Two recent studies on diet show that consumption of animal proteins and fats help young and old alike.

Finland: vegan diet ‘remodels metabolism’ in young children

A group of researchers conducted a study on vegan diets in small children attending Finnish nurseries:

They published their results in February 2021: ‘Vegan diet in young children remodels metabolism and challenges the statuses of essential nutrients’.

There is a lot to read, which is, nonetheless, very interesting.

I will cover only the highlights.

This is the top-line summary (emphases mine below):

Vegan diets are gaining popularity, also in families with young children. However, the effects of strict plant‐based diets on metabolism and micronutrient status of children are unknown. We recruited 40 Finnish children with a median age 3.5 years—vegans, vegetarians, or omnivores from same daycare centers—for a cross‐sectional study. They enjoyed nutritionist‐planned vegan or omnivore meals in daycare, and the full diets were analyzed with questionnaires and food records. Detailed analysis of serum metabolomics and biomarkers indicated vitamin A insufficiency and border‐line sufficient vitamin D in all vegan participants. Their serum total, HDL and LDL cholesterol, essential amino acid, and docosahexaenoic n‐3 fatty acid (DHA) levels were markedly low and primary bile acid biosynthesis, and phospholipid balance was distinct from omnivores. Possible combination of low vitamin A and DHA status raise concern for their visual health. Our evidence indicates that (i) vitamin A and D status of vegan children requires special attention; (ii) dietary recommendations for children cannot be extrapolated from adult vegan studies; and (iii) longitudinal studies on infant‐onset vegan diets are warranted.

More summarised points follow.

On metabolism and vitamin intake:

The children who followed the vegan diet from birth showed a metabolic profile and nutrient status distinct from those of lacto‐ovo‐vegetarians and omnivores, indicating that only relatively little animal source foods are enough to shift the metabolism of children. The main findings in vegan children included very low cholesterol concentrations and modified bile acid metabolism, as well as their markedly low fat‐soluble vitamin status despite their nutrient intakes matching current national recommendations fairly well. Despite of the adequate estimated vitamin A intake, the RBP results of vegan children in our sample indicated insufficient vitamin A status. Their vitamin D levels were low although the samples were taken during and after summer with expectedly high sunlight exposure and vitamin D storage. Our evidence indicates that special attention is needed to ensure adequate status of these important micronutrients for children on a vegan diet.

On cholesterol levels:

The low cholesterol levels resulting from adult vegan diet have mostly been linked to positive cardiovascular health effects (Appleby & Key, 2016; Elorinne et al, 2016), although a recent study also suggested an increased risk for stroke (Tong et al, 2019). The markedly low cholesterol in vegan infants and children in our study raises the question of whether such levels are healthy, as cholesterol is essential for cellular growth, division, and development of physiological systems due to its major role in the synthesis of cell membranes, steroid hormones, bile acids, and brain myelin.

A dysfunction with brain myelin means that the myelin sheaths, which cover our nerves, are not getting the fat necessary for healthy maintenance and function. Low-fat diets are thought to contribute to Alzheimer’s (see second study below).

On bile acids:

The main route of cholesterol excretion from the body is through bile acids, the biosynthesis of which occurs in the liver. Our metabolomics analysis indicated that bile acid biosynthesis was the pathway that differed most significantly between the diet groups. In vegans, direct measurement revealed higher primary bile acids, cholic acid, and chenodeoxycholic acid, which were previously reported to increase upon fasting in children (Barbara et al, 1980), and a lower taurine to glycine ratio in bile salt conjugation than omnivores. Vegan diets contain only little taurine, and the relatively low taurine‐conjugation compared to glycine conjugation of bile salts in vegan children is in accordance with previous adult studies (Ridlon et al, 2016). In addition to the role of bile acids in digestion and absorption of fat‐soluble components from the diet, recent studies have elucidated their diverse roles in endocrine and metabolic signaling and gut–microbiome–brain interactions (De Aguiar Vallim, 2013; Ridlon et al, 2016; Kiriyama & Nochi, 2019). What physiological consequences such findings indicate in children following a strict vegan diet remains to be studied. Our evidence indicates that vegan diet remarkably modifies bile acid homeostasis in young children.

The conclusion indicates that, in a vegan household, it might be a good idea to give small children some animal protein outside of meat:

The evidence indicates that even part‐time consumption of lacto‐ovo‐vegetarian products in an otherwise strict vegan diet may substantially alleviate the risk to nutrient deficiencies in children. Our data indicate the importance of studying vegan children to enable evidence‐based nutritional recommendations.

As this is the first time Western countries are seeing an increase in vegan children, more research is necessary.

With regard to Finland, the study says:

Our data of lower status of several biomarkers in vegan children compared to omnivores, in the relatively low number of study subjects, calls for larger studies before early‐life vegan diet can be recommended as a healthy and fully nourishing diet for young children, despite its many health‐promoting effects in adults. We suggest that the metabolic effects of vegan diet in adults cannot be generally extrapolated to children. Long‐term follow‐up studies are needed to clarify the causes and consequences of lower levels of vitamin D, RBP, transthyretin, essential amino acids, total cholesterol, and DHA in vegan children.

New Zealand: ketogenic diet can help some Alzheimer’s patients

Researchers in New Zealand found that a ketogenic diet might help patients with milder cases of Alzheimer’s:

I suspect that the lack of fat inhibits the proper maintenance and function of the myelin sheath. Our nerve coatings need fat. Well functioning connections to the brain are likely to lessen the possibility of Alzheimer’s.

