Vitamin D and Alzheimer’s Disease

Unfortunately there is currently an absence of curative and preventative interventions for Alzheimer’s Disease (AD). Last year, Panza et al. reviewed the research on the links between vitamin D and AD. Low vitamin D levels have been associated with an accelerated decline in cognitive functions. They have also been associated with the development of chronic brain conditions such as AD and other dementias. As such, vitamin D is often thought of as a neurosteroid due to its effect on brain conditions. The authors believe more research is required to determine the effect of vitamin D supplementation on the prevention and/or treatment of AD.

Eating For Health And Longevity

Valter Longo et al. recently published a paper that examined research on the relationships between nutrition, health and longevity. Here are some of the main components of a longevity diet:

  • mid to high carbohydrate intake (45-60%) – mostly non-refined
  • fat intake (25-35%) – mostly plant-based
  • low protein intake (10-15%) – mostly plant-based but includes regular consumption of peso-vegetarian-derived proteins. Low protein intake or normal protein intake (with high legume consumption) lowers the intake of amino acids such as methionine. This in turn lowers pro-aging substances such as GHR, IGF-1, insulin and TOR-S6K.
  • over 65s need to be careful to avoid malnourishment and prevent frailty and diseases resulting from reduced muscle mass, reduced bone mass or low blood cell count.
  • the largest gains in longevity come from diets rich in legumes, whole grains and nuts. With reduced amounts of red meat and processed meats
  • a 12-13hr daily fasting period is key to reducing the insulin resistance that may have developed from a high calorie diet. The fasting window also helps decrease levels of IGF-1, lowers blood pressure, lowers total cholesterol and decreases inflammation.
  • our daily food intake should be established by our body fat/lean body mass composition rather than generic pre-set calorie amounts.

Sweeteners Increase Cancer Risk

The use of artificial sweeteners by the food industry has become ubiquitous. They reduce the sugar content whilst still retaining the sweet pleasant taste. However, the safety of artificial sweeteners has been questioned, particularly regarding carcinogenicity.

Last month, Charlotte Debras et al. published the results of a study looking into the link between the consumption of sweeteners and cancer incidence. They followed a group of over 100,000 French adults for about 8 years.

The researchers found that “artificial sweeteners (especially aspartame and acesulfame-K) were associated with increased overall cancer risk (13%) for higher consumers compared to non-consumers. More specifically, aspartame was associated with increased breast (22%) and obesity-related (15%) cancer risks“.

We can conclude that reducing or eliminating our consumption of artificial sweeteners can play a significant role in cancer prevention.

Low Back Pain Could Affect How We Eat

A recent study by Lin et al. uncovered a relationship between longstanding low back pain and a preference for fat-rich foods. The authors found that the nucleus accumbens may be linked to the change in eating behaviour. The nucleus accumbens is a part of the brain that plays an important role in reward and pleasure processing. This could partly explain the high prevalence of obesity in people with longstanding pain.

Fat Injections For Plantar Fasciitis?

Beth Gusenoff et al. have just published the results of their study looking into the effects of fat cell injections for patients with plantar fasciitis. Plantar fasciitis is a common musculoskeletal condition that can lead to inflammation, degeneration and thickening of the plantar fascia. Patients usually present with heel pain during weight bearing activities. The symptoms are often worse in the morning and after periods of inactivity.

There are treatments such as arch-supporting insoles, night splints, soft tissue work, acupuncture, progressive stretching and strengthening, steroid injections, etc. But, the condition sometimes becomes chronic and lingers.

This was a very small study but it showed significant improvements in pain, function and structure of the plantar fascia after receiving perforating fat injections into the plantar fascia. It’s possible that the beneficial effects may be due to a healing response from the microtrauma caused by the needle. And/or the regenerative ability of stem cells and growth factors within fat.

The authors are planning large scale clinical trials to validate their results. It would be interesting for the authors to have a control group that is exposed to the needle microtrauma without the injection of fat cells. This would help determine whether it is the fat or the microtrauma that is responsible for the positive findings.

