that obesity can cause or exacerbate osteoarthritis (OA) through excessive mechanical loading. But another mechanism through which obesity can affect joint health is via inflammation and we now know that our gut microbes play a crucial role.

Recent research by Schott et al. has looked into the link between obesity, gut microbes and OA. They found a difference between the types of gut bacteria in obese mice compared to lean mice. The obese mice had more pro-inflammatory and fewer anti-inflammatory species than lean mice. The imbalance led to accelerated knee OA due to systemic inflammation and macrophage migration to the synovium. Interestingly, they found that oligofructose, a non-digestible prebiotic fibre, can help restore a normal lean gut microbiota in obese mice. The restoration of lean gut microbes was “associated with reduced inflammation in the colon, circulation and knee and protection from OA”.

Obviously one could wonder whether these findings apply to humans. About a year ago Dai et al. published the results of long-term studies on around 6000 people. Their findings consistently showed that higher total fibre intake was related to a lower risk of getting symptoms of knee OA!