The researchers published ‘Randomized crossover trial of a modified ketogenic diet in Alzheimer’s disease’ in February 2021.

Excerpts follow:

Brain energy metabolism is impaired in Alzheimer’s disease (AD), which may be mitigated by a ketogenic diet. We conducted a randomized crossover trial to determine whether a 12-week modified ketogenic diet improved cognition, daily function, or quality of life in a hospital clinic of AD patients …

This is the first randomized trial to investigate the impact of a ketogenic diet in patients with uniform diagnoses of AD. High rates of retention, adherence, and safety appear to be achievable in applying a 12-week modified ketogenic diet to AD patients. Compared with a usual diet supplemented with low-fat healthy-eating guidelines, patients on the ketogenic diet improved in daily function and quality of life, two factors of great importance to people living with dementia

Brain energy metabolism is impaired in AD. Compared with healthy controls, people with AD display lower levels of brain insulin signaling and fewer brain insulin receptors, culminating in brain insulin resistance [3, 4]. PET studies demonstrate a 20–25% deficiency in cerebral glucose metabolism [5]. AD neurons also exhibit diminished numbers of mitochondria, many of which show reduced citric acid cycle and respiratory chain activity, culminating in decreased energy production [6].

Ketogenic diets can theoretically mitigate impaired brain energy metabolism in AD, leading to improved cognition, daily function, or quality of life. Ketogenic diets are high-fat, low-carbohydrate diets that shift the body towards fat metabolism. Neurons cannot metabolize fats directly, but the liver converts fats into ketones, which can serve as a major neuron energy source [7]. During a typical western diet, the concentration of the primary blood ketone, beta-hydroxybutyrate, supplies less than 5% of brain energy requirements and its blood concentration rarely exceeds 0.5 mmol/L. By contrast, a ketogenic diet induces a state of “physiological ketosis” in which beta-hydroxybutyrate provides a greater contribution to brain energy metabolism and its blood concentration exceeds 0.5–0.6 mmol/L …

This was a single-phase, assessor-blinded, two-period randomized crossover trial conducted at Waikato Hospital, a tertiary hospital in Hamilton, New Zealand …

To our knowledge, this is the first randomized trial to investigate the impact of a ketogenic diet in patients with uniform diagnoses of AD. Our findings suggest that high rates of retention and adherence are achievable in applying a 12-week modified ketogenic diet to AD patients. Compared with a usual diet supplemented with low-fat healthy-eating guidelines, patients on the ketogenic diet improved in daily function and quality of life. Changes in cardiovascular risk factors were mostly favourable and adverse effects were mild …

Compared with usual diet, patients on the ketogenic diet improved in daily function. Given that a 2-point change on the ADCS-ADL is considered clinically meaningful [22], the observed increase of 3.13 points implies that the ketogenic diet imparted a meaningful benefit in our patients to a degree that rarely occurs with medications [33]. Since an ongoing decline in daily function is a core feature of AD [2], this finding may be potentially important. By contrast, the decline in function observed in patients on low-fat healthy-eating guidelines may raise questions as to whether this dietary advice should be provided in AD.

Compared with usual diet, patients on the ketogenic diet also improved in quality of life. Given that a 3-point change on the QOL-AD is considered clinically meaningful [23], the observed increase of 3.37 points again implies that the ketogenic diet may offer a substantial benefit. By comparison, cholinesterase inhibitors show inconsistent effects on quality of life [34].

Whether ketogenic diets offer benefits on cardiovascular risk factors remains controversial [35]. The changes observed in this trial were mostly favourable. Compared with usual diet, patients on the ketogenic diet lost 2.62 ± 3.29 kg. Weight loss has been associated with increased mortality in AD [36], but that observation may relate to appetite changes resulting in cachexia in later-stage disease. By contrast, our patients were generally overweight (and pleased with their weight loss). Moreover, patients on the ketogenic diet decreased their HbA1C, did not alter triglycerides, and increased their HDL. There were modest increases in LDL and total cholesterol, but the impact of these changes on cardiovascular health remains debated [37].

I have been saying for several years that keto is likely to help some Alzheimer’s patients, and I’m delighted that this group got funding to try it out in a properly randomised fashion.

I hope there are many more studies such as these. The simplest remedies are often the best. There is no cure for Alzheimer’s but those who are not in advanced stages can benefit from a modified — and tasty — diet.

Food notes

We receive so much propaganda about our food choices, that it is time to present the other side of the coin.

Eating meat is at the top of the list. With regard to beef, much depends on who is producing it and the target market. Brazil produces beef for China. That agribusiness cycle has nothing to do with Europeans or North Americans:

Traditionally processed meats are nutritious. People living in the countryside, especially in mountainous areas, have been curing meat for centuries. Here’s a comparison between veggie nuggets and proper Spanish ham:

Cheap, modest foods can help provide the nutrients we need.

Real cheese might help reverse diabetes:

It looks as if liver could also help put diabetes into remission:

A good friend of mine hears ‘liver’ and says ‘yecch’, but sautéed chicken livers are out of this world. So is chopped liver:

What about liver and bacon? A good quality liverwurst is excellent, too:

Plant-based diets, especially if they are low-fat, might not be all they are cracked up to be. Ancel Keys had a lot to answer for in recommending low-fat diets in preventing heart disease.

One of his contemporaries would have disagreed with him:

After 60+ years, low cholesterol diets are beginning to be questioned:

The truth hurts, especially in med school:

I have much more about the ketogenic diet on my Recipes / Health page. They are one-third of the way down the page. Search for ‘diet’ and ‘low-fat, high-carb diet’.