Covid-19 Research Update

Gu et al. (Nature) recently published a paper explaining the association between Covid-19 and inflammatory and blood coagulation disorders involving platelets and endothelial cells. This is probably why patients with cardiovascular risk factors such as diabetes, obesity and ageing have been particularly vulnerable to Covid-19.


Malas et al. have published a meta-analysis of 42 studies (8271 patients) looking into the association between thromboembolism (blood clots) and Covid-19. The overall venous thromboembolism rate was 21%, deep vein thrombosis (DVT) rate was 20% and pulmonary embolism rate was 13%. There was a positive correlation between disease severity and risk of blood clotting. The risk of thrombosis can affect any organ in the body. This has led to guidelines recommending the use of anticoagulants for Covid-19 patients, especially when hospitalised.


A Chinese cohort study published in The Lancet followed 1733 patients after they were discharged from hospital. They found that at 6 months after onset of Covid-19 symptoms most patients still had at least one symptom. The most common persisting problems were: fatigue or muscle weakness (63%), sleep difficulties (26%) and anxiety and/or depression (23%). Those that had been more severely ill had a high risk of pulmonary diffusion abnormalities and abnormal chest imaging. Persistent kidney dysfunction, diabetes and blood clotting disorders were also observed.

Vegans At Greater Risk of Fracture?

About a month ago a worrying study was published by researchers working on the EPIC-Oxford Study. They looked into the differences in fracture risk between meat eaters, vegetarians and vegans. It was done by following a group of around 55,000 men and women for an average of 17 years. It should be said that most fractures are generally due to poor bone health leading to decreased bone mineral density (BMD) and eventually osteoporosis.

The authors note that previous studies have shown that vegetarians (and vegans) have lower BMD than non-vegetarians but that the associated fracture risk is unclear. The combination of vitamin D and calcium has been found to be effective in decreasing fracture risk. Studies have also linked protein intake to bone health. High protein intake increases intestinal calcium absorption and stimulates the production of insulin-like growth factor (IGF-1) which is associated with better bone health. And finally, body mass index (BMI) could also play a part in fracture risk. The lower BMD found in US vegetarians may be explained by their lower BMI.

Tong et al. summarise their findings as follows:

 “The higher observed risks of fractures in non-meat eaters were usually stronger before BMI adjustment, which suggests that the risk differences were likely partially due to differences in BMI. Vegetarians and vegans generally have lower BMI than meat eaters, and previous studies have reported an inverse association between BMI and some fractures, particularly hip fractures, possibly due to reasons including the cushioning against impact force during a fall, enhanced oestrogen production with increased adiposity, or stronger bones from increased weight-bearing.”

Although a statistically significant higher risk of total and hip fractures was only observed in vegans in the lower BMI category (<?22.5?kg/m2), our interpretation is limited by the small numbers of cases in each stratum in these analyses, especially because of the strong correlation between diet group and BMI, which results in very few vegans in the higher BMI category, and vice versa comparatively small numbers of meat eaters with a low BMI.”

In this study and previous studies, vegans had substantially lower intakes of calcium than other diet groups since they do not consume dairy, a major source of dietary calcium, while both vegetarians and vegans had lower protein intakes on average. In the human body, 99% of calcium is present in bones and teeth in the form of hydroxyapatite, which in cases of calcium deficiency gets resorbed to maintain the metabolic calcium balance, and thus, osteoporosis could occur if the calcium was not restored.”

Overall, vegans in this study had higher risks of total and some site-specific fractures (hip, leg, vertebra) than meat eaters. The strongest associations were observed for hip fractures, for which fish eaters, vegetarians, and vegans all had higher risks. These risk differences might be partially explained by the lower average BMI, and lower average intakes of calcium and protein in the non-meat eaters. However, because the differences remained, especially in vegans, after accounting for these factors, other unaccounted for factors may be important.

