Lactose intolerance: the dietary blind spot shipping still ignores

By Dr Jens Tulsner, Marine Medical Solutions, member of OneCare Group

The global shipping industry relies heavily on multinational crews, many of whom come from South and Southeast Asia. Yet one simple biological reality still receives surprisingly little attention in shipboard catering and health planning: a large proportion of these populations are lactose intolerant.

This is not a marginal issue. Due to genetic factors, lactose intolerance is extremely common across much of Asia. In South Asia alone, studies suggest that between 60% and over 90% of adults may have reduced ability to digest lactose, the sugar naturally found in milk and dairy products. In practical terms, this means that for a significant proportion of the world’s seafarers, dairy-heavy diets can lead to discomfort and gastrointestinal symptoms.

And yet, the issue is rarely discussed in maritime health conversations.

Interestingly, from the perspective of telemedical support, lactose intolerance is almost never raised as a formal medical problem from ships. In the many consultations we handle, I cannot recall a single case where a vessel contacted us specifically because lactose intolerance was suspected.

At first glance that might suggest the problem simply does not exist onboard. In reality, the opposite explanation is far more likely: seafarers manage the issue themselves.

Many crew members from regions where lactose intolerance is common already know how their bodies react to dairy products. They simply avoid them. In practice, this quiet self-management means the issue rarely escalates into a medical consultation.

Another important factor is the adaptability of shipboard catering. Most experienced cooks on vessels serving multinational crews understand very well that not everyone tolerates dairy products. Meals often reflect this reality, particularly where Asian-style dishes dominate the menu and dairy ingredients are limited.

However, this informal approach also raises a question for the industry: are ship operators paying enough attention to the nutritional needs of their crews?

Shipping companies invest significant effort in safety procedures, fatigue management and mental health awareness. Yet the basic issue of diet, something that affects every crew member every day, is often treated as an operational afterthought.

For seafarers who are lactose intolerant, symptoms are usually predictable: abdominal pain, bloating, flatulence, diarrhoea or nausea after consuming dairy products. These symptoms are not life-threatening, but they can be extremely uncomfortable and persistent gastrointestinal problems are hardly ideal for people working long shifts in demanding conditions.

The reality is that the most effective ‘treatment’ for lactose intolerance is very simple: avoid exposure to lactose. If symptoms occur, management focuses on treating the resulting gastrointestinal upset while adjusting the diet to remove the trigger.

From a telemedical standpoint, if lactose intolerance is suspected, the advice would normally be straightforward. Remove dairy products from the diet temporarily and observe whether symptoms resolve. If they do, the diagnosis becomes fairly clear.

This is not a complicated medical problem. But it is one that the maritime industry could address more consciously. The answer is not to remove dairy products from ships. For many crew members, dairy remains an important and well-tolerated source of protein and calcium. The real issue is choice and awareness.

Catering plans on vessels with multinational crews should recognise that a large proportion of seafarers may prefer, or require, non-dairy alternatives. That might mean ensuring meals are not overly reliant on cheese, milk or cream-based ingredients, and providing options that suit different dietary tolerances.

Many ships already operate this way simply through experience. But given the demographics of the global seafaring workforce, it may be time for the industry to acknowledge lactose intolerance not as an occasional medical curiosity – but as a predictable biological reality for a majority of its workforce.

Seafarers should not have to quietly navigate around the menu to avoid discomfort. In an industry that increasingly recognises the importance of crew wellbeing, even something as simple as what is on the plate deserves more attention than it currently receives.

Author:

Dr Jens Tulsner, Marine Medical Solutions, member of OneCare Group