In the news: Food & Mood Findings; New Research on Glucosamine, Chondroitin

Diet ‘Tune Up’ May Help Fight Depression

Extensive evidence from observational studies suggests that the quality of our diet could be a protective factor in fending off depression. Diets higher in plant foods (veggies, fruits, beans, nuts and whole grains) and lean proteins (i.e. fish) are linked to a lower risk for depression. Diets with more fast, processed and sugary foods increase the risk for depression.

Those findings led University of Melbourne researchers to conduct a randomized controlled trial, the “SMILES” trial (1), to test whether a modified Mediterranean diet could make a difference for those with major depression and already being treated with antidepressant drugs and/or psychotherapy. For 12 weeks, 67 participants received either social support (known to be helpful in depression) or nutritional support to improve the quality of their diet.

At the trial’s end, the dietary group had a greater reduction in depressive symptoms than the social support group. The dietary group also had a better rate of remission: 33% vs. 8% for the social support group.

This is the first controlled trial to ask: If I improve my diet, will my mental health improve? Larger trials are needed, but the findings are promising.

Glucosamine/Chondroitin: Cancer Risk Link?

Recent evidence from population health studies links the use of glucosamine and chondroitin supplements with reduced risk of both colorectal and lung cancers.

In the newest study (2), a research team from Harvard, the National Cancer Institute, and the Memorial Sloan Kettering Cancer Center explored the association between use of these supplements and the risk of colorectal cancer. The research was done over a 10-year period in participants of two large prospective studies: the Nurses' Health Study and the Health Professionals Follow-up Study.

The use of glucosamine and chondroitin was associated with a 25% reduction in risk of colorectal cancer. The lower risk was similar in both groups of participants after accounting for risk factors such

Similar findings were observed for participants in another trial (the VITAL trial) who used glucosamine and chondroitin 4 or more days a week, though the supplement takers were more likely to exercise regularly, and to eat less red meat and more veggies – factors also linked to lower risk.

In an earlier 2011 study (3), researchers at the Fred Hutchinson Cancer Research Center looking at participants in the VITAL trial, observed that use of glucosamine (though not chondroitin) at least 4 times weekly for 10 years was associated with a 23% reduction in the risk of lung cancer overall and a 51% risk reduction for adenocarcinoma of the lung – the most common type of lung cancer in the US. This association remained the same when aspirin use and smoking were taken into account.

These nutrients may well influence inflammation, as they have been shown to reduce markers of inflammation in healthy, overweight people (4). Inflammation plays an important role in lung carcinogenesis, and is also involved in colorectal cancer development. It’s also very important to point out that the studies to date are observational only, and that these observations must be validated in intervention trials.

So, for now, glucosamine alone or combined with chondroitin may provide useful support for our joints. When it comes to joint health, it’s worth noting that the supporting evidence for glucosamine alone is stronger than that for chondroitin alone.

References

1. Jacka F, et al. A randomised controlled trial of dietary improvement for adults with major depression (the ‘SMILES’ trial). BMC 15: 23, 2017.
2. Kantor ED, et al. Use of glucosamine and chondroitin supplements in relation to risk of colorectal cancer: Results from the Nurses' Health Study and Health Professionals follow-up study. Int J Cancer. 139:1949-57, 2016.
3. Brasky TM, et al. Use of glucosamine and chondroitin and lung cancer risk in the VITamins And Lifestyle (VITAL) cohort. Cancer Causes Control. 22:1333-42, 2011.
4. Navarro SL, et al. Randomized trial of glucosamine and chondroitin supplementation on inflammation and oxidative stress biomarkers and plasma proteomics profiles in healthy humans. PLoS One. 10(2), 2015.