We have known for some time that astronauts suffer from bone loss whilst in space. This is partly due to the effect of weightlessness and reduced physical activity leading to decreased bone compressive forces. Bone compressive forces help increase BMD and create stronger bones. As vegans usually have lower BMIs, their bones are subject to smaller compressive forces than meat-eaters. This can be overcome by resistance exercise and weight lifting. And of course, it is particularly important for those eating a plant-based diet to ensure they get an adequate intake of vitamin D, calcium and protein to maintain bone health.

Nutrition, Immunity and COVID-19

Our immune system protects us from pathogens like viruses, bacteria, cancerous cells, etc. and it can be separated into 2 distinct branches: the innate immune system and the adaptive immune system. Our innate immune system uses cells such as macrophages, neutrophils and mast cells to mount a fast, generic response to pathogens. Inflammation is the hallmark of the innate immune system. On the other hand, the adaptive immune system uses T cells, B cells and natural killer cells to mount a slow, targeted response to pathogens. It’s the adaptive immune system that’s responsible for life-long immunity to certain diseases. In practice, the 2 branches interact to provide a comprehensive immune response.

In a recent article, Butler and Barrientos (2020) summarised the interactions between diet, immunity and COVID-19. They state that the typical western diet (high in saturated fats, refined carbohydrates and sugars, and low in fibre, unsaturated fats and antioxidants) “significantly impairs adaptive immunity while ramping up innate immunity, leading to chronic inflammation and severely impairing host defence against viral pathogens.

The authors note that “T and B cell counts were also significantly lower in patients with severe COVID-19; thus, there could be a potential interaction between western diet consumption and COVID-19 on adaptive immunity impairment.” They suggest the higher rates of obesity and diabetes among ethnic minority populations may partly account for the health disparities seen in response to COVID-19.

Butler and Barrientos conclude “that individuals refrain from eating foods high in saturated fats and sugar and instead consume high amounts of fibre, whole grains, unsaturated fats, and antioxidants to boost immune function.”

Early Feeding Improves Pre-Diabetes and Blood Pressure

About a year ago Sutton et al. published a study that showed that intermittent fasting has benefits that are independent of food intake and weight loss. Their trial tested the effects of 5 weeks of “early time-restricted feeding” (eTRF) on 8 men with pre-diabetes. The subjects were asked to start breakfast between 6:30-8:30 and to eat their 3 meals in a 6-hour window with dinner before 15:00. They were fed enough food to maintain weight. The control group had similar meals but within a 12-hour feeding window. Five weeks of eTRF significantly improved insulin levels, insulin sensitivity, blood pressure and oxidative stress levels. The blood pressure improvements were particularly dramatic – morning levels of both systolic and diastolic blood pressure were reduced by about 10 mm Hg each.

Some of the benefits of eTRF are believed to originate from eating in alignment with our internal biological clocks which are primed for feeding early in the day. The authors state that “in humans, insulin sensitivity, beta cell responsiveness, and the thermic effect of food are all higher in the morning than in the afternoon or evening, suggesting that human metabolism is optimized for food intake in the morning”. Fortunately eTRF lowers the desire to eat in the evening!

Meal Times Crucial For Weight Loss

A few months ago Lopez-Minguez et al. reviewed studies looking at the effect of meal times on obesity and metabolic risk. Their findings are summed up in the following points:

  • skipping breakfast is linked to obesity
  • eating a large breakfast (within 2hrs of waking) decreases the probability of being obese by 50%
  • a late lunch (after 3pm) hampers weight loss and has a negative effect on the diversity and composition of our microbiota
  • a late dinner (less than 2hrs before bedtime) decreases glucose tolerance
  • eating a large, late dinner (less than 2hrs before bedtime) leads to a 5-fold increase in the risk of becoming obese
  • the timing of breakfast seems to be hereditary whereas the timing of dinner is mainly cultural

There may be some truth in the following quote by Adelle Davis.

Eat breakfast like a king, lunch like a prince and dinner like a pauper

As well as getting the timing right obviously!